Non-destructive testing method for natural frequency of transverse vibration of non-fully grouted anchoring bolt in coal mine

Abstract

The invention relates to a non-destructive testing method for the natural frequency of transverse vibration of a non-fully grouted anchor bolt in coal mine, which comprises the testing steps that: an exposed end of the anchor bolt is connected with a sensor connecting device and a sensor; nominal exciting force is applied to the sensor connecting device via a small hammer so that the anchor bolt generates transverse vibration; the vibration acceleration of the anchor bolt is acquired by the sensor and an acceleration signal is transmitted to a tester; the tester converts the received acceleration analog signal into an acceleration digital signal and stores the acceleration digital signal; simultaneously, the acquired signal is subjected to spectrum analysis to obtain the natural frequency of the anchoring system of the tested anchor bolt, and the resultant natural frequency of the transverse vibration of the anchor bolt is closely correlated with the axial stress of the anchor bolt and the bonding state between the anchoring section of the anchor bolt and coal. The device disclosed by the invention is simple and convenient in installation and connection, short in testing time required and capable of implementing large-area testing for the anchor bolt in a tunnel and monitoring the stability of the overall tunnel.

Description

technical field [0001] The invention relates to a method for detecting the natural frequency of the lateral vibration of a non-full-length bonded bolt in a coal mine, in particular to a non-destructive detection method for the natural frequency of the lateral vibration of a non-full-length bonded bolt in a coal mine. Background technique [0002] Bolt support has become the main support form of coal mine roadway. However, due to the characteristics of coal mine roadway engineering, complex geology, mining and other factors, engineering quality control is relatively difficult, and engineering quality problems often occur. According to the incomplete statistics of some mining areas, the annual maintenance amount of the bolt support roadway is more than 20%. Cracking, shedding and damage often occur in the roadway supported by bolts, and even quality accidents such as roof caving occur. There are many reasons for these problems. The main reason is poor engineering quality and...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the problems encountered in the detection of the natural frequency of the lateral vibration of the non-full-length bonded bolt in coal mines, the present invention provides a non-destructive detection method for the natural frequency of the lateral vibration of the non-full-length bonded bolt, which effectively solves the problem of Real-time monitoring of stress state and anchoring stability, simple and practical, high accuracy, can realize non-destructive testing of anchor rods

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