Abstract:
Star-shaped pile is a new type of special-section pile. It is formed by cutting five circular arcs in a circle pile. This paper aims to explore the uplifting bearing capacity of star-shaped piles. For comparison, the experimental tests on four single piles in dry sand by sand pourer construction are carried out in model tank of independent research and development. The four tested piles are the maximum ratio of perimeter and area of the five-star-shaped pile F
1,the maximum of the circumference of the five-star-shaped pile F
2,the round pile C
1 with the same section of F
2, and the round pile C
2 with the same cross-sectional area of F
2. Test results show:(1) The uplifting bearing capacity values of the pile F
1 and F
2 are basically the same. The maximum is the pile C
1. The minimum is the pile C
2. (2) The uplifting bearing capacity value of the pile C
1 is 1.73 times that of the pile F
1. The uplifting side resistance is weakened because of star-shaped section. (3) The side area of the pile C
2 is 0.66 times that of the pile F
2,but its uplifting bearing capacity is 0.8 times of the pile F
2. So it shows again that the star-shaped section weakens the uplifting side resistance. However, the uplifting bearing capacity value of the pile F
2 is 1.25 times that of the pile C
2,which shows that the circular section changing into the star-shaped section can improve the uplifting bearing capacity to some extent.(4) The distribution between uplifting side friction and displacement is hyperbolic. The side limiting friction is reached only by a little displacement.