Seismic bearing capacity of footings in c-Φ soil by using a non-associated flow rule

摘要

Limited investigations have been reported in the literature for finding out the seismic bearing capacity of foundations. Also, in order to find out the seismic bearing capacity of foundations, mostly the soil mass has been assumed to follow an associated flow. In general, frictional soils do not follow the associated flow rule strictly. In this paper a plane strain lower bound limit analysis technique in combination with the finite element and nonlinear programming is used to investigate the effect of considering a non-associated flow rule on the seismic bearing capacity of a strip footing. The bearing capacity factors (N_c, N_q and N_γ) with changes in soil friction angle (Φ) and seismic acceleration coefficient (k_h) for different values of dilative coefficient (η) are computed for rough strip footings. The analysis clearly reveals that, the bearing capacity factors under the seismic loading decrease drastically with a decrease in the magnitudes of η.