Probabilistic bearing capacity of strip footing on reinforced soil slope

Abstract

The probabilistic bearing capacity of the strip footing placed on the edge of a reinforced cohesionless soil slope is computed by combining lower bound finite element limit analysis method with anisotropic random field modelling and Monte Carlo simulation technique. Friction and dilation angle of purely cohesionless soil are considered as log-normally distributed random variables. The mean value of the bearing capacity factor Nγ reduces with the increasing randomness of the soil friction angle for particular values of correlation length in the horizontal and vertical directions. At smaller correlation lengths, the mean Nγ values of unreinforced and reinforced slopes are always lower than the deterministic values. However, the difference reduces with the increasing values of correlation lengths. At a higher correlation length, the deterministic and probabilistic mean values become almost equal. With the increasing value of correlation lengths and factor of safety, the failure probability of the bearing capacity factor associated with the reinforced slope reduces. Failure mechanisms of unreinforced and reinforced slopes obtained from the deterministic and probabilistic analysis are illustrated.