A simplified method for optimization of foundation with irregular planar pile raft

A simplified analysis method based on that the transmission of the load in pile raft foundation is characterized by a sort of its localization. In this method, the connection between the raft slabs and the piles around the column is simulated by a cantilever beam to calculate the settlement of the pile top and, further, the bending moment of the raft slabs with finite difference method. A mathematical model of optimization design of the irregular pile raft foundation is established by considering simulta neously both the elastic supporting of the pile and the contribution of the soil around the pile. A pile raft foundation for an actual engineering project is optimized by using feasible direction method defined by active constraints with variable tolerance.