Rapid assessment of regional superficial landslide under heavy rainfall

Abstract

In order to establish a rapid method for regional slope stability analysis under rainfall, matric suction and seepage force were taken into account after obtaining explicit solution of infiltration depth. Moreover, simplified analysis model under 3D condition was put forward based on identification and division of slope units, as well as modification of sliding direction of each column. The result shows that explicit solution of infiltration depth is of good precision; for the given model, safety factors without taking seepage force into account are 1.82–2.94 times higher; the stagnation point of slope angle is located approximately in the range of (45°, 50°); the safety factor changes insignificantly when wetting front is deeper than 2 m; when matric suction changes in the specified range, the maximum variations of safety factor are less than 0.5, which proves that matric suction plays an insignificant role in maintaining slope stability compared to the slope angle and infiltration depth. Incorporated with geographic information system, a practical application of regional slope stability assessment verifies the applicability of the proposed method.