METHOD FOR DECREASING NEGATIVE FRICTION OF PILE IN SOFT SOIL LAYER

摘要

PURPOSE:To decrease negative friction by contraction of an external coating film, by a method wherein the external plastic coating film applied around the outer peripheral surface of a pile is cut in pieces in the longitudinal direction after driving in of the pile. CONSTITUTION:A pile 1, forming a bituminous layer 2 on its outer peripheral surface and further being applied with an external plastic coating film 3 thereon, is driven into the earth. Then, contractile force of the file is released by cutting the external plastic coating film 3 into pieces in the stretched direction of the pile 1. The cutting of the film is made by sending an electric current to a Nichrome wire placed between the bituminous layer 2 and the external plastic coating film 3. By this method, deterioration of the negative friction effect to be occurring because of the plastic layer after the driving-in of the pile can be prevented, and reduction of design load can be materialized thereby.