Abstract:
In order to study the load-bearing properties of taper-cylinder pipe-piles with holes, three model piles with different taper sizes and one model pile without holes were tested by emloying indoor models and numerical simulations. The distribution rules of pile load-settlement, pile axial force and pile side friction resistance during the process of static pile sinking were investigated. The test results show that the total settlement of the combined pipe piles in the taper without hole 1/70 (No.1), taper 1/80 (No.2), 1/70 (No.3) and 1/60 (No.4) are 19.41 mm, 17.49 mm, 16.15 mm and 14.07 mm, respectively. And the total settlement of pile foundation can be effectively controlled by changing the taper angle of taper-cylinder pipe piles with holes The vertical compressive ultimate bearing capacity of the combined pipe piles including No.1, No.2, No.3 and No.4 are 4800 N, 3600 N, 4200 N and 4800 N, respectively. Combined pipe piles of No.3 and No.4 have 116.67% and 133.33% increase in bearing capacity compared with the combined pipe pile of No.2. And combined pipe pile of No.3 has a 12.5% reduction in bearing capacity than combined pipe pile of No.1. The side friction force increases first and then decreases along the pile direction, and the maximum value appears in the tapered section of the pile. That’s because the compression area of the soil is in extended due to the increased the taper angel in the tapered pile section and the holes in the column-shaped pile section. Therefore, the water content of the soil is rapidly reduced, alongside improved interaction effect between the pile and the soil, which results in the full play of lateral frictional resistance of each pile section and promotes the vertical compressive bearing capacity of the single pile. The results have certain guiding significance for the application, optimal design of taper-cylinder pipe-piles with holes.