A multi-block model and a corresponding computer program have been developed which predict the kinematics of landslides. Furthermore, a unique event for studying different models simulating the triggering and movement of landslides is the 2008 Wenchuan earthquake in the mountainous region in Sichuan Province of China, which caused a large number of rapid landslides. The purpose of the paper is two-fold: (a) to propose and incorporate into the multi-block model constitutive relations predicting soil response along slip surfaces, and (b) to apply the multi-block model with the constitutive relations at landslides triggered by the Wenchuan earthquake. The proposed constitutive equations predict the shape of the shear stress-displacement response measured in ring shear tests. In the application, four landslides caused by the Wenchuan earthquake were considered. Only in one of these landslides
the shear resistance-displacement response along the slip surface has been measured in laboratory tests. At this landslide, the triggering and movement of the landslide was predicted. In the other landslides, back analyses were performed and it was observed that the multi-block model predicted reasonably well the final configuration of all slides. In addition, as the measured and back-estimated total friction angle of all landslides was less than 18°, and the materials along the slip surface were sandy, it is inferred that some, or all of the slip surface during these slides was sheared in an undrained manner and excess pore pressures generated during sliding played a key role in the triggering and movement of these landslides. Concluding, the paper (A) proposed and validated a multi-block
constitutive model which can be applied to predict the triggering and movement of earthquake-induced slides and (B) by analyzing four landslides of the 2008 Wenchuan earthquake, it concludes that some, or all of the slip surface during these slides, was sheared in an undrained manner and excess pore pressures generated during sliding played a key role in the triggering and movement of these landslides.
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