盾构隧道施工引起的地基土超孔压特性模拟与分析

考虑盾构机盾壳与自重、开挖面正面推力、盾尾空隙、千斤顶推力和同步注浆等因素,利用有限元软件模拟研究了盾构施工过程引起的周边土体超孔压,并与实测值进行对比分析,以此验证了模拟方法的可靠性。基于单层软土、中等埋深条件下的盾构施工有限元模拟,分析了超孔压随施工过程的分布特性。研究表明,施工过程中周边土体的超孔压变化明显,随着盾构机的推进先不断增大,盾构机头到达或盾尾脱出时达到最大,盾构机离开后又逐渐减小。软土层中125 d后隧道四周超孔压的衰减率约为92%。

Modelling Research and Analysis on Excess Pore Water Pressure Caused by Shield Tunneling

A 3D FEM method is used to simulate the excess pore water pressure on the surrounding area caused by EPB (electric park brake) shield construction,with full consideration of factors like TBM (tunnel boring machine) shell and weight,shield face pressure,tail void,jack thrust and tail void grouting.The simulation result is compared with measured data to verify the reliability of the simulation.In addition,based on the 3D FEM simulation of one layer soft soil in the medium depth tunnel construction,the distribution regularities of excess pore water pressure during tunneling is analyzed.The research shows that the excess pore water pressure changes sharply with the advance of EPB,it decreased by 92％ in soft soil around the tunnel after 125 days.