Geomechanical model tests were performed on wet sand in a glass-walled fault rest box to investigate the relationship between the propagation of fault rupture and the shapes, and the locations of failure surface. Three CCD cameras were used to capture the process of the surface rupture development and to analyze the displacement field by using the digital speckle correlation method. Based on the experiment, it was observed that when the thrust fault moved upward, the sediment layers formed a shear zone. The smaller the angle of faults, the wider of shear zone was formed in the sediment layer. The vertical displacement and the movement velocity of the fault are greater, the deformation of sediment layer is wider, and the deformation of the soil layer is stronger. When the vertical displacement of the fault exceeds 40% of the soil thickness, the deformed soil will form tension crack at the surface of the sediment. For a fixed sediment thickness with a fixed vertical displacement, the width of the deformation bands decreased with the increased fault movement velocity. However, the degree of deformation and failure will become more intense under a faster fault movement. Experimental results of this study on fault angle, fault movement velocity and sediment thickness is an important issue in further studies on ground deformation and failure characteristics of a thrust fault.
