摘要
以某城际铁路跨既有线特大桥为工程背景,针对其主桥桥墩基础施工对既有线变形的影响问题,运用FLAC3D软件建立数值分析计算模型,从承台基坑开挖深度对既有线路的变形影响入手进行分析和探索.在既有线单侧进行基坑开挖以及双侧同时开挖两种不同施工组织下,探讨了随基坑的开挖深度增加对既有线路各个部分的变形影响及规律,得出以下结论:(1)两种开挖方式下线路各个部分的沉降量及水平位移均随基坑开挖深度的增加而增加,但是在10 m开挖深度内,均可满足规范要求。(2)采用双侧同时开挖基坑的方式,可有效减少既有路基的水平位移量,且避免两钢轨存在沉降差;但路基的总沉降值会增大,且这种开挖方式需要保证开挖进度的同步性,以避免产生偏载变形。
Based on a extra large railway bridge project across existing railway lines,the 3D numerical anslysis model has been built by using FLAC3 D software,analysis and exploration of excavation depth on the influence of the subgrade. Through existing lines in one foundation pit and both side of foundation pit under different excavation depth of subgrade impact analysis,have the following conclusion:(1) Subgrade settlement and horizontal displacement increases with the increase of excavation depth,but within 10 m excavation depth,meet the specification requirements.(2) Both side of foundation pit excavation can effectively decrease horizontal displacement of subgrade,and don't have differential settlement between the two rail,but will increase the subgrade settlement. And the excavation method need to make sure that the excavation progress of synchronicity,to avoid the partial load deformation.
出处
《南阳理工学院学报》
2016年第2期102-105,共4页
Journal of Nanyang Institute of Technology
关键词
基坑开挖
既有铁路
数值分析
FLAC3D
pit excavation
existing railway lines
numerical simulation
FLAC3D
