Logistics of Limited Space Urban Tunnelling at Singapore’s Mega Metro
Today’s mega metro projects are using multiple TBMs in difficult ground, short tunnels, and in urban settings: Factors that create unique challenges. At Singapore’s metro construction, 21 km of tunnel for the Downtown Line 3 are underway using 29 TBMs boring between 16 station sites in short bores often less than 1.5 km each. By 2017, 39 km of new construction will cut commute times in half in one of the world’s most densely populated locales. This paper will detail six earth pressure balance machines on the project, analyzing the challenges of boring in a highly urban setting through rock and soft ground under water pressure. Machine performance at the Singapore Downtown Line will be analyzed with a discussion of the challenges involved.