Structural engineering part 2 - Auckland Transport · PDF fileTechnical Report to support Assessment of Environmental Effects (City Rail Link Notice of Requirement): Structural Engineer

Technical Report to support Assessment of Environmental Effects (City Rail Link Notice of Requirement): Structural Engineer

Assessment.

B1

Appendix B

Construction Vibration Receiver Types

Technical Report to support Assessment of Environmental Effects (City Rail Link Notice of Requirement): Structural Engineer Assessment.

B2

a. Built Heritage

EBS_ID St. No Street Building Name/ Description Category

709 12 Queen Street Former Central Post Office Built Heritage

710 2 Queen Street Endeans Building Built Heritage

109 12-14 Customs Street West Former Customs House Built Heritage

19 3 Albert Street West Plaza Built Heritage

14 13 Albert Street Yates Building Built Heritage

14 15 Albert Street Link House Built Heritage

27 46-56 Albert Street APN NZ Complex Built Heritage

20 35 Albert Street Price Buchanan Building Built Heritage

21 37-39 Albert Street Building Built Heritage

22 41 Albert Street Prince Albert Apartments Built Heritage

24 51-53 Albert Street Retail and Office building Built Heritage

25 55 Albert Street Retail and Office building Built Heritage


28 61 Albert Street Shakespeare Hotel Brewery Built Heritage

549 26, 34-36 Wyndham Street Former Gas Co Building Built Heritage

719 9-11 Durham Lane Bluestone Store Built Heritage

1 98-102 Albert Street Armishaws Building Built Heritage

511 43 Victoria Street West Retail Building Built Heritage


1118 66 Victoria Street West London Dairy Built Heritage

1117 68 Victoria Street West J H Hannan Built Heritage

542 24 Wellesley Street West Bledisloe House Built Heritage

541 15-31 Wellesley Street West T&G Building Built Heritage


B3

EBS_ID St. No Street Building Name/ Description Category 193 11 Mayoral Drive Former Public Trust Office Built Heritage

517 105 Vincent Street Auckland Chinese Presbyterian Church Built Heritage

526 133 Vincent Street Juliette's Built Heritage

199,198,1022 290 Queen Street Aotea Centre Built Heritage

336 70-74 Pitt Street The Chatham Building Built Heritage

724 1 Beresford Square Former Pitt Street Fire Station Built Heritage

724 53 Pitt Street Old Central Ambulance Station Built Heritage

330 59 Pitt Street Retail Building Built Heritage

1119 283 Karangahape Road Samoa House Built Heritage

1120 16-18 Beresford Square Office Building Built Heritage

178 251-253 Karangahape Road Retail and Office building Built Heritage

333 61-65 Pitt Street Dentists Chambers Built Heritage

337 78 Pitt Street Pitt St Methodist Church Built Heritage

176 238 Karangahape Road George Court Building Built Heritage

212 9 Mercury Lane The Mercury - kings theatre Built Heritage

97 1 Cross Street George Court Factory Building Built Heritage

297 151 Newton Road Commercial Building Built Heritage

458 215 Symonds Street Edinburgh Castle Building Built Heritage

459 221 Symonds Street Interface Architecture Building Built Heritage

464 233 Symonds Street Altezano Built Heritage

464 235 Symonds Street French Connection Restaurant Built Heritage

464 237 Symonds Street Retail and Residential Building Built Heritage




466 245-247 Symonds Street Retail and Residential Building Built Heritage

467 249-251 Symonds Street Retail and Residential Building Built Heritage


B4

EBS_ID St. No Street Building Name/ Description Category 468 253-255 Symonds Street Retail and Residential Building Built Heritage

257 21 New North Road Retail Building Built Heritage

213 1-13 Mount Eden Road Retail and Residential building Built Heritage

1132 29 Brentwood Avenue Residential Building Built Heritage



76-86 Albert Street Historic Toilets/ bluestone retaining wall Built Heritage


B5

b. Residential

EBS_ID St. No Street Building Name/ Description Category 33 8-12 Albert Street Quay West Hotel Residential

15 17 Albert Street Cohesive Technology House Residential

16 22-26 Albert Street The Stamford Residential

31 74 Albert Street Chifley Suites Residential

32 76-84 Albert Street City Gardens Apartments Residential

4 103,105,107 Albert Street Manhattan Apartments Residential

8 109-125 Albert Street Sky City - Grand Hotel & Convention Centre Residential

5 106-108 Albert Street Elliot Tower (Proposed) Residential

11 128 Albert Street Crown Plaza Residential

515 103 Vincent Street YWCA Accommodation Residential

519 109 Vincent Street The Rodney Apartments Residential

520 113 Vincent Street Winsun Heights Apartments Residential

528 135 Vincent Street Dynasty Gardens Hotel Residential

531 150 Vincent Street The City Lodge Residential

532 156 Vincent Street Eclipse Apartments Residential

201 71-87 Mayoral Drive Rendezvous Grand Hotel Residential

326 29,39,41 Pitt Street Hopetoun Delta Apartments Residential

1063 22-28 Beresford Square The Beresford Residential

1068 259-281 Karangahape Road Retail and Residential building Residential

1121 14 East Street Residential Building Residential

1123 9 A-C Mercury Lane Residential Building Residential

1124 18 East Street Residential Building Residential

298 153 Newton Road Beatnik Residential

144 10 Flower Street Eden Terrace Apartments Residential

1129 1 Akiraho Street Eden Oaks Residential


B6

c. Commercial

EBS_ID St. No Street Building Name/ Description Category 707 21 Queen Street Zurich House (Anzo Tower) Commercial

23 7 Albert Street Retail and Office building Commercial

38 9-11 Albert Street Food Alley Commercial

17 23-29 Albert Street ANZ Centre Commercial

424 12-26 Swanson Street Affco House Carpark Commercial

26 58 Albert Street APN NZ Complex Commercial

29 63 Albert Street AMI House Commercial

30 65-69 Albert Street Auckland District Court Commercial

552 38 Wyndham Street Wyndham Towers Commercial

36 92-96 Albert Street Former Telecom Tower Commercial

35 85 Albert Street Retail and Office building Commercial

37 87-89 Albert Street Albert Plaza Commercial

39 99 Albert Street AA Building Commercial

13 135 Albert Street ASB Building Commercial

10 120 Albert Street BDO Tower Commercial

546 44-52 Wellesley Street West Wellesley Centre Commercial

534 67-101 Vincent Street Auckland Police Station Commercial

113 22 Dundonald Street Soundcraft Ltd Commercial

189 3 Flower Street TV3 Building Commercial

1126 32 Normanby Road Commercial Building Commercial

1127 3 Enfield Street Horse and Trap Commercial

1128 101 Mount Eden Road Hometune Commercial


Assessment.

C1

Appendix C

Settlement Contours


C2


C3


C4


C5


C6


C7


Assessment.

D1

Appendix D

Indicative Settlement Profiles


Assessment.

D2

- CH350 Albert Street Open Cut and Cover


0.0

2.0

4.0

6.0

8.0

-40.0 -30.0 -20.0 -10.0 0.0 10.0 20.0 30.0 40.0 50.0

Sett

lem

en

t (m

m)

Offset from Downtrack Centreline (m)

CH350 - Albert Street Open Cut and Cover

0.0

4.0

8.0

12.0

16.0

-50.0 -40.0 -30.0 -20.0 -10.0 0.0 10.0 20.0 30.0 40.0 50.0 60.0

Sett

lem

en

t (m

m)




Assessment.

D3


- CH1000 Aotea Station

0.0

3.0

6.0

9.0

12.0

15.0

18.0

-60.0 -50.0 -40.0 -30.0 -20.0 -10.0 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 80.0

Sett

lem

en

t (m

m)



0

5

10

15

20

25

-40 -30 -20 -10 0 10 20 30 40 50

Sett

lem

en

t (m

m)


CH 1000m - Open Cut and Cover Aotea Station


Assessment.

D4

- CH1150 Mayoral Drive TBM

- CH1450 Vincent Street TBM

0

5

10

15

20

25

-30 -20 -10 0 10 20 30 40

Sett

lem

en

t (m

m)


CH 1150m - Mayoral Drive TBM

0

5

10

15

20

25

-30 -20 -10 0 10 20 30 40

Sett

lem

en

t (m

m)


CH 1450m - Vincent Street TBM


Assessment.

D5

- CH1800 Pitt Street TBM

- CH1850 Karangahape Road Station

0

2

4

6

8

10

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Sett

lem

en

t (m

m)


CH 1800m - Pitt Street TBM

0

5

10

15

20

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Sett

lem

en

t (m

m)


CH 1850m - Karangahape Road Station


Assessment.

D6

- CH1900 Karangahape Road Station

- CH2200 Central Motorway Junction

0

10

20

30

40

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Sett

lem

en

t (m

m)


CH 1900m - Karangahape Road Station

0

5

10

15

20

-40 -30 -20 -10 0 10 20 30 40 50 60

Sett

lem

en

t (m

m)


CH 2200m - Central Motorway Junction


Assessment.

D7

- CH2650 Symonds Street TBM

- CH2800 Newton Station

0

3

6

9

12

15

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Sett

lem

en

t (m

m)


CH 2650m - Symonds Street TBM

0

5

10

15

20

25

30

35

-50 -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100

Sett

lem

en

t (m

m)


CH 2800m - Newton Station


Assessment.

D8

- Ch3030 Newton Open Cut and Cover

- Ch3100 NAL West Open Cut and Cover

0

3

6

9

-50.00 -30.00 -10.00 10.00 30.00 50.00 70.00 90.00 110.00 130.00

Sett

lem

en

t (m

m)


CH3030 - Newton Open Cut and Cover

0.00

4.00

8.00

12.00

16.00

-50.00 -30.00 -10.00 10.00 30.00 50.00 70.00

Sett

lem

en

t (m

m)


CH3100 - NAL West Open Cut and Cover


Assessment.

D9

- Ch3100 NAL East Open Cut and Cover

0.0

4.0

8.0

12.0

-60.0 -40.0 -20.0 0.0 20.0 40.0 60.0 80.0 100.0

Sett

lem

en

t (m

m)


CH3100 - NAL East Open Cut and Cover

Alber

Appendix E

Settlement Principles Report

Project: Auckland City Rail Link

Settlement Principles Report

Reference: 228072

Prepared for: Auckland Transport

Revision: 1

10 August 2012

In association with

Aurecon | Mott MacDonald | Jasmax | Grimshaw Project 228072 | File Appendix E Settlement Principles Report.docm | 10 August 2012 |

Revision 1

Document Control Record

Document prepared by:

Aurecon New Zealand Limited

Level 4, 139 Carlton Gore Road Newmarket Auckland 1023

PO Box 9762 Newmarket Auckland 1149 New Zealand

T

F

E

W

+64 9 520 6019

+64 9 524 7815

[email protected]

aurecongroup.com

A person using Aurecon documents or data accepts the risk of:

a) Using the documents or data in electronic form without requesting and checking them for accuracy against the original hard copy version.

b) Using the documents or data for any purpose not agreed to in writing by Aurecon.

Report Title Settlement Principles Report

Document ID 228072-AC-WPP-012 Project Number 228072

File Path C:\Users\David.Mockett\Documents\228072 City Rail Link\Settlement Principles Report\228072-AC-RPT-012[0]Rev1.docx

Client Auckland Transport Client Contact Steve Hawkins

Rev Date Revision Details/Status Prepared by Author Verifier Approver

0 12 July 2012 Issued Draft DRM Bill Newns as part of CDR

1 10 August 2012 Issued Draft DRM Bill Newns as part of CDR

Current Revision 1

Approval

Author Signature Approver Signature

Name Name

Title Title

E4


Revision 1

Contents 1. Overview 5

1.1 General 5

1.2 Settlement Caused by Excavation 5

1.3 Settlement Caused by Groundwater Drawdown 6

1.4 Potential Seismic Effects 6

2. Buildings 7

3. Utilities 9

3.1 Pipelines 9

4. Settlement Prediction 10

4.1 Tunnels 10

4.2 Cut and Cover Tunnels and Shafts Error! Bookmark not defined.

5. Interim Conclusions 11

5.1 Condition Surveys 11

5.2 Surface and Structural Settlement Monitoring 11

5.3 Groundwater Levels and Pressures 11

5.4 Response Plans 11

E5


Revision 1

1. Overview

1.1 General

Settlement observed at surface resulting from tunnelling and excavation can be divided into those

occurring as a result of ground deformations (volume loss or immediate settlements) or from effective

stress changes, as a result of soil pore water pressure decreases in compressible soils

(consolidation).

Tunnel shaft and cut and cover excavations reduce groundwater levels and soil pore water pressures

via drainage over the design life such that settlements will occur where there are compressible soils.

Settlement trough curvature induced by excavation (volume loss/immediate settlements) is the

principal factor in determining the potential for adverse effects upon existing buildings and structures.

That is, the potential for damage arises largely from tensile strains associated with the settlement

trough gradient as opposed to the magnitude of the settlement itself.

The potential for adverse effects arising from settlement is directly related to settlement curvature,

relative to the dimensions of the structure at risk and the resulting strains induced in the buildings. A

greater magnitude of consolidation settlement has a much lower potential for adverse effects in

comparison to settlement associated with ground deformation (volume loss).

Many methods for mitigating settlement effects are possible. More detailed assessment of the

vulnerability of existing buildings and structures may result in further consideration of such settlement

mitigation measures.

1.2 Settlement Caused by Excavation

Settlements observed at surface are typically in the form of a settlement trough. The ratio between the

volume of the settlement trough and the excavated volume is called the volume loss. This parameter

depends predominantly on the type of ground, tunnelling method and standard of workmanship.

For a TBM tunnel with a segmental lining, the volume loss has the following components:

Face Loss – Elastic deformation of the ground towards the advancing tunnel could be up

to 1/3 of the final unsupported radial convergence.

Shield Loss – Convergence occurring due to the annulus surrounding the shield. This is

affected by TBM advance.

Post shield / pre-grout & post grout loss – convergence that occurs before the grout is

either injected or gains sufficient strength to interact with the ground and lining.

The initial ground surface settlement and lateral displacement due to the tunnelling induced volume

loss have been assessed based on the widely used Gaussian distribution form.

For the platform tunnels and launch adits volume loss is associated with face loss and deformation of

the excavated periphery which is a function of the interaction of the ground with the installed

temporary support. Given that this is typically installed at the face this often a smaller percentage of

the excavation than for TBM tunnelling.

E6


Revision 1

In shaft excavations and those for cut and cover tunnels, the support offered by the walls is also

largely passive in nature. Deflection of the walls will create a corresponding volume loss to the side of

the shaft excavation that will be translated at the surface as a settlement trough.

Settlements associated with ‘volume loss’ have the greatest potential to cause adverse effects upon

existing buildings and structures as described above. As the volume loss component of tunnel

excavation occurs almost contemporaneously with tunnel excavation.

Consolidation effects have a time dependence which is related to the permeability of the ground.

‘Volume-loss’ cannot be measured directly, and is only established from back-analysis of the surface

settlement data.

Good construction practices will assist in the reduction of volume losses.

1.3 Settlement Caused by Groundwater Drawdown

Depending on geological and hydro-geological conditions at or near the excavation and the timing of

and degree of water-tightness of excavations there may be additional settlements due to

consolidation of soils arising from groundwater drawdown. This is also dependent upon the

relationship between geological history and consequent geotechnical characteristics of the soils

experiencing the groundwater pressure changes and the actual groundwater pressure changes.

During tunnelling operations the period for which the ground may drain to the tunnel is limited, as the

permanent lining will be installed and grouted into place close behind the advancing TBM. Based on

the project assumptions for advance rate this is likely to be within 3 days of excavation although TBM

delays may extend this period. The lining must be opened to form the pedestrian cross passages,

which provides a further opportunity for groundwater diversion for approximately 2 months.

Should detailed condition surveys and monitoring results indicate the need, pre-treatment of the

ground (i.e., prior to segmental lining breakout) with grouting may reduce the potential for groundwater

flows at these locations. Various methods exist for sealing tunnel lining joints that are likely to provide

significant water ingress.

1.4 Potential Seismic Effects

The tunnel structures will be designed in accordance with established industry practice and in

accordance with New Zealand Standards such as NZS 1170.5. Although underground structures

perform much better than surface structures during earthquakes, it is conceivable that local increases

in groundwater ingress may occur to the tunnels as a result of lining joint displacement at fault or

shear zones. Such increases in groundwater ingress will not significantly increase the potential for

‘damage’ to existing buildings and structures (not already damaged by the seismic event itself).

Consolidation effects associated with a driven tunnel do not contribute greatly to settlement trough

gradients, as they influence a wide zone of ground above the tunnel.

E7


Revision 1

2. Buildings Tension induced in buildings as a result of settlement may be caused by two separate effects:

Direct Tension which is the result of the horizontal displacement field predicted by the

Gaussian method, such that if one corner of the building experiences more horizontal

displacement than the opposite corner, the building will experience tensile strain.

Flexural Tension which is caused by the building being forced to sag or hog, inducing

tensile strain in the building at the extreme fibre of the building represented as a beam, or

diagonal tension due to shear effects.

Table 2 - 1 – Classification of Visible Damage to Walls with Particular Reference to Ease of Repair of Plaster and

Brickwork or Masonry

Source: Mair, Taylor and Burland (1996)

Category of

Damage

Normal Degree of

Severity

Description of Typical Damage

(Ease of repair is in bold type)

0 Negligable Hairline cracks less than about 0.1 mm.

1 Very slight Fine cracks which are easily treated during normal decoration. Damage

generally restricted to internal wall finishes. Close inspection may reveal some cracks

in external brickwork or masonry. Typical crack widths up to 1 mm.

2 Slight Cracks easily filled. Re-decoration probably required. Recurrent cracks can be

masked by suitable linings. Cracks may be visible externally and some repointing

may be required to ensure weathertightness. Doors and windows might stick

slightly. Typicial crack widths up to 5 mm.

3 Moderate The cracks require some opening up and can be patched by a mason.

Repointing of external brickwork and possibly a small amount of brickwork to

be replaced. Doors and windows sticking. Service pipes may fracture.

Weathertightness often impaired. Typical crack widths are 5 to 15 mm or several

greater than 3 mm.

4 Severe Extensive repair work involving breaking out and replacing sections of walls,

especially over doors and windows. Windows and door frames distorted, floor

sloping noticably1. Walls leaning

1 or bulging noticeable, some loss of bearing in

beams. Service pipes disrupted. Typical crack widths are 15 to 25 mm but also

depends on the number of cracks.

5 Very Severe This requires a major repair job involving partial or complete rebuilding. Beams

lose bearing, walls lean badly and require shoring. Windows broken with distortion.

Danger of instability. Typical crack widths are greater than 25 mm but depends on

the number of cracks.

E8


Revision 1

Category of

Damage

Normal Degree of

Severity

Description of Typical Damage

(Ease of repair is in bold type)

Note: Crack width is only one factor in assessing category of damage and should not be used on its own as a direct measure

of it. Local deviation of slope, from the horizontal or vertical, of more than 1/100 will normally be clearly visible. Overall

deviations in excess of 1/150 are undesirable.

The terms “slight”, “moderate”, etc in Tables 2 – 1 do not necessarily correspond to building owners’

perceptions. Such terminology is widely accepted and the classification system illustrated by Table 2 -

1 has been adopted by organisations such as the Institution of Structural Engineers London, the

Institution of Civil Engineers and the Building Research Establishment (BRE).

The division between category 2 and 3 is considered particularly significant, with damage up to

category 2 resulting from a variety of sources within the building itself.

Because the above process incorporates the effects of distortion and deflection of the building, the

tensile strain can be used directly with Table 2 - 1 without reference to angular distortion of the ground

surface.

E9


Revision 1

3. Utilities

3.1 Pipelines

The treatment of pipelines is similar to that for buildings, whereby pipelines and duct banks are

modelled as circular tubes. It is then assumed that the settlement profile of the ground beneath the

pipe is the same as the deformation induced in the pipe. This is a conservative assumption as there

will be some slip at the soil pipe interface causing a smaller deformation in the pipe.

These results have also proven in the past to be conservative for larger pipes because of the effects of

pipe stiffness and joint release. For smaller pipes, the reduction in strains from these effects will

reduce strains by 50%.

Figure 3 – 1 shows how deflection of utilities due to the settlement of the ground follows the settlement

trough. It can be seen that the utility does not deflect to the extent of the settlement trough, with this

difference in deformation due to the stiffness of the pipe material and the joint types.

Figure 3 – 1 – Pipe Deflections due to Settlement of Ground from Tunnelling

The potential damage to utilities will be assessed on a case by case basis. The utility owner should be

notified of the potential settlement and slope induced in utilities and advice sought on the requirements

for each service.

Assessment of utilities in conduit, such as electricity and telecommunications, and pipes <200 mm

diameter are considered to be sufficiently flexible to absorb the effects of settlement without damage.

Utilities like these may only be assessed for damage where they lie within proximity to shaft

excavations.

Settlement Profile at Surface

Z

Smax

H

Settlement Profile at Pipe

Ground Surface x

Tunnel

Pipe

Deflection

D Differential settlement between pipe and ground results in stress within pipe

E10


Revision 1

4. Settlement Prediction

4.1 Tunnels

Initial surface settlements attributed to stress redistribution in rock due to tunnel excavation have been

predicted utilising the computer program “XDISP”.

XDISP is a 2-dimensional settlement analysis program which applies the method for determining

immediate settlement troughs. XDISP identifies tunnels as tubular sections, with each section

assigned a face-loss parameter which accounts for the proposed ground support to be installed, the

tunnelling method and the quality of the rock mass.

E11


Revision 1

5. Interim Conclusions

5.1 Condition Surveys

Pre-construction and post construction inspections will be undertaken to establish the condition of

structures and utilities within the zone of influence of the works, (defined as the predicted contour for

5mm settlement) to determine whether these properties have been affected by the construction

activities and the extent of damage, if any.

Any particularly vulnerable structures, e.g., those with mixed foundation structures would be identified

and highlighted for special attention well in advance of construction.

5.2 Surface and Structural Settlement Monitoring

Provision, installation and monitoring of surface settlement makers will be required as a result of the

settlement estimations and pre-construction inspections indicated above.

These would be sited along each tunnel alignment at regular intervals to measure settlement directly

above the tunnels. Transverse arrays to measure settlements horizontal to the tunnel alignment would

be installed at a lesser frequency. This monitoring (in conjunction with piezometers) will enable a route

wide monitoring of effects.

At buildings and structures of concern additional monitoring measures may be required which may

include settlement monitoring at corners of the buildings and at any points of particular structural

concern.

Monitoring will commence 18 months prior to work starting in order to measure natural movement of

existing structures from seasonal changes in the water table. Monitoring will also continue for at least

6 months after completion of construction.

5.3 Groundwater Levels and Pressures

Additional boreholes and piezometers are expected to be undertaken to complete regional

groundwater monitoring and provide such additional geotechnical investigation as required to

complete the detailed design.

5.4 Response Plans

The requirement for ‘mitigation’ should be based on;

The detailed assessment of the vulnerability of structures within the zone of influence of

the tunnels and excavations.

The derivation of limits of settlement for the vulnerable structures according to the

vulnerability assessment described above.

Such assessment would be expected to form part of a subsequent submission as part of a

Construction and Environmental Management Plan (CEMP), once the CRL moves into a construction

phase.