膨胀土裂隙对渠坡稳定的影响分析

Analysis of influence of expansive soil fissure on canal slope stability

根据地质编录资料,介绍了南水北调中线工程南阳段膨胀土渠坡裂隙的基本特征,分析了膨胀土中裂隙对渠坡稳定的影响,并在滑动面组合形式、拉裂缝位置和指定滑动面搜索3个假定条件下,通过正交试验,分析了滑动面倾角对渠坡稳定影响的主次因素。结果表明,裂隙的规模、裂隙面形态和填充情况可以采用滑动面的抗剪强度来反映,缓倾和中倾滑动面对渠坡稳定影响较大,倾向坡外的缓倾角和中倾角长大裂隙是渠坡失稳的主控裂隙。

According to geological logging data, the basic fissure characteristics of expansive soil canal slope of Nanyang sec-tion of Middle Route Project of South-to-North Water Diversion is described and the influence of expansive soil fissure on the canal slope stability is analyzed. Meanwhile, under the assumed conditions of sliding surface combination form, tension fissure location and sliding surface search, the priority of influential factors of sliding surface dip angle to canal slope stability are ana-lyzed by orthogonal test. The analysis results show that the fissure scale, fissure surface morphology and fissure filling can be ex-pressed by anti-shear strength;gently low-angle and moderate dip angle sliding interfaces have larger influence on the canal slope stability, and if the low-angle dip and moderate dip angle fracture orientation is the same as the canal slope＇s, the canal has a higher landslide chances.