Seismic response of rigid-drainage pile-superstructure-quay wall system subjected to lateral spreading

Many examples of earthquake damage show that liquefied lateral spreading is the main cause of pile foundation failure. Rigid-drainage piles installed two drainage grooves with plastic drainage plates are a new type of liquefaction-resistant pile that can take into account the bearing capacity and drainage function. In this paper, a series of 1-g shaking table tests were carried out to analyse the seismic response of a rigid-drainage pile-superstructure-quay (RSQ) wall system subjected to lateral spreading. Three levels of earthquake intensities, including small earthquakes (peak ground acceleration, PGA=0.05 g), moderate earthquakes (PGA=0.1 g), and large earthquakes (PGA=0.2 g), were investigated. The improvement in the anti-liquefaction performance of the rigid-drainage piles was comparatively analysed. Moreover, the influences of far-field and near-field ground motions were also discussed. The experimental results showed that rigid-drainage piles could effectively reduce the liquefaction degree and the horizontal flow of the sand stratum. In addition, the internal force and displacement of the superstructure built on drainage piles were small. The observations of the influence of far-field and near-field ground motions indicated that the seismic response of near-field ground motion was more significant than that of far-field ground motion, but the effect of far-field ground motion could not be disregarded. The results of these tests could provide useful information for the design of rigid-drainage pile groups in a typical pile-superstructure-quay wall system.