High-precision distributed tunnel crack monitoring system and method

Abstract

The invention, which belongs to the technical field of disease monitoring in tunnels, relates to a high-precision distributed tunnel crack monitoring system and method. The high-precision distributedtunnel crack monitoring system comprises a broadband light source, a signal processing system, a first coupler, a second coupler, a signal arm, an LCI optical fiber sensor, a reflector, an optical fiber with the tail end cut flatly and a reference arm. A tunnel segment is arranged on the inner wall of the tunnel, the LCI optical fiber sensor is tightly attached to the tunnel segment, the startingpoint and the terminal point of the LCI optical fiber sensor are located at the same horizontal position, and horizontal projection is circularly arranged in a V shape; and the starting point and theterminal point of the LCI optical fiber sensor are in a stretching state. With the detection system and method, the development condition of segment cracks in the tunnel can be monitored; the system and method have advantages of high monitoring precision and high electromagnetic interference resistance; the optical fiber sensor can be arranged on the surface of the segment to facilitate managementand replacement, long-term monitoring of the tunnel becomes convenient; and the high-precision distributed tunnel crack monitoring system and method can be popularized and applied to crack monitoringof engineering tunnels on a large scale.

Description

technical field [0001] The invention relates to the technical field of defect monitoring in tunnels, and more specifically, the invention relates to a high-precision distributed tunnel crack monitoring system and method. Background technique [0002] Optical fiber sensing technology, as a new monitoring technology, has been gradually applied to tunnel crack prediction, structural settlement, segment dislocation, etc. in the past ten years, and has developed rapidly. [0003] Some crack monitoring methods based on different types of optical fiber sensor technologies are disclosed in the prior art, which mainly include the following types: [0004] CN108709856A Concrete structure crack monitoring and early warning system and early warning method have the advantages of higher automation and intelligence in the monitoring process; CN109682308A discloses a plastic optical fiber crack monitoring device and monitoring method, which is based on optical time domain reflection. With ...

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Problems solved by technology

However, the monitoring systems listed above have complex structures and strict conditions. Generally, the optical fiber is embedded in the object to be measured (inside the concrete of the tunnel), which greatly limits its application.

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