【摘要】 随着全国铁路网的扩大,许多既有车站需要在维持既有线路运营的情况下进行改扩建,在这些工程中存在既有线列车荷载作用下基坑与线路之间相互影响的问题。该文以某邻近既有线施工在深基坑开挖工程为例,对此问题进行分析。根据系统动力学、有限元理论,建立铁路路基-土体-邻近线路基坑-支护结构数值计算模型,分析列车振动荷载作用下,邻近既有线的深基坑开挖过程中路基-基坑体系的动变形响应规律。基坑开挖过程中,路基中心处和基坑边坡坡顶的水平和竖向动位移均增大,且水平动位移增长率大于竖向动位移增长率,但从绝对值而言,变形仍以竖向动位移为主。由于基坑开挖,邻近既有线的路基中心最大竖向动位移增大到2.0 mm,尚不超过铁路路基动变形3.5 mm的控制标准。说明实施的保护措施是有效的。更多还原

【Abstract】 With the expansion of the national rail network,many existed rail stations have to be enlarged with-out disturbing transportation of existed lines.The most serious problem in these projects is the interaction be-tween the new excavation pit and the adjacent railway lines,especially influence of running trains on the stabili-ty of the adjacent foundation.This paper analyzes this issue based on a practical engineering project in Suzhou.By establishing the numerical model of roadbed-ground-ditch-supporting structure coupling system based on theory of the vehicle-track coupling system and the finite element method,the disciplines of roadbed subsid-ence caused by excavation of foundation ditch and the displacement of the foundation under the vibration load-ing caused by passing trains are studied.It shows that dynamic vertical and horizontal displacements of the road-bed and slope crest both increase along with the excavation,and the growth rate of the horizontal displacements is higher than that of the vertical ones,with the maximum value of 2.0mm,satisfying requirement of the dis-placement control standard.更多还原