基于水平旋喷桩处置优化的地铁隧道施工变形控制分析

Analysis of Deformation Control During Subway Tunnel Construction Based on Optimization of Horizontal Rotary Jet Grouting Pile Disposal

为研究富水砂层隧道中水平旋喷桩+超前小导管组合预加固的效果,以青岛地铁某区间段隧道为依托,采用有限元数值模拟方法,对比分析了无预加固、单独使用水平旋喷桩及旋喷桩配合超前小导管组合预加固三种工况的加固效果。结果表明,与无预加固方案相比,单独使用水平旋喷桩预加固可使地表沉降、拱顶沉降、掌子面纵向位移分别相应减少约61%、59%、38%;而水平旋喷桩与超前小导管组合预加固方案可使地表沉降、拱顶沉降、掌子面纵向位移分别相应减少约66%、77.6%、38.9%,典型开挖断面处与拱脚处地下水渗流量分别减少93.4%、96.7%,预加固效果与止水效果显著。

In order to study the effect of horizontal rotary jet grouting pile plus advanced small pipe combination pre-reinforcement in the rich water sand layer tunnel,based on a section of the Qingdao Metro tunnel,the finite element numerical simulation method was used to compare and analyze the reinforcement effect of three working conditions:non-pre-reinforcement,using horizontal rotary jet grouting pile alone,and rotary jet grouting pile combined with advanced small pipe combination pre reinforcement.The results show that compared with the non-pre-reinforcement scheme,the use of horizontal rotary jet grouting pile pre-reinforcement alone can reduce surface settlement,arch settlement,and longitudinal displacement of the palm face by about 61%,59%,and 38%,respectively.The combination of horizontal rotary jet grouting pile and advanced small conduit pre reinforcement scheme can reduce surface settlement,arch crown settlement,and longitudinal displacement of the palm face by about 66%,77.6%,and 38.9%,respectively.The groundwater seepage flow at typical excavation sections and arch feet can be reduced by 93.4%and 96.7%,respectively.The pre-reinforcement effect and water stop effect are significant.