Evaluation of seismic active earth pressure using the concept of soil arching

The evaluation of seismic active earth pressure is a classical problem in geotechnical earthquake engineering. The earth pressure distribution is idealized as linear in conventional theories, but this is not valid in reality. Utilizing the concept of soil arching, the present study attempts to evaluate the seismic active earth pressure on an inclined rigid retaining wall that supports a horizontal cohesionless backfill. By considering the planar failure surface and pseudo-static seismic forces within the failure domain, an analytical formulation is proposed to determine the optimum rupture surface and maximum seismic active earth pressure. It is observed that the soil arching effect influences the stress distribution behind the wall due to the presence of wall roughness. The normalized stress distribution throughout the depth of the backfill is found to be curvilinear, contrary to the conventional theories. It is primarily influenced by soil-wall interface properties, wall geometry and seismic inertial forces. Further, the point of application of seismic active thrust depends on various input parameters and tends to ascend towards the ground surface as seismicity and wall roughness increase.