斜坡软弱地基路堤工程特性的数值模拟  

Numerical Simulation on the Engineering Behavior of Embankment over Sloped Weak Ground

作　　者：刘晋南[1] 蒋鑫[1] 邱延峻[1] 

机构地区：[1]西南交通大学高速铁路线路工程教育部重点实验室,四川成都610031

出　　处：《中国铁道科学》2011年第2期8-14,共7页China Railway Science

基　　金：国家重点基础研究发展计划项目(2008CB425802);中央高校基本科研业务费专项资金资助项目(2009QK05)

摘　　要：在斜坡软弱地基上修筑填方路堤容易出现滑塌失稳、侧向变形过大等重大工程事故。运用非线性有限元及剪切强度折减法,模拟路堤分步建造的施工力学行为,建立斜坡软弱地基在路堤自重荷载作用下的数值分析模型,从土体变形和稳定安全性2方面研究表层软弱层、地面横坡对路基结构工程特性的影响。结果表明:斜坡软弱地基不能被简单视为斜坡地基和软弱地基的等权重线性叠加;表层软弱层、地面横坡可加剧结构的侧向位移、竖向沉降,改变潜在滑移面的形态,导致路堤结构稳定性降低;实际工程中应高度重视下坡脚方向侧向位移和表层软弱层的处理;运用非线性有限元法结合剪切强度折减法,能同时进行斜坡软弱地基在路堤自重作用下变形与稳定性分析。Major engineering accidents such as slump, large lateral deformation occurred when people constructed fill embankment on sloped weak ground. Using nonlinear finite element method and strength reduction method, simulating the mechanical behaviour of the embankment of staged construction, building numerical analysis model of embankment over sloped weak ground which is only loaded with gravity, analyzing the relationship between deformation and stability on soil body, combining the results of geotechnical centrifuge model experiment, this paper comprehensively demonstrates the effect of the weak surface layer and lateral slope of ground on the engineering behavior of embankment over sloped weak ground. Research results show that sloped weak ground can not be simply regarded as the linear superposition of sloped ground and weak ground which are not equal-weight. Weak surface layer and lateral slope of ground amplify the lateral displacement and vertical settlement, and change the shape of the potential slip plane. These factors lead to reduce the stability of embankment, and in engineering people need to attach great importance to the lateral displacement of toe and the treatment of weak surface layer. The nonlinear finite element method with strength reduction method can synchronously analyze the deformation and stability of embankment over sloped weak ground which is only loaded with gravity.

关 键 词：斜坡软弱地基 填方路堤 强度折减法 土体变形 稳定安全性 

分 类 号：U213.11[交通运输工程—道路与铁道工程] TU751.4[建筑科学—建筑技术科学]