Surrounding rock stress disturbing degree test device

Abstract

The invention relates to a surrounding rock stress disturbing degree test device. The invention aims at providing a surrounding rock stress disturbing degree test device which can simply, rapidly and directly evaluate the stress disturbing degree of surrounding rock and does not affect the state of the surrounding rock. According to the technical scheme, the surrounding rock stress disturbing degree test device comprises a packer device which is arranged in a surrounding rock borehole and a gas supply device which is arranged outside the surrounding rock, the packer device comprises two packers for packing the surrounding rock borehole, a pressure-bearing section cavity is formed between the two packers, the gas supply device comprises a nitrogen tank, the nitrogen tank is communicated with a multichannel conversion switch by virtue of a gas conveying pump, a gas conveying pipe, a flow sensor and a check valve, the nitrogen tank is divided into three branches by virtue of the multichannel conversion switch, one branch is communicated with the pressure-bearing section cavity by virtue of the gas conveying pipe, the other two branches are respectively communicated with the two packers by virtue of the gas conveying pipe, and the gas conveying pipe of each branch is provided with a check valve and a pressure release valve; and the multichannel conversion switch is provided with a pressure sensor for detecting the air pressure in each gas conveying pipe, and each pressure sensor is electrically connected with a pressure gauge and a recorder.

Description

technical field [0001] The invention relates to a testing device for surrounding rock stress disturbance degree. Applicable to the field of underground engineering. Background technique [0002] After the excavation of underground engineering, the surrounding rock will have stress redistribution, and the redistribution of stress will lead to irrecoverable damage in the surrounding rock. These damages are mainly caused by the expansion of internal cracks, so the internal structure of the surrounding rock will also have permanent Variety. The changes in the mechanical and hydraulic properties of the surrounding rock caused by these changes can be directly quantitatively tested, such as crack number statistics, acoustic wave testing, acoustic emission monitoring, penetration testing, etc. [0003] Because the surrounding rock is affected by stress redistribution differently, there will also be different disturbance degrees in the stress disturbance area of ​​the surrounding r...

AI Technical Summary

Problems solved by technology

Due to the difference in the degree of stress disturbance, the above-mentioned test methods generally have certain limitations when they are applied to the field. For example, only when the crack opens can the wave velocity decrease. Small or even tightly closed, it will not cause changes in the wave velocity of the surrounding rock

For another example, when using water permeability change test, the change of rock hydraulic properties will lead to inaccurate secondary test, especially for soft rock, this effect is more obvious, and even lead to the inability to complete subsequent tests

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