地震荷载作用下非饱和土边坡三维极限承载力研究  

Three-dimensional Limit Bearing Capacity Analysis of Unsaturated Soil Slope Under Seismic Loads

作　　者：易舜 陈光辉 YI Shun;CHEN Guanghui(Hunan Provincial Traffic Construction Quality and Safety Supervision and Administration Bureau,Changsha,Hunan 410116,China;School of Civil Engineering,Central South University,Changsha,Hunan 410075,China)

机构地区：[1]湖南省交通建设质量安全监督管理局,湖南长沙410116 [2]中南大学土木工程学院,湖南长沙410075

出　　处：《公路工程》2024年第2期61-68,共8页Highway Engineering

基　　金：湖南省交通科技项目(202238)。

摘　　要：研究旨在对地震荷载作用下非饱和土边坡稳定性进行分析。为了考虑地震荷载时间效应、边坡放大效应及土体阻尼特性的影响,采用修正拟动力法对边坡动力响应进行描述。采用考虑基质吸力影响下非饱和土广义黏聚力和饱和土摩擦角定义非饱和土剪切强度参数。基于三维离散破坏模型,采用极限分析上限法构建了地震荷载作用下非饱和土边坡三维极限承载力分析模型,通过已发表文献结果验证了所提出模型的有效性。最后,提供了非饱和土边坡三维极限承载力设计图表。研究结果表明:①与二维破坏模型相比较,所提出三维破坏模型能实现对边坡稳定性更为准确的评估;②忽略非饱和土剪切强度参数影响往往导致边坡稳定性评估结果偏于保守。The aim of this study is to analyze the stability of unsaturated soil slope under seismic loads.To consider the impact of time effect,slope amplification effect and soil-damping property,the modified pseudo dynamic approach is adopted to describe the dynamic response of slopes.The shear strength parameters of unsaturated soil are defined by the generalized cohesion of unsaturated soil with considering the influence of matric suction and friction angle of saturated soil.Based on the three-dimensional discretized failure mechanism,a three-dimensional limit bearing capacity analysis model of unsaturated soil slope under seismic loads is conducted using the upper-bound limit analysis method.The effective of the proposed model is validated by results from published work.Finally,design charts of three-dimensional limit bearing capacities of unsaturated soil slope are provided.The results show that:①compared with two-dimensional model,the proposed three-dimensional model can provide more accurate assessment of slope stability;②neglecting the influence of shear strength parameters of unsaturated soil often leads to conservative estimations of slope stability.

关 键 词：地震荷载 非饱和土边坡 三维极限承载力 三维离散破坏模型 极限分析上限法 

分 类 号：U416.14[交通运输工程—道路与铁道工程]