隔离墙对顶管顶进背土效应的抑制作用研究

Study on Restraining Effect of Separation Wall on Carrying-soil Effect of Pipe Jacking

浅埋大断面矩形顶管顶进产生的背土效应对上覆土层和上部构筑物的影响较大,在实际施工中应采取措施减小其不利影响。采用有限元数值仿真分析,研究了设置隔离墙对顶管顶进背土效应的抑制作用。结果表明:隔离墙的抑制效果随隔离墙组数的增加而增强;相比于无隔离墙的情况,采用三组隔离墙可使上部箱涵迎土面中心点的最大水平位移减小45.70%、最大竖向位移减小28.46%,地层沉降量减小41.24%;相比于竖向位移,隔离墙对箱涵水平位移的抑制作用更明显。

The carrying-soil effect,as induced by jacking of shallow-buried large-section rectangular pipe,has a great impact on the overlying soil layer and the superstructure.In actual construction,measures should be taken to reduce its adverse effects.The finite element numerical modelling is adopted to study the restraining effect of separation walls on the carrying-soil effect of pipe jacking.The results show that the restraining effect of separation walls increases with the increase of the number of walls.Compared with the case without separation walls,the use of three groups of walls reduces the maximum horizontal and vertical displacements at the center point of the soil-facing surface of the overlying box culvert,and the ground settlement by 45.70%,28.46%and 41.24%,respectively.Compared with the vertical displacement,the restraining effect of the separation wall on the horizontal displacement of the box culvert is more obvious.