New course trains engineers to build underground tunnels in Singapore

SINGAPORE – At 43m deep, Bencoolen MRT Station on the Downtown Line is Singapore’s deepest MRT station to date.

Commuters must descend five escalators from street level just to reach the train platforms. The tunnel connecting Bencoolen and Fort Canning MRT stations also runs just 1m above an existing North East Line tunnel, making it difficult to construct.

Such engineering feats are increasingly becoming the norm for MRT engineers and contractors as more and more MRT lines are planned deeper underground to avoid affecting buildings above ground.

The Land Transport Authority (LTA) and the Singapore Institute of Technology (SIT) on Monday (December 20th) signed a Memorandum of Understanding to establish an Infrastructure and Tunnel Engineering Centre, focusing on skills development in terms of underground tunnels which are still lacking among many other countries. Industry.

It is hoped that SIT’s expertise in education, research and development, combined with the hands-on experience of LTA, will equip more engineers with the specialist skills needed as Singapore aims to double the length of its lines. MRT at 360 km by 2030.

LTA chief executive Ng Lang said the center can provide a pool of tunnel engineers to support the agency’s ongoing projects, which increasingly include projects deep below the earth’s surface.

“Our rail lines and road projects go deeper underground to make better use of above-ground space and preserve our natural environment. This requires expert knowledge in the field,” he said.

SIT Chairman Tan Thiam Soon said the center aims to be “at the forefront of applied research and advanced training in Singapore, preparing future graduates and the workforce to meet the challenges of the constant evolution of infrastructure and tunnel developments”.

Of Singapore’s six operational MRT lines, only the two oldest lines – the North-South and East-West lines – have sections above ground.

A section of the Cross Island line still under construction will run 70m below the Central Catchment Nature Reserve, the LTA said, and new technologies have made building deeper an increasingly viable option.

Traditionally, the cut-and-cover method – where the ground is open, the station built, and then the ground backfilled – has been used. But it is less suitable for deeper constructions, and in recent years tunnel boring machines have been tested and have become the norm here.

The Thomson-East Coast Line’s Orchard station used a retractable micro-tunnel borer to dig a tunnel in the ground and install interlocking steel pipes.

A two-lane tunnel between Aviation Park Station and Loyang Station on the Cross Island Line will also be built using a large-diameter tunnel boring machine, a first for the country.

Additionally, new methods are also being used to stabilize the underground soil to prevent it from collapsing during and after construction. The Thomson-East Coast Line Marina Bay station used a ground freezing process to create ice walls to stabilize the ground before excavation work began.

Bonny J. Streater