岩溶区偏心荷载下路基承载力有限元极限分析  

Finite Element Limit Analysis of Subgrade Bearing Capacity Under Eccentric Loads in Karst Area

作　　者：谭进 彭文哲 赵明华[1] TAN Jin;PENG Wengzhe;ZHAO Minghua(Geotechnical Engineering Institute,Hunan University,Changsha,Hunan 410082,China)

机构地区：[1]湖南大学岩土工程研究所,湖南长沙410082

出　　处：《公路工程》2022年第4期89-94,共6页Highway Engineering

基　　金：国家自然科学基金项目(51908208)。

摘　　要：为探究偏心荷载下路基下伏溶洞对其不排水承载力的影响,基于有限元极限分析方法建立了相关数值模型,并将数值所得结果与已有研究进行对比,验证了有限元极限分析方法的合理性。在此基础上,用一个无量纲参数N_(c)来衡量溶洞对路基承载力的影响,通过一系列参数分析深入分析了不同变量(如路基与溶洞相对位置、溶洞尺寸、荷载偏心率e/B和土体抗剪强度变化无量纲参数kB/c_(u0)等)对路基极限承载力的影响。结果表明:N_(c)随e/B、R/B(洞径)的增大而减小,随α/B(溶洞偏心量)、β/B(溶洞埋深)、kB/c_(u0)的增大而增大,其中e/B和kB/c_(u0)是影响路基承载力的关键因素。此外,以剪切耗散云图为依据,对各工况下路基-溶洞系统的破坏机理进行探究,在分析各变量影响的同时,总结了3种典型破坏模式。In this study,finite element limit analysis was adopted to investigate the ultimate bearing capacity of subgrade lying on karst caves.By comprehensive parametric studies,effect of many variables including void location,void size,load eccentricity and variation rate of soil strength on the subgrade stability were investigated.The results indicated that the ultimate bearing capacity of subgrade decrease with the increase of load eccentricity and void size;increase with the increase of horizontal offset distance of voids,void depth and variation rate of soil strength.In addition,the typical distribution of shear dissipation were summarized for deeper insight into how the failure mechanism involving with different variables.Finally,the results from this study were compared with existing studies for verification purpose.

关 键 词：岩溶区 路基承载力 有限元极限分析 偏心荷载 破坏模式 

分 类 号：U416.16[交通运输工程—道路与铁道工程]