非平衡荷载下地铁车站深基坑支撑结构力学特性研究

以杭州某地铁车站深基坑为工程背景，运用PLAXIS 3D对非平衡荷载作用下支撑受力特性进行三维数值模拟研究。结果表明:随着基坑开挖深度的增加，支撑最大轴力先增大后趋于稳定且有变小的趋势，支撑最大剪力和最大弯矩逐渐增大且增加幅度逐渐减小，支撑变形先减小后增加；基坑内土体竖向位移先增大后减小；应注意第三阶段土体稳定性及开挖后期工程安全性问题。

Study on Mechanical Properties of Supporting Structure of Deep Foundation Pit in Subway Station under Non-equilibrium Load

Taking the deep foundation pit of a subway station in Hangzhou as the engineering background, the three-dimensional numerical simulation study on the force characteristics under non-equilibrium load was carried out by using PLAXIS 3D. The results show that with the increase of foundation pit excavation depth, the maximum axial force of the support increases first, then trend to be stable and has a decreasing trend, the maximum shear force and the maximum bending moment increase gradually and the increasing range decreases gradually, and the deformation of support decreases first and then increases. The vertical displacement of soil in the foundation pit increases first and then decreases. Attention should be paid to the stability of the soil in the third stage and the engineering safety in the later stage of the excavation.