Analysis on load transfer for large area composite foundation with rigid piles and cushions

A method to analyze load transfer was presented for composite-foundation with rigid pile and cushion by means of iterative process.A single pile with surrounding soil in large scale pile group was taken as a column system with interaction force.A single pile was analyzed by load transfer method,while interaction was analyzed by iterative process.The pile-soil-cushion-cap interaction and the nonlinearity of load transfer for layered soil could be considered conveniently in this method.The correctness of this method was validated by a practical example.Factors influencing the stress ratio of the pile and soil were studied including the cushion thickness,cushion modulus,pile spacing,soil modulus,etc.