Multi-point displacement sensor for slope monitoring based on optical fiber bending loss

Abstract

The present invention relates to a slope monitoring multi-point displacement sensor based on fiber bending loss. The sensor comprises a plurality of displacement sensing units, there are one or more than one displacement sensing units which are connected in series in order, and each displacement sensing unit comprises one protective cover, one right connection leading optical fiber, one upper endtop plate, one capillary steel pipe, base materials, one lower end bottom plate, one left connection leading optical fiber and one optical fiber bow-tie modulation mechanism; the protective covers areconnected with the upper end top plates through bolts; the upper and lower surfaces of the base materials are fixedly connected with the upper end top plates and the lower end bottom plates; an axlewire of the base materials is provided with a guide groove hole, the capillary steel pipes pass through the guide groove hole, the lower ends of the capillary steel pipes are fixed at the lower end bottom plates, the upper ends of the capillary steel pipes are connected with the optical fiber bow-tie modulation mechanisms, and anchor heads are fixed at the lower surfaces of the lower end bottom plates; and the optical fiber bow-tie modulation mechanisms are arranged in the protective covers. The slope monitoring multi-point displacement sensor based on the fiber bending loss solves the problems of slope internal displacement distribution and remote real-time monitoring.

Description

technical field [0001] The invention relates to optoelectronic landslide measurement technology, more specifically, to a multi-point displacement sensor for slope monitoring based on optical fiber bending loss and its application method. Background technique [0002] Landslides are one of the most frequent and harmful natural disasters on the earth, and methods and technologies for landslide monitoring emerge in endlessly. The internal displacement monitoring of slopes has always been an important topic in the geotechnical engineering field. The internal displacement monitoring of landslides can not only provide important information such as accurate sliding mass displacement and sliding surface position, but also facilitate long-term and continuous understanding of landslide status and realize landslide mass monitoring. Long-term stability evaluation and early warning judgment. At present, for monitoring the internal displacement of rock and soil, sensors such as borehole ...

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Problems solved by technology

[0004] Chinese invention patent CN102252703A discloses an "optical fiber composite sensing module", which uses mortar to wrap the base material, and an optical fiber passing through a capillary steel pipe is arranged on the surface of the base material, and the optical fiber at the upper end of the base material is installed as a bowknot modulation mechanism to remove The bending loss is formed. Through specific examples, it is proved that the device can realize the characteristics of high initial measurement accuracy, large measurement stroke and dynamic range, and judgment of the direction of the load. It proves that the sensor using the principle of optical fiber bending loss can It is used to measure the shearing sliding body, but the device is too rough to be installed and used on site, and the bowknot modulation mechanism is exposed outside, which is easily affected by the environment; and it cannot realize distributed multi-point displacement measurement inside the landslide body

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