Fiber Grating Tunnel Monitoring System

With the development of the fiber and the optical communication technology, the fiber sensing technology gradually comes into being. Thanks to it, many complicated full-fiber communication and sensing net are possible and largely broaden the application field of the fiber technology. The fiber grating sensor has many merits, such as light weight, corruptness resistance, electromagnetism interference resistance, useability on the safe side, transmitting and sensing at the same time, continuous and long-term measurement and so on. Because it can realize distributing sensing conveniently using the fiber grating, it has wide application foreground and huge market potential in the bridge, the tunnel and avigation spaceflight and so on.Compared to the traditional fiber sensors, the wavelength-modulate fiber grating sensor has the high reliability and stability, has large application advantage in the fiber inspection, is convenient to continuous measurement in compound material and inside state of the huge construction ,and is convenient to form all kinds of the fiber sensing net to measure multi-point. Through measuring the strain of the ridge, mine, tunnel, dam and so on, we can detect the structure's load status in order to maintain and detect conveniently. The fiber grating tunnel safety inspection system is mainly used to measure the strain, temperature, displacement and crack in the tunnel engineering. Once we use the fiber inspection technology, we can truly measure the strain and temperature along the fiber grating in order to improve the validity of the tunnel safety inspection.There isn't successfully practice engineering in our country and abroad like the structure model of the fork tunnel from Yi-chang to En-shi in Huibei province, which lies in the trunk line of Lu-rong freeway. To research the stress state and stability of the fork tunnel' middle rock pole and simulate the stability of the wall rock and rock pole in the different stress state of the process of the link-arch to normal tunnel, through setting the fiber gratings in the process of the link-arch to normal tunnel, the grating wavelength datum can be achieved and be compared with...