考虑多因素的双线水平平行盾构施工引起地表隆陷研究

Research on Surface Heave and Subsidence Caused by Multi-factor in Double-line Shield Tunnels Construction

对双线水平平行盾构施工引起的三维地表隆陷计算方法进行研究。考虑正面附加推力、盾壳与土体的摩擦力、注浆压力和土体损失的共同作用,基于先、后行隧道地表隆陷的叠加原理和相互影响,求解得到双线盾构施工引起的总的三维地表隆陷,该方法适用于施工阶段。考虑两条隧道轴线间距J和先行、后行隧道开挖面前后距离K改变的影响。结果表明:本文方法预测值与实测值比较吻合;减小K值,地表纵向沉降曲线形状逐渐由阶梯型转变成S型,最大地表沉降量和隆起量均有所增加;增大J值,地表横向沉降曲线形状由V型缓慢转变成W型,最大地表沉降量逐渐减小。

Three-dimensional calculation approaches of surface heave and subsidence caused by double-line parallel shield tunnel （DLPST） construction is studied in the article. Considering the combined action of the bulkhead additive thrust, the friction force, the grouting pressure and the ground loss, basing on the superposition principle and mutual influence between the first and the second tunnel, the total three-dimensional surface subsidence caused by DLPST construction is obtained. This method can be applied to the stage of construction. Considering the influence of the distance J of the tunnel and the change of K, which is the distance of the excavation face of the first and the second tunnel, the analysis results of the examples show that the proposed method is consistent with the measured values. If K is decreasing, the shape of the surface verti- cal subsidence curve will be from ladder shape to S shape and the maximum surface settlement and the amount of bulge both will increase. If J is increasing, the shape of the surface lateral subsidence curve will be from V shape to W shape and the maximum surface settlement will de- crease.