Seismic bearing capacity of foundations on slopes

The effect of pseudo-static horizontal earthquake body forces on the bearing capacity of foundations on sloping ground has been assessed using the method of stress characteristics. Two failure, mechanisms were considered, based on the extension of the characteristics from the ground surface towards the footing base from either one side or both sides. The magnitude of N-gamma based on the both-sides failure mechanism, for smaller values of earthquake acceleration coefficient (alpha(h)), has been found to be significantly smaller than that obtained using the single-side mechanism; however, in the presence of alpha(h) the both-sides mechanism becomes kinematically inadmissible in many cases for higher values of phi. Only the single-side mechanism was found statically admissible for computing the bearing capacity factors N-c and N-q on sloping ground. All the bearing capacity factors reduce considerably with increase in ah for various ground inclinations.