Edinburgh Napier University

  Evidence from field case studies, as well as from experimental and theoretical research, suggest that the detrimental effects of seismic liquefaction on the performance of surface foundations on level ground may be mitigated in presence of a non-liquefiable soil crust of adequate dimensions and shear strength. This paper refers to the case where the non-liquefiable crust is not natural, but it has been artificially created by ground improvement, and focuses upon the effect of the size (thickness and width) of the improved area on the seismic settlement and the degraded post-seismic bearing capacity of the foundation. Size effects are evaluated numerically, starting from the reference case of an infinitely extending improved soil crust and progressing to more realistic cases of ground improvement of gradually decreasing lateral extend of improved soil. Guidelines are provided for a cost-effective design of ground improvement, based on the rate of seismic settlement reduction with increasing dimensions of the improved ground.