邻近堆载作用下桥梁桩基内力与变形数值分析

Numerical Analysis of Internal Force and Deformation of Bridge Pile Foundation under Adjacent Surcharge Loading

采用数值分析方法,研究堆载对邻近桥梁桩基内力与变形的影响。使用耦合欧拉-拉格朗日法建立了堆载作用下某特大桥654#桥墩桩基三维有限元模型,以桥墩轨道顶面横向位移实测值与计算值对比验证了模型的有效性。据此模型计算结果分析了邻近大量堆土情况下桩基的内力和变形特性:各桩水平位移都在1/2L附近的淤泥质粉质黏土层达到最大值;各桩1/6L~2/3L范围内桩身产生附加弯矩的最大值为210 kN·m;且在距堆载较近的桩基上部引起了负摩擦力,进而产生了581~1368 kN的附加轴力。结果表明堆载严重劣化了桩基的工作性能。可为主动防控堆载引发的墩台偏移等病害研究提供一种可行的方法。

In this paper,the influence of pile load on the internal force and deformation of adjacent bridge pile foundation is studied by numerical analysis.The CEL method was used to establish a three-dimensional finite element model of the pile foundation of a bridge.The validity of the model is verified by comparing the measured and calculated transverse displacement of the track top surface.Based on the calculation results of the model,the internal force and deformation characteristics of pile foundation near a large number of piles are analyzed:Each pile’s maximum horizontal displacement appears at 1/2 L of the pile body.In the range of 1/6L~2/3L of each pile,a large additional bending moment was generated.The upper part of the pile closer to the surcharge has a negative frictional force,which in turn produces an additional axial force of 581~1368 kN.It is obvious that the surcharging load seriously deteriorates the pile foundation.It can provide a feasible method for active prevention and control of pier deflections caused by surcharge load.