Failure of an under-dip shale slope and its response under excavation conditions

A landslide occurred in the cut slope located in Chongqing Xi railway station, this slope belongs to a shale under-dip slope and has a complex failure mechanism. Some on-site investigations have been made to explore the deformation characteristics of this slope and structural geology analyses and outcomes of geological investigations in-situ are firstly described. Subsequently, the discrete element method has been employed in simulations to elucidate the deformation behavior exhibited by under-dip slopes under the long-term influence of gravity and material deterioration. The simulated deforming patterns have proven to be in strong agreement with the actual deformation at each stage. The results suggest that sliding, buckling and toppling can occur on the studied slope in the deformation process. Moreover, the progressive failure process of the slope during unloading excavation has also been simulated by the discontinuum mode UDEC. The obtained deformation and stress distribution of the slope have proven to well-match the field measurements, which verifies the practicability of the UDEC model. In addition, some reinforcement measures have been suggested and verified in the UDEC models.