(1 School of Civil Engineering, Beijing Jiaotong University, Beijing 100044; 2 Tunnel and Underground Engineering Research Center of Ministry of Education, Beijing Jiaotong University, Beijing 100044; 3 Beijing Municipal Engineer Group Co. Ltd., Beijing 100045;
4 Suzhou Rail Transit Co. Ltd., Suzhou 215003)
Abstract：
The Suzhou Metro Line 2 passes beneath 480 buildings in the old town of Suzhou. Since most of the buildings have no foundations or have simple strip foundations, they are inclined to crack or collapse due to deformation. Line 2 is constructed in silt and silty sand with a high water table and high water permeability, and potential drift sand or soil hardening can easily result in work-face failure because of soil disturbances caused by shield tunnelling. Although shield tunnelling technology has been developed along with the improvement of shield performance, it is still a new challenge to successfully tunnelling adjacent to a large number of buildings. Based on the driving speed, grouting material and grouting trials on-site, the scope of influence, control standards for surface settlement, driving speed, grout components and mix proportion, grouting volume and grouting time during shield tunnelling are given, which provides technical support for the safe shield tunnelling of the Suzhou Metro Line 2.
2014, Vol. 51 