管片透水条件对地铁隧道长期沉降影响的数值计算

Numerical Calculation of the Influence of Segment Permeability on Long-Term Settlement of Metro Tunnel

采用PLaxis3d对隧道管片透水条件下引起的地层长期沉降情况进行了研究分析。通过隧道施工完成瞬时地层的沉降云图、隧道施工完成瞬时地层中的超静孔隙水压力分布图等分析可知,管片透水诱发地层长期沉降主要是地层中的渗流场决定的。管片透水时造成的地表最大沉降约为不透水时的2倍,地表沉降槽宽度也约为管片不透水时的2倍。

The long term settlement of stratum caused by tunnel segment permeability is studied by PLaxis3 d. Through the settlement nephogram and the pore water pressure diagram of stratum as soon as the tunnel construction is instantaneously completed, long-term settlement is mainly induced by the formation of permeable lining seepage field in the formation. The maximum settlement of the ground surface when the segment is permeable is nearly 2 times that the segment is impermeable, and the width of the surface settlement is about 2 times as much as when the segment is impermeable.