ANALYTICAL APPROACH FOR ESTIMATING GROUND DEFORMATION PROFILE INDUCED BY REVERSE FAULTING IN OVERLYING SOIL

Structures at the ground surface and underground structures may be destroyed when overlying soil is significantly deformed by bedrock fault movement during an earthquake. Currently no analytical solution is available for estimation of soil deformation at the surface and subsurface that induced by faulting. Moreover, the influences of key factors on the deformation mechanism of the overlying soil are not yet fully understood. In this paper, complimentary error function is adopted and used to represent soil vertical displacement profile at different depths. A soil deformation mechanism, which consist a stationary zone, a shearing zone and a rigid body zone, is adopted. By applying reasonable boundary conditions for the deformation mechanism, a theoretical model is then developed to predict the undrained deformation of the overlying soil induced by reverse faulting of bedrock fault. The theoretical model is further verified by independent centrifuge and numerical data. Comparison between calculated data from the proposed model, measured data from the centrifuge tests and computed results from numerical simulation show that both surface and subsurface deformation can be fairly well represented by the complimentary error function. Parametric studies show that the influences of the magnitude of the bedrock fault movement on the locations of heaving deformation zone at the ground surface are not significant. Increasing in shape parameter results in a narrower zone of heaving deformation. In addition, bedrock fault with larger dip angle drives the heaving deformation zone move towards the side of bedrock hanging wall.