The 1st Stage

On 23 April 2004, LTA proceeded to fill the collapsed site with ‘foam’ concrete. This type of concrete can flow into the small voids between the debris and displace the water that had seeped into the excavation.

Filling the site with concrete served to stabilise the void and prevent further soil movement and subsidence of the surrounding areas. The low strength of this concrete mix allows it to be removed later when excavation resumes following the recovery process.

The 2nd & 3rd Stages

Several days later on 27 April 2004, a mixture of soil and cement, were poured into the site to form a level platform.

After the ground in the collapsed site had stabilised, we concentrated our efforts on stabilising the outer areas of the collapsed slopes. That was the third stage of the recovery work. The outer slopes were filled with mass concrete. Once this was done, a delicate operation to remove debris at the top commenced. On 14 May 2004, cranes were brought in to clear the debris, which included a crane boom and several steel beams. These had to be cut into smaller pieces before they could be moved. This intricate process took about two months to complete.

The 4th & 5th Stages

The stretch of Nicoll Highway was rebuilt on bored piles to strengthen the new road to withstand changes in soil conditions. Re-building on bored piles also means that the new road will not be affected by future excavation works. Reconstruction works began on 24 August 2004. Fifty-seven bored piles were sunk 50m into the ground to support the 150-metre new road.

After that, concrete slabs were cast followed by tarring. Structures such as streetlights were then added before the road was re-opened on 4 December 2004. Reconstruction of Nicoll Highway took about three months, and motorists are now able to travel on the highway.

Take a look at how the reconstruction works were carried out here.

The 6th & 7th Stages

Backfilling of the affected area at the Nicoll Highway MRT worksite has been completed. The ground level has been restored to its original pre-excavation level.