Lower a cage and excavating on the Cut & Cover Section

Client: Land Transport Authority
Main Contractor: Nishimatsu-Lum Chang JV

Contact the Project Director, Patrick BRAUN
or Project Manager (BLV), David MALKA
or Project Manager (NCH), Kusno AKBAR

Quantities: Diaphragm Wall - 120,000 m2

These works form part of the Circle Line Phase 1 (CCL1) also known as the Marina Line going from the Dhoby Ghaut Interchange Station at the bottom of Orchard Road to Boulevard Station adjacent to the National Statium. Contract C824 involves the construction of two stations, Nicoll Highway and Boulevard, and cut & cover tunnels and the twin tube bored tunnels under the Kallang River. As a design & build contract, the Main Contractor, NLC JV, came up with a very economic design for temporary retaining walls using 600mm, 800mm and 1000mm thick diaphragm walls, the stations and the cut & cover tunnels would be built within these structures.

Starting in May 2002 with 2 conventional rigs, the resources increased as areas became available until 5 conventional rigs and 1 hydraulic, KS grab for the areas where verticality was critical. At maximum production the site team were constructing up to 7,000m2 of diaphragm wall per week. Following traffic diversions and changes in design due to the award of the adjacent C823 contract also to the NLC Joint Venture, the job will complete in January 2003.

Installing a cage at NCH Station

Concreting & Excavating at the Cut & Cover

 

Excavation at the Cut & Cover