地铁盾构隧道穿越采空区地面注浆保压技术对地表沉降影响研究

Research on the impact of grouting and pressure maintenance technology on surface settlement of metro shield tunnels passing through the gob area

盾构隧道在采空区周围施工时,由于采空区内部结构的特殊性和不稳定性,极易导致围岩失稳。为保证地铁施工期间隧道围岩稳定性以及地表沉降的控制效果,文章针对地铁盾构隧道穿越采空区引起地表沉降过大问题,提出一种注浆保压的采空区提前处理工法。依托广州地铁12号线工程,运用FLAC3D数值模拟软件,研究采空区注浆对围岩的支撑能力以及地表沉降控制的影响,并将模拟结果与实际工程数据进行对比分析,验证模拟结果的正确性并总结规律性成果。结果表明,注浆保压控制地表沉降技术在实际应用中具有良好效果,研究成果可对其他盾构隧道穿越采空区地表沉降控制提供参考和借鉴。

When the shield tunnel is constructed around the gob area,it is very easy to cause surrounding rock instability due to the special characteristics and instability of the internal structure of the gob area.To ensure the stability of tunnel surrounding rock and the control effect of surface settlement during metro construction,this article proposes a grouting and pressure maintaining method for early treatment of gob area,targeting at the excessive surface settlement when metro shield tunnels pass through the gob area.Based on the Guangzhou metro line 12 project,FLAC 3D numerical simulation software was used to study the influence of grouting in the gob area on the support capacity of surrounding rock and surface settlement control.The simulation results were compared and analyzed with actual engineering data to verify the correctness of the simulation results and summarize the regularity results.The results show that the grouting pressure control technology for surface settlement has good effects in practical applications,and the research results could provide reference and inspiration for surface settlement control of other shield tunnels crossing the gob area.