| 摘要 |
PROBLEM TO BE SOLVED: To provide a construction method for press-in steel pipe pile having the tip as an open end and a close end by clarifying the torque value which can be determined the most easily in the work execution management and the relation between the N-value expressing the strength of ground and the supporting force Qu at the tip, allowing to select adequate heavy machinery and to discriminate a supporting layer for obtaining a bearing power conforming to the design and limiting the embedding length of the pile tip portion to a minimum. SOLUTION: In a work method for a press-in steel pipe 1 which is equipped with a spiral impeller vane 3 and is pressed into the ground by rotation, a torque value required during the execution of work is calculated by the following equation from the ground strength (N-value) obtained from the results of a ground survey: Tt=a.N.Dpm-b.Lt.Dp. The bearing power (Qu) at the tip is calculated by the following equation from the torque value acting to the heavy machinery during work, and the penetration continuance or penetration completion of the rotary press-in steel pipe pile 1 is controlled depending on the Qu value, Qu=X.Dpn.Tt.
|
