Deformation Intensity Distribution and Zoning of Seismic Deformation Fields in Near-Fault Areas

Abstract

To describe the distribution law of the degree of stratigraphic deformation in the cross-fault region under the influence of fault dislocation, the concept of deformation intensity is introduced, and a computational model of the coseismic deformation field in the cross-fault region is established based on the dislocation model theory and the rich fault inversion parameters in the Sichuan–Tibet region. According to the deformation law of a typical earthquake in Yushu, key sections and parameters are selected for analysis. The results show that the maximum dislocation of the deformation field in the cross-fault region decays from the fault rupture to the surface, and the deformation influence extends from the upper edge of the fault to the surface, with an overall funnel-shaped symmetric distribution. The deformation intensity is elliptically distributed in the vertical profile. The maximum deformation of the strata across the fault within the burial depth of the structure is fitted to fill the lack of the existing statistical equation of coseismic deformation without considering the burial depth factor. Finally, the strata are zoned by deformation intensity according to the degree of deformation to provide a reference for the seismic protection of structures in the near-fault area.