METHOD, DEVICE, AND SYSTEM FOR DETECTING LIQUIDIZATION OF GROUND

PROBLEM TO BE SOLVED: To enable low-cost installation and to speedily make a reliable decision on whether or not liquidization has occurred. SOLUTION: This liquidization detecting device 100 is equipped with a seismic wave detection sensor 101 and a liquidization decision part 102. The seismic wave detection sensor 101 is equipped with a seismic wave detecting means 10, a maximum acceleration detecting means 12 which detects maximum acceleration (AMAX) on the basis of a seismic wave, and an SI value calculating means 13 for calculating an SI value (SI) on the basis of the seismic wave. The liquidization decision part 102 is equipped with a natural cycle detecting means 11 of natural period (T) of the seismic wave vibration detected by the seismic wave detecting means 10, a ground displacement detecting means 11 which detects the displacement (D) of the ground, and a liquidization decision means 15 which decides that the ground has liquidized, when the four parameter of T, D, AMAX and the SI value are all larger than threshold.