考虑饱和-非饱和渗流的土坡极限分析  

Limit analysis of a soil slope considering saturated-unsaturated seepage

作　　者：牛文杰[1,2,3] 叶为民[2,3] 刘绍刚[4] 禹海涛[2,3] 

机构地区：[1]浙江大学水工结构及环境工程研究所,杭州310058 [2]同济大学地下建筑与工程系,上海200092 [3]同济大学岩土及地下工程教育部重点实验室,上海200092 [4]同济大学环境科学与工程学院,上海200092

出　　处：《岩土力学》2009年第8期2477-2482,共6页Rock and Soil Mechanics

摘　　要：给出了均质土坝的下游坝坡的安全系数的计算方法。均质土坝的下游坝坡有可能会通过滑裂面发生破坏。土坝中的土坡通常处于非饱和状态。非饱和土坡的安全系数计算需要考虑吸力对抗剪强度的贡献以及土坡中的非饱和渗流。给出处于饱和-非饱和渗流状态下的土坡的安全系数,有助于评价均质土坝的安全系数。下游坝坡的安全系数计算方法有:极限平衡法、上限解法和下限解法,该算法适用于非饱和土坡,且是在饱和土坡安全系数的计算方法上修正得到的。算例中非饱和土坡安全系数的计算考虑了吸力对抗剪强度的贡献。考虑非饱和渗流理论的土坡安全系数计算方法通常更加接近现场实际情况,并且对于同一坝坡,考虑非饱和渗流计算出的土坡安全系数要比饱和渗流理论计算出的安全系数大。This computing method addresses safety factor with respect to unsaturated slope of downstream homogeneous earth dam. Method to calculate safety factor of unsaturated slope is highly connected with shear strength criteria of unsaturated soil and seepage analysis of unsaturated slope. There is a potential risk for the soil slope of a downstream earth dam to burst along the sliding surface. Most slopes in earth dams are in unsaturated state. This computing method is intended to provide safety factor of a soil slope in seepage. Determining the safety factor of a slope provides information to facilitate the safety assessment of a homogeneous earth dam. This computing method covers a procedure for determining safety factor of unsaturated slope of a downstream earth dam with limit equilibrium method, lower-bound and upper-bound method. This computing method is suitable for unsaturated slope. It is revised on the method to evaluate the safety factor of a saturated soil slope. The contribution of suction to the shear strength of unsaturated soil has been considered. In an example, safety factor of a soil slope is calculated in saturated seepage theory or saturated-unsaturated seepage theory. It is found that the safety factor of a slope considered the saturated-unsaturated seepage in a slope and the suction contribution to shear strength is larger than the one only considers the saturated seepage of a slope.

关 键 词：饱和-非饱和渗流 土坡 极限分析 安全系数 均质土坝 

分 类 号：TU443[建筑科学—岩土工程]