Optical fiber inhaul cable prestress monitoring method and sensor thereof

Abstract

The invention provides an optical fiber inhaul cable prestress monitoring method and a sensor of the optical fiber inhaul cable prestress monitoring method. According to the prestress monitoring method, a single-mode optical fiber wound around the outer surface of a prestress monitored part serves as a sensing unit, and long-term and stable monitoring of the prestress is achieved. The sensor of the optical fiber bridge inhaul cable prestress monitoring method comprises a prestress monitoring module, a temperature compensation module, a signal transmission segment optical cable and a protecting steel sleeve. The prestress monitored part is used for monitoring the stress on a prestressed anchorage device stressed part, and then the prestress on an inhaul cable is obtained. An optical fiber coil wound around a temperature compensation monitored part is used for correcting influence on the prestress monitoring result from environment temperature, so that strain monitoring is more accurate, and meanwhile measurement of the interior temperature of a cable body is achieved, wherein the temperature compensation monitored part is of the same specification as the prestress monitored part, is not stressed and is located in the same temperature environment as the prestress monitored part. The method is suitable for long-term monitoring of the prestress on the bridge inhaul cable and has the advantages that precision is high, the service life of the sensor is long and the cost is low.

Description

technical field [0001] The invention belongs to the field of civil engineering structure safety monitoring and relates to an optical fiber monitoring method for cable prestress monitoring. More precisely, the invention relates to a method capable of monitoring the prestressing force of the cable during its service. Background technique [0002] Since the 1950s, prestressed cables have been widely used in bridge structures, especially the materials and anchorage systems of prestressed cables in cable-stayed bridges have experienced many technological innovations and leapfrog developments. In the bridge structure, the cables transmit the deck system load to the tower (main arch). The bridge deck system load includes the dead load of the bridge deck’s own weight and the loads of vehicles, wind and temperature. The cables will fatigue under the live load. effect, leading to fatigue cumulative damage; in addition, since the cable bridge is a statically indeterminate structure, t...

AI Technical Summary

Problems solved by technology

The disadvantage is that the cost is high

5) Fiber grating pressure ring method: The bridge prestress measured by this method has high accuracy, but the durability of the adhesive of the grating sensitive element is poor, resulting in a short life of the sensor. This method needs to be further improved and perfected

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