钻孔灌注桩基础变形对既有线影响的模拟分析

Simulation and Analysis to Impact of Bored Pile Foundation Deformation on Existing Railway

新建高速铁路跨越既有线施工过程中,存在诸多工程问题,包括基坑开挖、现浇箱梁支架钻孔灌注桩基础变形等对既有线的影响等。采用三维有限元方法模拟分析跨越既有线连续梁现浇支架的基础灌注桩施工的"缩颈效应"、支架基础变形引起的"牵连作用"等对既有线的影响。针对计算结果及工程经验,建议灌注桩施工期间采取限速等措施,以确保既有线行车安全。

In the newly construction of high-speed railway,many engineering problems exist when the plan line is across the existing highway,such as foundation pit excavation,deformation of cast-in-place box girder scaffold bored pile foundation,etc.In this paper,based on an actual project example,threedimensional finite element method is adopted to analyze the necking effects of continuous beam foundation bored piles,and implicated effects of scaffold foundation deformation.Calculation results indicate that more attention should be paid to the effects,and in order to ensure the traffic safety,the running speed of train on existing highway must be limited.