ABSTRACT
The Contract C708 of the North-East line at Clarke Quay includes the construction of a 23 m deep station and 1.5-km long twin bored tunnels. The tunnel route passes beneath (or near) buildings, pedestrian bridges, utilities, the Singapore River and beneath the existing Dhoby Ghaut tunnels with a clearance of a mere 4 m. The station excavation is constrained by the presence of buildings and utilities within its influence zone. An extensive instrumentation was implemented to ensure the construction of the station and the tunnels proceeded safely without any adverse effects to the adjacent structures and utilities. This paper summarizes the instrumentation scheme adopted.
