Rainfall infiltration is considered as one of the most significant factors triggering slope instability as a number of slope failure occurrences have been documented during or immediately after a rainfall. The rainfall-induced slope instability is governed by a complex interaction of topographical, hydrological and geological conditions of the slopes. Hence slope inclination is vital in determining slope stability under rainfall. Although studies have been carried out to investigate the mechanism of rainfall-induced slope failure, limited compelling experimental studies have been conducted on the factors influencing the initiation of slope failure. In this study, instrumented model slopes were subjected to artificial rainfalls to investigate the effects of the slope inclination on slope stability, and a validated numerical model was developed using the test results from the instrumented model slopes. The outcomes of the study prove that the slopes become more susceptible to sudden collapse during rainfall as the slope angle increases. Further, the results highlight that when the slope inclination is 1.2 times greater than the friction angle of the soil, the failure is initiated by the loss of soil suction, and when it is smaller than or equal to 1.2 times the friction angle of the soil, the failure is initiated by the positive pore water pressure developed at the toe of the slope.

降雨入渗被认为是触发边坡失稳的最重要因素之一，因为在降雨期间或降雨之后已经记录了许多边坡破坏事件。降雨引起的边坡失稳取决于边坡的地形，水文和地质条件的复杂相互作用。因此，斜坡倾角对于确定降雨条件下的斜坡稳定性至关重要。尽管已经进行了研究以研究降雨引起的边坡破坏的机理，但是对影响边坡破坏开始的因素进行了有限的令人信服的实验研究。在这项研究中，对仪器模型坡度进行了人工降雨，以研究坡度对边坡稳定性的影响，并使用仪器模型斜率的测试结果开发了经过验证的数值模型。研究结果表明，随着降雨角度的增加，降雨过程中斜坡更容易突然坍塌。此外，结果表明，当坡度大于土壤摩擦角的1.2倍时，破坏是由土壤吸力的损失引起的，而当坡度小于或等于土壤摩擦角的1.2倍时，则破坏开始。 ，破坏是由斜坡的脚趾处产生的正孔隙水压力引起的。