Project

Circle Line Stage 5 (Contract 856) covers the construction of West Coast, Pasir Panjang, Labrador, Cut and Cover Tunnels for the Cripple Sidings and Cross Over adjacent to these stations. The length of the project is about 5.5km.

Jet Grouting works were performed to create a semi arch shape JGP block at the tunnel break in/out location. The jet grouting works were carried out in soft marine clay, silty clay and peaty clay. The target unconfined compressive strength of the jet grout material was 0.60 to 0.90 MPa.

The major challenge for this project is the need to perform the work under a low head room condition as part of the JGP area is under an elevated expressway. As there are existing utility on top of the JGP block, inclined drilling and jet grouting were performed to overcome these obstruction.