Apparatus used for monitoring loss of pre-stress of steel stranded wires

Abstract

The invention relates to an apparatus used for monitoring the loss of pre-stress of steel stranded wires. The apparatus comprises optical fiber sensors, temperature compensating sensors, a bellows, a leading wire protective bushing, sensor leading wires, a sensor protection gasket and a fiber grating demodulator, the optical fiber sensors are distributed at inflection points of the steel stranded wires along the length direction of the steel stranded wires in the bellows, the optical fiber sensors and the temperature compensating sensors are both connected with the fiber grating demodulator through the sensor leading wires, and the fiber grating demodulator is used for obtaining wavelength information acquired by the sensors in real time to further obtain the real-time pre-stress change condition of the steel stranded wires. According to the apparatus, the problem of the lack of a direct monitoring method of the loss of the pre-stress in a construction process of a large-scale building pre-stress member can be solved, the construction is convenient, the operation is simple, and the engineering applicability is good.

Description

technical field [0001] The invention relates to the field of monitoring the prestress loss of steel strands, in particular to a device for monitoring the prestress loss of steel strands. Background technique [0002] On the one hand, at present, the monitoring method for the prestress loss of steel strands can only measure the effective prestress at the tension end, and cannot know the distribution of the effective prestress of the steel strands inside the beam body. Moreover, the current strain sensors are mostly point sensors, which have a short measurement range and large uncertainty and limitations of the measurement effect, and cannot realize long-term monitoring of prestressed steel strands; on the other hand, according to the actual engineering Requirements, large-diameter sensors are not allowed inside the bellows used in construction, and the steel strands in the bellows are mostly curved, requiring the sensor itself to be bent, that is, the sensor cannot be rigidly...

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Problems solved by technology

[0002] On the one hand, at present, the prestress loss monitoring method for steel strands can only measure the effective prestress at the tension end, and cannot know the distribution of the effective prestress of the steel strands inside the beam body.

Moreover, the current strain sensors are mostly point sensors, which have a short measurement range and large uncertainty and limitations of the measurement effect, and cannot realize long-term monitoring of prestressed steel strands; on the other hand, according to the actual engineering Requirements, large-diameter sensors are not allowed inside the bellows used in construction, and the steel strands in the bellows are mostly curved, requiring the sensor itself to be bent, that is, the sensor cannot be rigidly packaged, and the steel wires inside the same bundle of steel strands are pulled and slide , and the friction and sliding between the steel strand and the corrugated pipe can easily cause the strain gauge and the wire to be cut

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