库区水位下降作用下非饱和土坡稳定性分析

Stability Analysis of Unsaturated Soil Banks During the Fall of Water Level

针对库区及河道沿岸岸堤和边坡由于水力作用侵蚀和水位变动形成折线形土坡,影响边坡稳定性的问题,基于卢宁提出的非饱和有效应力理论,运用极限平衡方法,采用对数螺旋滑动面建立的平衡方程求解安全系数,开展了土坡不同几何参数和土性参数下水位变动对边坡稳定性影响的变化规律研究.通过对比非饱和与饱和土边坡安全系数计算结果,进一步揭示参数反演中不应忽略非饱和吸力作用对边坡稳定的贡献,分析水位缓降与骤降不同工况下可以得到危险水位高度,对指导工程有一定参考价值.

Due to the influence of hydraulic erosion and water level fluctuation,the folded-line slopes are produced by the embankments and slopes along the reservoirs and rivers. Based on the strength theory of unsaturated soil proposed by Lu Ning and the limit equilibrium method,the log- spiral failure surface derived from variational analysis is employed to calculate the factor of safety. We investigate the influences of water level fluctuation during the different geometrical parameters of slope and soil properties. We find the contribution of unsaturated suction to slope stability is considered in parameter inversion,comparing the safety factor analysis of unsaturated soil slope with that of saturated soil slope. Hazardous water level height is obtained by analyzing the different working conditions of water slow drop and sudden drop,which has a certain reference value for guilding the engineering.