Experimental investigation of reverse fault rupture propagation through cohesive granular soils

Naturally occurring dry cohesionless soil is rarely found in urban areas; however, previous studies on surface fault rupture propagation using physical modeling has usually concentrated on dry cohesionless soil. In this investigation, the effects of cohesion on fault rupture propagation through granular soil were studied. Physical models were developed in which inherent cohesion was produced by adding different percentages of clay to the sand. A dry test also was conducted for comparison. The results show that changes in cohesion affect all aspects of the behavior of faulting, including fault rupture propagation, fault scarp at surface and required displacement at bedrock for outcropping. It was found that the vertical fault displacement required for outcropping (h0∕H) increased as the percentage of clay increased.