列车交叠动荷载对邻近基坑结构动力响应分析

Dynamic Response of Adjacent Foundation with Overlapping Dynamic Load on Trains

运用Abaqus有限元软件,开展了在地铁列车交叠动荷载作用下基坑结构的动力响应研究。通过考虑7种不同工况,分析了基坑开挖过程中,地铁列车交叠动荷载存在对基坑结构内力与变形的影响规律。分析结果表明,地铁列车交叠动载对表层土体沉降有较大影响,且这种影响随着列车时速的增大而不断增大。地铁列车交叠动载对围护结构变形和弯矩有一定影响,但列车静载部分起控制作用。地铁列车交叠动载对支撑轴力影响不大。列车交叠动荷载的作用规律与单层列车动荷载作用规律有一定差异,在列车交叠动荷载的作用过程中,上层列车荷载起主要控制作用。

This paper addresses the dynamic response of foundation pit structure under the overlapping dynamic loads of subway trains by using the finite element software Abaqus.We consider seven working conditions and analyze how overlapping dynamic loads impact on the internal force and deformation of foundation pit.Analysis results show that the overlapping dynamic loads of subway trains have a great influence on the settlement of surface soil.In addition,this influence increases as the speed of trains increasing.The overlapping dynamic loads of subway trains also have influence on the deformation and bending moment of the retaining structure,where the static load part of the trains plays a controlling role.However,the overlapping dynamic loads of subway trains have little effect on the support axial force.Moreover,there are differences on action laws between overlapping dynamic loads of subway trains and dynamic loads of single-layer train.The upper train load plays a controlling role during the overlapping action process.