Modelling of pile foundations retrofitting strategies against seismically induced lateral spreading

Abstract

Experience from earthquakes and centrifuge models have shown the great importance of the shallow nonliquefiable soil in increasing the forces and moments imposed on the pile cap and pile foundations subjected to liquefaction-induced lateral spreading. A series of centrifuge tests were conducted to study the great importance of the shallow nonliquefiable soil in increasing the bending response of the pile foundation. A promising rehabilitation approach of existing foundations is to replace the shallow soil in a trench around the pile and pile cap by a soft material that will yield under constant lateral soil forces. Seven centrifuge experiments are performed to study lateral spreading and its effect on single pile foundations. Retrofitted and non-retrofitted pile tests in three-layer soil systems, with and without a mass above the ground, are preformed. All centrifuge tests are conducted at the 100 g-ton RPI centrifuge, using the inclined laminar box and model piles as research tools. The specific objectives of this study are accomplished mainly through the centrifuge experiments and corresponding interpretations and comparisons.