True-triaxial loading and unloading rock stress relaxation test device and test method

Abstract

The invention discloses a true-triaxial loading and unloading rock stress relaxation test device and a test method, and belongs to the technical field of test detection and monitoring of mining industry and geotechnical engineering. The true-triaxial loading and unloading rock stress relaxation test device is characterized in that supercharging devices comprise a vertical supercharging device, a horizontally-lateral supercharging device and a horizontal longitudinal supercharging device, wherein the supercharging devices are connected with an upper computer by a wireless pressure transmitter respectively for uploading a pressure signal to the upper computer in real time; an ultrasonic monitoring device and a camera device which are connected with the upper computer are further arranged; the ultrasonic monitoring device comprises an ultrasonic monitoring probe (9) and a nonmetal ultrasonic detector; and the ultrasonic monitoring probe (9) is arranged in an opening in the middle of a loading board and is pressed by springs supported on the supercharging devices. According to the true-triaxial loading and unloading rock stress relaxation test device disclosed by the invention, a test sample can be kept unchanged for a long term, and the supercharging devices are independently loaded in three directions respectively; and the test method agrees with the actual situation better, so that theoretical basis is provided for roadway (tunnel) stability and control research.

Description

technical field [0001] A true triaxial loading and unloading rock stress relaxation test device and test method belong to the technical field of test detection and monitoring of mining and geotechnical engineering. Background technique [0002] There are dangers such as surrounding rock slabs, roof caving, water inrush and rockburst dynamic disasters in the underground of the mine, which pose a direct threat to the staff and equipment, affect the progress of the project, and cause support failure and even earthquakes. With the continuous increase of mining depth, the frequency and intensity of surrounding rock damage are getting higher and higher, engineering disasters are becoming more and more serious, and safety issues need to be solved urgently. It is necessary to strengthen the research on rock mass engineering stability, especially long-term stability. [0003] Rock rheological properties are an important branch of rock mechanics, among which creep and stress relaxatio...

AI Technical Summary

Problems solved by technology

Creep and stress relaxation often do not exist independently. The two rheological mechanisms jointly affect the mechanical properties of rocks, and they are related to each other. The development of creep promotes the relaxation of stress, and the decrease of stress during the stress relaxation process reduces the Stress conditions for creep development. Research on rock rheology from the perspective of creep has achieved relatively fruitful results. In contrast, stress relaxation tests require instruments to maintain constant strain for a long time, and the test technology is more difficult. At present, there are not many studies in this area, and the published research results are relatively few, and there is no test device specially used for rock stress relaxation test, especially the true triaxial loading and unloading rock stress relaxation test device.

In engineering, it is difficult to ensure that the rock is only loaded in one direction, so it is difficult to ensure that the test results are true and reliable with one-way loading

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