坑间既有地铁隧道侧方土体加固对隧道水平收敛的影响研究

The Effect Study of Lateral Grouting Reinforcement on Horizontal Convergence of Neighboring Subway Tunnel between Bilateral Deep Foundation Pit

以南京某邻近弧形地铁隧道两侧的深基坑工程为实例,重点研究深基坑施工过程中,坑间既有弧形地铁隧道侧方注浆加固对隧道水平收敛的影响。利用Midas/GTS对车站深基坑的施工过程进行模拟,得出了本基坑条件下的合理的加固范围:高5.0m、隧道外侧宽1.8m/隧道内侧宽2.4m,结合工程实际情况,对既有隧道侧方土体进行微扰动注浆加固,注浆前后的监测资料对比表明,侧方土体加固能有效控制既有隧道的水平收敛,在深基坑施工过程中对临近既有隧道进行保护。

Based on the deep excavation of adjacent metro tunnel in Nanjing, in-situ monitoring data of curved subway tunnel and nighboring curved subway tunnel are analyzed, the effect of lateral grouting reinforcement on horizontal convergence of neighboring curved subway tunnel between bilateral deep foundation pitare studied.Midas/GTS is used to simulate the construction process of the deep foundation pit of the station. The reasonable reinforcement range under the condition of the foundation pit is obtained: 5.0m high, 1.8m wide outside the tunnel and 2.4m wide inside the tunnel. According to the actual situation of the project, the side soil of the existing tunnel is reinforced by micro-disturbance grouting. The comparison of monitoring data before and after grouting shows that the lateral soil reinforcement can effectively control the horizontal convergence of the existing tunnel and protect the nearby existing tunnel during the construction of deep foundation pit.