EVALUATION METHOD OF ROD DIAMETER OF CURED ROD-LIKE BODY BY CAST-IN PLACE CEMENT BASED CURED MATERIAL AND VIBRATION MEASURING INSTRUMENT

摘要

PROBLEM TO BE SOLVED: To longitudinally provide a hole of an upper end opening on a cured rod-like body made from a cement based cured material and to provide a method for evaluating a rod diameter by a peak frequency obtained by hitting inside the hole and a measuring instrument suitable for the execution of this method.SOLUTION: This method is a method for evaluating a rod diameter of a cured rod-like body C made from a cement based cured material cast-in place in a vertical cave B, and includes: a step of drilling a boring hole B in the rod-like body; a step of inserting a hitting device 8 with an acceleration sensor into the boring hole; a step of hitting a predetermined place of an internal surface of the boring hole using the hitting device; a step of measuring a time history waveform of the cured bar-like body by the cement based cured material of a hitting place; a step of obtaining a peak frequency of the vibration of the cured rod-like body by the cement based cured material by subjecting the waveform to Fourier transformation: and a step of evaluating the rod-diameter of the hitting place of the cured rod-like body by the cement based cured material from this peak value.