考虑边坡效应的铁路桥台桩基力学行为分析  

Mechanical Behavior of Railway Abutment Piles Considering Slope Effect

作　　者：蔺鹏臻[1,2] 武发辉[1] 杨子江[2] 孙理想[2] 

机构地区：[1]兰州交通大学甘肃省道路桥梁与地下工程重点实验室,甘肃兰州730070 [2]兰州交通大学土木工程学院,甘肃兰州730070

出　　处：《中国铁道科学》2014年第2期32-37,共6页China Railway Science

基　　金：铁道部科技研究开发计划项目(2012G013-H);长江学者与创新团队计划项目(IRT1139);甘肃省杰出青年基金资助项目(1210RJDA009);中国博士后科学基金资助项目(2012M521815)

摘　　要：以位于黄土高边坡上的某铁路桥梁为例,采用有限元软件ANSYS,建立考虑材料和桩土接触非线性影响的边坡—桥台—桩基系统力学分析模型,研究边坡—桥台—桩基系统在地震时无车和有车通过工况下的力学行为。研究结果表明,对处于高陡边坡上的桩基础桥台,边坡水平抗力对桩基的受力影响较大,受水平地震和边坡推力的综合作用,桩基靠边坡一侧越近,其竖向位移和正应力越大。工程算例计算结果表明,边坡外侧桩基的位移和应力可达内侧桩基相应部位位移和应力的6倍多;对于多层的土质边坡,桩基的位移和应力在土层分界处存在突变,桩基在分层部位存在受力不利区域,设计中应考虑该部位受力的特殊性。Taking a railway bridge located on loess slope for example,a whole systematic model including slope,abutment and pile foundation was built using finite element software ANSYS.The nonlinear material characteristics and nonlinear contact between piles and soil were considered.The mechanical behaviors of slope-abutment-pile foundation system were studied under the conditions of train passing and non-train passing during earthquake.The results show that,for the abutment with pile foundation on high and steep slope,the stress of pile foundation is more influenced by the horizontal resistance of slope.With the combined effect of horizontal earthquake and slope thrust,the nearer is the pile foundation to the slope,the greater is its vertical displacement and normal stress.The calculation results of an engineering example show that the displacement and stress of the pile foundation on the outer side of the slope are six times more than the inside ones.For multi-layered soil slope,there is an unfavorable mechanical region on the layered part of pile foundation because the displacement and stress change drastically on strata boundary.In design,it＇s necessary to take these special mechanical behaviors into consideration.

关 键 词：桩基础桥台 力学行为 黄土边坡 边坡抗力 地震 

分 类 号：U443.21[建筑科学—桥梁与隧道工程]