地震与水压力耦合作用下岩质边坡倾覆解析方法  

Analytical Method for the Overturning Stability of a Rock Slope under the Coupling Action of Earthquakes and Water Pressure

作　　者：张彦君[1] 年廷凯[1] 郑路[2] 刘凯[1] 宋雷[3] 

机构地区：[1]大连理工大学土木工程学院及海岸和近海工程国家重点实验室,辽宁大连116024 [2]四川大学灾后重建学院,四川成都610065 [3]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221008

出　　处：《地震工程学报》2015年第2期428-433,438,共7页China Earthquake Engineering Journal

基　　金：国家自然科学基金项目(No.51179022;No.41474122);地质灾害防治与地质环境保护国家重点实验室基金项目(SKLGP2010K005)

摘　　要：以往对平面破坏模式的岩质边坡稳定性评价,主要关注潜在滑坡体在自重、坡体内静水压力和地震荷载耦合作用下沿破坏面的抗滑稳定性,并未涉及各类外荷载作用线不通过潜在滑体重心而引起的绕坡趾倾覆稳定性。针对这一问题,提出地震与张裂缝水压耦合作用下的岩质边坡倾覆稳定性解析方法,基于力矩平衡原理推导出岩质边坡抗倾覆稳定性系数的一般表达式;通过深入的变动参数比较研究,探讨张裂缝水压和地震荷载对抗倾覆安全系数的影响,认为水压是控制岩质边坡倾覆破坏的决定性因素,而地震荷载处于次要因素,其在一定程度上增加或减小抗倾覆稳定性。在此基础上建立不同参数组合下的岩质边坡抗倾覆稳定图,为工程技术人员快速评估饱水岩质边坡地震倾覆稳定性提供直接依据。The failure modes of rock slopes can be classified into five types：plane,wedge,circular,toppling,and buckling failures.These failure modes mainly depend on the lithological characteristics of the rock,properties of the discontinuities,and degree of weathering.Generally,rock slope stability analysis under the plane failure mode mainly focuses on the sliding stability of a potential sliding mass subjected to gravity,hydrostatic stress in the slope,and seismic loads.However,there exists the possibility of overturning failure around the toe of slopes because of the fact that all loadings do not act through the centroid of the sliding mass.This failure mode is completely different from common topping failure,which involves the rotation of columns or blocks of rock about the fixed base,mainly occurring in anti-dipping layered rock mass slopes with steep dipping discontinuities.Thus,the existing methods for the stability assessment of the five common failure modes are no longer applicable,and a new method to determine the overturning failure is required.Note that although this overturning failure mode has not been observed and recorded,it is not impossible under extreme rainfall conditions coupled with the strong ground motion in Southwest China.Aiming to resolve this issue,this study presents an analytical approach for the stability analysis of overturning rock slopes.Considering the combined loadings mentioned above,the generalized analytical formula for the anti-overturning stability factor is derived based on the moment equilibrium theory.Based on the definition of the safety factor against overturning for earthretaining structures,an anti-overturning stability factor is defined as the ratio of the resultant resistant moments to resultant driving moments.A comparative analysis by the variation of parameters was implemented,and the effects of the hydrostatic stress and seismic load on the anti-overturning stability factor of rock slopes are discussed.For a steep rock slope with a tension crack,the stability factor

关 键 词：岩质边坡 倾覆破坏 静水压力 地震荷载 解析方法 

分 类 号：TU45[建筑科学—岩土工程]