The Research Of Anchor Monitoring On Optical Fiber Sensor For Railway Slope

The rise of the railway brought convenience to people’s lives, contributed to the development of economic to a great extent. But in the process of railway construction, landslides and debris flows often induced in some areas, which is a great threat to the railway system. Bolt is an effective technology which used be worked in rock and soil reinforcement projects and widely used in the railway slope reinforcement. But the long-term monitoring is always lack of effective methods. There is a new sensing technology called fiber grating sensor which has many advantages such as anti-jamming, high-sensitivity, remote transmission and adaptation to the environment. And the packaged sensor is smart and light-weight. Therefore, a slope remote distributed fiber optic monitoring system is built with those technologies to realize continuous real-time online monitoring of the slope. It has a great scientific significance to study on slope stability and prevent landslide disasters. This paper aims at the anchor rod reinforcement at landslide and disaster prevention needs, studied the anchor measurement theory and methods based on fiber Bragg grating. Then successfully developed a bolt sensor based on fiber grating sensor technology, and according to the actual needs of the project research and development of a fiber grating slope safety monitoring and early warning system. The system runs effective and successful so far.The main research content and conclusion are as follow.(1) In view of the current defect of landslide monitoring technology as well as the fiber grating sensing technology, studied the anchor slope monitoring technology and method based on fiber grating.(2) According to the mass stress distribution characteristics of the bolt in rock and its metal characteristics, the paper deals with fiber grating strain for metal matrix theory, and proposed the fiber grating anchor strain monitoring system. Developed a new system for fiber grating anchor strain monitoring, and studied the sensing characteristics.(3) Based on the fiber grating anchor strain sensor experimental study, the paper proposed the technology and packing method of the fiber grating anchor strain monitoring system and the calibration of the sensor. It provides good foundation in the practical of the application. According to the experiment result, the sensor is high-sensitivity, which is a good linear relationship with tension and pressure to meet the requirements of anchoring engineering.(4) In view of the railway high and steep slope characteristics, the paper establish a fiber grating smart bolt rock mass deformation and loose monitoring subsystem, and operated long-term effectively for nearly a year. It effectively realizes the monitoring of deformation of rock mass and rock mass monitoring. As the railway side slope safety monitoring provides an effective technical means, guarantee the safe operation of the railway.