燃气管线保护涵基坑开挖对临近高铁影响数值仿真分析

Numerical simulation of influence of gas pipeline culvert foundation pit excavation on adjacent high-speed railway

由于城市建设与铁路事业的发展,导致临近高铁路线的工程日益增多,此类工程的基坑施工会对临近高铁产生影响,然而运营期的高铁对于变形控制极为严格。为了确保铁路运营安全,针对这种现象,以某中压燃气管线保护涵下穿大西高铁桥梁为背景,建立三维数值仿真分析模型,对基坑施工全过程进行分析模拟。得到以下结论:基坑防护桩施打结束以后,临近高铁桥墩总沉降值达到最大;"开挖至坑底"施工阶段对各桥墩竖向变形及水平变形影响最大,该阶段结束时高铁桥墩产生最大的附加水平变形和附加不均匀沉降。

Because of the urban construction and railway development, crossing phenomenon give rise to more and more adjacent-railway project. The foundation pit excavation of such projects can lead to an influence on high-speed railway close to it. Deformation control of operating high-speed railway is very strictly. To ensure the operation safety, in view of this appearance, this essay erects a 3D numerical simulation and analysis mod- el based on one mid-pressure gas pipeline culvert underpass DAXI high-speed railway bridge. And the whole construction process of the foundation pit is simulated. The following conclusions are obtained： the whole set- tlement of the adjacent pier achieves maximum when the fender pile construction comes to an end; the ＂exca- vation to the bottom＂ construction step influence the vertical and horizontal deformation most. At the end of this stage, maximum additional horizontal deformation and vertical additional uneven settlement emerge.