SEISMIC BEARING CAPACITY OF SPREAD FOUNDATIONS ON SLOPING GROUND

The seismic bearing capacity factors of spread foundations on sloping ground have been theoretically investigated. The pseudo-static approach was used, and the seismic forces consisted of a horizontal load applied to the foundation and the inertia of the soil mass. The upper-bound method of limit analysis was also employed. A non-symmetrical failure mechanism was proposed. The mechanism was composed of a triangular active wedge, a logarithmic spiral shear zone and a passive wedge. The case of embedded foundations on sloping ground was considered. The shear transfer coefficient was introduced to calculate the seismic bearing capacity of spread foundations with variable shear transfer. The validity of the results from the present analysis was confirmed by comparing with other investigators' results. Finally, the lowest upper-bound solutions of the seismic bearing capacity factors were presented in the form of design charts for practical use. The seismic bearing capacity factors reduce considerably with the increase of horizontal seismic coefficient. In addition, the magnitudes of bearing capacity factors decrease further with the increase of slope inclination.