降雨渗流及干湿循环作用下红砂岩顺层边坡稳定性分析  

Stability analysis of red sandstone bedding slope under rainfall infiltration and dry-wet cycling

作　　者：曾胜[1] 李振存[1,2] 韦慧[1] 郭昕[1] 王健[1] 

机构地区：[1]长沙理工大学交通运输工程学院,长沙410004 [2]长沙理工大学公路工程省部共建教育部重点实验室,长沙410004

出　　处：《岩土力学》2013年第6期1536-1540,1559,共6页Rock and Soil Mechanics

基　　金：国家西部交通建设科技项目(No.2011318824350);公路工程省部共建教育部重点实验室(长沙理工大学)开放基金资助项目(No.kfj110104);教育部新世纪优秀人才支持计划资助项目(No.NCET-11-0977)

摘　　要：针对红砂岩顺层岩质边坡稳定性问题,建立顺层岩质边坡力学模型,对降雨渗流条件下边坡受到的力学作用进行了计算;选取典型结构面,通过室内干湿循环试验,分析了结构面强度参数衰减规律;综合考虑降雨渗流及结构面强度弱化,对降雨渗流及干湿循环综合影响下红砂岩顺层岩质边坡稳定性进行了分析,获得了边坡稳定性衰减变化规律;通过炎汝高速公路边坡稳定性监测对理论计算结果进行了验证。结果表明,边坡受到的水力作用与后缘张拉裂隙充水高度呈正比;干湿循环作用下,结构面黏聚力呈幂指数形式衰减,内摩擦角呈二次函数衰减;边坡稳定性与后缘张拉裂隙充水高度呈线性关系,而与干湿循环呈指数关系,且干湿循环对边坡稳定性影响比后缘裂隙充水高度大;在降雨渗流及干湿循环综合作用下,边坡稳定性系数降低了约66%,较考虑单一影响因素有了大幅度降低;边坡稳定性监测结果与理论计算结果吻合较好,进一步证明了理论计算结果的正确性。According to the stability of red sandstone bedding rock slope, a mechanical model is established; the hydraulic effect on slope under rainfall infiltration is calculated. Selecting a typical structural plane, through dry-wet cycling test, strength attenuation law of structural plane is analyzed. Comprehensive considering the rainfall infiltration and dry-wet cycling, the stability analysis of red sandstone bedding slope is analyzed; and the stability attenuation law is achieved. At last, by slope stability monitoring of Yan-Ru expressway, theoretical calculation results are verified. The results show that the hydraulic action is proportional to the water height in rock crack. Under dry-wet cycling, the cohesion of structural surface decays in the form of power function; and the internal frictional angle decays in the form of quadratic function. The slope stability has linear relationship with water height in rock crack and exponential relationship with dry-wet cycling. The dry-wet cycling has a greater influence on slope stability than that on water height in rock crack. Under the combined action of rainfall infiltration and dry-wet cycling, slope stability coefficient reduces by about 66%. Compared with considering single influence factor, the stability coefficient attenuation range has a great increase. The slope stability monitoring results agree well with theoretical results, the validity of theoretical results is further proved.

关 键 词：降雨渗流 干湿循环 红砂岩顺层边坡 稳定性分析 衰变规律 

分 类 号：U416.1[交通运输工程—道路与铁道工程]