以甘肃省黑方台地区滑坡为研究对象,在非饱和土特性试验基础上,根据地下水位的监测资料建立典型斜坡饱和-非饱和渗流模型,模拟斜坡灌溉作用后裂隙对斜坡渗流场的影响,研究斜坡裂隙效应对斜坡稳定性的影响。结果表明:灌溉水迅速沿裂隙下渗,形成渗流优势通道;裂隙附近土体的孔隙水压力迅速升高,导致其局部形成饱和区域;随着裂隙数量的增加,饱和区域明显增大,且裂隙的位置越靠近台塬边缘,对斜坡边缘的孔隙水压力及基质吸力影响越显著。综合斜坡稳定性分析结果可知:裂隙发育位置越靠近台塬边缘,斜坡稳定性越差;而裂隙数量的增加对于斜坡的稳定性影响更大,且裂隙对于斜坡稳定性的影响是一个短时间过程。夯填裂缝是控制滑坡发生的有效途径。
Based on the tests of unsaturated soil characteristics and monitoring data of groundwater levels, this paper takes the landslides in the Heifangtai area in Gansu Province as the research objects, builds a typical slope saturated-unsaturated seepage model, and imitates the influence of fissures on the slope seepage field after the slope irrigation. The influence of the fissures effect on slope stability is studied. The results show that the irrigation water rapidly infiltrates along fissures and it leads to the pore water pressure to rise around the fissures, and the slope stability shows a linear decrease during ten days after irrigation. It is the short-term effect of influence of the fissures on the slope stability. The location of the fissures is much closer to the slope edge and the quantity is much larger. The influence on slope stability is much greater and it is easier to cause landslides along the crack surface. The punning and filling fissures are the efficient path of the control of a landslide.