Model tests on piles with branches and plates in unsaturated silt under cyclic loads

A model test equipment was designed to study the bearing capacity and deformation behavior of the piles with branches and plates. Five cycles of circulating load on the model pile with two plates were done. By studying the collected data, the load transfer behavior, the characteristic and the variation of pressure on piles were analyzed, especially the case that the skin friction of the silt between the plates was positive or negative under different conditions. The variation of soil pressure around plates under each loading was also analyzed. It was proved that after each loading and unloading of silt a new state would be established until a stable state was reached. At last it was suggested how to design the spaces of piles and plates to assure the performance of piles.