紧邻基坑的地铁隧道跟踪注浆保护模型试验

以宁波轨道交通3号线陈-姜区间隧道为依托,开展了紧邻基坑的地铁隧道跟踪注浆保护模型试验研究,测试了隧道的位移、隧道外侧土压力与孔隙水压力、地连墙压力和位移及地表位移等,分析了注浆在土体内部的流动机理及对隧道位移的影响机理,结果表明:注浆后隧道位移有一定幅度的减缓,注浆停止后位移继续增大;土体中孔压、土压力增量较小,约为...

Model Test on Tracking Grouting Protection of Subway Tunnel Adjacent to Foundation Pit

Based on the Chen-Jiang interval tunnel of Ningbo Rail Transit Line 3, this paper carried out a test study on the tracking grouting protection model of the subway tunnel adjacent to the foundation pit, and tested the displacement of the tunnel, the earth pressure on the outside of the tunnel and the pore water pressure, and the ground wall. The flow mechanism of grouting in the soil and the influence mechanism on the displacement of the tunnel were analyzed. The results show that the displacement of the tunnel is slowed down after grouting, and the displacement continues to increase after grouting stops. The pore pressure and earth pressure increment in the soil are small, occupying about 1/70~1/50 of the value of grouting pressure, and the grouting pressure is rapidly attenuated by the resistance of the soil. When the grouting is closer to the wall, the pressure and horizontal displacement of the grounding wall are significantly increased, which is unfavorable to the stability of the foundation pit. The cracking surface of the grouting is parallel to the length of the grounding wall, and the slurry is always the most stress along the soil. The weak surface, that is, the small principal stress surface is split in the vertical direction.