| 摘要 |
PROBLEM TO BE SOLVED: To provide a joining structure of a steel pipe that can be compatible with a large rotation torque of a rotary pile work method, and constitutes a rational rotary pile considering the positive rotation and reverse rotation of the rotary pile.SOLUTION: A joining structure between a lower steel pipe 3 and an upper steel pipe 5 constituting a rotary pile 1 related to the present invention includes: a first outside joint pipe 9 attached to an upper end of the lower steel pipe 3; a second outside joint pipe 11 attached to a lower end of the upper steel pipe 5; and an inside joint member 13 for joining the first outside joint pipe 9 with the second outside joint pipe 11 while bringing the upper end surface of the first outside joint pipe 9 into abutment with the lower end face of the second outside joint pipe 11. The first outside joint pipe 9 comes into abutment with the second outside joint pipe 11 through joining end faces (joining end face 15, joining end face 17) having two or more spiral slopes (spiral slope 15a, spiral slope 17a) becoming the direction that both are separated in the vertical direction when the rotary pile 1 rotates positively. The inside joint member 13 serves as resisting that the first outside joint pipe 9 is going to be separated from the second outside joint pipe 11. |
