盾构隧道近距离下穿既有建筑物的沉降分析及控制措施研究

Study on the influence and control methods of shield tunneling through the existing buildings

随着我国城市化进程快速发展,大中城市的地下工程不断增加,隧道工程对周围环境的影响受到极大关注,尤其是对重要建筑物和敏感建筑物的影响有严格限制。结合杭州之江路隧道下穿白塔公园1号建筑的实际工程,采用ABAQUS有限元分析软件建立了地基-隧道-1号建筑三维计算模型,考虑MJS倾斜桩基加固工况下分析计算盾构施工对既有1号建筑的沉降影响。结果表明:由盾构施工引起的既有建筑基础主要沉降发生在盾构穿越阶段;盾构施工引起的建筑物沉降在靠近隧道一侧更明显,其中同一建筑物下采用阀板基础的累积和差异性沉降均要小于独立基础;由于MJS隔离桩保护作用,有效控制了加固区段盾构掘进对地表及建筑物的沉降影响,可以满足规范的要求。

Underground engineering increases steadily in large and medium-sized cities as unban construction develops rapidly.Surrounding effect caused by tunneling is of great concern.Especially,effect to important building and vibration-sensitive buildings are strictly restricted.Based on the tunneling engineering construction of Hangzhou Zhijiang road to Hangzhou white pagoda,Three dimensional Foundation-tunnel-building FEM model has established.Effect caused by shield tunnel construction to existing building is calculated with ABAQUS software.Furthermore,the strengthening effects of tilting MJS piles is calculated.The results show that the stage of shield tunneling through the building has the greatest settlement,the building settlement near the tunnel is more obvious,and the total settlement and buildings differential settlement that the shield crossing the isolated foundation is greater than that of the raft foundation.Moreover,due to the protection of isolation piles,the settlement of building in reinforcement section greatly decreases,and the settlement satisfies the requirement.