Pseudo-dynamic bearing capacity factor for strip footings considering Coulomb failure mechanism

In earthquake prone areas, computation of bearing capacity under seismic condition is very important for the safe design of foundations. In previous years, attempts were made to use pseudo-static approach and a very few investigators used pseudo-dynamic approach to compute the seismic bearing capacity. Using the limit equilibrium method, the values of bearing capacity factor for surface strip footings resting on cohesionless soil are obtained by considering simple planar rupture surfaces under seismic conditions. The seismic forces are computed using the modified pseudo-dynamic method in which dry cohesionless soil is assumed as visco-elastic medium subjected to harmonic base shaking. Width of the footing, seismic wave velocities and angular frequency of the input motion influence the value of seismic bearing capacity. Comparisons of the proposed method with available theories in the seismic case are also presented to highlight the advantages of the present method for the design of surface strip footings considering seismic waves.

Keywords:

bearing capacity , limit equilibrium method , pseudo-dynamic approach , strip footings , visco-elastic medium , Coulomb failure mechanism