VERTICAL ACCURACY MANAGEMENT METHOD OF UNDER-GROUND PILED COLUMN

PROBLEM TO BE SOLVED: To provide a vertical accuracy management method of an under-ground piled column capable of sufficiently managing vertical accuracy when the under-ground piled column is built in a pile hole in the case that the under-ground piled column is not cylindrical or even in the case that the under-ground piled column is long.SOLUTION: A vertical accuracy management method of an under-ground piled column includes: a step of installing a cylindrical measurement pipe 14 on an outer surface of the under-ground piled column 1 so as to be approximately parallel to a column core of the under-ground piled column 1 and installing a target plate 15 on an end side of the measurement pipe 14 on ground; a step of inserting the under-ground piled column 1 into a pile hole 2 with the measurement pipe 14 and supporting an upper end part of the under-ground piled column 1 by a frame 11 for the under-ground piled column installed on ground; a step of installing a laser plummet instrument 17 right above the measurement pipe 14 on ground and radiating laser light vertically below through the measurement pipe 14 by the laser plummet instrument 17; and a step of measuring deviation of the under-ground piled column 1 by sighting a point of the laser light on the target plate 15 and correcting plumbing of the under-ground piled column 1 based on the measured deviation.