The optimization design of Piled raft foundation for substation building in US code

In order to get a more safety and economic foundation, finite element method was performed for a piled mat cap and piled strip cap by the software of STAAD. Through the finite element analysis, plate distribution region of bending moment and shear stress were researched; meanwhile, considering the compatibility of deformation of element plate, how to chose the design value of plate stress was researched. The result showed that: single plate value is not representative, average of value of 9 plates (3x3 array) is close to the fact. Strip cap is better than mat cap both from the moment value and shear value of plate element in this project; strip cap was recommended due to its remarkable economic benefit.