Bearing Capacity of Stone Column Reinforced Foundation Subjected to Inclined Loadings

This paper presents a numerical study of the effect of concentric inclined loading on the undrained bearing capacity of stone column group. The stone columns are arranged in a group of four columns with toe sitting on a hard stratum. A rigid square footing is placed on top of the stone columns. The soft soils and the stone columns are modelled as linear-elastic perfectly plastic material with non-associated flow rule. In this study, the area replacement ratio varies from 0.2 to 0.5 and the load inclination angle varies from 0° to 45°. The numerical results are first compared with the limit analysis for both non-reinforced foundation and a stone column reinforced foundation under vertical load. Subsequently, an analysis is carried out for cases with inclined load. Based on the results, a prediction equation is developed to estimate the modified bearing capacity factor for stone columns with inclined loads. The effect of embedment depth on bearing capacity is also investigated. The failure mechanism for stone column group is identified and found to extend deeper and larger compared to non-reinforced foundation. The inclined load has caused the failure surface to be altered and tilted.