| 摘要 |
PURPOSE:To provide a pile which is highly endurable to moment produced during earthquake, by a method wherein a section, ranging from the upper end of a pile to a specified depth in a ground, where pile head restraining moment is decreased to zero, is reinforced by a outer shell steel pipe, and prestress is introduced throughout the overall length of a pile. CONSTITUTION:A section, ranging down to a depth of pi/4beta(beta=(KhB/4EI)<1/2>, (wherein Kh is the coefficient of ground reaction force in a horizontal direction, B is outer diameter of a pile, E is the coefficient of elasticity of concrete, and I is secondary moment of equivalent cross section), where pile head restraining moment, produced by a horizontal force during earthquake, is decreased to zero, is defined as a necessary reinforcement section. An outer shell steel pipe 3, having length being long enough to allow reinforcement of the section, is mounted to the upper part of the pile 1. A PC steel rod 6 is inserted throughout the overall length of the pile 1, and prestress is exerted. This prevents the pile 1 from being broken by bending moment during earthquake. |
