优势流入渗与坡体变形关系研究及应用

部分降雨型滑坡的地表裂缝会随着变形的不断增加逐渐形成完整配套的裂缝体系,针对此类滑坡的降雨入渗过程,指出沿地表裂缝形成的优势通道而形成的优势流入渗主导着滑坡稳定性的恶化过程,促进变形的持续发展。系统分析了优势流入渗与地下水位升降、坡体变形之间的相互关系。在此基础上,以王家坡滑坡为典型案例,分析了优势流入渗通道形成的时空规律及对应的变形特征,发现滑坡累积位移曲线上的变形加速区间呈不规则阶跃状,并将加速区间的起点与终点定义为加速拐点和减速拐点。然后以W3监测点的实际监测资料对滑坡变形过程中的地下水升降特征进行反演并获取对应的稳定性演化规律,发现变形加速区间上的加速拐点和减速拐点与稳定性出现变化的起点和终点相吻合,依此可建立确定变形加速区间的方法,进而获取位移速率阈值。

Study and application of the relationship between preferential flow penetration and slope deformation

The cracks on the ground surface will form a complete crack system gradually with the increase of the slope deformation. In view of the rainfall infiltration process of this type of landslide, it is pointed out that the preferential flow penetration developed along the dominant channel formed along the surface crack leads to the deterioration process of landslide stability and promotes the development of deformation. This paper systematically analyzes the relationship between the preferential flow penetration, the fluctuation of groundwater level and the slope deformation. Taking the Wangjiapo landslide as the research object, the temporal-spatial deformation evolution of the dominant channel and the corresponding deformation characteristics are studied, and the starting and ending points of the irregular "step" shaped deformation acceleration interval on the cumulative displacement deformation curve are named as the "acceleration point" and "deceleration point". And then, the groundwater fluctuation rule in the process of landslide deformation is inverted and the related stability evolution rule is obtained by using monitored data of W3 monitoring points. It is found that the "acceleration points" and "deceleration points" of the deformation acceleration interval of landslide are consistent with the starting and ending points of the stability changes. The method for determining the deformation acceleration interval can be established, and then the displacement rate threshold is determined.