METHOD OF EXCAVATING HOLE WITH SPREAD BOTTOM BY MEANS OF EARTH DRILLING PROCESS AND DEVICE THEREOF

摘要

PURPOSE:To provide the accurate shape of a pile with a spread bottom, by a method wherein an excavating device is lowered in an excavated hole as the device is monitored by a depth display device in which depth display at a reference point is reset at zero, and after it is confirmed that the excavating device is lowered to a given depth, unfloding blades are unfolded for excavation. CONSTITUTION:An excavating device for the spread bottom part of a pile with a spread bottom is lowered in an excavated hole 11 as the device is monitored by a depth display device 30 which has function to set depth display at the reference point, arbitrarily determined, of the excavated hole 11 to zero. After the depth display device 30 ascertains that the excavating device is lowered to a depth, where a spreading bottom is excavated, with unfolding blades 63 unfolded, the spread bottom part is excavated through rotation of a bucket 60. When a case 61 is full of excavated earth, the unfolding baldes 63 are folded and the unfolding blades are lifted up to bedrock to discharge the earth.