Dynamic centrifuge model tests on piled raft foundation and evaluation of sectional forces of piles

Abstract

This paper offers dynamic centrifuge model tests on a piled raft foundation supporting a plate-shape building on soft clayey ground. The dynamic tests were conducted in 50 g field in order to investigate the lateral load sharing ratio of piles and sectional forces on the piles during large earthquakes. The model ground was made of wet tamping loam to reproduce the soft clayey ground with a shear wave velocity from 100 m/s to 200 m/s. The vertical load sharing ratio of piles was about 20 % before and after the shaking and also during the shaking. On the other hand, the lateral load sharing ratio of piles was considerably small about 10 % even in a large earthquake. In addition, the shear force and bending moment acting on the piles were evaluated by simplified equations based on Mindlin’s solution which is derived from making some approximations and assumptions. The experimental results were compared to the calculated values and the lateral load sharing between piled and raft was discussed