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Gammon Construction successfully installed Precast Retaining Wall at Tolo Highway project

Gammon Construction Limited successfully adopted precast panels in constructing the retaining wall at the Widening of Tolo and Fanling Highways Project for the first time. Several green initiatives had also been stringently implemented at this project in controlling noise and minimising carbon emission. Site Safety has also improved.


In constructing the retaining wall, Gammon Construction applied precast method instead of using the traditional formwork. The usage of precast panels and hanging working platforms had streamlined working procedures as well as reduced waste generation. A total of 450 concrete panels sized at 4 metres long and 2 metres wide were precast in advance and each panel contained the quarter rounded recess at each corner for weep holes installation.


Moreover, working platforms were hung on the panel which could create working spaces on ground level for other works and provide safer working environment. As a result, this innovative method had successfully reduced the use of timber by 70% and also prevented tree removal by 70%.


The adoption of mini piles in replacement of traditional bored piles significantly limited the open cut excavation to form the retaining wall foundation. Meanwhile, nearly 90% of excavated materials were reused by nearby construction sites so as to ease the burden of the landfill. In addition, the mini piles also minimised the application of heavy machinery and helped reducing carbon footprint.


Road construction often required building temporary roadways. Gammon recommended an alternative Temporary Traffic Arrangement at this project to accommodate the busy traffic at Tolo Highway during the construction period, when Tai Wo Road in Tai Po was to be closed. Gammon’s proposal in exercising traffic diversion rather than building temporary structure was accepted, which not only maintained a smooth highway operation but also avoided construction waste caused by building temporary road structure.


During the project period, Gammon team maintained good community relations with local residents surrounding the Tolo Highways. We hosted regular meetings with residents, village representatives, district councilors and other stakeholders so as to solicit their needs as to minimise construction impacts on them. Tree planting day and elderly visiting were among those activities organised by the project team.


On completion of the project, the widened section has helped alleviate traffic congestion at Tolo and Fanling Highways and benefited the community development. Gammon has been striving for introducing diversified engineering technology, providing a safer working environment and minimising the impact to the environment.


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For further information please contact:

Candy Chan                

Corporate Communications Manager

Tel: + 852 2516 8733



About the Project:

The widening works of the Tolo and Fanling Highways are proposed to alleviate the traffic congestion problem on Tolo Highway and to meet the anticipated traffic growth.


The scope of the contract by Gammon mainly includes widening of a section of Tolo and Fanling Highways of 3.5 km long between Ma Wo and Tai Hang from the existing dual 3-lane carriageway to a dual 4-lane carriageway.


Works also include constructing eight vehicular bridges with a total length of 1.31 km and modification or demolition of the existing bridge, including all associated interchanges and utilities.

The construction also covers 53 numbers of retaining walls of a total length of 1.85 km, 28 numbers of associated slopeworks, as well as ancillary works including drainage and sewerage, geotechnical and landscaping works, construction of water-mains and noise barriers, installation of fire hydrants, traffic control and surveillance system.