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1SSN 0111– 6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

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Page 1: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

1SSN 0111–6851

Issue 66Newsletter of the New ZealandGeotechnical Society Inc.

NZ Geomechanics NewsDecember 2003

Page 2: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

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Page 3: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

Chairman’s Corner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2Editorial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Editorial Policy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Report from the Secretary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4Letters to the Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5International Society Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

ISSMGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6ISRM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7IAEG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Conference Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9ISRM Council Meeting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 910th ISRM International Congress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10Soft Soil Workshop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122nd International Young Geotechnical Professionals Conference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17NZSOLD Symposium, Dams – Consents and Current Practice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Standards, Law & Industry News . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24National Networks of Technological Societies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24NZGS Legislative Submission – Building Bill to Repeal Building Act 1991 . . . . . . . . . . . . . . . . . . . . . . 25Soil & Rock Description – Comments on Present and Proposed Guidelines . . . . . . . . . . . . . . . . . . . . . . 29

Reviews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31In-Situ Characterization of Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31TBM Tunnelling in Jointed and Faulted Rock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33Slide 5.0, Rocscience Inc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Project News . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44Landslides, Gully Erosion and Debris Flood Effects During the 3rd October Paekakariki Floods . . . . . . . 44Wet Weather and an Earthquake = Landslides . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49Welded Gabions for Decorative Landscaping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52South American Sojourn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

Special Interests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54Effect of Vertical Shaking on the Displacement of Earth Retaining Structures . . . . . . . . . . . . . . . . . . . . . 54Numerical Modelling in Geotechnics, Part VII . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

NZ Geotechnical Society 2003 Photo Competition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59Laurie’s Brain Teaser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63Company Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Hawthorn Geddes Engineers and Architects Ltd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64Maunsell Ltd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

Member Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66Tim McMorran . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

The Bob Wallace Column . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67Events Diary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68New Zealand Geotechnical Society Inc. Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72New Zealand Geotechnical Society Inc. Publication Information . . . . . . . . . . . . . . . . . . . . . . . . . . 75Advertising Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76




Cover photo: Damage to the Paekakariki Hill culvert caused by the 3 October storm event. A large volume of gravel hasbeen carried down from the head of the gully above but was trapped behind fence and gate just above the road. Onlywater appears to have crossed the road and washed out the edge of the road fill and the culvert.Photo Credit: G.T. Hancox, Geological & Nuclear Sciences

Page 4: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

New Zealand Geomechanics News

2 Newsletter of the New Zealand Geotechnical Society Inc.


It is hard to believe 6 months have passed since writing mylast column, but passed they have and Christmas will soonbe upon us! With those festive tidings in mind, a verywarm welcome to this December issue of theGeomechanics News.

The June issue followed the successful 2003Geotechnical Symposium in Tauranga, and as theDecember issue goes to print the organizing of the 9thAustralia New Zealand Geomechanics Conference ismoving to full speed ahead. The 9th ANZ will be held inAuckland from 8–11 February 2004, and promises to be aspectacular event. The conference venue has moved to thenew Hilton Hotel on Auckland’s spectacular waterfront,and the conference dinner will be an occasion to remember.The organizing committee of Geoffrey Farquhar, PhilKelsey and myself has been ably supported by DebbieFellows and the University Conference Company, and thefinal preparations are now being made.

Some of the highlights include Professor Geoff Martinmaking the keynote address, together with Dr LaurieWesley and Professor Ted Brown presenting the NZGeomechanics Lecture and the John Jaeger MemorialLecture respectively. Congratulations to Laurie on beingawarded the Geomechanics Lecture. Approximately 130papers have now been accepted, and as many of these aspossible will be presented during the conference. Inaddition there will be several ‘Hot Topics’ workshopsessions, chaired by leading ANZ practitioners andresearchers, as well as those member of the ISSMGE Boardable to attend the conference as well as their Board meetinglater in the same week. So while a number of papers havealready been received from New Zealanders, the whole

organizing committee warmly welcomes you to attend theconference, and to reply to the registration brochure sentto you. The ANZ conference only comes to New Zealandevery 12 years, and it will be a conference to remember.

Also on conferences, the next ANZ Young Professionalsconference has made its first announcement, and will beheld in Brisbane in July 2004. Abstracts are due byDecember 2003, so hopefully your planning of papers iswell under way.

Finally, we are delighted to enclose with this issue yourvery own Christmas present from the NZGS of allexisting issues of the Geomechanics News dating back to1970 scanned onto a CD. This CD has followed theexample of the Australian Geomechanics Society, and hasbeen put together by our Secretary Debbie Fellows, and ateam of clever editors, graphic designer and computerwhizz’s. It couldn’t have been possible without donationsof issue sets from John Galloway, John Blakeley and KenOrams.

So enjoy reading the back issues of the GeomechanicsNews over the summer break, and a very HappyChristmas from all on the NZGS ManagementCommittee.

John MarshChairman

Beca Carter Hollings & Ferner LtdPO Box 6345AucklandPhone: 09 300 9174Email: [email protected]

NZ Geotechnical Society Contact Details

PO Box 12-241WellingtonWeb: nzgeotechsoc.org.nz

Secretary: Debbie Fellows Ph (09) 813 0012 Fax (09) 813 0014Email [email protected]

Page 5: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

December 2003, Issue 66

New Zealand Geomechanics News



The Editorial Team:Phil GlasseyGeological & Nuclear SciencesPrivate Bag [email protected]

Debbie FellowsAssistant EditorAdvertising Manager

Sally Fullam of ArtDesignDesign and typesetting

Beverley ElliottWord Processing

Recently, I survived a fearsome easterly storm (albeit witha little bit of seepage in around the aluminium windows ofmy house), witnessed flooding and inundation from astorm at Paekakariki and the effects of a large earthquakein the relatively unpopulated area in the FiordlandNational park, which generated over 200 landslides. I alsowent to the Ports and Coasts conference in Auckland,where the power of the sea was to the fore. A dynamicnatural environment in which we live, methinks.

Having survived the leaky building syndrome with littleapparent damage, I was interested in the GeotechnicalSociety’s submission on the Building Bill to repeal the 1991Building Act (see submission in this issue by PaddyLuxford)). As indicated in the submission, subsidence isclearly an omission from the bill.

While my house is relatively solid, it was built in 1979with some less than adequate workmanship (e.g. windowsonly flashed along the top – hence the water intake blownin around the sides), and I wonder how many othercorners were cut. What of the inspection process? While Iam not a fan of over-regulation and bureaucracy, I believethat building inspection has been both under-valued andunder-resourced. Part of this stems from the onus placedon city and district councils who seem to not want tospend valuable rates on such mundane regulatory matters.But have they considered the cost of not doing so? Myhope for the Building Bill is that it doesn’t greatly increasethe cost of compliance and that we are all prepared to payfor proper inspection and quality advice.

The storm at Paekakariki was spectacular in bringingdown debris from surrounding catchments. The BelvedereMotel was inundated by material that went through a 1 mdiameter culvert; a material with a consistency of ‘sloppy

concrete’ as one commentator put it. This issue featuressome of the washouts from this event provided viaGraham Hancox and the Kapiti Coast District Council.

The M 7.1 Earthquake in Fiordland on the 22 Augustshould be a reminder of the seismic forces we can expectin New Zealand from time to time. Fortunately, theepicentre location meant that there was little at risk fromsuch a hazard. A brief summary of the event is given inGrant Dellow’s Wet Weather and an Earthquake =Landslides report.

The Ports and Coasts conference in Auckland againbrought my attention to the dynamic environment. Thepresentations I attended were a mixture of numericalmodelling, effectiveness of coastal protection structures,new techniques for monitoring change and how to livewith the processes rather than fight them.

It is New Zealand’s relatively dynamic environmentthat we as geotechnical professionals apply our craft,experience and knowledge to facilitate the design andconstruction of infrastructure. This is also the backdrop tothe 9th Australia New Zealand Conference onGeomechanics To the eNZ of the earth to be held inAuckland in February 2004. This is a great opportunity tosee how others have designed for this dynamicenvironment, but also to experience how our overseascolleagues design, taking into account sometimes differentenvironmental factors. The ISSMGE is to have a boardmeeting at this conference and delegates will be comingfrom all over the world. See you there!

Phil GlasseyEditor

A Dynamic Place To Live

Page 6: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

New Zealand Geomechanics News

4 Newsletter of the New Zealand Geotechnical Society Inc.



NZ Geomechanics News is a biannual newsletter issued tomembers of the NZ Geotechnical Society Inc. It isdesigned to keep members in touch with matters of interestwithin the Geo-Professions both locally andinternationally. The statements made or opinions expresseddo not necessarily reflect the views of the New ZealandGeotechnical Society Inc.

The editorial team is happy to receive submissions ofany sort for future editions of NZ Geomechanics News.The following comments are offered to assist potentialcontributors. Technical contributions can include any ofthe following:• Technical papers which may, but need not necessarily be,

of a standard which would be required by internationaljournals and conferences.

• technical notes• comments on papers published in

NZ Geomechanics News• descriptions of geotechnical projects of special interest.

General articles for publication may include:• letters to the NZ Geotechnical Society• letters to the Editor• articles and news of personalities

• news of current projects• industry news.Submission of text material in camera-ready format is notnecessary. However, typed copy in Microsoft Word isencouraged, particularly via email to the Editor or onfloppy disk or CD. We can receive and handle file types ofalmost any format. Contact us if you have a query aboutformat or content.

Diagrams and tables should be of a size and qualityappropriate for direct reproduction. Photographs shouldbe good contrast black and white gloss prints or highresolution digital images in jpeg format.

NZ Geomechanics News is a newsletter for Societymembers and articles and papers are not necessarilyrefereed. Authors and other contributors must beresponsible for the integrity of their material and forpermission to publish. Letters to the Editor about articlesand papers submitted by members will be forwarded tothe contributing member for a right of reply.

Persons interested in applying for membership of theSociety are invited to complete the application form in theback of the newsletter. Members of the Society are requiredto affiliate to at least one International Society and the ratesare included with the membership information details.

Here in my little corner of the Society, it has been a verybusy few months co-ordinating the review of all thepapers for the ANZ Geomechanics Conference which willbe held in February 2004.

I am continuing to up date the Society web page as andwhen time permits. The What’s On, Society News andBranch Activities and Conference Diary are regularlyupdated. The employment opportunity section continuesto be popular with employers and several companies areusing this advertising avenue repeatedly. If you have asituation vacant you wish to advertise simply send me aword or PDF file and I will do the rest. It only costs $50plus GST per month. I will continue to send out emailsabout what is new on the web page. If you havesuggestions for additions to the web page or have somemembership queries please email me.

Society membership is currently flourishing with a totalof 483 members.

New MembersIt is a pleasure to welcome the following new members intothe Society since the last issue of NZ Geomechanics News:

ResignationsGraham Hancox has resigned from the Society.

SubscriptionsYour subscription invoices for the 2003/2004-year have nowbeen sent out. Please don’t file them in the pay sometimelater file. PLEASE PAY YOUR SUBSCRIPTIONSPROMPTLY. Thank you.

CongratulationsThe 2004 Geomechanics Lecture will be given by DrLaurie Wesley. It is to be titled Geotechnical Engineeringin and out of the Ivory Tower. The lecture will be givenfirst at the ANZ conference in Feb 2004 and then will tourthe branches later in the year.

Debbie FellowsManagement [email protected]

Jonathon DevineHseuh Lyn KuehThomas Newell

John MorrisJames MuirsonPaul Wopereis

Page 7: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

NZ Geotechnical Society has a number of recently published books available for review. Thesebooks have been supplied free to the Society, by the publishers, for review purposes. We are lookingfor eager volunteers to review the following books:

• A short course in Geotechnical Site Investigation (Simons, Menzies, Matthews) 2002. • A short course in Foundation Engineering (Simons, Menzies) 2000. Thomas Telford.• A short course in Soil and Rock Slope Engineering (Simons, Menzies, Matthews), 2001. Thomas Telford

The reviews are to be succinct and critical appraisals of the books in the order of 1 or 2 A4 pages inlength. Reviews will be forwarded to the publishers. Upon completion of the review the bookreviewers can keep the book – now there is a good incentive for you!

If you are interested please contact:Debbie Fellows, Management Secretary Ph (09) 813 0012 Email [email protected]

New Zealand Geomechanics News

December 2003, Issue 66 5


WANTED – Book Reviewers

I am perplexed by the comments on responses to theproposed revision, and the change in title, to theGuidelines for the field description of soils and rocks inengineering use (1988) as discussed on page 26 of NZGeomechanics News, Issue 65, June 2003. We once had amethod for field description, and the ‘revision’ seems tohave abandoned any suggestion of field description.

Besides the change in title, the omission of the secondsentence of the introduction to Description of Soils (Part2 of the1988 guidelines) is a mistake. To ignore theimportant aspect of in situ soil description means that wemight as well just use the Unified Soil ClassificationSystem. In fact, given the ‘revised’ title, there is no need foranything other than the Unified System. However, thesecond sentence in the introduction to description of soilssays: “The description of soils in situ requires theintroduction of additional terms while retaining importantfeatures of the USBR method such as the unified symbol”.That is the whole point of the 1988 “Guidelines for theFIELD (my stress) description of soils and rocks inengineering use”. The proposed revision flies in the face ofthe original concept, which is reflected in its title.

The definition of ‘classification’ in the article is odd.Usually in soil mechanics, the word has a very specificmeaning relating to laboratory test results. So is a field‘classification’ seen as something different? In the sense ofthe title of this draft revised document, we are supposed toadopt a very loose definition of the word? This will lead toconfusion. The title almost implies that the UnifiedClassification is being revised here. It would be better toremove ‘classification’ from the title, and stick to‘description’, especially ‘field description’, given that theprimary intended use of the guidelines was as a field tool.

Does it matter whether something is a silty sandygravel, or a sandy silty gravel? I think not, and in future Iwill refuse to change my initial field assessment on thebasis of later laboratory results. What is more important iswhether the gravel clasts are rounded, angular, or a mix ofboth; weathered, unweathered, or a mix of both. This canbe vital for determining the origin of the soil, which willhave an important bearing on application of geotechnicalengineering practice at a site.

Should I expect the slavish use of the Unified System tellme these details? In my experience, the degree ofroundness of gravel clasts and whether or not they are incontact is almost never recorded in practice, even thoughthe USBR classification chart includes this aspect as“information required for describing soils”. I have alsoseen too many descriptions of bedrock as ‘gravel’ becauseof disturbance in drilling. Such an erroneous description issomething that the Unified System would seem toencourage, if taken in isolation. Colour is another vitalaspect of a material that should not be ignored. It isridiculous to make colour an optional item in a description,(is it so hard to state a colour?) because colour can providevital clues about current and former groundwater levelsand can also aid geological correlations, the correctness ofwhich may be important to a project.

In summary, the new ‘revision’ seems to have lost sightof the fact that we need is a consistent system for the fielddescription of rock and soil materials to provide additionalvital information to a site investigation other than whatthe Unified System provides.

Nick PerrinGeological and Nuclear Sciences, Lower Hutt

Guidelines for Classification and Description of Soils and Rocks

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New Zealand Geomechanics News

6 Newsletter of the New Zealand Geotechnical Society Inc.

Board MeetingsA Board Meeting was held in Prague ahead of the Mid-Term Council Meeting at the European RegionalConference. The next Board Meeting will be held inAuckland immediately after the ANZ conference inFebruary.

Mid Term Council MeetingThis event was very interesting and a number of issueshave risen that both the NZGS and AGS will have toaddress prior to February. These include:• The ISSMGE constitution on voting procedures.• The Member Society subscriptions. • Cooperation between the International Society’s and a

joint Secretariat.

These three issues will likely overshadow and impact onthe progress being made in the various Task Forces (IT,Education, Conference Format, Professional Practice andIndustry Liaison). These should not be ignored, but forthe time being they are less important than resolving theabove issues.

Constitution, Subscriptions and Voting PolicyAs reported previously, there are problems associated withthe current method of calculating subscription rates andthere are some perceived problems with the voting policyat Council. The International Society currently recovers amembership fee from member societies around the globethat mostly reflect geo-political boundaries (New Zealand,Australia, Japan, Bolivia etc). The cost of membership toeach member society is based on a complicated formulathat incorporates the countries economic indicators andthe number of individual members the society declares.

The direct consequence of this formula is that smallmember societies with low individual membershipseffectively pay significantly more per member than largermember societies. When the International Society wasestablished it was written into the statutes that the richer,more affluent member societies should carry the bulk ofthe financial burden of administration. However,

individual members in Tunisia and Costa Rica currentlypay up to five times more than individual members in theUSA or Canada.

A motion was drafted for the Council Meeting inPrague that addressed the problem associated withsubscriptions. The Board’s motion was relatively simple inthat it was proposed to establish a uniform fee perindividual member. Council rejected the motion after asuccessful challenge by five of the fifteen or so largermember societies that would end up with a net increase intheir fees to the International Society (USA, Canada,Brazil, UK and Australia).

The bases of their argument would appear to be that ifthe larger member societies are to contribute more fees tothe International Society then they should also be affordedmore influence in the management and administration ofthe Society by strengthening the value of their vote atCouncil. At the moment every member society, regardlessof the size of its individual membership and financialcontribution, is afforded equal rights at Council.

The Board is now faced with a potential stalemate, thesubscription fee cannot change until voting policy is ‘fair’and voting policy is unlikely to change until thesubscription fees are ‘fair’.

Co-operation with the ISRM and IAEG.This issue was also discussed at Council and it has thepotential to impact on the operation and function of allthree international societies. The proposal is to establishan umbrella, or parent, Federation of InternationalGeotechnical Societies. The form, structure, cost andimplications are being reviewed by a group of BoardMembers from each society – including Harry Poulos.

J Grant MurrayVP Australasia Region

Sinclair Knight Merz LtdPO Box [email protected]


ISSMGE – Vice President’s Report, April 2003

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New Zealand Geomechanics News

December 2003, Issue 66 7

ISRM – Vice President’s Report, September 2003

ISRM Council and Board Meeting inSandton, 11th September 2003I took over the role as VP for Australasia from ChrisHaberfield at the 10th ISRM Congress held at Sandton,Johannesburg, South Africa on September 8–12, 2003.Chris Haberfield has made a report to the AGS, on theactivities of the Society up to Congress. These are justadditional comments on the direction of the new Boardand events since Congress.

The main items the new Board discussed were focussedon the phasing out of the printed News Journal which is amajor cost item on the budget. There will be much moreemphasis on electronic communication together with asubstantial upgrade of the web site. The intention is to makeabstracts of ISRM conferences available on the web in asearchable form. The ISRM Directory will not be printedand distributed to members. It is intended to publish this onthe web site if the legal issues can be resolved.

CommissionsThe commissions on Geophysics and Natural Stone havebeen extended while those on Swelling Rock andFragmentation have been discontinued. There are proposalsfor new commissions on Case Studies from China,Maintenance from Lisbon and Mine Closure from Poland.

ISRM meetings• Nov 30 to Dec 2 Kyoto, Japan is the 2004 ISRM

International Symposium.• The 53rd Geomechanics Colloquy, to be held in

Salzburg hosted by the ISRM National Group Austria,in October 2004 has been approved as an ISRMRegional Symposium.

• May 18–20 Brno, Czech Republic is the 2005 ISRMInternational Symposium.

• Lisbon was confirmed as the venue for the 11th ISRMCongress in 2007.

As an initiative of the new Board, each VP has been askedto identify potential growth areas and any problems intheir region. This is essentially a SWOT analysis(strengths, weaknesses, opportunities and threats). For theAustralasian region there was mention of the need toembrace the Strata Control groups in WA and on the eastcoast (NSW/Queensland) into the Society. I wouldwelcome any thoughts from members on where you seethe Society developing and also any ideas about how theSociety can better serve its members in the region.

John St George ISRM VP for Australasia

Department of Civil and Environmental EngineeringUniversity of AucklandPrivate Bag 92019AucklandNew ZealandEmail: [email protected]

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New Zealand Geomechanics News

8 Newsletter of the New Zealand Geotechnical Society Inc.

IEAG – Vice President’s Report, September 2003

IntroductionThis is the IAEG Australasian Region report for thesecond half of 2003. The report is by Vice President (VP),Dr Fred Baynes for submission to the AustralianGeomechanics Society and the New Zealand GeotechnicalSociety. The report for the first half of 2003 was notproduced due to my being overseas in remote locations forprolonged periods.

IAEG IssuesThe newly elected President Niek Rengers requested theExecutive to comment by email on a range of issues duringthe first part of 2003 in preparation for our Executivemeeting in September. I attended the Executive meeting on13 September and the Council Meeting on 14 September2003 in Istanbul, Turkey. At those meeting a whole rangeof issues were discussed, the following being the moreimportant:• There has been discussions between the IAEG, ISSMGE

and ISRM concerning the sister societies forming anumbrella society – possibly to be called Federation ofInternational Ground Engineering Societies. ThreeIAEG representatives were nominated to participate inongoing discussions and the IAEG position wasendorsed by Council.

• The Bulletin continues to improve in terms of technicalcontent and timely delivery. However it is still not partof the citation index but it might eventually be includedif contains sufficient numbers of important good qualitypapers that are cited elsewhere.

• The IAEG website needs to be upgraded and financialsupport for action this was agreed.

• There has been a useful report produced by the JointEuropean Working Group of IAEG, ISRM andISSMGE relating to Professional Tasks Responsibilitiesand Co-operation in Ground Engineering.

• Planning continues for the IAEG Congress inNottingham, UK, for 2006

• The Executive feels that a review of the technicalcommissions and working groups is necessary. Such areview may also be related to definition of the ‘corevalues’ of the IAEG prompted by Sir John Knill’s HandsCloos lecture. I am to lead a task force charged withreviewing the workings of Technical Commissions andrelating them to core values.

Australasian Region IssuesActivities to Date• The members of the Australasian IAEG Group steering

committee and those nominated representatives fromeach Australian State and New Zealand major centre thatwere asked to contribute in 2000 have not been active.

• I attended the International 9th IAEG Congress inDurban when I was elected as Regional VP, attended theCouncil meeting as Australia representative and asubsequent Executive meeting as Regional VP.

• Sir John Knill’s Hans Cloos lecture was published in theAustralian Geomechanics Journal. I chaired andreported a discussion of core values at the Durban IAEGCongress which will be published in the Bulletin.

• I produced a short paper on Responsibilities ofEngineering Geologists which was published in theTauranga Symposium; a modified shorter version waspublished in the AEG newsletter in USA.

• Registration issues continue to be an agenda itemAustralia although most practitioners do not seem to betoo concerned about it. I have attempted to pursue thisissue but achieved little. A report on the importance ofthis issue in New Zealand is suggested.

• The 16th NZ Geotechnical Society Symposium inTauranga in March 2003 included workshops on soil androck description and engineering geology.

Planned Activities• The New Zealand Geotechnical Society is considering

nominating for the IAEG Congress in 2010.• A geology for engineers training course is to be held in

Adelaide, Australia in April 2004• A survey of teaching at an under-graduate and post-

graduate level in Tertiary Institutions throughoutAustralia and New Zealand is planned to find out whatcourses are available for engineering geology andgeology for engineers is throughout the region.

• Planned succession for the Australasian Group VP is tobe addressed.

Fred Baynes IAEG Vice President for Australasia

9 Chester Street,Subiaco,Western Australia 6008,[email protected]

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New Zealand Geomechanics News

December 2003, Issue 66 9


The 2003 International Society for Rock Mechanics(ISRM) Council meeting was held in conjunction with10th International Congress in Johannesburg. Thirty of46 National Groups attended, including New Zealand(John St George and Stuart Read) and Australia (ChrisHaberfield).

Apart from the ongoing operation of the Society, thegreatest significance of the meeting is the four-yearly isthe changeover of the Board. Following his election in2001, Prof Nielan van der Merwe (South Africa)commences his term as President for the 2003–2007period, replacing Prof Marc Panet (France) who chairedthe Council meeting as a final duty. The followingregional vice-presidents for 2003–2007 were elected:Africa Mr Martin Pretorius (South Africa)Asia Prof Zhao Jian (Singapore)Australasia Dr John St George (New Zealand – last

kiwi was Prof Mick Pender in 1991–1995)Europe Dr Claus Erichsen (Germany)North America Dr François Heuzé (USA)South America Dr Eda Freitas de Quadros (Brazil – first

woman Vice President to be elected).

Consideration of up to 3 Vice-Presidents-at-large is for thenew Board. Dr Luís Lamas (Portugal) has taken over thepost of Secretary-General since May 2003, and DrDelgado Rodrigues who had performed the role since 1990was thanked, including a African-flavour gift. Profiles ofthe new Board plus other Society personalities areincluded in ISRM News Journal 8(1) circulated recently.

Other items from the Council meeting included:1 Membership numbers in recent years are reasonably

consistent (5,000 world-wide) after declines in late1990s, but active promotion of the Society is needed topreserve or increase this level.

2 Communication with Society members will be moreelectronic. The website, www.isrm.net, will beenhanced including becoming more interactive. NewsJournal 8(1), which is the last to be circulated in hardcopy, is the first volume to be available on the website(pdf format). The ISRM Directory (4 yearly

membership list – last in 2000 in hard copy format) isdiscontinued and the next issue will be in electronicform after legal issues are resolved.

3 Interaction between the three international societies(ISRM, International Society for Soil Mechanics andGeotechnical Engineering (ISSMGE), InternationalSociety for Engineering Geology and the Environment(IAEG)) continues, including consideration of aconfederation of geotechnical societies.

4 Future Council and Board meetings were confirmed as;2004, Kyoto, Japan in late November, and 2005, Brno,Czech Republic in May. Lisbon, Portugal is the venueof the 11th Congress in July 2007.

5 A proposal to change the name of the Society to theInternational Society for Rock Mechanics and RockEngineering (ISRME) was defeated.

6 The Rocha Medal 2004, selected by the Board, has beenawarded to Dr Giovanni Grasselli (Italy) for his PhDthesis Shear strength of rock joints based on quantifiedsurface description.

7 Technical Commissions remain active (see also website)and reports from three current ones were presented:• Application of Geophysics to Rock Engineering –

current emphasis on standardisation of methods,• Testing Methods – current emphasis on stress

measurement, and• Landslides and Engineered Slopes, joint with

ISSMGE & IAEG and overlapping withInternational Commission on Landslides (ICL)which is getting underway.

The meeting marked the end of Chris Haberfield’s term asAustralasian Vice-President on the Board. Chris hasactively promoted the Australasian viewpoint, and suchenthusiasm and effort is appreciated as we are a smallregion in comparison to the others. He also played aleading role in the staging of GeoEng2000, a highlysuccessful conference of the three societies (ISRM,ISSMGE and IAEG) in Melbourne in November 2000and which was attended by a large kiwi contingent (seeGeomechanics News 61). A report on the activities of thenew Board is given separately by John St George.

ISRM Council Meeting 7 September, Johannesburg, South Africa

Reported by: Stuart Read Geological & Nuclear Sciences, Lower Hutt

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New Zealand Geomechanics News

10 Newsletter of the New Zealand Geotechnical Society Inc.

The theme of the 10th congress of the InternationalSociety for Rock Mechanics (ISRM) held in South Africain September was Technology Roadmap for RockMechanics. The two volume printed proceedings contain240 papers from 33 countries (1 New Zealand, 13Australia,) and the congress was attended by 300 delegatesfrom 34 countries (2 New Zealand, 5 Australia).

South Africa is a world leader in rock mechanics, beinglargely practiced in surface and subsurface hard rockmining, as well for coal extraction and infrastructure civilengineering (e.g. dams). Johannesburg is a city dependanton mining that has gown rapidly since the discovery ofgold in 1886. It is therefore not too surprising that SouthAfricans contributed the largest number of papers (21) aswell as congress registrations (35) and a high level of thesponsorship (>60%).

The South Africans ran the event differently fromprevious congresses. While 6 keynote-type addresses inthe plenary sessions remained along with fullpresentations of 27 selected papers (1 New Zealand, 1Australia), gone were general reporters for each congresstheme. In their place to encourage greater authorparticipation conference theme topics were addressed inconcurrent mini-symposia during which short, 5 minute,presentations of 15–20 selected papers were interspersedwith panel discussions. Posters, which were first tried atthe last congress in Paris in 1999, were also invited inparticular for the 95 papers not selected for presentation.Field trips to deep mines extracting gold from theWitwatersrand reef provided a contrast to the sessions.There were also 4-day post-congress tours to mines north(Bushveld igneous complex) and east (Palaborwa &Middlelburg) of Johannesburg.

The keynote addresses covered a range of themes. Tostart things off Clem Sunter (South Africa – co-author ofthe book Mind of a Fox) gave an illuminating address onthe value of scenario planning and dealing withuncertainty. This included insights on HIV/Aids inSouthern Africa and the significant impact on theworkplace together with comments on some of the sociale.g. ABC guidelines – Abstain, Be faithful, if not use aCondom, or company policy (treatment assistance)counter measures. Charles Fairhurst (USA) gave theLeopold Muller award address on rock mechanics forradioactive waste disposal and the varying approachesaround the world.

Other keynote topics included open cast mining

(Steffen, South Africa) and how high and how steep willpits become as depths approach 1 km and are slope failuresacceptable to a certain level; an introduction to uncertaintyin rock engineering – both deterministic and probabilistic(Einstein, USA), and design and construction of largeunderground caverns for emergency storage of items suchas food (Lee, Korea). Linzer (South Africa) presented herRocha medal PhD thesis on modelling solutions to locatedeep mine induced seismicity.

The 3 hour mini symposia or workshops were run inthe following concurrent sessions:• Rock mass classification; Mine closure; Tunnelling• Large underground openings; Rock fracture and rock

mass failure; Slope stability• Numerical modelling; Seismicity; Risk and other mining


Each session addressed specific topics such as: doclassifications provide realistic values for rock massdeformability? Are support procedures available for allground conditions? Do Mohr-based failure criteriacorrectly predict strength? Cohesion – can we rely on it?Two-dimensional verses three dimensional modelling? Dowe understand wave propagation in fractured rock masses?

Although the format of individual sessions developedduring the congress, they all provided opportunities forpaper presentation, questions and answers, and discussion.Those that I attended had a mix of industry and universitydriven papers, complemented by a good number of casehistories (e.g. shallow large openings in Singapore arefeasible because of high horizontal stresses). They alsoillustrated large budgets available in some researchorganisations for both major and minor items (e.g. 10 mlong models of underground openings in China),solutions for innovative technology (e.g. storingcompressed air in Japan for electricity generation). Asexpected computer modelling and simulation receivedtheir share of attention (but if you have a hammer, shouldone always be looking to use a nail, when say a screwmight be better?).

The mid-session field trips highlighted deep gold minedevelopment near Johannesburg in the Witwatersrandbasin. Mining is commonly at depths of 2500–3500 mwhere ground temperatures are >40 °C and the extensivegold-bearing reef (a conglomerate) is about 1 m thick.Mining at these depths (see Vierra & Budavari, SouthAfrica) is resulting in modifications to traditional mining

10th International ISRM Congress8–12 September 2003, Sandton, Johannesburg, South Africa

Reported by: Stuart ReadGeological & Nuclear Sciences, Lower Hutt

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December 2003, Issue 66 11

techniques such as breast stoping, advance drilling toreduce mine-induced seismicity, hydraulic backfilling, andcooling using iced water rather than air.

Technically there was something for everybody,though numerically-based modelling was the dominanttopic. The challenges in rock mechanics remain as: gettingrepresentative data, characterising rock massperformance, reliability of modelling for design analysis,predicting behaviour and monitoring. These have notchanged since the 1970s though design is evolving toinclude probabilistic risk as well as deterministic. In hissummary Wagner (Austria) felt that the conference hadpreserved a technology theme, but that areas missingwere rock excavation, petroleum reservoir engineering,and the use of geophysics. He also felt that classificationstill needs a lot of attention, and that fundamental

research needs greater promotion. Interdisciplinaryactivities benefit this and there must also be an increase inthe awareness of the importance of rock engineeringscience for society.

It is a challenge to successfully run an internationalconference, particularly when changes to a traditionalformat are introduced. Activities were conveniently closeto each other e.g. posters and sponsors booths adjacent tothe catering facilities and main auditorium, while littletouches such as lion cub displays and praise singersreflected a local flavour. Sure numbers were down on Parisin 1999; times and location influence such things.However, the changes in format with greater authorparticipation more than compensated, so that in myopinion it proved a successful venture. We can all lookforward to the next congress in Lisbon, Portugal in 2007.

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New Zealand Geomechanics News

12 Newsletter of the New Zealand Geotechnical Society Inc.

The European training network set up a collaborationbetween 5 European universities (TU Graz, Universityof Stuttgart, NTNU Trondheim, Helsinki University,and University of Glasgow) entitled Soft ClayModelling for Engineering Practice. This workshop wasthe ‘final’ output from this collaboration, open to thewider community, and specifically sought input fromconsultants and contractors to broaden the scope. In theevent we ended up with about one day on theory, half aday on lab work and verification, half a day on analysis,and the final day on practical aspects including casestudies.

The workshop was held in a complex specifically set upto be a conference/training centre, and indeed during thetime that I was there held concurrently a number of othergroups. The first two days had four 1.5 hour sessions, andthe final day had three with what appeared to be generouscoffee and lunch breaks. This left plenty of time forsocializing after dinner in the bars. However, the coffeebreaks did not end up being so generous due to theamount of debate.

A development that the collaboration had beenfocussing on was the impact of structure and ofanisotropy on the modelling of soft clay soils. Many ofthe theoretical and lab papers were the results of thiseffort. This was of much interest to me as the results fittedvery nicely to some issues that I had been grappling withfor some time. Essentially, the group had set-up twodifferent modelling approaches to handle structure andanisotropy, and then tested the models against each otherand a number of real clays.

One approach was a mathematical based approachusing critical state soil mechanics, the second approachused a rather different hyperbolic soil model and appliedit to a number of planes at each point. Each approach gavesimilar results. Interestingly, a number of the other papers

from outside the collaboration gave quite different ideason how to approach the same problem. However, somequite important lessons came out of this, which sparkedconsiderable debate.

One of the important lessons is that the e-log p plot,even for soft clays, is not the best plot to use fordetermining the pre-consolidation pressure. In fact, one ofthe papers illustrated that really you needed to use twodifferent plots, a linear plot and a tangent modulus plot (p vs mv), to get the best results.

The collaboration also showed that anisotropy on itsown is not enough to model the soils that exhibit theanisotropy. One needs to include the effects of stress axisrotation from the anisotropic axis as well as the effects ofthe developed structure (bonding and fabric). Theyshowed that it is possible to pre-consolidate a soil simplyby rotating the stress axes (though this may be atheoretical application), and equally to fail a soil byrotating in a different fashion.

Ignoring the structure leads to underestimating thestiffness of the soil even during ‘virgin’ loading. Howeverthis led to some debate because, whilst the collaborationhad considered aging in the form of creep (secondarycompression), they had considered the effects of thedevelopment of structure. This debate then led to severetime overruns, an impromptu paper and a lot of discussionabout the visco-plastic behaviour of soils, which appearsto be present even at the incremental stress levelbehaviours of some soils.

The practical papers resulted in some debate on how todesign, or not design, structures using various techniquesand it was also interesting to see the methods adopted invarious countries for analysing ground improvements.

All in all, a very worthwhile conference, particularlygiven the relatively small and diverse nature of theparticipants.

Soft Soil Workshop 15–17 September 2003, Noordwijkerhout, Netherlands

Reported by: Sergei TerzaghiSinclair Knight Merz

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e-mail: [email protected]

AUCKLAND Tel: +64 9 355 6020LABORATORY e-mail: [email protected]


TAURANGA Tel: +64 7 571 0280LABORATORY e-mail: [email protected]



Cossey’s Dam, Hunua Ranges

Access thanks to Watercare Services

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Page 17: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

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New Zealand Geomechanics News

December 2003, Issue 66 17

If you like cabbages and potatoes then Romania is the placefor you. On the plane flight into Bucharest (the capital)looking out the window, over a rather large Romanianwoman and her husband, there were cabbage fields as far asthe eye could see. I’m sure one field had a sign declaring itonly for the young geotechnical engineers!

On landing I was quickly whisked through passportcontrol (the lady got tired of repeatedly asking me after Itold her for the fifteenth time I didn’t know where I wasstaying) and then customs (the guy waved me throughand didn’t bother looking in my bags). From there anIsraeli, a Dutchman, a Canadian and his wife (no this isn’ta bad joke), along with myself were driven to ourovernight accommodation, a student hostel. Brokenwindows were the first sign that this wasn’t the Sheraton.The rooms were small, dark and insect friendly. AJapanese fellow flatly refused to stay and moved to thenearest Hilton! I enjoyed the eastern European style‘roughing it’.

The following day 75 young geotechnical ‘engineers’were packed into buses to be taken to the holiday resort ofMamaia on the Black Sea. On the way we were shown aconstruction site in Bucharest with a recently completed 5storey deep basement adjacent to existing buildings withdeflections with established tolerances. Impressive stuff

considering the deep alluvial sediments. From there wewere transported across the flat plains of southernRomania. An interesting lecture was given on the onagain/off again motorway between Bucharest and theBlack Sea port of Constantza. We stopped to view someamazing bridges crossing a river (name unknown).Somehow the Romanians had turned a two lane highwayand railway track into a spaghetti junction, all suspendedin the air!

The 2nd International Young Geotechnical EngineersConference started the following day at the OvidiusUniversity, Mamaia. Although the organisers claimedthere were 3 geologists at the conference, I never met theother two, despite talking to anyone who walked past. Itis a humbling experience to hear people from manydifferent countries communicating in English, whilst Istand there and realise I know only a few words of Frenchand Mandarin.

The conference was a well regimented affair withdelegates bused to the conference in the morning, busedback to the hotel and then bused to evening dinner typicallylasting until midnight (once a Canadian and myself missedthe evening bus and experienced the local cabs, they didn’tknow English until you discussed the price. I wanted todiscuss the unbraked, non seat-belted car).

2nd International Young Geotechnical Engineers Conference Report 7–10 September 2003, University ‘Ovidius’ Constantza, Mamaia, Romania

Reported by: Steven PriceRiley Consultants Ltd

Left: Bucharest Site –

Construction site with 5 storey

deep basement. Young

engineers milling around.

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A series of guest lecturers provided interestingspeeches, particularly one on the high-speed rail line fromthe Chunnel to London. The 15 minute talks by young‘engineers’ were divided into 3 parallel groups, sounfortunately you couldn’t hear them all. The standardwas very high. Some struggled with the English language,others were so quiet they needed a megaphone, but stillthe topics were interesting, such as continental slopestability and dealing with piping beneath a damfoundation. My speech went well, though some of thehumour I think was over the heads of many non-nativeEnglish speakers. A Canadian lecturer is intending to usesome aspects of my speech/overheads to highlight theimportance of understanding engineering geology to hisstudents. That makes it feel all-worthwhile.

At night-time the organisers would take us to variousrestaurants to experience a slice of Romania (typically apiece of cabbage). From traditional Romanian dancing, toballet, to the finest restaurant by the sea. Afterwards, asbeer was cheaper than water, some infrequent visits to thelocal establishments were made. But only for the purposeof networking with our international peers of course.

A visit was made to Constantza harbour. This thing isbig. I’ll never see the Ports of Auckland in the same way.

One regret of the conference was the lack of personaltime to explore the Romanian towns and countryside.Some people, like our Australian counterpart, stayed onafter but unfortunately experienced a storm that had comeacross from Italy. I personally spent a night in anotherstudent hostel in Bucharest, better than the first, then flewto Germany to let loose on the Autobahns.

The conference was an amazing event; a place to meetpeople of your on age from a variety of differentcountries and backgrounds. It was also an opportunity toprofessors and senior staff from universities andconsultancies throughout Europe. An experience that oneshall never forget.

I would personally like to thank the New ZealandGeotechnical Society, EQC and Riley Consultants Ltd forthe opportunity to attend this conference.

New Zealand Geomechanics News

18 Newsletter of the New Zealand Geotechnical Society Inc.

Right: Part of the

Constantza port where

scrap metal is loaded.

Right: Skoda Girls: How they sell cars in Romania.

If only it would catch on in New Zealand.

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New Zealand Geomechanics News

December 2003, Issue 66 19

The New Zealand Society on Large Dams (NZSOLD)symposium on 26 August 2003 continued a series of one-day symposia from 1997 and 2003. The themes of thesymposia have a broader base than purely technical itemsto include a wider spectrum of dam-related issues. This isintentional to provide value not only for Society membersbut also other parties with an interest in dams and damsafety assurance eg. regional authorities.

Water is a resource needed for electricity generation,domestic consumption, irrigation or industrial use anddemands for it is gaining wider attention. The 2003 themearose from the resource consent process being faced bymajor dam owners and regional authorities, plus providean update on recent activities in the dam industry,including legislation. Twelve papers, each prepared on aninvitational basis, plus a keynote address, were presentedto an audience of 115 delegates representing dam owners,regulatory authorities, planners and technical advisors.

The keynote address, which was given by Prof AngelaArthington, a river ecologist from Griffith University,Brisbane, provided a well presented educationalopportunity on ecological aspects of river systems andimpacts of dams. She outlined four guiding principles thatlink hydrology and aquatic biodiversity (flow regimedetermines habitat, species respond to flow regime,viability of species is related to pattern maintenance,change aids exotic species). Illustration of the impacts ofaltered flow regimes using these principles includedseveral case histories from New Zealand and Australia eg.Wivenhoe Dam, a multi-purpose dam constructedfollowing the Brisbane flood in the 1970s.

The rest of the morning satisfied the technical folk withfour recent case histories – treatment of soft soilfoundations using wick drains during construction of the18m high Wilsons earthfill embankment dam inNorthland (Weston et al.), environmental issues related todrawdown of the reservoir for the Cosseys Dam remedialworks (McQuarrie et al.), grouting high pressure seepageat Arapuni while maintaining full reservoir level andprotecting underdrainage systems (Amos et al.), andcurrent tailings dam embankment practice in NewZealand, primarily designing them as zoned waste rockembankments (Matuschka).

Dam safety related legislation was a topic at the 1993,

1997 (keynote address), and 2000 symposia. The hardyperennial has been revived and is included in the currentrevision of the Building Act 1991 (now at SelectCommittee stage) sponsored by the Ministry of EconomicDevelopment (MED). After perspectives from NZSOLD(Mulvihill) and regional councils (Jones), MEDrepresentatives (Mumford & Townsend) accepted theinvitation to outline the envisaged shape of the legislationrelating to dams. This produced the most lively discussionsession of the symposium, illustrating its significance tothe dam industry.

Experiences of dam owners (Scarlett) and regulators(Crequer) in the Mighty River Power consent renewalsthen illustrated the huge effort needed in the process. It isclear that we are moving into a new regime with greaterenvironmental and economic attention rather thantechnical. This was also illustrated in the consent processfor Project Aqua on the Waitaki River – a new project(Campbell), and some of the adjustments required fordealing with several councils when assets are spread aroundNew Zealand as is the case for TrustPower (Lilley).

The final two papers had a Canterbury flavourfocussing on real events and future demands. The Opuhadam overtopping during construction in February 1997illustrated the emergency management lessons that comefrom dealing with an actual event (Lees & Thomson),while there is a necessity for water storage if futureirrigation needs are to be met without constraints (Bright).

Overall the symposium achieved the Society’s aimswith an appropriate collection of papers presented toillustrate current industry-wide trends and promote bestpractice. A difference from previous symposia was thatthe discussion sessions (apart from legislation) were lesslively. This may beg the question of whether the venuewas too comfortable and/or the catering too sumptuous,but these like the numbers attending were similar toprevious years. As noted earlier topics for the symposiumpapers were agreed on an invitational basis. Calls forpapers are made for the combined NZSOLD/ANCOLD(Australian Committee on Large Dams) conferences,which are also held every 3 years. The next conference willbe held in Melbourne in October 2004 (watch theNZSOLD webpage www.ipenz.org.nz/nzsold – call forpapers likely around April).

NZSOLD Symposium, Dams – Consents and Current Practice26 August 2003, Wellington

Reported by: Stuart Read and Peter MulvihillGeological & Nuclear Sciences, Lower Hutt and Pioneer Generation, Alexandra

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8 –11 February 2004Auckland

Hilton Hotel

Register now for the premier event on Australasia’s geotechnical calendar. While heldevery 4 years, it is held in New Zealand only every 12 years, bringing togethergeotechnical practitioners involved in soil mechanics, rock mechanics and engineeringgeology. The conference is promoted by the Australian Geomechanics Society and theNew Zealand Geotechnical Society


“to the eNZ of the earth”

The conference theme aims to generate discussion on what makes geotechnical practicewithin New Zealand and Australia different to other parts of the world. This uniqueness isin part historic due to both countries being young nations and in part location as a resultof their position on or adjacent to a tectonic plate boundary.

The theme also encourages contributions to consider the influences of the ‘ElectronicAge’ on geotechnical practice.

Subject areasA total of 131 papers have been received for theconference. Conference sessions will be held for:• Foundations• Slope Stability• Site Investigations and Engineering Geology• Laboratory Testing• Retaining Walls, Anchors and Excavations

• Embankments and Ground Improvement• Rock Mechanics and Mining• Roading, Pavements and Rail• Tunnelling and Subsidence• Environmental Geotechnics and Hydrogeology• Modelling• Geosynthetics

Keynote speakers• Conference Keynote Address by Professor Geoff

Martin of the University of Southern California,international expert on liquefaction related groundstability, ground improvement and the seismicdesign of foundations and earth structures

• The John Jaeger Memorial Address by EmeritusProfessor ET (Ted) Brown AC FREng FTSE, co-author of two well-known books on undergroundexcavations, Underground Excavations in Rock,with Evert Hoek and Rock Mechanics for

Underground Mining with Barry Brady, and authorof the recently published book Block CavingGeomechanics.

• The New Zealand Geotechnical Society 2004Geomechanics Lecture by Dr Laurie Wesley ofthe University of Auckland, whose special researchinterest has been the properties of volcanic andresidual soils, in particular tropical red clays,allophone clays, and pumiceous sands, reinforcedearth, landfills, groundwater and seepage.


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Hot TopicsHot topics is a special new feature at the ANZ conference and is your chance to pick the brains of 2 to 3 experts ina particular area of geotechnical engineering (e.g. liquefaction, numerical modelling, landslide risk assessment etc)and ask them questions. The experts will provide a brief introduction to a ‘Hot Topic’ and the floor will be openedfor questions and discussion.

Post-conference ToursRotorua Technical Tour (Tour 1)This two-day tour to Rotorua and Taupo in the centre ofthe North Island is the perfect way to combine learningabout volcanic geology, sightseeing, cultural activities,good food and company. Travel by coach on Thursdayto Rotorua, while receiving a lesson in the geology ofthe North Island on the way. Walk through theWaimangu Valley where you will experience geothermalactivity at close quarters. End the day by swimming inthermal pools before heading out for an encounter withMaori culture and food. Rise on Friday morning to visitvolcanic geomorphology and active faults. Enjoy lunchat a prawn farm that utilises the discharge cooling waterfrom NZ’s largest geothermal power plant. Then sit backand enjoy the ride back to Auckland.

Auckland Technical Tour (Tour 2)Burn off post conference fatigue with a brisk walk cruisethe harbour of the City of Sails, climb Rangitoto, learnvolcanic geology first hand on the way, get spectacularviews while enjoying the morning tea you carried to thetop, return to the boat and cruise to Waiheke Islandwhere you will taste wine, tour a vineyard, and tastelocal cuisine at an iconic restaurant. Finish the day byenjoying a leisurely cruise back to Auckland.

Social EventsOpening Ceremony & ReceptionSunday 8 FebruaryThis is the official opening of the Conference with aPowhiri. Meet with old friends and new while enjoyingdrinks and canapés in the conference centre of theHilton Hotel Auckland.

Happy HourMonday 9 FebruaryJoin together for drinks and further viewing of posters

Conference Dinner (Pacific Party)Tuesday 10 FebruaryThe Conference Dinner is to be held at one ofAuckland’s spectacular catering venues. Enjoy asumptuous dinner and fine wines with friends andcolleagues, while being entertained by a variety ofperformers.

Exhibition FacilitiesAn area will be available for displays over the three days of the conference. Corporate sponsorship opportunitiesare also being offered. Contact the Conference Manager for details.

Conference ConvenorsGeoffrey Farquhar, Maunsell LtdPhilip Kelsey, Earthtech Consulting LtdJohn Marsh, Beca Carter Hollings & Ferner LtdDebbie Fellows, URS NZ Ltd

EnquiriesAll enquiries should be addressed to the: Conference ManagerBarry WilliamsCentre for Continuing EducationUniversity of AucklandPrivate Bag 92019, Auckland, New ZealandPhone: +64 9 373 7599 ext 88903Fax: +64 9 373 3419Email: [email protected]

Online Registration Formwww.art.auckland.ac.nz/cce/Conferences/index.cfm

FeesDelegate Type Up to From 16

15 Jan 2004 Jan 2004Full delegate $690 $790Student delegate* $500 $600Day delegate $230 $330Tour 1 $500 NATour 2 $200 NA

* Sponsorship is available for NZ students (see registration form for details)

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New Zealand Geomechanics News

24 Newsletter of the New Zealand Geotechnical Society Inc.

The NNTS is an organisation formed by the Institution ofProfessional Engineers (IPENZ – ENGINEERS NEWZEALAND) and the Royal Society of New Zealand(RSNZ) to support collaboration between technology-based learned societies. NNTS works to facilitate thesharing of knowledge and skills.

Members of the NNTS are not-for-profitorganisations, membership-based and democraticallygoverned. They must be representative of technologistsinvolved in their area of interest nationally. Memberorganisations operate in areas of interest on the spectrumfrom applied science to engineering, and they fill learned-society roles. The learned-society, public policy and mediacontributions of member organisations are peer-reviewedby individual members.

A key purpose of the NNTS is to disseminate the viewsof New Zealand’s technological ‘community of expertise’on issues of the day. There is a growing list on the NNTSwebsite of experts who are willing to provide informedcomment on technological issues.

The NNTS website allows members to register issueson which they think other Network members may be ableto make useful contributions. On the site at the momentare statements relating to IEC 61508 Safety StandardRatification, and public-private partnerships. Othermembers of the Network can endorse or oppose thestatement during a review period; then the statement ismoved to the public area of the site, so anyone interestedcan read the statement and the responses of otherNetwork members.

The NNTS also promotes the co-operation and sharingof best practice among Chief Executives or ExecutiveOfficers of member organisations. Some likely areas forco-operation are development and operation of codes ofethics, publishing, advertising of events; other possibilitiesare a national Technology events calendar and sharing ofadministrative service experiences such as databasedevelopments.

Find out more about the NNTS by visitingwww.nnts.org.nz.


National Network of Technological Societies

NNTS exists for the following purposes:• Facilitating the presentation of the informed views of New Zealand’s technological

‘community of expertise’ on issues of the day (by creating mechanisms for endorsementof non-aligned and learned contributions on technological issues affecting the widercommunity when they are presented to Government, the media, community leadersand the general public).

• Development of wide-ranging expertise listings as a resource for those in the communityseeking informed comment on technological issues.

• Sharing of best practice and cooperation amongst Chief Executives/Executive Officersof member organisations e.g. development and operation of codes of ethics, sharedpublishing possibilities, wider advertising of meetings/seminars/conferences etc.

• Possibly developing a national Technology Events calendar, sharing administrativeservice experiences e.g. database developments.

NZGS is now a member – so check out the websitewww.nnts.org.nz

National Network of Technological Societies (NNTS)

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The following is the submission sent to the parliamentselect committee on behalf of the Geotechnical Societyregarding the Building Bill to repeal the Building Act1991.

Introduction• This submission is from the New Zealand Geotechnical

Society, a specialist division of the Institution ofProfessional Engineers New Zealand (IPENZ). It isfocused entirely on the impact of natural hazards. Whilethere are other issues within the draft Bill which are ofconcern to many of our members, we have left thoseissues to be addressed by other learned Societies such asIPENZ, the Association of Consulting Engineers, andthe New Zealand Society on Large Dams. The Societysupports those kindred submissions.

• The Chairman of NZ Geotechnical Society (J Marsh)and the Chairman of the Working Party set up by theNZ Geotechnical Society (N Luxford) wish to appearbefore the ‘Select Committee’ to speak to thissubmission. The most appropriate contact for partiesdealing with this submission is through the Chairman ofthe Working Party:Mr N.S. (Paddy) LuxfordC/- Babbage Consultants Ltd (Auckland).Ph (09) 379 9980Fax (09) 377 1170

• The New Zealand Geotechnical Society, (NZGS), isthe society which represents more than 460 designprofessionals consisting of Geotechnical Engineers,Engineering Geologists and Technicians who dailydeal with the assessment of natural hazards in theireveryday working lives. These professionals areemployed by a mixture of Professional Consultants,Territorial Authorities and Legal Practices and thusrepresent the major cross section of individuals dealingwith natural hazards who will need to implement thelegislative changes which the Bill will have on thepublic at large. As a group we have previouslyprovided two submissions to the Department ofInternal Affairs, one dated 18 December 2000 whichset out most of the concerns which occur in current1991 Building Act and a second dated 15 October 2001which provided suggested solutions to overcome mostof these concerns.

SummaryNZGS is pleased to see that many of the suggestions madeby them have been adopted in the current Bill. In particular:• the extent of the effects of natural hazards applying to

the building works rather than the entire allotment,

• the removal of the archaic terms alluvion and avulsion,• the clarification of specific sub-items within each

specific category of natural hazard based on thedefinition of the hazards provided by NZGS,

• the quasi-removal of the prior provisions of s36(2) of the1991 Act,

• where a waiver is to be granted for a particular naturalhazard, the actual hazard for which the waiver is grantedis to be noted as part of the waiver which is registered onthe property title.

However, NZGS would be extremely concerned if anygroup endeavoured to remove insurance cover for anystructure constructed in accordance with a BuildingConsent issued subject to one or more waivers. As a groupwe consider it vital that insurance cover can be obtainedfor the risk associated with the granting of waivers, butacknowledge that increased premiums may be necessary insome instances.

Within the draft Bill there appear to be severalmodifications made where NZGS consider specificwording suggested should be improved and these arediscussed at length within the body of this submission.

However, there are a number of suggestions made byNZGS to the Department of Internal Affairs and theMinistry of Economic Development that have either beenoverlooked or not taken up, which it also considers to bevital to the successful implementation and satisfactoryperformance of the this part of the Bill. NZGS wishes tofocus on the reasons behind their position on these issueswhen they appear before the Select Committee. These aresummarised as follows:• the removal of the natural hazard of subsidence, • the lack of the inclusion of a time scale associated with

the assessment of a natural hazard, • no means of transference of the knowledge of the risk

associated with an identified natural hazard to a futureland (and building) owner other than where a waiver is issued.

All of the submissions made by the NZGS are with a viewto having clarity of issues associated with natural hazardsdefined so as to minimise risk from such issues to thegeneral public.

Background DataThe NZGS is very pleased that many of the changes it hassuggested to overcome many of the concerns which havearisen with the current legislation, have been adopted inthe draft version of this Bill. We attach for backgroundreading for the Select Committee copies of our prior

NZGS Legislative Submission – Building Bill to Repeal Building Act 1991

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submissions. The submission of 18 December 2000outlines many of the known concerns with the current Actand the submission of 15 October 2001 addresses thesuggested changes to the current Act made by the NZGSand in our opinion is essential background data.

Specific Details of Concern Associated withthe Drafted Sections of the BillIn this section we have quoted the actual page and sectionreference, a suggested amendment, and a reason andfurther comment. [see table on page 28].

Clarity of DefinitionThe current draft of this Bill has picked up all of thespecific types of natural hazards which the Societyconsiders appropriate to building development (exceptthose associated with Subsidence). Our discussions withthose who drafted these changes indicate that the removalof the term ‘Subsidence’ and the sub classes of settlement,liquefaction and shrinkage were a genuine oversight andwe have assumed that these will definitely be returned tothe final Bill.

However, an expanded definition of each of thesehazards as provided in the attached document is in theopinion of the Society very important as memberscontinually find that parties interpreting this part of theprior Act hold differences as to the legal meaning of manyof the hazards identified on a site.

We therefore believe it is important that either the Act(or the Building Regulations) must contain an expandeddefinition of the meaning of each of the hazards identifiedin the Bill.

Material DamageThe concept of ‘material damage’ will align this Act withthe equivalent section of the Resource Management Act.Without the addition of this term the Bill will in ouropinion become unworkable as it will prevent BuildingConsent approval being given without a waiver.

All land is subject to natural hazards. It is only whenthe degree of the effect of the natural hazard is sufficientlysevere to result in material damage to a building, that thehazard is of significance. The simplest specific exampleswhere the current drafting of the Bill would precludegranting of a consent under s159 would be any site onwhich a building undergoes settlement (more than 90% ofall land in New Zealand) or shrinkage (more than 60% ofall land in New Zealand). The Building Regulations alsorecognised that inundation of a building could occur whena flood event exceeds a 2% AEP event, but it should stillbe required that such a flood event does not cause materialdamage to the building structure.

Clearly minor land slippage which does not result inmaterial damage to a building may be an issue with alandowner because of loss of amenity of an allotment, but

should in our opinion not impact a Building Consent.We suggest that a definition of material damage should

be provided in the Bill (or at least in the BuildingRegulations) and propose the following definition:

‘Material damage’ is any displacement of abuilding or its elements or cracking ofindividual elements within a building that isother than aesthetic and has been caused by anatural hazard.

NZGS is happy the Bill as drafted will allow thecontinuation of some development by way of a waiverwhere there might be some risk of material damage tobuilding work from a natural hazard under reasonablyforeseeable conditions, providing the safety of theoccupants is still assured. This concept is not new and hasbeen the design concept to accommodate the naturalhazard of earthquake, where it is accepted within oursociety that under a severe event the protection of thesafety of the public is endeavoured to be maintained bydesigning to prevent collapse of a building, butrecognising that after such a severe event, the structuremay need to be reconstructed.

We are pleased to see the removal of s36(2) typeapprovals because of the unfair stigma that has resultedfrom this current process and are pleased to see that thishas been replaced by a waiver. We believe this will beappropriate in such circumstances. However, just asinsurance is available to deal with the risk associated withearthquake damage, we consider it vital that similarinsurance coverage be available to accommodate damageto building work for which a waiver has been granted. Weacknowledge however, that an increase in the insurancepremium payable for such cover might be applicable.

We note that historically the greatest risk to the safetyof society from those hazards that the Bill classifies as‘natural’ arises from ‘falling debris’. To the best of ourknowledge, in the past 50 years this is the only naturalhazard that has resulted in the occupant of a buildingbeing killed. For this reason we consider that TerritorialAuthorities should have specific rights to condemn abuilding as being dangerous where an adequately assessednatural hazard classified as ‘falling debris’ is considered toimpose an unacceptable risk to the continuing occupationof a building.

Time ScaleThe NZGS considers it vital that a time scale isintroduced into the Bill for which a natural hazard is to beassessed if reasonableness is to occur in the law produced.Ideally society would like to think that consentedbuilding work is protected from the effects of naturalhazards forever. However, human ability to foresee intothe future is not good at the best of time and society needsto recognise the limitations of any consent granted.

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Professionals have assessed historical flood recordsand predicted flood levels based on such records formany years. Analytical techniques have been availablefor about 50 years to undertake such futuristicpredictions. However, unforeseen climatic changes areproving that many of these earlier flood levelpredictions are now unreliable and even those madewith allowance for potential climatic changes are notproving to be robust.

The ability to assess the degree of stability of a parcel ofland in its present state has been significantly refined overthe last 30 years, but our ability to predict how that landmight perform in the future is subjective. This arisesbecause land stability is not only affected by weatheringchanges to the strength of the soil and variations ingroundwater levels, but also by erosive forces, climatechanges and the influence of human activity. Theseinfluences which cannot be reliably predicted can have asignificant impact on the future performance of the stability.

Thus while the profession through the NZGSacknowledges the desire to provide an indefiniteassessment of a natural hazard, this is not technicallypossible. We thus suggest that any assessment undertakenbe appropriate for a minimum of 50 years (consistent withthe minimum durability requirements of the Bill). Thistime gives society a reasonable degree of securityrecognising that after such time it would not beunreasonable for modifications to be undertaken tobuilding work to protect the work against any changeswhich might then be occurring. Implementation of such atime scale would allow a rational review of the hazards onwhich an original consent was based and the publicationof variations to conditions where appropriate. Aconsenting authority following such advice could thenreasonably require a building owner to reassess the impactof a particular hazard on their development.

Risk TransferAll building work is at some risk from natural hazards.The assessment of natural hazards and the impact they willhave on building work is an ‘inexact science’ and at best anassessment endeavours to quantify the risk of impact of

the hazard on the building work at an acceptable level.However, what is acceptable has not as yet been definedby society and can vary from person to person andTerritorial Authority to Territorial Authority. For thisreason the NZGS believes the best means of addressingthe impact of natural hazards on building work is allowingthe quantification of the risk to transfer with theownership of the allotment. They have previouslyprovided a suggested means by which legislation could beprepared to enable such to occur.

NZGS considers the potential impact of a naturalhazard on the future financial well being of a allotmentowner is so great it has and continues to advocate thatwhere a building consent is issued which makes relianceon an assessment of a hazard, the record of this assessmentmust be kept by a territorial authority, and the existence ofthis assessment should be recorded on the property title.The reason for this is to ensure that the risk associatedwith the natural hazard will have a degree of certainty ofbeing able to be transferred with the ownership of theallotment. Thus philosophically, the NZGS is at differencewith the current drafting of the Bill, as this is not providedfor within the current form.

However, as a minimum, we consider it essential thatthe Bill be modified to ensure that the TerritorialAuthority maintain on each property file a record of anyassessment of a natural hazard on which it has placedreliance in issuing a building consent and that the right toaccess this information by interested parties is maintainedat all times.

Oral PresentationsIt is our intention that we will concentrate largely ongiving background data on items 6, 7 and 8 during ourpresentation to the select committee and we wouldwelcome any questions from them to clarify our reasonsfor the concerns we now raise.

Yours faithfully

N S (Paddy) LuxfordChairman of Working Party of NZGS

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41 s51(2)(b)

50 s72(2)(b)

86 s159(1)(a)

86 s159(2)(a)

110 s205(1)

Suggested Amendment

Add (e) subsidence,including settlement,liquefaction, andshrinkage.

Add (viii) any professionalreport assessing a naturalhazard that is relevant to abuilding consent

Add (viii) any professionalreport assessing a naturalhazard that is relevant tothe building consent

Add that will result inmaterial damage to thebuilding work, or

Add for a period of morethan 50 years, or

c) if an assessment of thenatural hazard of ‘fallingdebris’ made by suitablyqualified professionalsindependent of a territorial authorityconsiders continuedoccupancy of a building is unsafe.


This forms an important class of‘natural hazards which affect theperformance of buildings and thesafety of the occupants.

The only place where a library ofsuch records can and must beretained is in the records of aTerritorial Authority

Any report relied on by a BuildingConsent Authority must behanded to the TerritorialAuthority for record keeping.

All land is subject to naturalhazards and therefore as drafted allconsents must be refused unders159(1)

It is not possible to predict theeffect of a natural hazard with anyreliability for more than about 50years. (With climatic changes eventhe assessment of flood levels arebeing upgraded).

(Falling debris is the naturalhazard most likely to affect thesafety of occupants of a building.

Additional Comments

The terms erosion, falling debris,inundation, slippage and subsidence shouldbe expanded to include definitions assuggested by the NZGS in their submissionto the DIA of 15 October 2001 so as toavoid alternative interpretations.

S 51(3) sets out clearly why it is importantfor such records on natural hazards to beretained.

This addition raises the need to define‘material damage’ in Subpart 2‘Interpretation’. NZGS has suggested sucha definition in their prior submission to the DIA.

The concept of a time scale is important inany assessment of a natural hazard or forexample, cliff top property will not be ableto be developed. Fifty years is a reasonabletime after which upgrading the assessmentto address changes to the risk from anatural hazard would be reasonable.

The only deaths of people inside buildingsarising from a natural hazard that we canrecall since the implementation of theBuilding Act have arisen from falling debrisand thus we consider this particular hazardjustifies particular consideration to raise theawareness of this issue to all partiesinvolved in the consent, assessment andoccupation regime.

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The 2003 draft revision of the 1988 soil and rockdescription guidelines circulated to members in March thisyear and discussed at the Society Symposium in Taurangaheralded changes through the respective titles of the twodocuments:

1988: Guidelines for the field description of soils androcks in engineering use

2003: Field description of soils and rocks. Guidelinesfor the classification and field description ofsoils and rocks for engineering purposes.

The introduction of the 2003 draft indicated that changesshould be made where clearly justified, result inguidelines that are clear and uncomplicated, whileconforming to international practice and reflectingproperties of engineering significance. In the event the2003 revision significantly changed the guidelineframework in the case of soils, but pretty muchpreserved the status quo for rocks. The changes for soilsincluded:

a) Priority to classification rather than descriptionb) Abandonment, or making optional, of descriptive

terms related to in situ conditions

This note provides commentary on the 2003 draftrevision based on a) my involvement with the 1988document committee, b) what has happened ininternational practice in the last 15 years, and c) the notesfrom the 2003 ‘revision’ committee in NZ GeomechanicsNews, June 2003, Issue 65 (GM65), that were in responseto members’ comments including those at the SocietySymposium seminar. The intent of the note is to look atfundamental issues in particular for soils (eg.classification) and overall framework, rather the detail ofsome individual sections within the documents (eg. scalacorrelations, weathering).

The changes for soils are best examined on two pointsa) intent ie. description v classification and b) internationalpractice since 1988. The 1988 guidelines had the followingtwo sentence introductory statement:

“The guidelines for soil description method arelargely based on the method originally given inthe USBR Earth Manual, which was primarilydesigned for the classification of construction(ie. remoulded or excavated) materials. Thedescription of soils in situ requires theintroduction of additional terms whileretaining important features of the USBRmethod such as the unified symbol.”

In the 1988 guidelines the second of these two sentenceswas considered the more important, yet it is completelyomitted from the committee comments in GM65. Onemay ask why – is engineering performance based solely onclassification of remoulded materials? One could argueyes for embankments, but could one for foundationswithout an appreciation of in situ ground structure? Is theintent of the person in the field to describe (as in 1988) orto classify (as in 2003)? Can you classify withoutdescribing? Whatever your viewpoint may be draws apretty strong line in the sand.

The next step is to look at international practice. In the1988 guidelines the references include three principal siteinvestigation standards or guidelines – USBR EarthManual (2nd Ed, 1974), American Standard ASTM D2488(1969), and British Standard BS 5390 (1981), but excludeAustralian Standard AS1726 (1981). Since 1988 all four ofthese documents have been revised, in 1998, 2000, 1999,and 1993 respectively. Apart from Australia, all three havea fundamental change of splitting of visual/manualdescriptive (field) procedures from classification(laboratory) procedures.

In the USA this translates into the lack of a soilclassification chart as part of the visual/manualdescription of soils (USBR 5005-86 and ASTM D2488-00), and treating the Unified Soil Classification System(USCS) with the unified soil symbol as a laboratoryprocedure (USBR 5000-86 and ASTM D2487-00).Section 42 of BS5930 (1988) goes as far to state that thefield description should stand as the record of theundisturbed nature of the soil, thereby indirectlysupporting the primary intention of the NZGS 1988document. BS5930 does not recommend a classificationstating that classification can provide additional usefulinformation as to how the disturbed material behaveswhen used as a construction material.

The lack of the unified soil classification chart for theidentification and description of soils in the updatedUSBR method was recognised in the introduction toNZGS 2003 draft revision. So why is classification afundamental platform of change in the 2003 draftdocument? Apart from stating that the separation ofdescription (in situ properties) from classification(composition and intrinsic properties) is logical, thegreatest reason seems to be that sometimes only disturbedsamples are available or relevant. Sounds more like the tailwagging the dog rather than reducing the subjective natureof descriptions from site investigations.

In GM65 it was stated that we should follow the practiceof the Australians. This could ask a rhetorical question of

Soil and Rock Description – Comments on Present and Proposed Guidelines

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why did we change our Society name from Geomechanicsto Geotechnical in 1990 while they have retainedGeomechanics in Australia. However, more importantly,AS1726 (1993) states that the soil description method(Section A2.1) is based on mass characteristics as assessed inthe field and material characteristics assessed from disturbedsamples. It then states that soil classification places a soil intoa number of groups whose characteristics are independent ofthe particular condition in which a soil occurs is treatedseparately and useful as a guide for construction material.The order of description (Section A2.3) is given as:

Composition of soil (disturbed or undisturbed state) -which should include:• Classification group symbol (a mixture of field and

laboratory characteristics)• Soil name (use block letters)• Plasticity or particle characteristics and colour of soil• Secondary soil components and other minor soil

components• Conditions of soil• Moisture condition and consistency (undisturbed

state only)• Structure of soil• Zoning, defects, cementing• Additional observations (such as soil origin)

This listing, apart from the order of terms, is little differentfrom the NZGS 1988 approach that included a soil nameplus a unified soil symbol at end of the description, ratherthan the beginning. The order from AS1725 given above isgiven in GM65 as:

• Classification – symbol or soil name (colour is gone) • Condition of soil – moisture condition and

consistency• Structure of soil – zoning, defects etc• Additional observations (such as soil origin)

The order in GM65 is not a direct translation of the orderin AS1726. The differences (symbol/name etc vclassification) basically encapsulates the nub of the soildescription / classification discussions.

– On one hand soil name is derived from particle sizedistribution characteristics for coarse-grained soilsand behavioural characteristics for fine-grained soils.That was the platform of the 1988 document and isthe platform of the current visual/manual descriptivemethods in England (with Europe) and the USA. Allof these consider in situ characteristics an integral orequal component, while in the case of Australia (likethe 1998 guidelines), the classification group symbolis an additional item.

– On the other hand classification is the basic means ofassigning soil groups, which are given names in a

system also based on particle size distribution andbehavioural characteristics. This is the platform of the2003 document (and as modified from AS1726 inGM65). This approach considers in situ characteristicsas less important or as a maximum of a secondarynature.

Given the demise of the unified soil symbol from the mostrecent international soil description practice, accompaniedby acknowledgement of the importance of in situcharacteristics, the most logical conclusion is thatclassification should not form part of soil description.Classification seems to have been introduced for no goodreason (except under the guise of possibly changing theorder of terms to describe a soil, so that if was not ‘out ofthe air’ it was certainly from Casagrande’s work onairfields). The GM65 comments also have the title ofClassification and Description of Soils and Rocks ratherthan Field Description of Soils and Rocks. Is this a furtherclassification shift as there is an additional criterion thatthe guidelines should cover both field and laboratorydescription (does that mean classification? or arelaboratory samples sometimes undisturbed?).

GM65 also comments on differences betweendescriptions of soils and rocks, stating that there is no goodreason for treating soils and rocks in the same manner, aswas the approach in the 1988 guidelines. The implicationthat soil properties have no relationship to geologicalorigin is fallaceous. Fine-grained soils are different fromcoarse-grained soils because of different depositionalenvironments and subsequent loading histories. Simplyrelying on classification from remoulding does not give afull picture of engineering properties for use in design.Which brings up a final point – if the basis for soils in the2003 revision is classification then why don’t rocks receivesimilar treatment. Rock classification systems (eg RockMass Rating, Geological Strength Index) are used bygeotechnical engineers as part of defining rock massproperties and use in design.

The 1988 guidelines were intended to provide a methodto describe the spectrum of rocks and soils in a consistentmanner in the field for engineering geologists andgeotechnical engineers. The revised document of 2003 andin particular the comments in GM65 have a divisiveflavours (ie. soils for soils engineers, rocks for geologists)that is a backward step for the geotechnical fraternity andthe inclusion of the title classification in the title isinappropriate, against the original intention of the 1988guidelines and in the case of soils a fatal flaw consideringcurrent international practice.

Stuart ReadGeological & Nuclear Sciences, Lower Hutt

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This is a Balkema publication, and is a collection of ninediscrete papers on the general subject of site investigationand in-situ testing. It is of a relatively small size,approximately 50 mm shorter in both width and heightcompared to an A4 sheet, and has a total number of 291pages. It is printed in India on relatively good qualitypaper. Due to the nature of such a compilation, it is in thefirst instance a little disjointed compared to a text book,and reads more like a journal, however it does have auseful topic index at the end of the book.

Site investigation, in situ testing and laboratorytesting are topics close to the heart of all geotechnicalengineers. Some things change with time (e.g.mechanical ‘Dutch Cones’ c.f. electric friction-piezo-cone penetrometers) and some don’t change very muchat all (e.g. Standard Penetration Tests). However, the testof any book of this ilk is an evaluation of the amount ofuseful new information that it may contain, togetherwith the textbook tried and true in-situ testing methodsetc, and guidance on ‘putting it all together’ tocharacterise soils. As this book is, as already stated, acompilation, its review is best dealt with on a paper-by-paper basis.

1st Paper: In-Situ Characterization of Soils, Sharma V.M.This paper is very poorly-structured (e.g. there is aheading titled Economic Justification for UsingGeophysics between a description of several geophysicalmethods (in a low level of detail) and a more detailed(but still inadequate) section on Seismic Response ofDifferent Soils. This paper provides an introduction togeophysics (seismic refraction, electrical resistivity,down-hole and cross-hole seismic, electrical resistivityand gamma radiation). Neither typical seismic velocitiesfor varying materials, their relevance, nor an explanationof why seismic velocity is required to increase withdepth in order for seismic refraction to be valid areprovided. There is no reference to Ground PenetratingRadar, which is a common technique now in thedeveloped world.

A reasonable amount of detail is described on drilling(although beware of statutory obligations with respect tocarte-blanche invitations to physically go down holes ofup to 1200 mm diameter for the purpose of collection ofsamples and visual inspection) and a little less on samplingmethods. A few diagrams or photographs would havebeen useful here, particularly as the text is quite tortuousand torturous, as in the description of rotary drilling: “The

bit cuts, chips and grinds away material which is thenlifted from the hole by circulating drilling fluid.” Thiscompares extremely unfavourably with the description ofrotary drilling provided in Foundation EngineeringHandbook, edited by Fang. The Standard Penetration Testis described in detail. Similarly, the Cone Penetration Test(CPT) is reasonably described, but it couldn’t be regardedas definitive.

What this paper fails to do is to address the subject ofits title. It describes a variety of in-situ tests, andgeophysical techniques, but it doesn’t provide any adviceon how to model soils based on in-situ testing results. Itdoesn’t mention engineering judgement, or reason, orsimplification or the implications of errors.

2nd Paper: Characterization of Strength ofIn-Situ Soils, Ting W.H.In contrast to the previous paper, this deals with derivationof parameters and application into a model. It explains thevarious models i.e. elastic, elasto-plastic and Cam-clay.There is a section on practical approach, statistical methodsand lo and behold… Engineering Judgement! This is aworthy paper to read, and is recommended. It is, in fact, arose amongst a few thorns. The reference list is less than 2pages, and about 20% of the citations belong to the author.The most recent references are from 2000.

3rd Paper: The Use of In-Situ Tests forFoundation Design, Lehane M.This is a brief paper (about 15 pp including just over 1 pageof references) that categorises in-situ tests into ‘QualitativeTests’ (e.g. SPT); ‘Miniature Load Tests’ (e.g. CPT); and‘Soil Parameter Measurement’ (including Pressuremeter,Vane and CPT). It includes a case history of bearingcapacity and consolidation. It is a ‘light-weight’ paper thatdoesn’t really add to the value of the book.

4th Paper: In-Situ Characterisation ofCoarse-Grained Weathered SoilsLaterite sites typically have a hard crust overlying softersilts. This phenomenon may also be found in NewZealand. Unfortunately, this is an atrocious paper. Itincludes a figure that is probably the worst published inthe 21st century, and would rank with some of the worstof all time. It shows a map, which looks like a poorquality facsimile transmission. Sadly, the quality ofillustrations throughout this book is generally extremelylacklustre. In contrast, the best illustration is alsocontained in this paper. It shows, at good resolution, a


In-Situ Characterization of Soils

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New Zealand Geomechanics News

32 Newsletter of the New Zealand Geotechnical Society Inc.

monochrome photograph of a wet hole in the ground.Naturally, the reader is thrilled to bits. This paper is verysite-specific to the so-called laterite belt of southernIndia. If one was to carry out work in the vicinity ofZaheerabad or Bidar then one should read it forbackground purposes.

5th Paper: Ground Investigations andParameter Assessment for DifferentGeological Deposits in Sweden, Berdgahl et al.This paper describes the current state of the art of siteinvestigation in Sweden. It indicates a remarkablesimilarity in many respects to the current state of the artof site investigation in New Zealand, with the exceptionthat the Marchetti Dilatometer is not commonly used inNew Zealand. It includes a chart for inferring soil typefrom CPT results. Without direct comparison to similarcharts produced in New Zealand, it seems to bereasonable, and simple. It only attempts differentiationbetween sand, silt and clay/organic soil. Reiterating, thisis a simple chart, and one that might well work. Thepaper includes a reference list extending to almost 4pages, the most recent citation in which is from 2001.The authors’ own citations would represent about 25%of the total. One is left wondering whether Larson’s 1989paper entitled Dilatometerförsök – En in-situ metod förbestämning av lagerföljd och egenskaper i jord –Utförande och utvärdering might have an Englishtranslation.

6th Paper: In-Situ Tests for DynamicProperties of Soils, Puri V.K. and Prakash S.Again, we have a paper that is probably below par. Forsuch a critical analytical area, it compares poorly with theinformation provided in Foundation EngineeringHandbook in terms of both the quality of the informationprovided, and the type of information provided. Forinstance, it fails to mention the Ultrasonic Pulse Testamongst the appropriate laboratory tests.

7th Paper: AMAP’sols Static Penetration inDense Sandy Gravel, Sandstone and HardClaystone (CPT Revel in Gravel), Sanglerat G. et al.This paper is faithful to its title. It describes a static-dynamic penetrometer that was developed in France in1992 for the purpose of testing the soils that a static-thrustCPT would be unlikely to penetrate. The quality of thephotographs in this paper are of very low resolution, andthe figures are typeset very unprofessionally.

8th Paper: In-Situ Characterization of CreepParameters by Instrumentations, Justo J.L. et al.There may be a few dams in the Marlborough region, andperhaps elsewhere in New Zealand, that will be built in thenext few years with rock fill. On the face of it, this paperwould appear to be relevant to these structures.

9th Paper: Soft Ground Improvement byVertical Drains, Buddhima Indraratna et al.One might ask what this paper is doing in this book. Thereis, in fact, a section on this paper entitled Soft ClayModelling, including Cam clay and Modified Cam clay.There is also a section on Salient Aspects of NumericalModelling. The quality of the figures in this paper arebetter than most of those elsewhere in this book. Logically,however, this paper belongs in a journal or similar book on‘Ground Improvement’, not ‘Soil Characterisation’.

Reviewer’s Conclusion:It is frustrating that the book is not organised into sectionscontaining relevant papers: say, a section on site investigationmethods (including drilling, test pit excavation, samplingetc), a section on in-situ testing, a section on laboratorytesting and a section on data analysis and model synthesis. Itwould be even better if the editors had made a valuablecontribution to the book by thorough editing.

Ultimately, the book is disappointing. It is one to beborrowed from a library if one of the papers within isrequired for reading.

Reviewed By: Bruce Grayson,Connell Wagner Ltd, Auckland

In-Situ Characterization of Soils

Editors: Saxena K.R. & Sharma V.M.Publisher: A.A. BalkemaDate published: January 2003Page extent: 306 pagesISBN: 90 5809 244 5

Web shopping at: http://balkema.jcn.nl/ima/balkema/index.htmlPrice: $US140.80 / EUR 128 Hardback

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New Zealand Geomechanics News

December 2003, Issue 66 33

TBM Tunnelling in Jointed and Faulted Rock

Author: Nick BartonPublisher: A.A. BalkemaDate published: January 2000Page extent: 306 pagesISBN: 90 5809 3417

Web shopping at: http://balkema.jcn.nl/ima/balkema/index.htmlPrice: $US44.30 / EUR 38.50

Nick Barton is the primary developer of the RockTunnelling Quality or Q Index, which for nearly 30 yearshas been used in the dimensioning of rock tunnels and thedesign of cavern support. In this book, Barton has taken theQ Index and modified it specifically for use in the design ofTunnel Boring Machine (TBM) excavations. The resultantQTBM is an attempt to predict TBM productivity andutilisation rates based on machine specifications, rock masscharacteristics and cutter efficiency.

The book is essentially a step-by-step description of thedevelopment of the QTBM, although it also providesuseful information on basic TBM designs, logging methodsand tunnel reinforcement. At 170 pages it is a relatively thinvolume, however it is packed with a large amount ofinformation. An unusual characteristic of the book is thevery short chapter lengths, which are typically 1 to 3 pages.

The development of the QTBM came from a desire bythe author to use existing rock mass characterisationmethods to be able to better predict the performance ofTBMs. Barton recognised that several modifications wererequired to be made to the Q parameters in order for TBMperformance, and particularly penetration rate, to bereliably predicted. The primary difference between thestandard Q index and QTBM is that the rockdiscontinuity parameters reflects the orientation of thetunnel as well as the tendency for joints to either assist orhinder the cutting process. The author describes thedevelopment of the QTBM parameters as being a process

of trial and error using case records.In an attempt to account for the variables that are

recognised as having an impact on TBM performance, theQTBM incorporates eleven different input parameters,and many of these are a function of several variables. Beingempirically based, the QTBM has essentially been backanalysed from the performance of TBMs on some 145different projects. Whilst this has as given the QTBM apractical like with real world performance, it is highlyquestionable whether an engineer planning a TBMexcavation would have sufficient data to make ameaningful use of the QTBM, especially as the output canvary over several orders of magnitude.

The worked example in the back of the bookdemonstrates how complex the process of derivingQTBM really is and how dependant it is on a good supplyof rock mass and TBM parameters. The complex nature ofrock mass behaviour has previously made mathematicallybased attempts at rock modelling cumbersome andsomewhat suspect in their results. The development of theHoek-Brown rock mass failure criterion, is an example ofthis, where after many years of development, the criterionbecame more observational in approach and easier to use.It will be interesting to follow the development of theQTBM and see whether the same process occurs.

Reviewed by: Kevin J. HindURS New Zealand Ltd, Auckland

TBM Tunnelling in Jointed and Faulted Rock

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New Zealand Geomechanics News

34 Newsletter of the New Zealand Geotechnical Society Inc.

I first came across an early version of this softwarepackage several years ago when I was assigned the taskedof finding a replacement 2D slope stability package for aprevious employer. My objective was to find a packagethat was technically sound, easy to use, cost effective,efficient and provided high quality output, with Slidebeing the eventual winner.

I consider this package to be the most comprehensiveslope stability analysis package that I am aware ofcurrently available on the market for the windowsoperating system. The package includes most commonlyused analytical methods (i.e. Bishop, Janbu, Spencer, etc)as well as sensitivity, probabilistic and back analysiscapabilities and can be used to model both soil and rockslopes. With a built-in, steady-state, unsaturated,groundwater analysis capability, using the finite-elementmethod, pore pressures can be seamlessly integrated intoslope stability analysis. If desired groundwater analysiscan be undertaken independently of stability analysis.

Slope models are created using the ‘Model’ interface, aneasy to use CAD based graphical interface. The sameModel interface is used for both Slope Stability and/orGroundwater Analysis. Problems may be scanned andoverlain onscreen so that they can be traced over, draw onscreen freehand, defined by typing coordinates into adialogue box at the base of the screen, or by defining linetypes that Slide recognises within AutoCAD drawingsand imported via the dxf file type. Slide is also capable ofreading Slope/W and XStable files. Seismic loads, pointloads as well as uniform, triangular or trapezoidaldistributed loads may be applied to problems. Circular,non-circular and composite slip surfaces may be definedmanually or alternately utilising one of automated searchfunctions. A comprehensive range of support options areavailable including grouted tiebacks, soil nails, geotextilesand piles. The creation of meshes for undertakinggroundwater analysis is fully automated.

The Modelling InterfaceBoth slope stability and groundwater analysis results aredisplayed in the graphical ‘Interpret’ interface that has

diverse set of tools that can be used to annotate results withtext, arrows, lines, dimensions and angles. Results may beexported to the JPEG, Windows Bitmap, Windowsenhanced metafile and Windows metafile file types.

So what makes slide better than the alternative packagesavailable? The modelling interface is very easy to use. Theway in which problems are inputted is straightforward andcan be quickly and easily created and edited with theextensive range of modelling and editing tools, meaningmodelling time is keep to a minimum. For example onaverage it would take me approximately half the time toinput and analyse a problem in Slide than another leadingpackage commonly used, with this efficiency improvingwith increased model complexity. In terms of features itoffers more than any other package that I have comeacross, at a cost of only US$1495 making it one of thecheaper packages available. The only limitation I considerthe package to have is the inability to undertake transientgroundwater seepage analysis, however the softwarevendors has recently indicated to me that this functionalitywill be include with the release of the next major version.

Reviewed By: Michael LawsConnell Wagner Ltd, Auckland

Slide 5.0, Rocscience Inc

Figure 1. Example of slope stability model using Slide 5.0

Page 37: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

• Pavement Investigations

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Page 38: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003
Page 39: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003
Page 40: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003
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Page 42: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

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Page 43: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

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Page 44: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

New Zealand Geomechanics News

42 Newsletter of the New Zealand Geotechnical Society Inc.

The rainstorm that hit Paekakariki on Friday 3 October2003 affected many parts of the Wellington regioncausing flooding and slips that closed roads, with theKapiti Coast being one of the worst affected areas.Rainfall appears to have been much heavier in thePaekakariki area, where it was probably well in excess of100 mm in 24 hours, causing severe flooding andextensive landsliding, gully erosion and debris flooddamage on the steep coastal hills. The area of greatestground damage coincides with the area of maximumrainfall accumulation indicated by radar imagery. Thisshows that the heaviest rainfall occurred in a narrowband about 10 km wide and extending from just south ofKapiti Island and directly across Paekakariki towardsUpper Hutt (Figure 1). Data provided by NIWAsuggests that the average return interval of rainfall in the

most damaged area (>82 mm in 4 hours) is estimatedfrom nearby rain gauges to be greater than 125 years. Inother areas where there was less rainfall the landslidingand flood damage was generally minor.

The areas most affected by landslides and debrisfloods were around the junction of the Paekakariki Hillroad with State Highway 1, and across the hills ~2 kmsouth of Paekakariki, especially in the Fly-by-Wire gullyabove the BP Service Station and Belvedere Motel, andthe Hill Road gully ~700 m to the south (Figure 2).About 3000 m3 of gravel from the flooded Fly-by-Wiregully was deposited around the Belvedere Motelbuildings and across SH 1 at the bottom of thePaekakariki Hill Road (Figures 3 and 4). All of the floodwater and gravel was passed through the culvert underthe hill road, which was not affected at this site. Based on


Landslides, Gully Erosion, and Debris Flood Effects During the 3rd October 2003 Paekakariki FloodsGraham Hancox, Geological & Nuclear Sciences, Lower Hutt

Figure 1. Radar-derived

rainfall accumulation image

for Friday 3 October 2003,

showing total rainfall over the

Wellington region for the

period 6:45 am to 10:00 pm.

Darker shades represent the

heaviest rain and lighter

shades the lightest. The band

of heaviest rainfall coincides

with the severe landsliding

and flood damage observed

in the Paekakariki area (Image

supplied by John Crouch, MetService)

Page 45: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

New Zealand Geomechanics News

December 2003, Issue 66 43

Figure 2. Map of the Paekakariki

area showing the main landslides,

gully erosion features and debris

flood deposits resulting from the

flood of 3 October 2003. The main

areas affected were the Fly-by-

Wire gully and Hill Road gullies to

the south of Paekakariki (main

damage sites numbered 1–8). The

former caused significant

damage to the motel and

another building sited on a debris

fan at the bottom of the

Paekakariki Hill Road (site 1). Sites

4–7 were the most damaged

parts of the hill road. The total

cost for road repairs has been

estimated at around

$400,000–500,000, and the road is

not expected to reopen until

early November 2003.

Figure 3. Aerial photo taken on

Wednesday 8 October 2003

showing the gravel (g) from the

Fly-by-Wire gully (fg) deposited

around the Belvedere Motel

(M) and Showroom (S, formerly

the 1906 Restaurant) at the

bottom of the Paekakariki Hill

Road (HR), and across SH 1. A

new stream channel (sc) was

dug the day after the flood.

The hill road and vegetation at

the gully exit was unaffected

by the flood, showing that all

the debris passed through the

culvert (c) below the road. The

BP Service Station (BP) was

flooded but was largely

unaffected by gravel

inundation. A small shallow soil

flow slide (sf) spilled debris on

to the hill road ~70 m south of

the gully exit.

Page 46: NZ Geomechanics News · 1SSN 0111–6851 Issue 66 Newsletter of the New Zealand Geotechnical Society Inc. NZ Geomechanics News December 2003

Figure 4. View of the debris flood gravel deposited around the Belvedere Motel and buried cars from the gully exit on the

Paekakariki Hill Road. SH 1 is visible in the distance (top right).

Figure 5. Aerial view of damage Sites 5 (left) and 6/7 (top) on the lower Paekakariki Hill Road on Wednesday 8 October

after remedial work had begun. It shows two gullies (sites 5–7) where debris control fences could be effective in preventing,

or at least reducing such damage in the future.

New Zealand Geomechanics News

44 Newsletter of the New Zealand Geotechnical Society Inc.

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New Zealand Geomechanics News

December 2003, Issue 66 45

the lack of damage to buildings the gravel was depositedgradually as a debris flood over several hours, not as asingle debris flow. The buildings on the east side of SH 1at the bottom of the Paekakariki Hill Road are built onan old debris fan formed at the gully exit. This makes itpotentially a dangerous site for future flooding, debrisfloods, and possibly debris flows which can cause muchmore damage.

The upper part of the Fly-by-Wire gully was severelydamaged by numerous shallow slumps and deep erosiongullies (Figure 2). Geomorphic evidence suggests thatlocally the flood was a very rare event with a returnperiod of more than 100 years, possibly several hundredyears. A large amount of soil and gravel from steep slopesand gullies was transported down the stream anddeposited on the debris fan around the motel buildingsand across SH 1. However, much of the gravel was alsodeposited in the stream channel and will continue to betransported downstream during future floods. Thisproblem could be minimised by erecting steel catch fencesin the upper reaches of the stream, and/or by constructinga stream bypass with a debris fence and accumulation areaat the culvert entrance just above the motel site.

Damage to the northern end of the Paekakariki Hill

Road was the result of flood water and gravel depositionas a debris flood, rather than debris flow (Figure 5).Damage to road cuts on the hill road was generally minor,with only a few small rock and soil falls observed north ofthe summit. Gravel trapped behind fences and gatesabove the road suggests that this material accumulatedslowly. Most of the silt and sand was carried away inflood water, which flowed over the road and washed outroad edge fills and severely undermined the road inseveral places. This mechanism suggests that steel catchfences above the road and culvert entrances could be usedto trap gravel during floods, while allowing water to passthrough culverts. The control of debris in the head ofgullies would potentially reduce gravel inundationproblems for the Paekakariki Hill Road, and for SH 1 andthe NIMT railway line.

Reference:Hancox, G.T., 2003. Preliminary report on landslides,gully erosion, and debris flood effects in the Paekakarikiarea as a result of the 3 October 2003 flood. Geological &Nuclear Sciences client report 2003/120,19 p, 20 October2003. Report prepared for and made available by courtesyof the Kapiti Coast District Council.

Check it out – we are online!• New NZ Geotechnical

Society website

• Regularly updated

• Has a comprehensive

list of what is on

• Includes the Shear

Vane Guidelines


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New Zealand Geomechanics News

December 2003, Issue 66 47

The wet weather during winter and spring this year, and ashallow, large magnitude earthquake in Fiordland havecaused a large number of landslides throughout NewZealand. The significant landslide generating events thatoccurred during this period are briefly described below.

Rainstorm 8–10 June 2003, west coast of the North IslandLandslides were reported on the west coast of the NorthIsland from Auckland, Hamilton, Taranaki andWellington. Rain in the northern half of the North Islandover 8–9 June caused minor slips in Auckland andHamilton. Heavy rain overnight on 9–10 June in theWellington to Taranaki region caused many minor slips,closing a number of roads. A slip of about 80 cubic metrescame down behind two houses in Newlands, Wellington.

Rainstorm 28–29 June 2003, Tasman District and Nelson CityHeavy rain in the Tasman District and Nelson City overthe weekend caused problems with flooding, minor slipsand rockfalls throughout the region. The heaviest rainfallover the two days was recorded in the Takaka and Upper

Takaka areas of Golden Bay with over 200 mm recordedin the space of 48 hours. Minor slips were reported on theTakaka Hill road and on SH 60 at Bird’s Cutting. In theRichmond/Brightwater/ Mapua area the rainfall was moreconcentrated with 115–155 mm reported over 24 hours (73 mm in 3 hours between Richmond and Brightwater;52 mm in 4 hours at Mapua). Landslides in this areaoccurred on Aniseed Valley Road and on new cut slopes atthe Nelson water treatment plant. The rain also causedvery minor rockfalls along Rocks Rd (SH 6) in Nelson anda slip with blocked SH 60 near Ruby Bay (Mapua). Minorslips were also reported on SH 6 over the Whangamoa andRai saddles.

Earthquake 22 August 2003, FiordlandA shallow (12 km), magnitude 7.1 earthquake occurred at12:12 am on 22 August with an epicentre location justoffshore from Secretary Island in Fiordland. Because anearthquake of this magnitude could be expected togenerate landslides with a volume greater than onemillion cubic metres, GeoNet organised a landslidereconnaissance in conjunction with the deployment ofadditional seismographs and strong motion instruments

Wet Weather and an Earthquake = LandslidesGrant Dellow, Geological & Nuclear Sciences, Lower Hutt

Below: Landslide in Deas Cove, Thompson Sound resulting from the 22 August M7.1 earthquake. A DoC hut is located within

50 m of the toe of the slide.

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New Zealand Geomechanics News

48 Newsletter of the New Zealand Geotechnical Society Inc.

to monitor the aftershock sequence. Those involved inthe landslide reconnaissance included Mo Turnbull andSimon Cox (GNS, Dunedin), Graham Hancox (GNS,Wellington) and Professor Mike Crozier from VictoriaUniversity (Wellington). Over 200 individual landslideshave so far been identified. These include a landslide inthe Gold Arm of Charles Sound that generated a tsunamiand a large landslide above Deas Cove in ThompsonSound where the debris came to within 50 metres of aDOC hut. The landslide magnitude/ density relationshipshave been used to develop isoseismals for this earthquake.Minor liquefaction effects were observed around theshoreline of Lake Te Anau and along the banks of theWaiau River.

Rainstorm 23–24 August 2003, Hastings District and Napier CityHeavy rain in the Hastings District and Napier City overthe weekend of 23–24 August caused problems withflooding, minor slips and rock falls throughout thedistrict. The heaviest rainfall over the two days wasrecorded in the main axial ranges with 480 mm at Ngahereand 450 mm at Te Koau. 10–50 km further east over 300mm reported from as far afield as Wakarara (330 mm),Patoka (350 mm) (both east of main ranges in foothills)and Kahuranaki (325 mm) in the coastal ranges. Hastingsrecorded 106 mm and Napier 71 mm. Many slips and

dropouts were reported on country roads and on farmsfrom Waipukurau, Wakarara and Kahuranaki. To thenorth (Wairoa District Council) 92 mm was reported fromWairoa and 110 mm reported from Ruakuturi (furthernorth). To the south Waipukurau reported 91 mm with160mm further south from Hatuma near Waipukurau(Central Hawke’s Bay District).

On SH 5 between Bay View and the Mohaka River innorthern Hawke’s Bay, 3000 cubic metres of debristumbled onto SH 5 in a series of slips from Bay View tothe Mohaka Bridge. Several of the larger slips containingnearly 300 cubic metres each, covered the roadway. Nearthe Titiokura Summit on SH 5 a major slip of 300 cubicmetres near the summit blocked the road. Soccer ball sizedrocks caused problems on SH 50 near Maraekakaho. Slipsand rock falls were reported through the entire length ofthe Matahorua Gorge on SH 2 and a slip also blockedmost of the roadway at White’s Pine Bush on SH 2 northof Napier and had to be cleared before the road could bere-opened. At the Tangoio soil conservation area, slipswere reported on tracks inside the erosion prone area.

Rainstorm 10–11 September 2003, Wairarapa to Hawke’s BaySlips, dropouts and washed out culverts were reportedfrom the north and west of Hastings District. A small slippartially blocked SH 2 on the eastern side of the Rimutaka

Above: This landslide in Charles Sound caused a tsunami which left a 2 m plus tide mark on the island in the left foreground.

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New Zealand Geomechanics News

December 2003, Issue 66 49

Hill. A small slip blocked SH 2 for 3 hours at the MohakaViaduct. On SH 2 between Waipawa and Pakipaki in thecentral Hawke’s Bay small slips onto road shoulders,partially blocking roads were reported. From Bay View toTe Hauroto in the Hawke’s Bay small slips occurred ontoroad shoulders, partially blocking some roads. On SH 50between Maraekakaho and Tikokino in the centralHawke’s Bay small slips fell onto road shoulders, partiallyblocking some roads. In the Tukituki Hills, near HavelockNorth, 40 pine trees and a fence line were destroyed by asmall debris flow. On the Breakwater Road below BluffHill in Napier, one lane was blocked for 3 hours after a slip.

Rainstorm 28 September, Wellington to Taranaki Rain over the southern half of the North Island on 28 September caused numerous small landslides in theWellington and Taranaki regions. On SH 2 near Mt Brucein the Wairarapa traffic was delayed by small slips and alsoon SH 2 on the eastern side of the Rimutaka Hill. On BlueMountains Rd in Upper Hutt one lane partially blockedby a very small rock fall of 1.5 cubic metres. On SH 1 inthe northern Rangitikei-Taihape area the road shoulderwas closed by small slips. Near Taumaranui, the road

shoulder was also closed by small slips. At Burgess Hillnear New Plymouth in Taranaki SH 3 was partiallyblocked by a small slip.

Rainstorm 3–4 October, Wellington regionA localised high intensity rainstorm caused extensivelandsliding near Paekakariki. Flood mobilisation oflandslide debris resulted in extensive aggradation of debrisfans near Paekakariki, partially burying a motel andcovering the tracks of the North Island main trunk railway.The northern end of the Paekakariki Hill Road was alsoextensively damaged. Landslides were also reported on SH 58 near Haywards, SH 2 over the Rimutakas, on theAkatarawa Rd and on the Paekakriki Hill Road, effectivelyisolating Wellington from the rest of the North Island.

Rainstorm 13–14 October, North IslandWidespread rain over the entire North Island causedlandslides in Northland, Coromandel, Bay of Plenty, EastCape and Wellington City. The greatest density oflandslides was in the Wellington City area wherenumerous roads were partially blocked including theMiramar Cutting and the Takarau Gorge between Makaraand Johnsonville.

Below: The carpark and playground at the Belvedere Motel, Paekakariki following the 3 October storm

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Herceg Architecture & Design Ltd. has creatively appliedPermathene welded wire Gabions in their designs. Overthe past few years gabions are being used in new andrevolutionary ways, including being used as a signboardstand, an applique design on a fireplace, retaining wallsaround the BeesOnLine Ltd building, and a large wallaround a coastal residential property which offered bothprivacy and a weather screen. Gabion has a lot of greataesthetic design possibilities. They can be used effectivelyand economically in parks along highways and aroundbridge approaches to create walkways, rock gardens,patios and terraces. Gabions beautify the banks of lakesand ponds and accent trees and other plantings. In fact,their application to decorative landscaping is limited onlyby the ingenuity of the landscaper or the architect.Gabions can be vegetated offering a new technique in bio-engineering for strength and beauty.

Permathene gabions are easily handled and installed onsite. Permathene engineering staff gave technical supportto the contractor on site at the start of the project. Gabionconstruction is simple and does not require skilled labour.Gabion installations are more economical than rigid orsemi-rigid structures.

Terrafirma has successfully completed the gabionproject with ease. In one area the architect used the gabion

baskets stacked 4.0 m high x 0.457 m wide x 13.60 mlength cladded to 240 mm thick block support wall. Using12 mm x 125 mm galvanised dynabolt with squaregalvanised washers at 1m centres, they provided attractiveand natural building blocks for decorative landscaping.Spiral connectors and dimensional accuracy eliminate timeconsuming hand tying of baskets hence welded meshassemble in 1/2 to 1/3 the time of twisted mesh. Any size orshape can be constructed from a single roll of mesh withno effect on structural quality or corrosion resistance.

Terrafirma were pleased with the support they got fromPermathene technical staff. In addition to welded gabions,Versicell Interlocking Modules were also supplied for thesame job. Versicell modules were used on the roof gardenarea of the building. Versicell modules are lightweight andoffer efficient drainage solution for roof gardenapplications. They have high compressive strength and areeasy to install on site.

Permathene is the exclusive distributor of WeldedGabions manufactured in USA for New Zealand,Australia and the Pacific Islands. For additionalinformation regarding the use of welded gabions, contactMoninder (Witty) Bindra, Civil Engineering Division, ph09 829 0741 or e-mail [email protected].

Welded Gabions for Decorative LandscapingMoninder Bindra, Permathene

Below: Welded Gabion Wall

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Peru was one of those mysterious sounding places I’dalways wanted to visit, so when the call came for a shortassignment it didn’t take long to say yes. First to Lima, thechaotic and eternally misty Capital, and the joys of a 4 amarrival in a foreign country. After a few hours rest andafternoon introductions to the friendly folk at the localGolder office, another early start saw myself andBernardo, also an engineering geologist, back at theairport. Once the weeks worth of gold had been safelyoffloaded from the small mining company plane, westrapped ourselves in and headed north toward themountains. Our track took us right past NevadoHuascaran, Peru’s highest peak, and the scene of thedevastating landslide which wiped out the town of Yungayand 20,000 people following an earthquake in 1970. Thepath of the landslide running from high on the mountainsflanks to the now uninhabited lower valley was a somberreminder of the young and dynamic nature of thelandscape of the Andean Cordillera.

Landing at precipitous Chagual airstrip in the MaranonValley (where a missed approach is not a viable option),we made our way up-river by road to around 2800 m,arriving at a small mining town in the tributary ParcoyValley a dusty 3 hours later. Amongst spectacular scenerythat appears as high as it is long, gold rich quartz veins inthe granodiorite rock have spurned a fervent undergroundmining industry.

Our project required an investigation of the stability ofa terrace remnant high on steep slopes above the river. Theonly flat land for miles around, the mining companywished to use the site for a new mining camp, processplant and heap leach pad. The miners appreciated the valueof a good understanding of the geology of the site. Someyears previously a tailings repository had been built on asimilar-looking terrace some distance down the valley.This terrace failed as the facility was nearing completion,but fortunately before it received any tailings (Golder wasnot involved!).

Several days of field mapping and nights spent goingcross-eyed over aerial photographs confirmed thegeology at the site under investigation to be favourable.The terrace was the remnant of several huge debris flowswhich had choked the main valley at a time of greatersediment supply. Subsequent sculpting by bothdepositional and erosional river processes resulted in thelandform seen today.

From the 24 hour clamour of the mining town thereturn trip took us back to the northern city of Trujillo,and then by commercial airliner along Peru’s arid northcoast to Lima. A further week of report writing leftevenings free to explore some of Lima’s stark contrasts(and excellent restaurants), before the two-day flightsback to a very peaceful and flat-looking New Zealand.

South American SojournPaul Horrey, Golder Associates (NZ) Limited


Geotechnical InvestigationConstruction & Drainage Drilling

Mob: 0274 488 248 Ph: (09) 268 1046 Fax: (09) 268 1036Email: [email protected] Web: www.intorockdrilling.co.nz

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Research funded by the Earthquake Commission (EQC)was carried out to assess the effect of vertical groundmotions on the seismic displacement performance ofretaining walls. In near-fault areas, vertical shaking can besignificant. The research included a literature review andnumerical analyses of a Reinforced Earth wall. The modelanalyses were carried out for a wall with an aspect ratio(the ratio of reinforcement length to height of wall) of one.Four different near-fault earthquake time histories fromCalifornia were used in the analyses and were modified tovary the intensity of earthquake shaking. The study waseffective in assessing the displacement performance ofwalls and the parameters that have a significant influenceon wall displacement behaviour when there is significantvertical ground shaking.

The effects of vertical earthquake shaking have not beenseriously considered until recently. Recent papershighlight the importance of vertical shaking to theassessment and design of retaining walls. These recentstudies have involved pseudo-static analyses. No modelstudies, either physical or numerical, have been carried outto verify the effects of vertical shaking or to assessparameters that might be important.

The authors’ project was the first model study of theinfluence of vertical shaking on seismic displacement andwas carried out using the finite-difference numericalprogram FLAC, incorporating both vertical andhorizontal shaking. The analyses confirmed thevulnerability of the upper strips to pullout duringearthquake shaking, a factor that has long been recognisedin the practical design of reinforced earth structures.

Calculated outward displacement of this robust wallwas less than 25 mm for a modest energy of shakingassociated with the four earthquakes chosen, and up to 200mm for more intense shaking, both horizontal andvertical. The maximum calculated displacement (otherthan at the top where reinforcement pullout occurred)with horizontal shaking alone was only 23 mm.

The study showed that peak ground acceleration was apoor predictor of seismic displacement. The sum of thepower spectral density, which reflects the earthquakeenergy content, was found to better relate to thedisplacements in these different earthquakes.

Vertical shaking had a significant effect on thedisplacement of the wall. The calculated displacementsvaried significantly depending on the earthquake input,with vertical shaking than with horizontal shaking alone.The magnitude of the displacements was found to dependon both the energy content of horizontal and verticalearthquake shaking and the frequency content. This may bedue to the relationship between the frequency content ofthe earthquake and the natural response frequency of theretaining structure and indicates that the frequency contentof the earthquake and resonance effects can be important.

The authors postulate that the vertical shaking couldmodify the flexibility of the retaining wall, and hence itsnatural period. Where this shifts the period of thestructure to a frequency similar to a frequency of groundshaking with significant energy content, resonance effectsand hence greater displacements can result.

Currently design is based on pseudo-static methodsusing horizontal peak ground accelerations. The studyshows the importance of the energy and frequencycontent of both horizontal and vertical shaking to theseismic displacement performance of flexible retainingstructures. This is important to the design of retainingsystems that support other structures, particularly in near-field areas where vertical shaking can be strong.

Further research is recommended to assess theperformance of different wall systems under earthquakeswith different characteristics, and to develop appropriatedesign parameters and methods for situations wherevertical shaking is important.

References Brabhaharan, P., G. J. Fairless and H. E. Chapman (2003).

Effect of vertical earthquake shaking on displacement ofearth retaining structures. Pacific Conference onEarthquake Engineering, NZ Society for EarthquakeEngineering, Christchurch, 13–15 February 2003.

Opus International Consultants (2000). Effect of verticalearthquake shaking on the displacement of retainingstructures. Earthquake Commission Research Foundation– Project 99/419. Prepared by P. Brabhaharan, G. J.Fairless and H. E. Chapman, August 2000.

Effect of Vertical Shaping on the Displacement of Earth Retaining StructuresP. Brabhaharan, G.J. Fairless & H.E. Chapman. Opus International Consultants, Wellington

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I have talked about a number of topics over the last columnsusually backed up with some practical examples. This timeI want to diverge from this a little, in part to reflect on someitems that I learned about in a recent conference I attended(report elsewhere in the Journal), and although these issuesare important, I am currently not able to show the effects.

When we set up a numerical model (of any description,simple hand calculation or computer) we usually make anumber of assumptions about the soil. It is oftenworthwhile examining these assumptions and just checkingthat they are sufficiently valid for the problem in hand.Some of the usual assumptions include an elastic (usuallylinear) Mohr-Coulomb yield point and isotropic behaviour(where the soil behaves the same in all directions, under allloading conditions). We also assume that shear behaviourand volumetric behaviour are uncoupled, that groundwaterflow is Darcian and time effects are unimportant.

Some of the issues relating to elasticity and linearityhave been looked at in previous columns, and I willprovide further commentaries in the future. Research byGudehus (1972), and more recently Costanzo et al. (2003)suggests that soil is incrementally non-linear and behavesvery differently depending on the stress direction. Thisrelates directly to anisotropy of both strength and stiffness.

Theoretically, it is easy to decompose any stress stateinto hydrostatic stress components (an equal all aroundmean stress) and deviatoric stress components (shearcomponent). It is also relatively easy to measure these interms of p and q (or other so-called stress invariants).Whilst this is sufficient for isotropic soils a third invariant,the lode angle, is required for anisotropic soils. The lodeangle represents the direction of the principal stress axes(C.F. Scott, 1980, R.F. Scott, 1981).

It is fairly easy to infer that changes in mean stressinduce volumetric strain, whereas changes in deviatoricstress induce both shear strain, and in the presence ofdilation, volumetric strain. It can also be concluded thatthe usual geotechnical assumptions that settlementbehaviour can be considered separately from shearbehaviour is acceptable provided we are still in a more orless elastic region of soil behaviour.

However, these rules are not necessarily valid once weare on a yield surface for either volumetric behaviour orshear behaviour as the direction of the resulting stresschange is dictated by the ‘real plastic flow rule’ (this is atopic for future discussion) rather than by elastic behaviour.

Take for example the virgin consolidation line, bydefinition it is a yield surface for volumetric behaviour,whilst the Mohr-Coulomb line is a yield surface for shear.However, there may be other yield surfaces for shear

behaviour, defining transitions between elastic and plasticbehaviour (as compared to failure). In effect shear mayalso exhibit an unload-reload behaviour similar to thevirgin loading behaviour during consolidation.

Whilst we are examining this topic, it is useful to look atthe standard tests used to try and determine the variousstiffness parameters used in analysis. A quick considerationof the oedometer and standard triaxial tests reveals that bothtests include a combination of both hydrostatic (equal all-round mean stress) and deviatoric stress increase. The testsresults will therefore exhibit both volumetric and shearbehaviours. This can lead to inconsistencies if one is notconscious of the effects. A routine example of this could bethe typical analysis for the immediate settlement of footingon a cohesive formation. For this undrained loadingcondition an E value or some other compressive rule ofthumb factor is usually adopted. Because the loading isundrained with no volumetric strain, all the immediatesettlement must be the result of shear strain. However, shearmodulus is not directly measured in any of the routine teststhat provide characteristic compression properties.

Anisotropy makes the situation worse. There are severalaspects to anisotropy, the variation in strength/stiffness indifferent directions and the associated fabric or structurethat is, in part, responsible for this anisotropy. Loading thesoil may change the direction of the lode angle (thedirection of principal stress axes), which may in turninduce unanticipated behaviour. For example, the apparentpre-consolidation pressure may change (thereby inducingstiffer behaviour), or failure may occur because the loadingis occurring along a direction of weakness.

These behaviours can be seen in extreme cases bysimply rotating the stress field. It is often overlooked ormisunderstood that the real reason for applying the vanecorrection factors to shear strengths of a soft clayformation under an embankment is simply because ofanisotropy. Building an embankment on soft clays inducesloading along directions of weakness, whereas the vanetests in a direction of strength. Conversely, no correctionfactors would be necessary when doing a deep excavationin the same soil since it would appear to be loading the soilin the same direction of strength as the test.

Structure within the soil makes interpretation ofroutine test data even more difficult. For example, in aconsolidation e-log p curve the presence of structureinduces additional curvature onto the apparent virginconsolidation. Without taking this into account theinterpretation of this would suggest that at lower stresslevels the material will settle a lot more than reality. Also,the presence of structure makes it difficult to actually

December 2003, Issue 66

New Zealand Geomechanics News


Numerical Modelling in Geotechnics, Part VII Sergei Terzaghi, Sinclair Knight Merz

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> Geotechnical Engineers > Engineering Geologists

> Soils/Lab Technicians

For more information visit our website www.fel-nz.comor contact Julie Watson on ph +64 09 523 5626, email [email protected]

216 Great South Road, Newmarket, Auckland

determine the real pre-consolidation pressure. Currentresearch suggests that the use of two different curves, inparticular a linear e - p plot and also an mv -p plot usedtogether will be more appropriate (Koskinen et al., 2003).

Look again at the interpretation of laboratory tests andfield data with some of these results in mind. Theoedometer test imposes zero lateral strain (assuming aperfect fit between sample and ring) whilst increasing thevertical loading. In theory, this will induce loading up anormal consolidation, or ko, line (there will be an increasein both mean and deviatoric stress) but with no change inlode angle. A ko cell does this better, and may well be morerealistic since it allows one to measure the lateral pressures.

A triaxial cell in contrast, assuming conventional testprocedures, consolidates a sample under isotropic cellpressures (thereby getting a very good idea of the volumetricbehaviour), and then increases the axial, or deviatoric,pressure until failure. This leads to very significant rotationof the lode angle of the applied stress state in the samplecompared to the in situ stress state of the natural soil. Thusinfluencing and affecting the reported stiffness compared tothe in situ material. Compare these tests to the shear vane,pressuremeter and dilatometer which typically measure thehorizontal strength/stiffness and contrast with the CPT

cone that primarily measures failure in vertical strength.Time dependent behaviour adds a whole new dimension

to all of this, as the results of these tests may vary accordingto the rate. And that’s a whole new topic, food for thought!!

ReferencesCostanzo D., Tamagnini C., Viggiani G. (2003), Incremental

Behaviour of a reconstituted clay subjected to stressproving tests. In: Vermeer, Schweiger, Karstunen, Cudny(Ed), Int. Workshop on Geotechnics of Soft soils, Theoryand Practice, Verlag Gluckauf GmBH, Essen.

Gudehus, G (1979), A comparison of some constitutivelaws for soils under radially symmetric loading andunloading. In: Wittke (ed), 3rd Int. Conf. Num. Meth.In geomech. Aachen, 4:1309-1324. Balkema, Rotterdam.

Koskinen M., Karstunen M., Lojander M. (2003), Yieldingof ‘ideal’ and natural anisotropic clays. In: Vermeer,Schweiger, Karstunen, Cudny (Ed), Int. Workshop onGeotechnics of Soft soils, Theory and Practice, VerlagGluckauf GmBH, Essen.

Scott, C. F.(1980), An Introduction to Soil Mechanics andFoundations, Applied Science Publishers Ltd, London.

Scott, R.F. (1981), Foundation Analysis, Prentice HallInternational Inc., London.

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ph +64 09 523 5626fax +64 09 523 5627email [email protected]

or come in and see us at 216 Great South Road, Newmarket (Patey Street entrance)

We are pleased to introduce Mark Gjersoe, whojoins our team as Laboratory Manager, allowingBarry Coker to assume a complementary roleas Services Director. Mark will continue topromote our high level of service to both newand existing customers.To discuss all your testing requirements please contact Mark or Barry

IANZ Accredited since 1977 for more than 30 tests

Mark Gjersoe

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NZ Geotechnical Society2003 Photo Competition

The year 2003 theme is: “Habits of the species geotechnicalus”Show us the things that geotechnical engineers, engineering geologists,and technicians in the profession get up to!!. Photos of you or yourcolleagues doing what they do best… working hard!!

LEFT: Unlike the non-engineered fill found during thebulk earthworks, the missing link was observedduring the borehole investigation phase. Dave Dravitzki – Fraser Thomas

LEFT AND BELOW: Cause and effect of a keen but slightlyover-exuberant subsurface investigation.Dave Dravitzki – Fraser Thomas


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RIGHT AND BELOW: The CleanestDrilling site you’ll ever see. Notethe Vacuum cleaner.Michael Laws, Connell Wagner Ltd

LEFT: “Slip…..? I don’tsee no slip! I mightjust put a boreholedown here and makethe rest up in the car.” Dave Dravitzki – Fraser Thomas


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LEFT: Meritec, in conjunction with Transit,have developed a unique solution tothe problem of getting CPT rigs to sites.CPT operator George Probe said that thesigns have saved his companythousands of dollars in travel costs.However, Mr Probe expressed concernat the number of campervansapparently blocking the entries to sites.Transit are investigating this unusualcampervan activity.John Underhill, Meritec Ltd

RIGHT: Planned Construction?Anonymous

LEFT: Homage to Menard –George Mullenger andPierre Foray, at the ThreeChannel Flatsite, in pursuitof liquefiable sand, Buller Gorge. John Berrill, University of Canterbury

ABOVE: A hell of a way to start a Friday morning.Glen Guy, Tonkin & Taylor Ltd

LEFT: Quality control engineer adjustsmoisture content in backfill. Jeff Bryant



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The diagram shows a seepage flow net, obviously generated by a computer programme.

What is wrong with this flow net, if anything? If nothing is wrong with it, what does it represent? (To view and print this diagram in colour, please see the NZ Geotechnical Society webpage –www.nzgeotechsoc.org.nz)

Answer at the 9th Australia New Zealand Conference on Geomechanics (Auckland 8 – 11 Feb 2004).


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62 Newsletter of the New Zealand Geotechnical Society Inc.

Contact DetailsPeter Geddes – Director Ph 09 4387139Email: [email protected]

Hawthorn Geddes Engineers and Architects Ltd is amulti-disciplinary consultancy based in Northlandcovering civil structural and geotechnical engineering andarchitecture. The firm is in the small to medium categoryof engineering business with a steady staffing level of 19, 3dedicated to a client’s site.

The geotechnical section consists of two societymembers Peter Geddes Director and Rostyn Lomax, staffengineer with two other dedicated staff and assistance inenvironmental and stormwater work from our other civilengineers. Main work areas include:• Geotechnical appraisals of subdivisions and building

proposals,• Infrastructure design for industry and subdivisions

specialising in stormwater treatment design.,• RMA evidence for subdivisions and marinas,• Heavy industrial design including buildings structures

and infrastructure, • Commercial building design. including light weight

integrated concrete panel steel roof structures, • Cost effective educational buildings.

The current geotechnical issue in Northland is still theapplication of the Building Act section 36 to predominantlydomestic house sites. There is increasing clarity as to howthe various territorial bodies will apply the law but ascoastal values rise we have noticed a trend for considerablylarger houses on increasingly more marginal sites. The mostdifficult (and common) situation is where the consent issueaffecting the proposal is not located on that land. Forexample, active slips on sections above the property beinginvestigated. In other words it is often inappropriate orimpossible to alleviate the issue on the property for which aconsent is being sought. This raises ethical issues in relationto responsibilities to inform neighbours territorialauthorities etc, while avoiding compromising our client’sright to seek legal remedies. What are other practices doing?Will the Building Act Amendment help?

Our business aim is to provide appropriate solutions forour client’s projects. Being a multi-disciplinary company isoften thought to bring its own constraints. We have foundhowever, that we are frequently able to combine theresolution of geotechnical issues into the architectural formof a building that allows an integrated and more costeffective overall solution. Members will know how hardthis can be to achieve with independent designers.


Hawthorn Geddes Engineers and Architects Ltd

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The new name in the NZ geotechnical scene is not a new entrant but ratheran established provider of geotechnical services. Formerly Meritec it nowoperates under the Maunsell brand – part of US-based AECOM group ofcompanies – one of the largest infrastructure design groups in the world andis also ranked as the world’s leading pure design company by EngineeringNews Record. AECOM employs 17,000 staff world-wide.

Maunsell is a multi-discipline engineering organisation employing 1900 staffin the Australasian region and 300 in NZ.

Maunsell’s geotechnical group comprises engineering geologists and geotechnicalengineers, and was an early provider of engineering geological services in NZ, astrength that it retains today. Geotechnical engineering has always been centralour multi-discipline firm which is reflected in part by the current and previousmanaging directors both being geotechnical engineers.

The group provides geotechnical services in the transportation,power & energy, facilities and environmental sectors. Staff workmainly on NZ projects but also on international projects.

Challenges our geotechnical staff have faced in the pastyear include:• Stabilising transmission towers on razor back ridges• Supervising construction in the jungles of Lao PDR• Assessing settlements beneath embankments• Seismic stability of underwater retaining walls• Installing an earth dam chimney drain• Mitigating Mt Ruapehu lahar hazard• Monitoring slow moving landslides• Assessing the risk of rock falls

Maunsell Ltd

Maunsell LtdPO Box 4241AucklandWebsite: www.maunsell.comContact: Geoffrey FarquharPhone: 64 9 336 5328Fax: 64 9 379 1210Email:[email protected]

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In The BeginningAfter a typically indecisive start to his career, whichincluded a Forestry intermediate, followed by interestingbut false starts in botany and chemistry, Tim settledcomfortably into geology gaining a Masters degree inEngineering Geology from the University of Canterbury.During his Masters thesis he studied the structure andpaleoseismicity of the Hope Fault near to Hanmer. Thissatisfied his interest in those areas of geology and kindledhis enthusiasm for South Island high country.

Shortly after graduating, Tim met John Braybrooke,Principal Engineering Geologist with Douglas Partnersand a fellow Kiwi, who offered him a job in Sydney. Withnew wife Karen, Tim settled in Sydney and spent threeenjoyable years supervising drilling and logging vastquantities of core before returning to Christchurch. In1994, soon after returning, Tim joined the fledglingWoodward-Clyde Christchurch office, which afternumerous mergers, amalgamations and name changes,became the Christchurch URS office. URS provides Timan enjoyable work environment, a mix of work projectswith enough challenges to keep an engineering geologistinterested and busy, and fulfils the lingering need for a paycheque every fortnight.

Work ExperiencesIn his nearly ten years with URS, civil, mining andenvironmental engineering projects have been keepingTim occupied. Memorable projects have included theMatahina Dam Strengthening Project, which returnedTim to the seismic hazard work of his university saladdays. The project included paleoseismic studies, design ofremedial measures and construction supervision, duringwhich Tim was geologist on the spot. Following thehazard quantification phase with construction of a worldclass remedial solution was very satisfying, particularly

when the postulated hazard was realised by exposingseveral active faults within the dam foundation excavation.

In the Roxburgh Gorge landslides are almost asplentiful as rabbit warrens. Many are large and present apotentially serious risk to the Roxburgh Dam reservoir.Tim has enjoyed many weeks spent mapping thelandslides and implementing of a monitoring programmewhich has addressed the risk for the first time, indicatingwhich of the landslides present negligible risk and whichneed to be more closely monitored. Tim has gainedknowledge of schist landslides under the guidance ofmentor Don Macfarlane. The mapping usually coincideswith the drying off of the wild thyme in the gorge, whichwreaks havoc with Tim’s sinuses, though trampingthrough the thyme adds a more fragrant note to the smellof his boots. And no, Tim says it isn’t true that most of thegoats in the gorge know him personally, though theyoccasionally attempt to share his lunch.

During the slope failure risk assessment project on SH 73, Tim and colleagues Gordon Ashby and MattHoward were able to apply some of the risk assessmentmethodology developed by Gordon Ashby. This was thefirst time that such an ambitious quantitative riskassessment has been undertaken on the highway, and itwas particularly satisfying for Tim to continue some of thepioneering work started by mentor and father-in-law, thelate Brian Paterson.

Outside workTim is an enthusiastic founding member of the URS troutbothering team, which meets annually at a secret highcountry locality. He enjoys cryptic crosswords, barbecues,beer and malt whiskey, though seldom simultaneously.More active pursuits include running around the PortHills and an occasional half marathon. It’s all a great wayto see the country!


Tim McMorran

OccupationAssociate Engineering Geologist, URS, ChristchurchField Manager, Geotechnical investigations Project Aqua.

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New Zealand Geomechanics News


I mostly enjoy my work. I take great pleasure in providingwhat I think are sound, rigorous effective solutions forground engineering problems. Most of the time the bestjobs involve the simple application of basic engineeringprinciples – what we do is not rocket science but when it’sdone well there are tremendous benefits for our clientsand society.

Although there are some characters in the geotechnicalbusiness that like to encourage the reputation that ourprofession is a Black Art, I firmly believe that this does usmore harm than good. There is no need to perpetuate themyth that a good Geotechnical Engineer must rely onexperience and gut feel. Our business is not 25% scienceand 75% judgement – it is a legitimate EngineeringScience. Experience is important, but without a soundgrasp of mechanics, properties of materials and maths anexperienced practitioner can be an embarrassment.

In most cases, these embarrassments are well hiddenand never exposed, but they do exist. You would thinkthat it should be difficult for someone who does not seemto understand the fundamentals to operate successfully inour business. Unfortunately, that is not the case. All toooften they prosper and maintain a reputation forproviding ‘good’ service whilst their clients remainignorant of their incompetence.

One of the reasons these dodgy practitioners remainsafe, secure and free to continue operating is that ourdiscipline is very forgiving. Our mistakes are readilycovered up, the margins of safety applied to the loads onour structures are very high and we are usually extremelyconservative in our selection of material properties.Occasionally, problems do occur. A foundation settlesmore than expected, a slope fails, a retaining wall leans ora pile/anchor yields. More often than not this is aconsequence of a genuinely unforeseeable circumstance –a natural defect, an unusual increase in groundwater or anunexpected load.

This is great news for the incompetent because it meansthat there is a ready excuse or, at the very least, there isenough uncertainty to provide sufficient ammunition to

muddy the waters of any forensic investigation.Another reason that the incompetent survive is because

we have never become codified. Unlike structuralengineering there are very few documented procedures thatare prescribed activities in executing a geotechnical design.There are guidelines and recommendations on best practicebut there is often a wide selection to choose from in any onesituation and they are always open to interpretation, misuseor abuse by the ‘experienced’ practitioner.

This is perhaps what upsets me the most in my job.There have been occasions when it would appear that anExperienced Engineer has made a bad judgement call andwhen called to task blatantly misrepresent fundamentalgeological or geotechnical principles in order to justify apatently erroneous position. I find this deeply disturbingbecause it is so unnecessary. We do our whole professiona disservice every time we use bluff and bluster to try andcover-up a mistake or a simple oversight.

I also believe that our own best intentions helpperpetuate our problems. Where attempts have been madeto document guidelines or recommendations for routineactivities, all too often it fosters malpractice and a slackapproach to proper Geotechnical Engineering. Examplesinclude reliance on the Hiley Formula for pile design andcertification, dependence on the Scala for foundationdesign verification and any number of proprietary designtools from suppliers of geotechnical engineering productsor well meaning colleagues in other professional societies.

I commonly see Experienced Engineers use poormethods and inappropriate theory without thinkingsimply because it was what they did last time and it‘worked’. I know I said that what we do is generally notrocket science and that pragmatic solutions are often thebest but that is not an excuse for being slack in analysisand applying poor judgement. These same ExperiencedEngineers will be very quick to descry the status of ourprofession – is it any wander? It’s often the pot calling thekettle black.

Without demonstrably sound, rigorous thinking andhonest endeavour we don’t stand a chance.


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JANUARY 21–23 2004, Singapore6th International Conference on DeepFoundation Practice (PILETALK 2004)For more information contact:The Conference DirectorCi Premier Pte Ltd150 Orchard Road #07-14Orchard Plaza, Singapore 238841Tel: 065 6733 2922 Fax: 065 6235 3530Email: [email protected]: www.cipremier.com

FEBRUARY 9–11 2004, Auckland, NZTo the eNZ of the Earth – 9th ANZConference on GeomechanicsConference theme aims to generate discussion on whatmakes geotechnical practice within NZ and Australiadifference to other parts of the world.Topics include:– Slope instability and remedial measures– Foundation performance and assessment– Dams, Roads, tunnels and mines– Laboratory testing– Earthquake Engineering– Contractural and risk issues– Case histories and failures– Environmental Geotechnics– Engineering Geology– Numerical modellingRegister now!http://www.cce.auckland.ac.nz/geomech04

MARCH 22–23 2004, Kuala Lumpur, Malaysia5th International Conference on GroundImprovement TechniquesConference themes:– Mechanical and chemical stabilisation of soils– Accelerating the consolidation of clayey soils and

electro osmosis– Soil reinforcement and earth reinforcement– Modification of marine soils and related topics– Grouting techniques and thermal stabilisation of soils– Evaluation of ground improvement and theoretical

methods– Densification of granular soils– Dynamic compaction and micropiles– Deep compaction, blasting heavy compaction,

vibroflotation– Innovative techniques in ground improvement– Environmental aspects– Deep soil mixing– Soil improvement by precompressionFor more information contact:The Conference DirectorCi Premier Pte Ltd150 Orchard Road #07-14Orchard PlazaSingapore 238841Tel: 065 6733 2922Fax: 065 6235 3530Email: [email protected]: www.cipremier.com

MARCH 24–25 2004, Kuala Lumpur, Malaysia4th International Conference onLandslides, Slope Sustainability and theSafety of Infra-structuresConference Themes:– Geological and geotechnical site investigations– Design shear strength parameters and their

measurements limit – Equilibrium and deformation slope stability analysis– Back analysis of slope failures– Landslide hazard and risk assessment– Landslide inventory and hazard zonation– Landslide Stabilisation and remedial measures– Observational methods: instrumentation and monitoring– Effects of rainfall and groundwater– Effects of seismicity– Slope instability of landfills and waste materials– Slope instability in coastal areas– Slope instability in urban area– Slope instability in special materials: residual soils,

shales, loess, soft sensitive claysFor more information contact:The Conference DirectorCi Premier Pte Ltd150 Orchard Road #07-14Orchard PlazaSingapore 238841Tel: 065 6733 2922Fax: 065 6235 3530Email: [email protected]: www.cipremier.com



Links are available from the NZ Geotechnical Society website – www.nzgeotechsoc.org.nz

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MARCH 29–30 2004, London, UKA.W. Skempton Memorial ConferenceTopics Include:– Influence of Geology on Civil Engineering– Soil Behaviour, Characterisation and Modelling– Slopes and Embankments– Foundations– Ground Performance and Building ResponseWeb: www.skemptonconference.com

APRIL 13–17 2004, New York, USA5th International Conference on CaseHistories on Geotechnical EngineeringTopics Include:– Geotechnical Aspects of Italy 2002 and Alaska, 2002,

Earthquakes including: Liquefaction, Ground Motionand Amplification, Comparison with other recentEarthquakes, Failure of Ground, Damage toGeotechnical Structures and similar topics

– Mitigation and Design for Liquefaction including:Analysis and Design of Laterally Loaded LargeDiameter Piles and Pile Groups using AdvancedCalibrated Computer Models in As-IS and LiquefiedConditions, Earthquake drains for Mitigation ofLiquefaction, Load tests for piles for Liquefied andImproved Soil Ground Conditions, Lateral LoadTesting of Pile Groups, Calibration Studies of the DSSIproblem from Recent Earthquakes in Seismological-geotechnical-structural hand shake in the performancebased design conditions of Ground DeformationsRelated to Soil Liquefaction and similar topics.


MAY 3–5, 2004, Hong Kong4th Asian Symposium on EngineeringGeology and the EnvironmentEngineering Geology for Sustainable Development inMountainous AreasSub-themes:– Natural and man-made geo-engineering/environmental

hazards: regional perspectives– Mechanisms of instabilities in mountainous terrains– Remote sensing and GIS in land-use planning and

hazard prediction– Origin, measurement and analysis of in situ stresses– Engineering geology for infra-structural development:

case histories– Geo-environmental impacts of natural resource

exploitation and engineering projectshttp://www.hku.hk/earthsci

MAY 4–7, 2004, Liege, BelgiumEurEnGeo 2004 – First European RegionalConference of the IAEGConference themes:– Professional Practices,– Engineering Geological Methods– Case Studies of Infrastructure Projects– Hazardous Geological Processes in Civil Engineering

(Workshop) – New developments in Risk Evaluation (Workshop)Submission of abstractshttp://www.EurEnGeo2004.org

MAY 19–22, 2004, Beirut, Lebanon International Conference of GeotechnicalEngineering – Beirut 2004Conference themes:-– Contribution of Geology– Slope stability– Deep excavations and retaining walls– Soils improvement– Foundations– Dikes and Dams– Soils identification– Natural risks– Environmental geotechnics– Case StudiesWeb: www.ul.edu.lb/activite/icge/geo-beyrouth2004.polytech-lille.fr

JUNE 5–9, 2004 Houston, Texas,USAGulf Rocks 04Rock Mechanics Across Borders &DisciplinesConference themes:– Constitutive Behaviour – Drilling and Hole Stability – Environments / Geohazards– Faults / Fractures / Fractured Rock Behaviour – Flow Through Porous Media – Foundations and Slope Stability– Geotechnical Engineering / Structures – In situ Stress, and Geologic Modelling– Mining / Tunnelling / Excavations– Pore Pressure and Pressure Seals – Property Characterization & Prediction – Reservoir Geomechanics– Risk and Uncertainty Management – Rock Physics, Dynamics and Seismicity – Underground Storage, and Sequestration– Well Completions and IntegrityWeb: www.GulfRocks04.com

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JUNE 22–26, 2004, Calgary, Alberta, Canada Geo-Engineering for ResourceDevelopment Conference themes:– Hydrogeology and Geo-engineering practice– Risk analysis in geotechnical design and construction– Advances in engineering geophysics– Advances in geo-engineering application of satellite

technology– Advances in data integration and numerical modellingCall for Abstracts: Jan. 30, 2003Web: http://www.geoerd.com

JUNE 28–JULY 2, 2004, Rio de Janeiro, Brazil IX International Symposium on Landslides –ISL’ 2004 Conference Themes:-– Advances in Geomorphological Mapping and

development of geological and geotechnical models inlandslide hazard assessment

– Advances in Rock and Mine Slopes design– Advances in Field Instrumentation and Laboratory

investigations– Pre-failure mechanics of landslides in soil and rock,

including creep, softening, progressive failure andsliding in contractive soil.

– Post failure mechanics of landslides, particularly earthand debris flow

– Advances in stabilization methods and risk reductionmeasures such as catch fences and debris dams

– Mechanisms of slow active landslides– Also includes short courses and international field

school.Web: http://www.abms.com.br/

AUGUST 2004, Santiago, Chile MASSMIN 2004 Conference themes reflect the main concerns andissues affecting the future of the world mining industry:– Mine Design Fundamentals– Mine Planning– Mine Operation– Applied Geomechanics in mining– Mass Mining Methods – Case Stories– Research and Technological Innovation– Transition from Open Pit to Underground MiningContact person:Chairman: Dr. Antonio KarzulovicEmail: [email protected]

SEPTEMBER 9–10, 2004 Paris, FranceInternational Symposium on Ground MovementConference Themes:– Ground Mass improvement techniques:– Dynamic Compaction– Vibroflotation– deep compaction– consolidation and preloading of fine grained and

organic soils– vertical drains– vacuum loading– electro-consolidation– Injection of granular and fine grained soils– Stone columns– Jet grouting– Lime/cement treated soil columns– Ground Freezing– Standards– Education.Submission of abstracts: 15 Feb 2004Acceptance of abstracts: 30 April , 2004Submission of full papers: 30 June 2004For information: [email protected]

SEPTEMBER 13–17, 2004, Thessaloniki, Greece International conference on Eco-Engineering:The use of vegetation to improve slope stabilityConference Themes:– Vegetation and eco-engineering– Interactions of vegetation and structures– Soil reinforcement by roots– Hydrology and land use– Soil erosion– Geotechnical methods and applications– Slope degradation and forest dynamics– Applications of land restoration– Modelling of slope stability– Decision support systems– Riverbank and coastline protection measures– Plant growth versus engineering stability– Benefits and liabilities in slope protection & erosion

controlCall for Abstracts: 1 January 2004For further information, please contact:Sanna Dupuy (conference administration)Laboratoire de Rhéologie du Bois de Bordeaux(Mixed unit : CNRS/INRA/Université Bordeaux I)Domaine de L’Hermitage69 route d'Arcachon33612 Cestas cedex, FranceTel: +33 5 57 12 28 36 Fax: +33 5 56 68 07 13Email: [email protected]://lrbb3.pierroton.inra.frhttp://www.ecoslopes.com

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SEPTEMBER 20–22, 2004, Porto, Portugal 2nd International Conference onGeotechnical Site Characterization– Sponsored by ISSMGE and endorsed by the ASCE

Geo-Institute and the ISRM, and will be scientificallyled by the members of Technical Committees of theISSMGE TC16 – for In Situ Testing – and TC10 – forGeophysical Methods.

Web: http://www.fe.up.pt/ISC-2

OCTOBER 18–20 2004, Nanjing, China4th International Conference on DamEngineeringFor more information contact:The Conference DirectorCi Premier Pte Ltd150 Orchard Road #07-14Orchard PlazaSingapore 238841Tel: 065 6733 2922Fax: 065 6235 3530Email: [email protected]: www.cipremier.com

OCTOBER 21–23 2004, Nanjing, ChinaInternational Conference on Soil Nailingand Slope StabilityFor more information contact:The Conference DirectorCi Premier Pte Ltd150 Orchard Road #07-14Orchard PlazaSingapore 238841Tel: 065 6733 2922Fax: 065 6235 3530Email: [email protected]: www.cipremier.com

MAY 23–25, 2005 Stockholm, SwedenInternational conference on Deep MixingBest Practice and Recent AdvancesConference Themes:– Infrastructure– Offshore/near shore– Environment– Earthquakes and vibrations– and eco-engineeringSubmission of abstracts: 31 Jan 2004Acceptance of abstracts: 29 Feb, 2004Submission of full papers: 15 Oct 2004For information: www.deepmixing05.se


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NAME POSITION ADDRESS, EMAIL PHONE, FAX Marsh, J (John)* Chairman Beca Carter Hollings & Ferner Ltd 09 300 9174 Work

P O Box 6345 09 300 9300 FaxWellesley [email protected]

Crawford, SA (Steve) Immediate past Chairman Tonkin & Taylor 07 571 3570 WorkPO Box 317 07 571 5508 FaxTauranga 021 675 468 [email protected]

Fellows, DL (Debbie)+ Management Secretary PO Box 60-213 09 813 0012 HomeTitirangi 09 813 0014 FaxAuckland 09 355 1310 [email protected] 029 355 1310 Mobile

Williams, A (Ann)* Treasurer 46 Whitehaven Rd, 09 300 9172 WorkGlendowie 09 575 6462 HomeAuckland 5 09 300 9300 [email protected]

Glassey, P (Phil)* NZ Geomechanics News Geological & Nuclear Sciences 03 479 9684 WorkEditor 764 Cumberland Street 03 477 5232 Fax

Private Bag 1930 027 201 7793 [email protected]

McManus, K (Kevin)* Committee member Department of Civil Engineering 03 364 2378 WorkUniversity of Canterbury 03 364 2758 FaxPrivate Bag 4800 027 201 7793 [email protected]

Laws, M (Michael)• Young Geotechnical 66 Greenlane Rd East, 03 520 6019 WorkProfessionals Representative Remuera 03 529 5373 Home

Auckland 021 393 334 MobileMurray, JG (Grant) ISSMGE Australasian Sinclair Knight Merz Ltd 09 913 8984 Work

Vice President P O Box 9806 09 913 8901 FaxAuckland 09 524 5078 [email protected] 021 271 1992 Mobile

Baynes, FJ (Fred) IAEG Australasian 9 Chester St +61 8 9382 1259 WorkVice President Subiaco +61 8 9382 1564 Fax

WA 6008, [email protected]

St George, J (John) ISRM Australasian Dpt Civil and Environmental Engineering 09 373 7599 x88195 WorkVice President University of Auckland 09 373 7462 Fax

Private Bag 92019 Auckland

* Elected members of committee+ Appointed position• Co-opted position


Management Committee Address List 2003

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a) To advance the study and application of soil mechanics, rock mechanics and engineering geology among engineers andscientists

b) To advance the practice and application of these disciplines in engineeringc) To implement the statutes of the respective international societies in so far as they are applicable in New Zealand.

MembershipEngineers, scientists, technicians, contractors, students and others who are interested in the practice and application ofsoil mechanics, rock mechanics and engineering geology.

Members are required to affiliate to at least one of the International Societies.Students are encouraged to affiliate to at least one of the International Societies.

Annual Subscription Subscriptions are paid on an annual basis with the start of the Society’s financial year being 1st October. A 50% discount isoffered to members joining the Society for the first time. This offer excludes the IAEG bulletin option and studentmembership. No reduction of the first year’s subscription is made for joining the Society part way through the financial year.

A $30 per year service centre will apply to all non IPENZ members.

Basic membership subscriptions (inclusive of GST)which include the magazine NZ Geomechanics News, are: Members $67.50Students $28.10

Affiliation fees for International Societies – Members must affiliate to one of the International Societiesare in addition to the basic membership fee:International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) $24.00International Society for Rock Mechanics (ISRM) $33.00International Association of Engineering Geology & the Environment (IAEG) $21.00

(with bulletin) $70.00

All correspondence should be addressed to the Secretary. The postal address is:NZ Geotechnical Society Inc.P O Box 12 241WELLINGTON


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The SecretaryNZ Geotechnical Society Inc.The Institution of Professional Engineers New Zealand (Inc)P O Box 12 241WELLINGTON


(A Technical Group of the Institution of Professional Engineers New Zealand (Inc))

Full Name (Underline Family Name)Postal AddressPhone No: Fax No: Email:Date of BirthAcademic QualificationsProfessional Memberships Year Elected Present EmployerOccupationExperience in Geomechanics

Student Members:Tertiary InstitutionSupervisor Supervisor’s signature

Note that the Society’s rules require that in the case of student members “the application must also be countersigned by the student’s

Supervisor of Studies who thereby certifies that the applicant is indeed a bona-fide full time student of that Tertiary Institution”;

Applications will not be considered without this information.

AFFILIATION TO INTERNATIONAL SOCIETIES: All full members are required to be affiliated to at least one Society, and student members are encouraged to affiliate to at least one Society.

Applicants are to indicate below the Society/ies to which they wish to affiliate.

I wish to affiliate to:International Society for Soil Mechanics and Geotechnical Engineering (ISSMGE) Yes/No International Society for Rock Mechanics (ISRM) Yes/NoInternational Association of Engineering Geology & the Environment (IAEG) Yes/No

(with Bulletin) Yes/No

DECLARATION: If admitted to membership, I agree to abide by the rules of the New Zealand Geotechnical Society Inc.

Signed Date

ANNUAL SUBSCRIPTION: Due on notification of acceptance for membership, thereafter on 1st of October. Please do not send subscriptions with this application form.

You will be notified and invoiced on acceptance into the Society.

PRIVACY CONDITIONS:Under the provisions of the Privacy Act 1993, an applicant’s authorisation is required for use of their personal information for Society

administrative purposes and membership lists. I agree to the above use of this information:

Signed Date


Received by the Society

Recommended by the Management Committee of the Society

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Publication Name List Price List PriceMembers Non-Members

New Zealand Geomechanics Society Conferences:Proceedings of the New Zealand Geotechnical Society Symposium – $50 $70Geotechnics on the Volcanic EdgeTauranga 2003

Proceedings of the New Zealand Geotechnical Society Symposium – $50 $70Engineering and Development in Hazardous TerrainChristchurch 2001

Proceedings of the New Zealand Geotechnical Society Symposium – $40 $70Roading Geotechnics 98Auckland 1998

Proceedings of Technical Groups, Vol 22, Issue 1G $20 $35Geotechnical Issues in Land DevelopmentHamilton 1996

Proceedings of the Auckland Symposium – $10 $45Groundwater and SeepageMay 1990

Australia – New Zealand Conferences on Geomechanics:Proceedings of the 6th Australia – NZ Conference on Geomechanics $50 $100Christchurch, February 1992

Proceedings of the 3rd Australia – NZ Conference on Geomechanics $10 $30Wellington, May 1980

Other Publications:Proceedings of the 2nd Australia – NZ Young Geotechnical Professionals $25 $40Conference, Auckland, December 1995

Shear Vane Guidelines $15 $20

Guidelines for the Field Description of Soils and Rocks in Engineering Use $10 $13

Stability of House Sites and Foundations – Advice to Prospective House $1 $1and Section Owners

Back Issues of NZ Geomechanics News (depending on availability) 50c 50c

Prices do not include GST or postage & handling

Orders to:Debbie FellowsManagement SecretaryPO Box 60-213, Titirangi, AucklandEmail: [email protected]


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Advertisement Location Single Issue Advert. Size (mm)

Black & WhiteBack Cover $300 210 wide x 297 high Inside Cover (Front or Back) $250 210 wide x 297 high Full Page Internal $225 185 wide x 265 high Half Page Internal $175 90 wide x 265 high

185 wide x 130 high Quarter Page Internal $150 90 wide x 130 high

ColourFull Page Internal $400 210 wide x 297 high A3 Centrefold $750 420 wide x 297 high

InsertsInsert to be posted with magazine – $200/flyerMaximum size single A4 page Special price given on request for other types and sizes

Note1. All rates exclude GST2. Space is subject to availability 3. 3 mm bleed4. Advertiser to provide all flyers

If you are interested in advertising in the next issue of NZ Geomechanics News please contact:

Management SecretaryDebbie FellowsPO Box 60-213Titirangi Auckland Tel: 09 813 0012Fax: 09 813 0014Email: [email protected]


NZ Geomechanics News is published twice a year and distributed to the Society’s 500 members throughout NewZealand and overseas.

The magazine is issued to society members who comprise professional geotechnical and civil engineers and engineeringgeologists from a wide range of consulting, contracting and university organisations, as well as those involved inlaboratory and instrumentation services.

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