Field Test and Numerical Simulation on Bearing Capacity of Squeezed Branch Pile in Transmission Line

  • Wang DEHONG
  • Zhao XIAOPAN


By applying static load tests and the finite element analysis method, this study assesses the load-bearing performance and load transfer mechanism of squeezed branch piles. This study also compiles data and discusses findings about the distribution of field displacement, the development of a plastic zone in the soil, and the influence of branch quantity and horizontal load on the vertical bearing capacity. The results show that the axial force of the squeezed branch pile changes obviously at the site of the squeezed branch. Additionally, this study identifies the sequenced effects of frictional resistance; the displacement patterns of the soil around the pile, particularly below the branch and pile tip; the minimum center distance between piles in a group, which should be greater than 1.5 times the branch diameter; and the location of plastic strain in the soil below the branches and pile tip. The data reveal that the vertical bearing capacity of squeezed branch pile is 16 to 30% higher than that of normal pile under the same conditions; furthermore, the vertical bearing capacity of squeezed branch pile increases as the number of branches and horizontal load increase. Considering geological engineering conditions and loading requirements, it is advisable to identify an optimum branch quantity for the specific bearing stratum; in this case, the optimum branch quantity was 1 to 3.