Displacement characteristics of pile groups with varying rigidity under axial load

A series of physical simulation experiments for pile groups with varying rigidity and those with uniformly distributed piles under static axial load were done,and the test results were analyzed and compared.It was indicated that for the displacement distribution type of the pile group with varying rigidity the displacement of the side piles was larger than that of middle piles,this was quite the contrary of uniformly distributed piles.The total settlement increased slightly and differential settlement decreased markedly.Increasing the length of middle pile could increase the bearing capacity both of the pile groups and soils under the pile cap for varying rigidity pile groups,indicating that the bearing capacity of the side piles was latent in uniformly distributed piles.The shaft friction developed along the lower part to the middle of the pile in pile groups,different from that of single pile.The less the pile spacing,the more obvious this trend.