Deformation of sand foundations induced by earthquakes

This paper discusses the deformation of sand foundations during earthquakes based on the experimental results of centrifuge tests. A group of tests was conducted on two types of buildings based on both dry and saturated sand foundations. It was found that the settlement and rotation of foundations gradually built up under cyclic loading. The magnitude of deformation was found to depend on the intensity of the earthquake, the bearing pressure, and the width of the foundation. The presence of water in the foundation often led to large deformations as a result of pore pressures which reduces effective stress of the soil. The permanent deformation of a foundation after an earthquake was found to be as high as the peak deformation recorded during an earthquake.