Lateral hysteretic behavior of an aluminum model pile in saturated loose sand

Pushover tests of an aluminum model pile in saturated loose sand were conducted at the National Center for Research on Earthquake Engineering of Taiwan (NCREE). The test data are analyzed to investigate the lateral hysteretic response of the pile. The pushover curves of the pile show a significant loop of hysteresis. Polynomial functions of fourth degree with constraints are applied to curve fit the measured curvature data for deducing the pile responses and the corresponding relationships of the soil reaction vs. the lateral pile displacement (i.e. p-y curves). The p-y curves obtained also exhibit significant hysteretic response. The backbone curves of the p-y curves can be expressed by the secant subgrade reaction modulus, which is a function of depth and lateral displacement. The hysteretic locus of the p-y curves can be simulated by the backbone curves with the restoring force model of Masing type to give consistent pushover curves to the measured.