不同降雨条件下花岗岩残积土边坡稳定性研究

Stability of Granite Residual Soil Slopes Under Different Rainfall Conditions

降雨诱发边坡滑坡是世界上最为普遍的地质灾害,为减少相关灾害的发生,以苍南县某边坡为案例,采用Flac3D软件建立了三维应力—渗流—变形耦合的边坡计算模型,分析了不同降雨强度、降雨时长下,边坡土体饱和度、边坡水平位移和塑性区的变化以及边坡安全系数时变规律。结果表明:随着降雨时间的增加,边坡坡面的饱和度由中部向底部发展,逐渐达到饱和状态;在暴雨工况下,边坡斜坡中下部的水平位移最大,达到2.51 cm;在长时间降雨的情况下,边坡的破坏形式逐渐由张拉破坏转为剪切破坏;在暴雨工况下,边坡安全系数下降最快,24h后达到1.189,低于标准值,导致边坡失稳。研究成果为类似降雨情况下花岗岩残积土边坡的稳定性研究提出了参考。

Rainfall-induced slope landslide is the most common geological disaster in the world.In order to reduce the occurrence of related disasters,taking a slope in Canglan County as a case study,and a three-dimensional slope calculation model coupling stress-seepage-deformity was established using Flac 3D software.The changes in slope soil saturation,horizontal displacement of slopes,and plastic zone,as well as the time-varying law of slope safety factor under different rainfall intensities and duration,were analyzed.The results show that with the increase in rainfall duration,the saturation of the slope surface develops from the middle to the bottom,gradually reaching saturation;under heavy rainfall conditions,the maximum horizontal displacement of the middle and lower parts of the slope reaches 2.51 cm;under long-term rainfall conditions,the failure mode of the slope gradually changes from tensile failure to shear failure;under heavy rainfall conditions,the slope safety factor decreases the fastest,reaching 1.189 after 24 hours,which is lower than the standard value,resulting in slope instability.The research results provide references for the research on the stability of granite residual soil slopes under similar rainfall conditions.