DETECTOR AND METHOD FOR DETECTING FLOATING OF REINFORCEMENT CAGE, AND CONSTRUCTION METHOD FOR UNDERGROUND CONCRETE STRUCTURE

PROBLEM TO BE SOLVED: To provide a simply-constituted detector capable of detecting the floating of a reinforcement cage when concrete is placed in a hole wherein the reinforcement cage for a method for constructing an underground concrete structure is arranged. SOLUTION: This detector comprises: a wire 140, the leading end of which is attached to a leading end of a reinforcement 22A constituting the reinforcement cage; a winding mechanism 120 which applies an upward tensile force to the wire 140 by applying a turning force to a winding frame 122 by means of a spiral spring 121; and an alarm mechanism 130 which permits the supply of electric power to a buzzer 133 and an LED lamp 134 from a battery 135, because the winding frame 122 for the wire 140 is turned and a magnet 136 gets closer to a reed switch 131, when the reinforcement cage floats. COPYRIGHT: (C)2010,JPO&INPIT