ABSTRACT
Singapore’s Mass Rapid Transit network has been expanding rapidly as part of the country’s roadmap towards developing a comprehensive public transport system. While the increased connectivity of the metro network brings about convenience to commuters, constructing additional infrastructure for the network has become increasingly challenging as a result. Contract T222 involves constructing the Outram Station and the Thomson-East Coast Line tunnels. The Outram Station will become an interchange connecting two existing lines in the central business district. The construction involves overcrossing the existing North East Line and undercrossing the East West Line (EWL) tunnels. As the new tunnels are located directly under the EWL tunnels in a parallel manner, this makes T222 a challenging project within the context of a highly dense urban district and complex geological conditions. This paper shall discuss the tunnelling methodology for the undercrossing of the EWL, challenges faced and key takeaways for future application.
