Centrifugal Model Test on Construction Process of a Super Large Diameter Shield Tunnel Passing under Existing Railway
(1 CCCC Second Highway Survey and Design Institute Co., Ltd., Wuhan 430056；2 College of Civil and Transportation Engineering,Shenzhen University, Shenzhen 518061；3 Key Laboratory of Coastal Urban Resilient Infrastructures (MOE), Shenzhen University,Shenzhen 518061)
Abstract：
The adjacent construction of a shield tunnel passing under operating high-speed railways will cause sub? grade settlement, uneven settlement of the track and other problems, which will affect the normal operation of the railway line and, in serious cases, also cause damage to the railway. In order to study the influence on settlement and settlement pattern of the intercity railways caused by the dynamic construction process of shield tunnels with super large diameters, based on the Wuhan Lianghu shield-driven highway tunnel with super large diameter and obliquely passing under the intercity railway, it simulates the whole dynamic process of the shield machine approaching-passing under-leaving the railway through geotechnical centrifuge model test. The research results show that: (1) the impact of shield tunnelling on the railway subgrade is mainly concentrated in the range of 25 m before and after the under-crossing point, while such impact beyond 25 m from the under-crossing point is quite small; (2) during the shield tunnelling process, the settlement of the railway subgrade caused by the tunnelling before under-crossing accounts for about 36% of the total railway subgrade settlement induced by tunnelling, while the settlement after under-crossing accounts for about 64%, and the settlement rate of the railway subgrade after the under-crossing increases rapidly and is greater than that before under-crossing; (3) taking 15 m where the shield has been passing under the railway as the dividing point, the settlement of the subgrade on the left side in the shield tunnelling direction is greater than that on the right side before the dividing point, and the opposite after, eventually the settlement of the railway subgrade on the right side in the shield tunnelling direction is greater than that on the left side.
YANG Linsong1 LIU Jiguo1 SHU Heng1 WU Shidong2 SONG Ming1 LI Jin1 WANG Xuetao2,
3
.Centrifugal Model Test on Construction Process of a Super Large Diameter Shield Tunnel Passing under Existing Railway[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(4): 170-177
2021, Vol. 58 