INTER-TWO-POINT DISPLACEMENT GAGE BY OPTICAL FIBER, AND REMOTE MONITORING METHOD FOR DISPLACEMENT BETWEEN TWO POINTS

PROBLEM TO BE SOLVED: To provide a technique capable of detecting quickly and properly a displacement amount of a structure all the time or in a disaster such as earthquake, in particular, a displacement amount between two points, even in a prescribed remote site. SOLUTION: An abutment or a pier 37 is arranged in a lower position between one girder 35 and the other girder 36, in the one girder 35 as the structure and the other girder 36 as the structure. The pier 37 may be constituted of a skeleton. An inter-two-point displacement gage 38 is arranged on an upper face of the pier 37, the inter-two-point displacement gage 38 is mounted with an optical fiber fixing jig, a rotatable optical fiber winding member comprising a plurality or a large number of pulleys constituted of a plurality of lines, and a displacement/load conversion member comprising a coil spring or the like, one side and the other side optical fibers 39, 40 having a strain sensor function are extracted from the inter-two-point displacement gage 38, and the one side optical fiber 39 is connected to a BOTDR (Brilloin Optical Time Domain Reflectometer) instrument 46. COPYRIGHT: (C)2006,JPO&NCIPI