A pressure-relieving device for accurate construction and monitoring of the pre-tightening force of roadway bolts and its application method

Abstract

The invention discloses a yielding device for accurate application and monitoring of a pretightening force of a roadway bolt and a use method and belongs to the technical field of mine roadway support. The yielding device comprises a piston rod and an air cylinder which are mutually connected, wherein a through hole matched with the tail of an anchor bolt is formed between the piston rod and the air cylinder; the sections of the piston rod and the air cylinder are of annular cylindrical structures; an air cylinder cavity is formed inside the air cylinder; the air cylinder cavity is filled withnitrogen; an air piston matched with the inner diameter of the cavity is arranged on the piston rod; an air hole communicated with the air cylinder cavity inside the air cylinder is formed in the side wall of the air cylinder; an inflation valve is arranged on the air hole; two annular sealing grooves are formed in the inner wall, in contact with the piston rod, of the air cylinder; anti-foulingscraping rings and sealing gaskets are respectively arranged in the annular sealing grooves. The yielding device is simple in structure and convenient to use and can be well matched with an existinganchor bolt; the yield device for accurate application and monitoring of the pretightening force of the roadway bolt and the use method have the advantages that the pretightening force can be monitored in real time and accurately applied; working conditions of the anchor bolt are judged, and the safety and the reliability of anchor bolt support are effectively improved.

Description

technical field [0001] The invention relates to a pressure relief device for precise construction and monitoring of the pretightening force of roadway bolts and a method for using it, belonging to the technical field of mine roadway support. Background technique [0002] At present, coal mine roadway support at home and abroad mainly adopts the bolt support method. According to statistics, the bolt support rate in the United States, Australia and other developed western countries has reached more than 90%, and the bolt support rate in most mining areas in my country has also reached 80%. % or even higher. One of the key parameters in bolt support is the pre-tightening force. The pre-tightening force of the bolt can change the bolt support from passive support to active support, so that the bolt and the anchored rock mass form a unified load-bearing structure. , which plays a decisive role in the bolt support effect, and the precise application of the bolt preload can realize...

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Problems solved by technology

[0003] In the coal mine roadway, the main method of applying the pre-tightening force of the bolt is to generate the pre-tightening torque by tightening the nut, and determine the magnitude of the applied pre-tightening force through the conversion relationship between the nut pre-tightening torque and the pre-tightening force, but the pre-tightening force of the bolt The relationship between the nut pretightening torque and the nut pretightening torque is more complicated. Affected by many factors, the error in the conversion process is relatively large; in the process of applying the pretightening force, workers often operate by experience, and the applied value of the actual pretightening force is consistent with the design Preload values ​​vary widely

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