Stress testing method for rod body of non-metal anti-floating anchor rod

Abstract

The invention belongs to the technical field of stress testing and relates to a stress testing method for a rod body of a non-metal anti-floating anchor rod. The stress testing method comprises the following steps: after a testing device is mounted, synchronous jacks are adopted to load by grades so that loads of all the jacks are balanced to ensure the synchronization of ascending and descending speeds and prevent a phenomenon that a load device is pulled to possibly generate a bending moment to cause that the anchor rod is broken early; in the pulled process of the rod body of the anchor rod, the wavelength change of a grating sensor and readings of oil pressure gauges on the jacks are recorded and the stress change of the rod body of the anchor rod in the testing process is inversely calculated; the testing method is simple; the used device is convenient to mount, high in measurement precision, high in sensitivity, strong in electromagnetic field interference resisting capability and high in survival rate, and can monitor automatically.

Description

Technical field: [0001] The invention belongs to the technical field of stress testing, and relates to a process for testing the stress of a non-metallic bolt body in geotechnical engineering, in particular to a method for testing the stress of a non-metallic anti-floating bolt body. Background technique: [0002] With the development and utilization of urban underground space, the buried depth of the foundation of buildings (structures) increases continuously, and the problem of anti-floating becomes more and more prominent. , anti-floating bolts have strong stratum adaptability, flexible layout, fast hole formation, small construction site, miniaturized construction machinery, economical and environmental protection, large bearing capacity in hard rock and soil layers, glass fiber reinforced polymer (GFRP) The emergence of bolts has added new means to rock and soil anchoring, especially the excellent corrosion resistance and anti-electromagnetic interference characteristic...

AI Technical Summary

Problems solved by technology

The surface of the GFRP spiral rib is uneven, and there are some problems in the existing stress test equipment for the anchor rod body. When the strain gauge is pasted or the surface of the rod body is implanted with optical fibers, grinding will cause the surface fiber to be broken, resulting in the initial defect of the anchor rod, and the strain gauge is easy to Therefore, it is not reasonable to use ordinary electrical measurement methods to comprehensively monitor the working properties of GFRP bolts. Optical fibers can be used to test them. Optical fiber testing mainly includes distributed (Brillouin method) and quasi- Distributed (Bragg grating method) two methods, distributed (Brillouin method) uses an optical fiber for continuous testing, suitable for long-distance measurement; quasi-distributed (Bragg grating method) uses a bare optical fiber to connect a string of grating sensors to the anchor rod carry out testing

At present, most of the fiber optic testing of GFRP anchor rods adopts distributed (Brillouin method). This method can test continuously in name, but the spatial resolution is low, and the accuracy of measuring point positioning can only reach 20cm at most, which is not suitable for fighting against floating anchor rods. Short components are tested, especially the stress concentration change area near the orifice cannot be accurately located

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