System and method for detecting and stabilizing effective anchorage prestressing force tested by clip piece displacement method

Abstract

The invention discloses a system for detecting and stabilizing effective anchorage prestressing force tested by a clip piece displacement method. The system comprises a main control terminal, a detecting terminal, a self-locking type electromagnetic switching control hydraulic system, a bridge-type pressure sensor and a displacement measuring fixture tool; an oil pipe of the self-locking type electromagnetic switching control hydraulic system is an ultra-high pressure resin hydraulic flow pipe, the end of an executing member of the self-locking type electromagnetic switching control hydraulicsystem is provided with the bridge-type pressure sensor, the other end of the bridge-type sensor is in front pressurized fit with the displacement measuring fixture tool, a clip piece in an anchor head hole is arranged at the end, away from the bridge-type sensor, of the displacement measuring fixture tool, and the clip piece is fixedly connected with the steel strand. The invention further discloses a method for detecting and stabilizing the effective anchorage prestressing force tested by the clip piece displacement method. The method and the system have the advantages that influence on original prestressing force does not exist, the detecting reliability is high, and the detecting precision is high.

Description

technical field [0001] The invention relates to the technical field of quality and safety detection of civil engineering, in particular to a system and method for detecting and stabilizing clip displacement method for testing effective prestress under anchors. Background technique [0002] The size of the post-tensioning prestress is an important indicator to directly measure the performance of the prestressed structure. At present, the most commonly used and relatively reliable detection method is the reverse tension method. [0003] There are also many kinds of tests for the reverse pull method, which can be roughly divided into two test forms: whole bundle and single root. The whole beam tension is to measure the sum of the effective prestress of the whole anchor head by simultaneously tensioning each steel strand of the anchor head, and the single tension is to stretch each steel strand separately, and the measured single The sum of the prestress values ​​is the effecti...

AI Technical Summary

Problems solved by technology

[0006] The biggest test of the current anti-tension method is mainly the inflection point method and the limit method. The inflection point method mainly judges the effective prestress value under the anchor through the inflection point of the overall displacement relationship curve between the force and the steel beam. The main problem of the inflection point method is: The incongruity of each steel strand caused by beam tension makes some clips have larger friction resistance, and some clips have lower friction resistance. For the clips with larger friction resistance, overshoot or Disturbance of the clip makes it impossible for the clip to return to its original position when it is released, and has a greater impact on the structural bearing capacity. For clips with small friction resistance, sometimes it is difficult to have a reverse pull inflection point, resulting in the result being unable to be interpreted normally. Affect the detection rate and detection safety; the main problem of the limit method is: generally when the limit point is reached, the value is read, because the length of the free section of the steel strand that participates in the stretch after overcoming the friction of the clip during the tensioning process The increase will cause the clip to retract, just reading the value of the limit point will cause the test result to be too large, and reading the stable value will lead to the test result being too small, resulting in unstable test results, and even loosening of the clip will cause safety accidents. There are many problems in the existing methods mentioned above, and it is difficult to guarantee the detection accuracy, stability and structural safety

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