Device and measuring method for measuring direct stretching mechanical parameter of rock

Abstract

The invention relates to a device and a method for measuring a direct stretching mechanical parameter of rock. The device comprises a strain gage, a resistance strain gauge, a computer, an upper pull rod component and a lower pull rod component which are same in structure, wherein the upper pull rod component comprises a ball hinge pull rod, an upper connecting base, a lower connecting base and a clamping sleeve; a mounting hole is formed at the center of the upper connecting base; the ball hinge pull rod is inserted into the mounting hole; the clamping sleeve is in threaded connection with the interior of the threaded hole of the lower connecting base through a connecting pillar; a rock sample is arranged between the clamping sleeves of the upper pull rod component and the lower pull rod component; the strain gage is arranged on the surface of the rock sample. The device applies the stretching load to the ball hinge pull rod so as to perform direct stretching test on the rock sample; the eccentric loading when the rock sample is pulled can be effectively avoided; the operation is simple and convenient; the rock sample is conveniently detached; the loading deforming condition of the rock sample can be directly measured through the strain gage; the measurement is accurate.

Description

technical field [0001] The invention belongs to the technical field of rock tensile tests, and in particular relates to a device for measuring direct tensile mechanical parameters of rocks and a measuring method thereof. Background technique [0002] Rock is a heterogeneous material with defects such as micro-cracks and pores inside, which makes the tensile strength of rock much lower than its compressive strength, so rock cannot bear tensile stress. Tensile failure is one of the main failure forms of engineering rock mass and natural rock mass. The failure of engineering rock mass often starts from the local tensile failure of the rock. The surrounding rock mass of underground engineering is mostly in a three-dimensional stress state. After unloading, the surrounding rock body may have a stress state of two directions of compression and one direction of tension in a certain direction, so it is necessary to study the strength characteristics of rocks under tension stress. ...

AI Technical Summary

Problems solved by technology

[0004] The tensile strength of the rock is measured by the direct tensile test method of the rock. The test conditions of this method are relatively high and difficult to implement, so the tensile strength of the rock is not easy to measure. There are significantly fewer experimental studies

Part of the tensile test method uses special rock samples and fixtures. Because the rock samples are difficult to process and it is very difficult to keep the tension of the fixtures coincident with the axis of the rock samples, eccentric loading is prone to occur, resulting in poor test results.

At present, the direct uniaxial tensile test is difficult and difficult to implement, while various indirect measurement methods are relatively simple and easy, but will cause large errors

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