FOOT PROTECTION STRUCTURE OF EXISTING PILE BASED ON BORED PRECAST PILING METHOD

摘要

PURPOSE: To prevent destruction by tensile strength and enhance a vertical supporting force by forming the tip of an existing pile at the depth of embedment in the shape of a cone of at most a specified angle or a conical trapezoid and injecting a foot protection liquid into an excavated hole and pressing a pile thereinto. ;CONSTITUTION: The tip 4 of an excavated hole 3 is formed in the shape of a cone whose conical angle θ is at most 120 degrees or a conical trapezoid. A foot protection liquid, such as cement milk is injected into the hole, thereby forming a foot protection part 1. Then, an existing pile 2 is pressed in and cured. A vertical component of a ground reaction force, which acts on the tip of the pile as compression stress, maintains an area inside the tip of the pile in a compression stress state and prevents the generation of tensile stress. This construction makes it possible to enhance the structural strength of the pile and obtain a high vertical supporting force.;COPYRIGHT: (C)1996,JPO