Physical modeling on failure mechanism of locked-segment landslides triggered by heavy precipitation

Physical modeling is an effective method for studying the failure process of locked-segment type landslides, whose stability is governed by the locking section along the potential slip surface. In this study, a series of large-scale laboratory tests were conducted using specific flume test equipment. Three slope models with different types of locked segment were tested simultaneously: a slope without a locked segment (S1), a slope with an anti-tipping locked segment (S2), and a slope with a retaining-wall-like locked segment (S3). The effects of the three locking-section configurations on the failure time and deformation behavior were investigated under the same rainfall conditions. The displacement of several characteristic observation points along the slopes and the pore-water pressure in the slopes were recorded using a laser scanner and pore-water pressure sensor; the initiation and evolution of cracks were captured by a high-resolution camera. Analysis of the monitoring data and the observations from the tests shows that the slope-crest settlement and pore-water pressure changes may be used to identify the type of locked segment of natural slopes.