Abstract
Simple theoretical equations in order to estimate the stress of pile and to evaluate the lateral load sharing ratio between piles and raft were derived for seismic design. First, this paper shows how to estimate the ground displacement caused by raft friction, second, shows how to do the differential equation of deflection of pile considering its ground displacement. Some approximations and assumptions are employed. First, soil deposit is homogeneous. In this case, a ground displacement is derived theoretically. Second, about interaction among piles-subsoil-raft, the influences from pile to pile and from pile to raft are ignored. This assumption is valid from the analytical results. Third, the ground displacement caused by raft friction is expressed as an exponential function or polynomial function. This approximation is effective to do the differential equation of deflection of pile considering ground displacement. These equations were compared with the lateral loading tests and numerical analysis on piled raft foundation subjected to lateral loading.
