椭球状溶洞上方路基稳定性数值分析  

Numerical Analysis of Highway Subgrade above an Elliptical Karstic Rock Cavern

作　　者：林智勇[1,2] 戴自航 

机构地区：[1]福州大学岩土工程研究所,福州350108 [2]福建工程学院土木工程学院,福州350108

出　　处：《土工基础》2013年第6期51-54,64,共5页Soil Engineering and Foundation

基　　金：福建省自然科学基金资助项目(2011J01308);福建省交通规划设计院委托项目

摘　　要：以某岩溶区高速公路为例,利用三维数值模拟,采用稳定安全系数、潜在破坏面(剪应变率及塑性区的贯通)作为失稳判据,分析了溶洞顶板厚度、顶板形式及路基坡脚与溶洞水平距离等因子对椭球状溶洞上方路基稳定性及路基顶面与基底面沉降的影响。结果表明,不同条件下,路基沉降均呈漏斗状,且随着顶板厚度的增大,路基顶面及基底面沉降逐渐变小,沉降漏斗变小,稳定安全系数变大,达到一定值后趋于稳定;椭球状溶洞路基失稳破坏形式分别以顶板岩层的拉裂破坏及路基填土的剪切破坏为主,而水平顶板则以冲剪破坏形式为主;对于椭球状溶洞,顶板安全厚度远小于同等条件下水平顶板的安全厚度。This paper presents the numerical analysis results of the stability of highway subgrade above an elliptical karstic rock cavern. The factor of safety, development of the potential failure plane, which defined as the connection of the plastic zones and the shear strain rates, are used as the failure criteria. The thickness of the overburden material, shape, horizontal distance of the embankment toe to the cavern on the stability of the highway subgrade above the elliptical karst rock cavern are investiga ted. The results indicate that the settlement shape of the subgrade is a cone type and the magnitude of the settlement is reduced with the increase of the overburden material. The factor of safety will also increase and tends to stable. The failure patterns of the subgrade above the cavern are： tensile failure of the overburden rock and shear failure of the embankment above. For ellip soid karstic rock cavern, the roof thickness was less than that for horizontal cavern roof.

关 键 词：数值模拟 椭球状溶洞 路基 稳定性 潜在破坏面 

分 类 号：U416[交通运输工程—道路与铁道工程]