Energy Response Characteristics of Laterally Loaded Piles

Abstract

A bounding surface plasticity p − y model is used to examine the internal energy responses of a laterally loaded pile in static and dynamic simulations. The model response is first compared with those observed in physical centrifuge tests, including monotonic and cyclic loading, in a normally consolidated fine-grained soil. Then, the model is used to examine hypothetical static and dynamic situations. The monotonic load capacities determined by the model and an upper-bound limit analysis method are in agreement with that inferred from the physical test. The work done by external loads in static conditions is principally balanced by the plastic work in the p − y springs and the elastic strain energy in the structural pile elements, which are comparable in the cases examined. The numerical model is capable of reproducing accurately the observed test structural responses as well as the characteristics of plastic energy dissipation. In a dynamic free-vibration simulation, the pile is highly damped as a result of the significant plastic energy dissipation. The simple work-hardening elastic–plastic p − y model is theoretically sound, applicable to arbitrary loading histories, and requires the same level of effort to use as traditional p − y methods.