This research project will investigate the behavior of subsurface rock subjected to dynamic loadings such as is generated by earthquakes or by explosions. The focus will be on porous rocks, specifically sandstone and tuff, saturated with fluid. Conditions of fracture, large displacement, and fluid transport will be examined experimentally with varying confining pressure representing different depths below the surface. This research has application in the area of earthquakes hazard assessment and mitigation, as well as in the field of excavation and rock comminution (breakage).