A Calculation Method of Stress and Settlement in Composite Foundation with Rigid Piles under Embankment Load Considering Soil Arch Effect

The embankment,composite foundation reinforcement area improved by rigid piles and the underlying layer is considered as a whole.Selecting a single pile reinforced unit located in the embankment center as the research object,based on preliminary design of the pile-soil load-sharing ratio and pile skin friction distribution,Mindlin and Boussinesq union method is used to calculate the stresses and settlements of pile and inter-pile soil.According to the conditions that the displacements at the junction of the embankment and the composite foundation surface are continuous,the distribution of skin friction is obtained using iterative method.The established coupled model of pile-soil load-sharing and pile-soil interaction of composite foundation has a rigorous theoretical basis,which solved the problem that MB union method needs to pre-known pile-soil stress ratio and the distribution form of pile skin friction.The results of pile-soil load-sharing and pile-soil settlement are all consistent with the project monitoring data,which verified the validity of the model.