陡坡桥梁桩基水平承载特性分析

Analysis of horizontal bearing characteristics of bridge pile foundation on steep slope

本研究以某陡坡桥梁桩基为研究对象,建立了倾斜荷载作用下桩基的有限元模型,分析了荷载加载顺序、荷载类型、桩身弹模和土体主要力学特性等因素对陡坡桥梁桩基水平承载特性的影响规律。研究结果表明:施加竖向荷载会增加桩顶水平位移和桩基内力,竖向荷载对桩顶水平位移的作用机理应同时考虑“P-△”效应和桩周侧向的土压力效应。本研究提出了坡顶荷载-桩身最大弯矩关系的三阶段特征,揭示了土体黏聚力、内摩擦角和弹性模量均与桩顶水平位移呈递减关系。该研究成果可为山区陡坡桥梁的设计与施工提供参考。

In this study,a steep-slope bridge pile foundation was taken as the research object,and a finite element model of the pile foundation under the action of inclined loads was established.The influences of load sequence,load type,elastic modulus of pile body,and main mechanical characteristics of soil on the horizontal bearing characteristics of pile foundation of a steep-slope bridge were analyzed.The results show that the horizontal displacement of the pile top and the internal force of the pile foundation increase when the vertical load is applied.The mechanism of vertical load acting on the horizontal displacement of pile top should consider the effect of"PΔ"and the effect of lateral soil pressure around the pile.The three-stage characteristics of the relationship between the load on the slope top and the maximum bending moment of the pile body are proposed.The exponential variation rule of improving soil cohesion,internal friction angle,and elastic modulus to reduce horizontal displacement of reduce is revealed.The results can provide a reference for the design and construction of steep slope bridges in mountainous areas.