Meso-behavior of single pile subjected to vertical load

Based on the experiment results for a sigle pile,a three-dimensional numerical analysis model was established by the secondary development of particle flow program.Characteristics under vertical loading such as load-bearing,load transfer,soil displacement around pile,soil stress and porosity changing regularity of single pile,were studied.Results show that the shaft resistance of single pile developed first than tip resistance and a shaft resistance weakening zone exists in the lower part of pile.The distribution of shaft resistance was consistent with that of pile side normal stress.It could also be found that the contact force on pile body increases gradually with pile depth the contact force,on pile side directs obliquely downward,and variation trend of soil porosity remains consistent with that of soil vertical stress.The particle flow numerical method enhances the recognition on meso-behavior of single pile.