| 摘要 |
PURPOSE:To increase the resistance of a ready-made concrete pile head against the horizontal force of the ground by enlarging the diameter of the broken part of the pile head in such a way that the lowering of the strength of the pile due to the releasing of prestress, the development of cracks, etc., resulting from the breaking of the pile head is compensated for. CONSTITUTION:A prestressed ready-made concrete pile (PG pile) 1 is penetrated to a given depth under the ground, and the ground around the PG pile 1 is excavated. Then the head of the pile is broken so as to expose part of PG steel bars 2 for the fixing bars of footing. And, a steel pipe 3 having an approriate length and a larger diameter than that of PG pile 1 is inserted into the surrounding space of the PG pile 1 and then soil and sand between the steel pipe 3 and the PG pile 1 are removed to form an annular aperture 4 around the PG pile 1. Then,concrete is placed into the annular space 4 and the diameter of the broken part of the pile head is enlarged. thus, bending moment by horizontal force encountered at the time of earthquake can be reduced. |
