LTA Contract T219: Platform Link between TEL Orchard Station and NSL Orchard Station

Abstract: The Thomson-East Coast Line (TEL) Orchard Station will serve as an Interchange Station between TEL and North-South Line (NSL). The platform link connecting TEL and NSL consists of an underpass across Orchard Boulevard and a new box structure underneath the existing NSL Orchard Station at a depth of approximately 30m below ground level. The underpass across Orchard Boulevard was constructed by pipe roofing method using a retractable Micro-TBM. The excavation works underneath the existing NSL Orchard Station were executed by incremental mining/underpinning steps of the base slab with total 156 nos. of Mini Piles. Extensive ground improvement in the form of horizontal soil mixing and TAM grouting were implemented to further reduce potential deformations and protect the station structure above.