不同降雨条件下高边坡的稳定性分析

为了研究不同降雨强度下雨水入渗对加固前后边坡的稳定性。以山西省吕梁市离石区某矿区边坡为例，通过PLAXIS有限元软件对该边坡进行渗流与应力耦合计算，根据该地记录的降雨量，分析了不同降雨强度下边坡孔隙水压力的变化规律，边坡的破坏趋势，预应力锚杆内力变化以及边坡安全系数的变化。研究表明：降雨强度越大，边坡的负孔隙水压力消散的速度越快，雨水入渗速度越快，且在相同计算时间内入渗深度也越深；边坡发生的破坏形式在降雨阶段往往浅层滑动，降雨结束后，雨水继续下渗，边坡的潜在滑动面逐渐过渡为深层滑动；在相同降雨条件下，各级边坡锚杆内力增量都会大幅提升，且越靠近下级边坡的预应力锚杆内力增量越大；增加预应力锚杆加固边坡可有效提高边坡的稳定性且减小降雨对边坡稳定性的影响。

Stability Analysis of High Slope Under Rainfall Based on PLAXIS

In order to study the stability of slope before and after reinforcement under different rainfall intensities. Taking the slope of a mining area in Lishi District, Luliang City, Shanxi Province as an example, the seepage and stress coupling calculation of the slope is carried out by using PLAXIS finite element software. According to the rainfall recorded in the area, the variation law of pore water pressure, the failure trend of the slope, the change of internal force of prestressed anchor and the change of safety factor of the slope under different rainfall intensities are analyzed. The results show that the higher the rainfall intensity is, the faster the negative pore water pressure dissipates and the deeper the infiltration depth is, and the deeper the infiltration depth is in the same calculation time; The failure mode of the slope is often shallow sliding in the rainfall stage, after the rainfall, the rainfall continues to infiltrate, and the potential sliding surface of the slope gradually transits to deep sliding; Under the same rainfall conditions, the internal force increment of anchor bolts at all levels of slope will increase significantly, and the closer to the lower slope, the greater the internal force increment of prestressed anchor bolts; Adding prestressed anchor can effectively improve the stability of the slope and reduce the impact of rainfall on the stability of the slope.