|
|
|
| Stratum deformation laws and influence factors analysis of tunnel excavation in sand |
| FANG Qian1, DU Jianming1, WANG Gan1, WANG Zhongju2,WANG Guanqing1
|
1. Tunnel and Underground Engineering Research Center of Ministry of Education, Beijing Jiaotong University, Beijing 100044, China;
2. China Railway Siyuan Survey and Design Group Co., LTD., Wuhan 430063, Hubei, China |
|
|
|
|
Abstract Aiming at the engineering problems of collapse caused by circular tunnel construction in sand, the influences of cover depths, ground loss ratio, particle size and gradation on the stratum deformation in sand were numerically simulated by PFC2D based on the physical model test results. The results showed that the transmission of disturbance force, which was caused by the circular tunnel construction in sand, was a gradual process, the deeper the buried depth was, the larger the width of settlement trough was, the smaller the maximum settlement value of the ground surface was, and the easier to form the completed arch-shaped stable zone and the “Λ” instability zone; the settlement trough width and the maximum settlement value of the ground surface became large with the increase of the ground loss ratio and there was a linear relationship between the ground loss ratio and the maximum settlement value of the ground surface; the larger the particle size was, the larger the width of settlement trough was, the smaller the maximum settlement value of the ground surface, the faster the disturbance force transmit and the less likely to form the arched stable zone; the influence of particle gradation on the settlement trough width and the maximum settlement value of the ground surface was not significant. The results are of great reference significance for the circular tunnel construction in sand.
|
|
Received: 18 June 2020
Published: 20 September 2020
|
|
|
|
|
|
|
|
