ABSTRACT
The underground railway project is an unusual challenge that tunnel excavation is executed without a big cover under existing railways on the surface or with an elevated frame structure. The underground railway project is now under construction in Yokohama adopting the dewatering in the sand strata at the congested area with buildings and underground utilities. The most important items are the design and construction, which can reduce settlement of the tracks or ground surface and the adjacent structures within allowable values. And also it is required to monitor the safety of ongoing train operations in real time. This paper describes the design, construction and observations.
