Settlement prediction model for pile group

The settlement behavior of pile foundation is an important index for construction and design especially for bridges built on poor hydrologic and geologic conditions. Because the main of Sutong Bridge is situated in the tideway of Yangtze River, the maximum variable load caused by tidal range is about 224MN. It acts on pile foundation circularly, and affects the settlement of the pile group foundation. In order to set up precise and brief settlement model considering tidal fluctuation and consolidation process, Biot's consolidation equation by finite element method is used to compute settlement under different load of superstructure and tide level respectively. Hyperbola constitutive model and nonlinear coupling model are adopted to give parameters of intensity and permeability of foundation soil respectively. Goodman element is adopted to simulate contact interface between piles and soil. Key parameters are back analyzed according to observed settlement during construction of pile cap. The prediction model of settlement is verified to be effective and rational by comparing predicted settlement with observed value during the construction of tower.