An experimental study of the failure process of en-echelon fault structure using the digital speckle correlation method
应用数字散斑相关方法实验研究雁列断层变形破坏过程

The failure process of en-echelon fault structure is experimentally studied and the evolution of the deformation filed during failure is inspected and analyzed using the digital speckle correlation method(DSCM).The fault structure is simulated by a marble plate with 2 parallel slits that firstly cut and then filled with gypsum.The specimens are loaded on a large-scale double-axis test machine.The DSCM system captures speckle images during the test process and then processes them to obtain deformation field.The whole failure process of the echelon fault structure is revealed by evolution of the deformation field.The result shows that the deformation is firstly localized around the fault and then the echelon area,where the two faults are interactive with each other.The failure also finally evolves in this echelon area.Moreover,the deformation field during loading is statistically studied and a quantitative C-v-value,which expresses the characteristics of deformation localization,is an indicator for the failure of the echelon fault structure.