Document Type : Geotechnical Earthquake Engineering
Fasa University, Fasa
University of Tehran
Although bearing capacity of footings on top of slopes under monotonic loadings have been investigated widely so far, safety and bearing capacity of these structures against repeated dynamic loads have not been considered well enough. In this paper, lower bound dynamic shakedown theorem in its numerical form has been employed to firstly obtain bearing capacity of strip footings on top of slopes, and secondly to determine safety factor of slopes by strength reduction method subjected to repeated dynamic loads. Following a try and error procedure, factor of safety against cyclic loads were determined based on the strength reduction concept. Results indicate that bearing capacity of footings is affected by dynamic properties of both slope and the loads so that minimum bearing capacity obtained when resonant occurs. Furthermore, results show that the safety factor of slopes is extremely affected by dynamic properties of both slope and dynamic load as well. The minimum factor of safety was found to arise at resonance. Besides, findings suggest that unlike Pseudo-Static method that does not differentiate between embankments (with wide crest) and slopes, here factor of safety of slope and embankment are not the same due to their difference in dominant natural period.