Stress Distribution in the Vicinity of Right Strike-Slip Fault, a Numerical Approach

Abstract

When fault exist in the formation, the local stresses in the shallow depth will be affected by presence of slip or displacement on fault and topography. If the trace of fault is not straight, the stress distribution near fault become more complicated. This feature is studied numerically using boundary element method. Related to this problem, a numerical procedure of 2 and 3 dimensional coupled fictitious stress method and displacement discontinuity method which takes joint element into consideration is adopted. A sinusoidal fault trace is used to modelize the non-straight strike-slip fault in 2 dimensions, while a sinusoidal fault plane buried in the middle of symmetrical valley is used as numerical model study in 3 dimensions. This model is then applied to the Mozumi Sukenobe fault as field case study. Our finding on local stress near fault is consistent with field measurement. If the far field stress is defined in proportion to depth, our finding also predicts that the applied far field stress in the Mozumi Sukenobe fault is in compression with σ_Ho oriented at -40゜ from fault strike and the magunitudes of far field stress components are σ_vo〓ρgh, σ_Ho〓0.74σ_vo and σ_ho〓0.5σ_vo.