库水位缓变作用下高陡边坡变形及稳定性分析

Analysis on Deformation and Stability of High and Steep Slope under Reservoir Water Slow Change

库水位缓变时,对边坡岩体在无裂隙、有裂隙、增大渗透系数、单独降水及升水等5种条件下,进行了流固耦合数值模拟试验,研究升、降水全过程条件下坡面裂隙及渗透系数对边坡岩体变形位移、近似蠕变及稳定安全系数的影响效应,以及单独升、降水条件下渗透系数对稳定安全系数的影响规律。结果表明,有近似平行坡面裂隙时,对坡面位移影响较大,对稳定安全系数几乎无影响;增大渗透系数时,对位移影响较小,下部1/3高度内观测点位移表现最敏感;升、降水全过程时,渗透系数越大,各阶段稳定安全系数越小;单独升水时,渗透系数越大,稳定安全系数越小,且裂隙的存在不影响此规律;单独降水时,渗透系数越大,稳定安全系数越大。

The coupled fluid-solid numerical simulations are carried out for slope rock mass under five conditions of no fissures, with fissures, permeability coefficient increasing, water falling and water rising in case of reservoir water slow change. The effects of slope fissures and permeability coefficient on deformation displacement, approximate creep and stability safety factor of slope rock mass during the whole process of water level fluctuation as well as the permeability coefficient on stability safety factor in separate falling or rising process are studied. The results show that, （a） the existence of approximate parallel slope fracture has a relatively large influence on slope displacement, but has almost no influence on stability safety coefficient; （b） the increase in permeability coefficient has a relatively smaller influence on slope displacement, and the displacement of observation points within 1/3 height in the lower part is the most sensitive; （c） the greater permeability coefficient of rock mass at each stage means smaller stability safety coefficient in whole process; （d） in separate rising process, the greater permeability coefficient means smaller stability safety coefficient, and the existence of approximate parallel slope fracture has no influence on this law; and （e） in separate falling process, the greater permeability coefficient means larger stability safety coefficient.