Context of the project<\/h2><\/div>Soletanche Bachy built the foundation of a road<\/a> portion located between Causeway Bay and North Point across the Hong Kong Yacht Club.<\/p>\nThe Central \u2013 Wan Chai Bypass and Island Eastern Corridor Link is a 4.5 km long dual tree-lane trunk road with a 3.7 km long tunnel<\/a> which forms part of an East-West stra\u00actegic route along the north shore of Hong Kong Island.<\/p>\nThe whole Central – Wan Chai By\u00acpass project comprised 10 contract packages. The foundation<\/a> works on Contract 15, which was awarded to Bachy Soletanche Group Limited (BSGL)<\/a> in April 2010, comprised the portion located between Causeway Bay and North Point across the Hong Kong Yacht Club.<\/p>\n<\/div>Description of the project<\/h2><\/div>Various technical options were ini\u00adtially contemplated by the local au\u00adthorities for the construction of the underground highway. After detailed analysis and due consideration to various technical and environmental constraints, the Highway department selected a cut and cover method with installation of a 1.50 m thick perma\u00adnent diaphragm wall<\/a> socketed into the Moderately Decomposed Granite on both sides of the future highway. The depth of the wall varied from 14 m to 74 m. The excavation had to be carried out through the com\u00adpletely decomposed granite with many boulders and core stones being encountered above bedrock level.<\/p>\n<\/div>Our solution<\/h2><\/div>Due to environmental constraints, dredging and reclaiming perma\u00adnently lands off-shore Hong Kong Island raises strong opposition from the community and does not constitute anymore an acceptable construction method. Consequently, a very speci\u00adfic construction sequence relying on the installation of temporary reclai\u00admed working platform has been chosen.<\/p>\n
The sequence of works was as follow:<\/p>\n
\n- within the Yacht Club Area ins\u00adtallation of \u201creclaimed islands\u201d to be used as temporary working platforms<\/li>\n
- From these platforms, installa\u00adtion of the permanent diaphragm walls and barrettes to form \u201ccut and cover boxes\u201d<\/li>\n
- excavation of the boxes with installation of temporary struts and construction of the permanent rein\u00adforced structure<\/li>\n
- backfilling of the boxes up to sea bed level, demolition and removal of the diaphragm wall above seabed level and removal of the temporary platform to reinstate the site to its original state.<\/li>\n<\/ul>\n
The diaphragm wall and barrettes being excavated through the uncon\u00adtrolled fill which was put in place without any specific compaction, ground treatment was required to prevent leakage of bentonite slurry and possibly trench instability and water pollution. For this reason, prior to start the diaphragm wall excava\u00adtion, a grout curtain was installed on both faces of the excavation. Furthermore, in specific areas, ground treatment using slurry wall technique was required to remove the temporary seawalls installed to form the working platforms.<\/p>\n
Marine logistics<\/strong><\/p>\nThe foundation works were car\u00adried out in 3 separate visits to site. For each of these visits, the works were executed from reclai\u00admed artificial islands with no land access. As a consequence, all manpower, plants, raw mate\u00adrials and consumables had to be brought by sea:<\/p>\n
\n- the concrete was supplied by conventional truck mixers trans\u00adported to site on specially desig\u00adned barges able to accommodate 8 to 12 trucks mixers,<\/li>\n
- at peak, 15,000 litres of die\u00adsel were required daily for BSGL plant and equipment. The diesel was pumped from land to the \u201cwor\u00adking island\u201d through a specially installed pipeline.<\/li>\n<\/ul>\n
Altogether, 10 barges and 10 tug boats were mobilized to deliver dai\u00adly materials, plant and consumable to site.<\/p>\n
A very tight programme<\/strong><\/p>\nIn addition to marine vessels, heavy specialist plants were also mobilized to site. Up to 2 Hydrofraises, 9 grabs, 8 service cranes (up to a capacity of 250 tonnes) were working concurrently on the 200 m x 80 m platform.<\/p>\n
An off-site steel yard was also set-up in order to produce 160 tonnes of bent and fixed steel per day and allow a production of 5 to 6 panels per week (3,200 m3 of concrete a week). The 3rd visit to site was particularly intense with 28 000 m2 of diaphragm wall and barrettes completed in 4.5 months.<\/p>\n<\/div>
![](\"https:\/\/www.soletanche-bachy.com\/wp-content\/uploads\/sites\/18\/2023\/08\/CWB-Typhoon-Shelter-2012-09-04_-slider-1024x436.jpg\")
<\/span><\/li>![](\"https:\/\/www.soletanche-bachy.com\/wp-content\/uploads\/sites\/18\/2023\/08\/CWB-Typhoon-Shelter-1-slider-1024x436.jpg\")
<\/span><\/li>![](\"https:\/\/www.soletanche-bachy.com\/wp-content\/uploads\/sites\/18\/2023\/08\/MG_4263-slider-1024x436.jpg\")
<\/span><\/li><\/ul><\/div><\/div><\/div><\/div>Type of project:<\/h3><\/div>![\"Road](\"https:\/\/www.soletanche-bachy.com\/wp-content\/uploads\/sites\/18\/2023\/03\/Route.png\")
<\/a><\/span>Road infrastructure<\/h4><\/div><\/div><\/div>Location:<\/h3><\/div>Hong-Kong<\/p>\n<\/div>
Subsidiary of Soletanche Bachy:<\/h3><\/div>Bachy Soletanche Group Limited (BSGL)<\/a><\/p>\n<\/div>Project owner:<\/h3><\/div>Hong Kong Road Authority<\/p>\n<\/div>
Prime contractor:<\/h3><\/div>AECOM ASIA COMPANY LIMITED<\/p>\n<\/div>
Consortium:<\/h3><\/div>China State Construction Engineering (Hong Kong) Ltd<\/p>\n<\/div>
Works period:<\/h3><\/div>05\/2011 \u2013 07\/2013<\/p>\n<\/div>
Types of techniques:<\/h3><\/div>![\"Icon](\"https:\/\/www.soletanche-bachy.com\/wp-content\/uploads\/sites\/18\/2023\/03\/Diaphragm-wall-copie.png\")
<\/a><\/span>Diaphragm wall<\/h4><\/div><\/div><\/div>![\"Icon](\"https:\/\/www.soletanche-bachy.com\/wp-content\/uploads\/sites\/18\/2023\/03\/Barrettes.png\")
<\/a><\/span>Barrettes<\/h4><\/div><\/div><\/div>![\"Icon](\"https:\/\/www.soletanche-bachy.com\/wp-content\/uploads\/sites\/18\/2023\/03\/Strut.png\")
<\/a><\/span>Struts<\/h4><\/div><\/div><\/div><\/div><\/div><\/div><\/div>\n\n<\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div>Key figures of the project<\/p><\/h2><\/div>
<\/div><\/div><\/div><\/div><\/div><\/div>0<\/span><\/div>barges<\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div>0<\/span><\/div>Hydrofraises\u00ae<\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div>0<\/span>m\u00b2<\/span><\/div>of diaphragm wall<\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div><\/div>Related techniques<\/h2><\/div><\/div><\/div><\/i>See all the techniques<\/span><\/a><\/div><\/div><\/div>- <\/span><\/a><\/span>
Struts<\/a><\/h3><\/div><\/div><\/div><\/div><\/div> Supports for all grounds Soletanche Bachy offers you the benefit of its experience [...]<\/p><\/div>
<\/i>Find out more<\/span><\/a><\/div>\n\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t![\"\"](\"https:\/\/www.soletanche-bachy.com\/wp-content\/uploads\/sites\/18\/2022\/05\/CH_20190930_179_Gare-de-Vitry_T2A-vignette.jpg\")
\t\t\t<\/a>\n\t\t\t\t\t\t\t<\/div>\n<\/div><\/div><\/li>\n- <\/span><\/a><\/span>
Diaphragm wall<\/a><\/h3><\/div><\/div><\/div><\/div><\/div> A Soletanche Bachy expertise A diaphragm wall is a support of excavation technique used by [...]<\/p><\/div>
Soletanche Bachy built the foundation of a road<\/a> portion located between Causeway Bay and North Point across the Hong Kong Yacht Club.<\/p>\n The Central \u2013 Wan Chai Bypass and Island Eastern Corridor Link is a 4.5 km long dual tree-lane trunk road with a 3.7 km long tunnel<\/a> which forms part of an East-West stra\u00actegic route along the north shore of Hong Kong Island.<\/p>\n The whole Central – Wan Chai By\u00acpass project comprised 10 contract packages. The foundation<\/a> works on Contract 15, which was awarded to Bachy Soletanche Group Limited (BSGL)<\/a> in April 2010, comprised the portion located between Causeway Bay and North Point across the Hong Kong Yacht Club.<\/p>\n<\/div> Various technical options were ini\u00adtially contemplated by the local au\u00adthorities for the construction of the underground highway. After detailed analysis and due consideration to various technical and environmental constraints, the Highway department selected a cut and cover method with installation of a 1.50 m thick perma\u00adnent diaphragm wall<\/a> socketed into the Moderately Decomposed Granite on both sides of the future highway. The depth of the wall varied from 14 m to 74 m. The excavation had to be carried out through the com\u00adpletely decomposed granite with many boulders and core stones being encountered above bedrock level.<\/p>\n<\/div> Due to environmental constraints, dredging and reclaiming perma\u00adnently lands off-shore Hong Kong Island raises strong opposition from the community and does not constitute anymore an acceptable construction method. Consequently, a very speci\u00adfic construction sequence relying on the installation of temporary reclai\u00admed working platform has been chosen.<\/p>\n The sequence of works was as follow:<\/p>\n The diaphragm wall and barrettes being excavated through the uncon\u00adtrolled fill which was put in place without any specific compaction, ground treatment was required to prevent leakage of bentonite slurry and possibly trench instability and water pollution. For this reason, prior to start the diaphragm wall excava\u00adtion, a grout curtain was installed on both faces of the excavation. Furthermore, in specific areas, ground treatment using slurry wall technique was required to remove the temporary seawalls installed to form the working platforms.<\/p>\n Marine logistics<\/strong><\/p>\n The foundation works were car\u00adried out in 3 separate visits to site. For each of these visits, the works were executed from reclai\u00admed artificial islands with no land access. As a consequence, all manpower, plants, raw mate\u00adrials and consumables had to be brought by sea:<\/p>\n Altogether, 10 barges and 10 tug boats were mobilized to deliver dai\u00adly materials, plant and consumable to site.<\/p>\n A very tight programme<\/strong><\/p>\n In addition to marine vessels, heavy specialist plants were also mobilized to site. Up to 2 Hydrofraises, 9 grabs, 8 service cranes (up to a capacity of 250 tonnes) were working concurrently on the 200 m x 80 m platform.<\/p>\n An off-site steel yard was also set-up in order to produce 160 tonnes of bent and fixed steel per day and allow a production of 5 to 6 panels per week (3,200 m3 of concrete a week). The 3rd visit to site was particularly intense with 28 000 m2 of diaphragm wall and barrettes completed in 4.5 months.<\/p>\n<\/div> Hong-Kong<\/p>\n<\/div> Bachy Soletanche Group Limited (BSGL)<\/a><\/p>\n<\/div> Hong Kong Road Authority<\/p>\n<\/div> AECOM ASIA COMPANY LIMITED<\/p>\n<\/div> China State Construction Engineering (Hong Kong) Ltd<\/p>\n<\/div> 05\/2011 \u2013 07\/2013<\/p>\n<\/div> Key figures of the project<\/p><\/h2><\/div> Supports for all grounds Soletanche Bachy offers you the benefit of its experience [...]<\/p><\/div> A Soletanche Bachy expertise A diaphragm wall is a support of excavation technique used by [...]<\/p><\/div>Description of the project<\/h2><\/div>
Our solution<\/h2><\/div>
\n
\n
<\/span><\/li><\/span><\/li><\/span><\/li><\/ul><\/div>Type of project:<\/h3><\/div>
<\/a><\/span>Road infrastructure<\/h4><\/div><\/div><\/div>
Location:<\/h3><\/div>
Subsidiary of Soletanche Bachy:<\/h3><\/div>
Project owner:<\/h3><\/div>
Prime contractor:<\/h3><\/div>
Consortium:<\/h3><\/div>
Works period:<\/h3><\/div>
Types of techniques:<\/h3><\/div>
<\/a><\/span>Diaphragm wall<\/h4><\/div><\/div><\/div>
<\/a><\/span>Barrettes<\/h4><\/div><\/div><\/div>
<\/a><\/span>Struts<\/h4><\/div><\/div><\/div>
Related techniques<\/h2><\/div><\/div><\/div>
Struts<\/a><\/h3><\/div>
\t\t\t<\/a>\n\t\t\t\t\t\t\t<\/div>\n<\/div><\/div><\/li>\nDiaphragm wall<\/a><\/h3><\/div>
![\"\"](\"https:\/\/www.soletanche-bachy.com\/wp-content\/uploads\/sites\/18\/2021\/01\/CH_20201109_001@1x_1.jpg\")
\t\t\t<\/a>\n\t\t\t\t\t\t\t<\/div>\n<\/div><\/div><\/li>\n<\/ul>![](\"https:\/\/www.soletanche-bachy.com\/wp-content\/uploads\/sites\/18\/2023\/09\/CH_25012011_014_Digue-Cusset_C.Helsy-vignette.jpg\")
<\/a><\/span><\/div><\/div><\/li>\n![](\"https:\/\/www.soletanche-bachy.com\/wp-content\/uploads\/sites\/18\/2023\/08\/3205-Trial-First-HC05-Barge-ABS_juin17-vignette.jpg\")
<\/a><\/span><\/div><\/div><\/li>\n