类矩形盾构隧道开挖引发土体沉降解析解研究

Analytical Solution for Soil Settlements Due to Quasi-rectangular Shield Tunneling

类矩形盾构隧道施工可能会导致明显的土体沉降,并进一步影响周围既有建筑物的安全。基于Verruijt解和积分法推导得到类矩形盾构隧道开挖作用下的土体响应解析解,并充分考虑土体等量径向收缩、类矩形隧道竖向、水平向以及旋转位移4个变形分量的影响,以全面描述复杂施工或地层情况下类矩形盾构开挖引发的土体位移模式。利用实际工程实测数据验证解析解的有效性,并通过参数分析研究各个变形参数对地表土体沉降的影响。研究结果表明,解析理论计算结果与实测数据较为吻合,可较好地评估类矩形盾构引发的土体沉降,类矩形隧道的水平位移和旋转位移会使地表沉降呈现非对称形态,并会使最大地表沉降增大。

The construction of the quasi-rectangular shield tunnel may result in obvious ground settlements.An analytical solution for quasi-rectangular shield tunneling-induced ground settlement is derived by using the solution of Verruijt and the integral method.Four tunnel deformation components,i.e.,the uniform radial contraction,the tunnel vertical displacement,the tunnel horizontal displacement and the tunnel rolling are fully considered to provide a comprehensive description for the soil displacement pattern caused by the quasi-rectangular shield tunneling under complex construction and load conditions.Field data from a case study are used to verify the applicability of the proposed solution,and the effects of the related parameters on the ground settlements are discussed through parametric analyses.The results show that the proposed solution can provide an acceptable description for the ground surface settlements caused by the quasi-rectangular shield tunneling.The soil settlements are asymmetric to the tunnel centerline,and the maximum soil settlements increase when the horizontal tunnel displacement and the tunnel rolling occur.