堆土对既有高速公路桥梁桩基稳定性影响分析

Analysis of the influence of heap of soils on the deformation and bearing capacity of existing highway bridge pile foundation

以杭州某机场高速路为例,结合现场地质勘查报告和设计资料,采用Midas有限元软件建立了高架桥箱梁三维模型,在桥面上施加移动荷载,获取各种组合效应下的高架桥墩顶反力,同时采用Plaxis3D有限元软件建立桥墩-承台-桩基-地基下部结构,并将上部高架桥墩顶反力作用至下部结构,计算分析了堆土作用下的桥梁桩基变形和内力变化规律;最后依据有限元计算结果和相关规范,从单桩竖向承载力、正截面抗压、斜截面抗剪和裂缝宽度等方面,分析了堆土作用对既有高速公路桥梁桩基的承载性能的影响。

Combining with the field geological survey report and design data of an airport highway in Hangzhou,a three-dimensional model of box-girder is established using the finite element software Midas.By applying moving loads on the bridge decks,the reaction force on the top of the viaduct pier under various combined effects is obtained.Furthermore,to analyze the deformation and internal force of bridge piles foundation under heap of soils,the pier,caps,pile foundation and the substructure is simulated using Plaxis 3D,and the forces obtained from Midas are applied to the top of the viaduct piers.Finally,according to the calculated results and related specification,the influence of pile of soil on load-bearing properties of bridge piles foundation is systematically studied from the perspectives of vertical load capacity,normal section strength,shear bearing capacity of oblique section and crack width.