Calculation of soil deformation caused by construction of shield tunnels in composite layered strata

In order to solve the problem of soil deformation caused by shield construction under the condition of multi-layer horizontal soil covering on the upper part of the shield and the upper and lower horizontal layers in the excavation face, on the basis of the unified analytical method for soils, the influence parameters of soil conditions are modified so that the soil deformation can be calculated under composite strata, and the focus range of soil movement is re-divided. By combining the modified unified soil analytical method with the analogous stochastic medium theory method (ASMTM), a method can be obtained to solve the problem of multiple soil strata on the shield excavation surface, and can be applied to the shield construction with any shapes of excavation surface. The results show that the feasibility of the proposed method is verified through several engineering cases. The nonlinear change of soil deformation occurs when the thickness of a certain soil layer increases by the same amount. Since the soil loss has more influences on the soil deformation than the deformation transfer path, the soil deformation may be different under the same cavity diameter ratio.