ON THE INFLUENCE OF TENSILE FAILURE ON THE FORMATION OF A DAMAGE ZONE IN THE VICINITY OF DYNAMIC SHEAR ALONG A FAULT

Abstract

To construct adequate computational models for the preparation of earthquakes, it is important to use correct estimates of the properties and dimensions of the fault damage zone, where the material has  increased fracturing and permeability, and reduced elastic wave propagation velocities. The article  presents the results of numerical modeling of the process of formation of a disturbed zone during  the dynamic propagation of an earthquake rupture. In this case, both shear and tensile failure of rocks were considered. It is shown that the overall pattern of rock destruction strongly depends on the depth of the rupture. With the parameters of the environment and the stress field used in the calculation, at a depth of more than ~ 9 km, lithostatic stresses completely block the destruction by tensile. At depths less than ~6 km, avulsion is the main mechanism of rock failure.