Apparatus and method for measuring wave velocity and thickness of loose circle in tunnel surrounding rock

Abstract

The invention provides a tunnel surrounding rock wave velocity and broken rock zone thickness test device. The device comprises sound wave receiving devices, an air-filling device, a signal collector,a signal excitation device and a telescopic connecting rod; at least two sound wave receiving devices are arranged in a drill hole wall after being serially connected through the telescopic connecting rod; each sound wave receiving device comprises a sound wave transducer and a volume-expandable airbag; all airbags are serially connected through airbag pipes to communicate with the air-filling device; the signal excitation device is used for exciting a sound wave signal by knocking the rock wall out of the drill hole; each sound wave transducer is used for receiving the sound wave signal, andconverting the sound wave signal into an electric signal to be output to the signal collector; the signal collector draws a deep wave velocity curve with different depth sections according to computed wave velocity values of rock bodies at different depth sections, and divides the broken rock zone thickness according to the curve change. The problem that the rock body wave velocity testing underthe anhydrous condition in the drill hole cannot be performed and the problem that the rock body wave velocity of the tunnel surrounding rock with the rock body wave velocity less than that of the water are solved.

Description

technical field [0001] The invention relates to the technical field of rock acoustic wave velocity testing, in particular to a device and method for testing the wave velocity of surrounding rock in a tunnel and the thickness of a loose ring. Background technique [0002] Affected by factors such as blasting vibration and unloading, the mechanical properties of the rock mass in a certain range around the tunnel chamber will deteriorate significantly, which is usually called a loose circle or a loose circle. The thickness of the loose circle and its mechanical properties are the surrounding rock support parameters. important basis. After the excavation of the cavern, the thickness test of the loose ring should be carried out to verify whether the support parameters are reasonable. [0003] At present, the testing of loose circles at home and abroad adopts the drilling sonic testing technology, and the thickness of the loose circle is divided according to the variation trend o...

AI Technical Summary

Problems solved by technology

[0005] The object of the present invention is to provide a device and method for testing the wave velocity of the surrounding rock and the thickness of the loose ring, which solves the problem that the wave velocity of the rock mass cannot be tested when there is no water in the borehole, and also solves the problem that the wave velocity of the rock mass is higher than that of water. The wave velocity of the surrounding rock mass in small tunnels cannot be tested. The test results can truly and efficiently determine the thickness and properties of the loose circle of the surrounding rock in the cavern.

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