不同水位下降模式下非均质及各向异性边坡稳定性分析

针对水位线下降会改变坡内的水力梯度,从而导致边坡失稳问题的出现,采用极限分析法和强度折减法建立二维含水边坡,通过优化迭代确定边坡安全系数Fs,并分别与稳定性图表、有限元方法得到的安全系数进行对比,同时探究水位线下降进程、非均质性、各向异性,以及坡脚等参数对边坡稳定性的影响规律。结果表明:水位高度一定时,非均质系数增加,安全系数也随之增大;各向异性系数的增大会降低安全系数,提高边坡失稳的可能性;坡度越缓,水位高度对边坡安全系数的影响越显著;同等条件下,边坡的稳定性受各向异性效应的影响更大。分析结果为水位下降过程中边坡稳定性评估及设计施工提供借鉴。

Stability analysis of nonhomogeneous and anisotropic slopes subjected to different water drawdown modes

In view of the fact that drawdown will change the hydraulic gradient in a slope, which will lead to the instability of the slope, the limit analysis method and strength reduction method were used to establish a two-dimensional water-bearing slope model, the safety factor F_s of the slope was determined by optimization iteration, and compared with the safety factors obtained by the stability chart and the finite element method. The influences of drawdown, nonhomogeneity, anisotropy and slope angle on the slope stability were explored. The results show that when the water level keeps constant, the safety factor of the slope increases with the increase of the heterogeneity coefficient; the increase of the anisotropy coefficient will reduce the safety factor and increase the possibility of slope instability; the slower the slope, the more significant the influence of water level height on the safety factor of the slope; under the same conditions, the stability of the slope is more affected by the anisotropy. The analysis results can provide a reference to the stability assessment of slopes during the drawdown process of the water level in practical engineering.