Seismic bearing capacity of strip footing above cavities in rock masses

This paper employs an adaptive finite element limit analysis (AFELA) combined with nonlinear programming (NLP) to investigate the seismic bearing capacity of strip footings overlying cavities in rock masses that obey the generalized Hoek–Brown (GHB) failure criterion. The feasible arc interior point algorithm (FAIPA) is utilized to solve the optimization models, and a novel imprecise step search algorithm is introduced to improve the NLP convergence. Based on the self-developed AFELA procedure, the bearing capacity reduction factor R of strip footing on a rock mass has been calculated, with the results presented in tables and charts. Parametric analysis reveals that a footing centered above a cavity does not exhibit the lowest capacity, likely due to a beneficial arching effect. Failure modes associated with varying parameters are also discussed, and the results show that increasing the horizontal seismic coefficient reduces the extent of the failure zone.