Influence of groundwater level lowering on working behavior of composite foundation

In order to study the influences of groundwater level lowering on the working behavior of composite foundation, both applied load and groundwater level lowering for composite foundation are analyzed by numerical analysis method. Considering the interaction between composite foundation, cushion and foundation, the working behaviors of composite foundation, such as the displacement of soil and reinforced piles, skin friction distribution of pile and pile axial stress are studied fore and after groundwater lowering. The results showed that, compared with non-groundwater lowering, the settlement of foundation, including soil and reinforced pile increase, axial stress in pile enhance, pile-soil stress ratio improve in the same applied load. Increase of load acted on the foundation would promote above-mentioned phenomena. In reinforced piles, the influences of negative skin friction increase gradually, neutral point move down, downdrag caused by negative skin friction increase, skin friction along the piles develop more fully with groundwater lowering more deeper. It may be useful for the research of working behavior of composite foundation after soil settlement.