Study on bearing capacity characteristics and practical application of composite ground pile foundation

Abstract

The composite foundation of piles with improved soil is proposed to resistant the intensive seismic horizontal force. A soft or loose ground at the shallow depth is improved by the cement mixing method. Piles are constructed through the improved soil mass in order to transmit vertical loads to bearing stratum. The laboratory horizontal loading test was performed to investigate the behaviors of the composite foundation. Moreover, the simulation analysis by 3-D FEM analysis was carried out. It is shown that the horizontal bearing capacity of the composite foundation was much greater than that of the piles without the ground improvement, and the improved soil mass and piles worked as a mass. We examined the application of the simple design spring model of the composite foundation (beam-spring model) with the results of the in-situ horizontal loading test that we carried out before and this laboratory test.