CAST-IN-PLACE CONCRETE PILE

摘要

PURPOSE: To prevent destruction attributable to tensile stress, and enhance a bearing power in the vertical direction by forming the tip of a pile hole whose tip is expanded on the bottom in a conical shape of at most a specified angle, a conical trapezoid or substantially hemi-spherical (egg like) shape. CONSTITUTION: An expanded bottom 3 is installed to a shaft 2 of an excavated hole while a cone angleθof a tip 4 is formed at 120 deg. where concrete is filled up, thereby forming a concrete pile 1. the tip 4 may be shaped up like a conical trapezoid or a substantially hemi-sphere. A direct component of a ground reaction which acts on the tip of the pile as a compression stress keeps the end area of the pile in a compression stress state, thereby preventing the generation of a tensile stress and protecting the tip area from being destructed by the tensile stress. This construction makes it possible to enhance structural strength and obtain a high vertical bearing power.