DIAMETER-EXPANSION EXCAVATION METHOD OF CAST-IN-PLACE CONCRETE PILE WITH RIB, AND DIAMETER-EXPANSION EXCAVATOR

摘要

PROBLEM TO BE SOLVED: To provide the diameter-expansion excavation method of a rib section for a cast-in-place concrete pile with a rib belonging to the field of technique, in which a multistage bottom-expansion pile particularly increasing pull-out resistance force or bearing force is executed, and a diameter-expansion excavator used for executing the method. ;SOLUTION: The shaft-section pit 4 of the cast-in-place concrete pile is excavated completely, an axial-center fixing-combining excavated-material recovery bucket 2 is installed at the front end section of a vertical driving shaft such as a kelly-bar shaft for an earth drill. The dismeter-expansion excavator formed by mounting a diameter-expansion excavation mechanism 3 is inserted to the intermediate section of a vertical driving shaft 1, and the axial-center fixing- combining excavated-material recovery bucket 2 is made to reach the pit bottom of the above-mentioned shaft pit section and the axial-center fixing of the vertical driving shaft 1 is conducted. The diameter-expansion excavation mechanism 3 is lifted and lowered along the vertical driving shaft 1 and positioned at the place of rib excavation, and the vertical driving shaft 1 is rotated and the diameter-expansion excavation of a rib section is performed.;COPYRIGHT: (C)1999,JPO