【摘要】 通过FLAC3D有限差分软件模拟分析铁轨分别处于无列车动荷载、列车等效静荷载、列车动荷载影响3种情况下和列车行驶速度不同时，基坑地连墙支护结构的水平位移及基坑外地表沉降变化规律。将不同情况下的计算结果与实测结果进行对比分析。计算结果表明：（1）列车运行产生的动荷载对基坑稳定性影响较大，采用叠加的连续正弦函数模拟的列车动荷载得到的地连墙水平位移变化规律与监测值基本一致，用叠加的连续正弦激振力函数模拟列车动荷载方法可行；（2）相比无列车动荷载影响或有列车静荷载影响时，列车动荷载作用下地表沉降最大值与地连墙水平位移最大值均增加较大，建议考虑列车运行产生的振动荷载对基坑稳定性的影响；（3）列车行驶速度增加使地表沉降和地连墙水平位移最大值均逐步增大，在进行基坑的稳定性分析时，按列车行驶最大速度产生的动荷载进行计算较为安全。更多还原

【Abstract】 Using FLAC3D finite difference software to simulate and analyze the horizontal displacement of the supporting structure of the connecting wall of the foundation pit and the change law of the ground settlement outside the foundation pit under the three conditions of no train load,equivalent static load of the train,and dynamic load of the train,and when the train speed is different to compare and analyze the calculated results in three different situations with the measured results.The results show that:(1)The dynamic load generated by train operation has a greater impact on the stability of the foundation pit.Using superimposed continuous sine function to simulate the train dynamic load,the horizontal displacement of the ground wall is basically consistent with the monitored value,and the superimposed continuous sine excitation force function is feasible to simulate the train dynamic load;(2)Compared with the case of no train load or train static load,the maximum ground settlement and the maximum horizontal displacement of the ground wall under the dynamic train load both increase significantly. It is recommended to consider the impact of the vibration load generated by the train operation on the stability of the foundation pit;(3)The increase in train speed gradually increases the maximum value of ground settlement and the horizontal displacement of the ground connecting wall. When analyzing the stability of the foundation pit,it is safer to calculate based on the dynamic load generated by the maximum train speed.更多还原