Shaking table tests on dynamic response of coral sand foundation under buildings

With the rapid development of coral island construction, the seismic safety of coral sand foundation is particularly important. To reveal the seismic response characteristics of coral sand foundation and buildings, the shaking table tests on a three-story frame structure on liquefiable coral sand are carried out. The pore pressure, acceleration, displacement and strain are tested for different relative densities of model foundation. The test results are compared with those of the liquefiable quartz sand. The results show that the coral sand is more difficult to be liquefied than the quartz sand under the same relative density and similar particle-size distribution. The liquefaction degree of the two kinds of sand decreases with the increase of foundation depth, and increases with the distance from the buildings. Compared with the quartz sand, the liquefied coral sand model foundation still has some shear transfer capacity, while this difference gradually weakens with the increase of foundation depth. The inclination, final settlement and column strain of the model buildings on the coral sand foundation are smaller than those on the quartz sand foundation. The liquefaction properties of coral sand with different relative densities are different.