1In this issue: Case History Interesting Projects New Product /
Application • TriAx Geogrid • Deckdrain with Woven
Geotextile • Mini Roll Geotextile for
Landscaping Technical Note European Union – Falling Rock Protection
Kit Certification Opinion Column Sheet Membrane Seaming For Your
Information • A Word from General
Manager • 35th Anniversary Recap Reader’s Response
September 2019. Issue No.32
Interesting Projects We have seen projects with very typical usage
of geosynthetics and related products, some in unique applications.
Here are several products that catch our attention and might be of
interest to you.
CV/2013/08 - at Liantang / Heung Yuen Wai Boundary Crossing, BOSTD
geocell is designed to retain 150 mm thick of planting soil on
steep cut slope for vegetation establishment.
[email protected].
At SENT Landfill – Bonar 185 l/m2/s high permeability woven
geotextile is used as French drain drainage filter separation. The
HF series allows up to a 400 l/m2/s water flow rate. ivan@g-
and-e.com.
CV/2012/05 - at Lung Mei Bathing Beach, Maccaferri gabion is used
to construct a 4 m high wing wall leading to an open drainage
channel extended from the box culvert to the outfall. natural@g-
and-e.com.
DC/2009/24 - at Harbour Area Treatment Scheme (HATS) Cyberport Port
landing, ACE high strength woven geotextile is prefabricated into a
150 mm φ x 4 m tube in which grout is infilled to form a concrete
joining pin to interlock vertical seawall blocks. ivan@g-
and-e.com.
In a Tsuen Wan Private Development – Daehan Hori- drain, a 200 mm
width x 9 mm thick prefabricated drainage composite is designed to
dissipate water pressure in the basement structure.
[email protected].
HY/2014/06, at Hiram Highway expansion, Maccaferri Macmat is used
for slope erosion protection, the polyamide mat offers distinct
fire-retardant characteristic.
[email protected].
NE201501, at Lam Tin – TKO tunnel – Bonar woven geotextile is sent
to Korea to fabricate into a hybrid silt curtain incorporating a
widely accepted Bontec SG110/110 geotextile to an engineered design
silt curtain.
[email protected].
G and E Times
September 2019. Issue No.32
New Product / Application TriAx Geogrid Tensar introduces the
concept of soft ground stabilization by confining and interlock
granular to initiate lateral restraint using radial stiffness of
triaxial geogrid, as opposed to tension membrane where high
strength geosynthetics are sought to carry the loading by anchorage
and friction.
site activity becomes more cost effective and efficient.
TriAx geogrid is developed under this principle. It is ideal for
formation of temporary access, haul road and working platform. The
geogrid can be laid on area with CBR as low as 2. A layer of
granular can be spread onto the geogrid to form an immediate stiff
formation for construction traffic and load bearing subgrade. For
more, talk to Steven Lee at
[email protected].
Extensive performance research has shown that hexagonal aperture
confines aggregate better to support and spread heavy load,
limiting rutting and differential settlement, prolonging
serviceability. With proper engineered design, thickness of
aggregate can be reduced to a minimum,
TriAx interlock granular material
Deckdrain with Woven Geotextile Filter ABG developed Deckdrain in
UK 20 years ago. The drainage composite has worldwide recognition
since. It has a single cuspated HDPE core and a non-woven
geotextile filter bonded to one side, an equivalent of Miradrain,
ideal for drainage behind retaining wall. Deckdrain now comes with
a woven geotextile filter which can be used as an engineered
drainage layer beneath concrete slabs and in subsurface structure.
For info, prices and availability, contact Ivan at
[email protected].
TriAx distribute heavy loading instantly
Mini Roll Geotextile for Landscaping Geotextile is commonly used as
soil and aggregate separation in planter boxes. Bonar used to
supply jumbo roll that suits most civil engineering. Mini rolls
Bontec NW 6 UV are now available. This has all the standard filter
and drainage characteristics but comes in 2 m width x 25 - 50 m
length, weighs 5 – 10 kg. It is ideal for small projects with
limited space where manual operation is essential. Some sample
rolls are available for trial. Contact Ivan at
[email protected].
Mini roll geotextile NW6
HKT submarine fiber optic cable between TKO and Siu Sai Wan –
Maccaferri prefabricated articulating concrete block mats are
fabricated in Malaysia and shipped to Hong Kong. It finds excellent
application in ballasting and protection of valuable cable laid on
seabed. ivan@g- and-e.com.
Deckdrain
Subgrade stabilization and reduction of differential settlement at
Cape Town Stadium, South Africa
3.
Technical Note European Union – Falling Rock Protection Kit
Certification European Organisation for Technical Approvals (EOTA)
published ETAG 027 a guideline for technical approval of falling
rockfall protection kits in 2008. The aim was to approve and
certify steel barriers according to a common European Union (EU)
standard and practice. In July 2018, EOTA issued the European
Assessment Document: EAD 340059, a new guideline in assessing
falling rock protection kit, replacing ETAG 027.
Under ETAG 027, the certificate issued was European Technical
Approval (ETA(Approval)) whereas under the EAD 340059, the
certificate refers to European Technical Assessment
(ETA(Assessment)). Both documents provide the same testing method
and assessment procedure, under which full-scale tests would have
to be done by a qualified conducting body and inspected and
certified by a Technical Approval/Assessment Body (TAB) designated
by EOTA. The TAB (as listed in EOTA website
https://www.eota.eu/en-GB/content/how-to-find-a-tab/55/) are
authorized and entrusted to issue the ETAG and EAD
certificate.
Notwithstanding this, all flexible barriers tested and certified
under ETAG 027 remain valid and comply to EAD 340059 based on the
equivalence of full- scale test procedures, method of assessment
and verification and of constancy of performance between ETAG 027
and EAD 340059. Current ETAG certificate with a 5 years validity
has been converted to EAD certificate which has an unlimited
validity. The certificate verifies and ensures the flexible barrier
meets the specific performance, based on which, many flexible
barriers are specified and approved. The approval procedure is
adopted not only within the EU, but worldwide including Hong Kong.
For more details, call Steven
[email protected].
European Technical Approval Guideline (ETAG 027)
European Assessment Document (EAD 340059)
Opinion Column Sheet Membrane Seaming Proper field seaming is
fundamental to the integrity of water tightness when working with
sheet membrane. There are several methods.
Extrusion welding of HDPE membrane into one integral sheet
Wedge welding into one integral sheet with air test channel
Wedge welding of HDPE membrane with double seam
Method Procedure Conditon Remarks
Thermal bonding
Surface cleaning & temp dependent
Chemical bonding
Controlled amount of solvent, curing, setting ; environment
condition & cleaniless dependent
Uncertain and inconsistent seam strength
Adhesive bonding
Durability of adhesion, low seam strenth
Extrusion welding
A ribbon of molten polyolefin is extruded over the overlap, melt
and bond
Surface grinding, equipment welding rod needed
Form one integral sheet, seam strength & integrity is
ensured
Thermal fusion welding
Double track hot wedge melts the surfaces, roll pressure to press
the heated surface
Equipment limited to straight seam
Reliable with double weld, seam quality is fully controlled
https://www.eota.eu/en-GB/content/how-to-find-a-tab/55/
mailto:
[email protected]
Sheet1
Method
Procedure
Conditon
Remarks
Overlapping
Surface cleaning & temp dependent
Chemical bonding
Controlled amount of solvent, curing, setting ; environment
condition & cleaniless dependent
Uncertain and inconsistent seam strength
Adhesive bonding
Durability of adhesion, low seam strenth
Extrusion welding
A ribbon of molten polyolefin is extruded over the overlap, melt
and bond
Surface grinding, equipment welding rod needed
Form one integral sheet, seam strength & integrity is
ensured
Thermal fusion welding
Double track hot wedge melts the surfaces, roll pressure to press
the heated surface
Equipment limited to straight seam
Reliable with double weld, seam quality is fully controlled
G and E Times
4.
Reader’s Response Let us hear from you. Write to us at
[email protected]. For back issue, please write to
[email protected] or visit our website at
www.g-and-e.com.
Disclaimer The materials contained in this newsletter are provided
for general information purpose only and do not constitute legal or
other professional advice.
G and E Company Limited 14th Floor, Kiu Yin Commercial Building,
361-363 Lockhart Road, Wanchai, Hong Kong Tel: 2570 0103 Fax: 2570
0089 e-mail:
[email protected] http://www.g-and-e.com
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September 2019. Issue No.32
G and E has established representation with more than 50 globally
renowned manufacturers covering a fully diversified range of
geosynthetics. From the early 1990’s, our scope extended from being
a distributor / supplier to engineering application, designer and
installation contractor. In the last issue, I began our history of
introducing geosynthetics into the market here, from 1987 to 2003,
our journey continues….
A Word from General Manager
For Your Information
2000 – 5,000 kJ rockfall barrier, Discovery Bay 2009 – GCL
Bentoliner, Route 8 Tsing Yi 2010 – 1,000 gsm non-woven, Central
Wanchai Bypass 2011 – Geotextile container, Express Railway Line
2011 – PVC T-keyed lining, Stonecutter Sewage Treatment Plant 2011
– Grass Paver, TKO landfill restoration 2012 – Geogrid reinforced
surcharge, Wo Shang Wai 2012 – Tunnel invert drainage geocomposite,
MTR West Island Line 2013 – Pre-fabricated band drain,
HK-Zhuhai-Macau Bridge
2003 – Geomembrane wetland, MTR West Rail Line, Kam Tin 2004 –
Concrete mat, Shing Mun River 2005 – Geogrid reinforced fill slope,
NENT Landfill 2005 – Woven geotextile for silt curtain, debut 2006
– Lining system with vegetation, Kau Sai Chau Golf Course 2007 –
Waterproofing lining system, design, supply and installation, the
Venetian, Macau 2008 – Light weight geotextile slope cover,
Anderson Road Development
While there are merit and drawback with each seaming method, the
key is to attend to details, to ensure all overlaps are seamed
properly and continuously. Seam quality can be verified by testing
during and post installation. Seam integrity can be affected when
the seam is subject to consistent straining, movement, environment
in contact and deterioration of seam components. Welding to form an
integral sheet seems to be the most effective.
Opinion Column (Con’t)
We stepped into our 36th year in business last June, with
enthusiasm, passion and some anxiety. The kick-off dinner was
shared with our principals, associates, partners and, of course,
our entire devoted company backbone, and some of our earlier staff
as well. Over sumptuous gourmet and wine, everyone cracked jokes,
reminded each others’ past glories, touched off embarrassments and
greeted with best wishes. I drew a recap on the pain and joy we
have come to this stage from 1984. It is this moment that we hope
we will be able to foster a more competent team to look after our
clients with commitment and dedication.
35th Anniversary Recap
A happy G and E team A moment of joy and sharing Some of our
principals from ACE, CeTeau, Bonar, Maccaferri, Q. One, Solmax,
Tensar