车辆荷载及盾构施工对既有快速路基坑三维数值模拟

以杭富城际铁路盾构下穿既有快速路基坑为研究背景,利用PLAXIS 3D对地面车辆动荷载及盾构施工下穿既有快速路基坑进行三维数值模拟,分析对既有快速路基坑力学性状的影响。研究表明,车辆动荷载和盾构施工对既有基坑的影响主要体现在对周围土体的扰动上,盾构施工主要影响基坑底板,使基坑底部隆起变形,车辆荷载主要影响基坑上部,车辆荷载影响深度在6m范围内。

Three-dimensional numerical simulation of vehicle load and shield construction on existing expressway foundation pit

Taking the shield tunnel of Hangfu railway underneath traversing the existing expressway foundation pit as an example, a three-dimensional numerical model is built to simulate the process of shield construction under vehicle dynamic loading by PLAXIS 3 D. The effect of passing through on the mechanical behavior of existing foundation pit is investigated. The results show that the vehicle dynamic load and impact on both the foundation pit of shield construction mainly reflects on the disturbance of the surrounding soil. The overlying soil under the foundation pit floor has undergone vertical uplift deformation, main influence of shield construction foundation pit bottom, make the bulge at the bottom of the pit deformation, vehicle load mainly affects both the upper foundation pit, the vehicle load impact depth within the scope of the 6 m.