Underground Pedestrian Underpass Using Rectangular Pipe Jacking Machine

The machine is utilized for the construction of the entrance of the T221 MRT station in Singapore, featuring a cross‑sectional size of 762mm ×5,645mm and a jacking length of 156m, with an overburden ranging from 5 to 7.2m. During the excavation process, the machine successfully navigated through an area with pipeline obstacles. The cutter head effectively broke through the cast iron pipelines, discharging hundreds of iron blocks along with other spoils, including auger drill bits.

Project Background

As the first project in Singapore to adopt the large‑section rectangular pipe jacking technology introduced by the Singaporean government, it holds significant importance for the development of Singapore's underground engineering. The T221 contract section of the project was successfully completed in November 2016 and also won Singapore's Project Management Gold Award of that year. Subsequently, this machine was used again in Singapore's T216 project for the construction of the underground passage connecting Exit D and Exit C. The tunnel has a total length of 63.86m, with the excavation direction from north to south, passing under 2 highways, 1 viaduct and 1 river channel. Excavation work began on October 28, 2017, and the maximum daily advance rate reached 2 m/day.

Singapore T221 Pedestrian Underpass Project Route

The project implemented standardized management and was awarded the Singapore Project Management Gold Award in 2016.

Launch preparation for the rectangular pipe jacking machine.