Gravity expanding constant-pressure loading coal rock creep test device and method

Abstract

The invention discloses a gravity expanding constant-pressure loading coal rock creep test device and method. The device comprises a triaxial pressure chamber which is internally provided with a coalrock test piece and is used for applying a confining pressure to the coal rock test piece, a closed water tank gravity loading system which is arranged above the triaxial pressure chamber and is usedfor adjusting the mass of the whole weight required by the test through the mass of water and adjusting the magnitude of the force applied to the coal rock test piece, and a force expanding device which is arranged above the triaxial pressure chamber, is connected with the closed water tank gravity loading system, and is used for expanding the force applied by the closed water tank gravity loadingsystem and carrying out axial loading on a coal rock test piece in the triaxial pressure chamber. The device is simple and convenient to operate and low in cost, stable test conditions are provided for researching the creep property of the coal rock in a complex stress state, relevant data of deformation of the coal rock along with time increase under the action of a constant load can be masteredaccurately, and the scientificity, accuracy and preciseness of research on deformation and instability of the coal rock are ensured.

Description

technical field [0001] The invention belongs to the technical field of coal mine experiment devices, and in particular relates to a coal rock creep test device and method under gravity expansion force constant pressure loading. Background technique [0002] Creep damage is one of the main failure forms of rock, and many rock engineering problems are closely related to rock creep. The destruction of a project often has a time process. In other words, it is controlled by the creep properties of the rock. Some researchers even pointed out that some basic issues of rock mechanics cannot be solved without considering the creep property of rock. In the process of coal mining, with the increase of mining time, the coal and rock are subjected to different loads, resulting in different degrees of creep deformation, and its stability will be greatly affected. After a long period of accumulation, the coal and rock will eventually be deformed due to and was destroyed. It can be seen...

AI Technical Summary

Problems solved by technology

The disadvantages of this technical solution: the constant load is applied through the counter force plate, loading spring, force sensor, and pressure plate, which has great limitations and cannot meet the force required by many test requirements; it cannot be accurately loaded with constant pressure, and it will be affected by the external environment. Larger errors due to changes

Insufficiency of this technical solution: Applying a constant load to the test piece by weights has great limitations and cannot meet the force required by many tests; it cannot be accurately loaded with constant pressure, which will cause large errors due to changes in the external environment, etc.

Insufficiency of this technical scheme: the constant load is applied to the loading system of the test piece through the reaction frame, loading system, controller and the interior of the reaction frame. Pressure loading; the grating and pressure sensor will have a large error, and accurate data cannot be obtained

Insufficiency of this technical solution: Although it is more automatic and precise to apply constant load by loading the motor and weight group, it cannot provide stable test conditions in time in case of power failure and other emergencies; Changes in weight due to changes in the external environment, etc.

Due to the limitation of the speed of manual observation and recording, it is difficult to record the output changes when the force of the sensor changes suddenly, so that some important information may be missed, or in case of a sudden power failure or leakage, etc. Unable to provide stable test conditions in time

At the same time, the creep test process is manually loaded by the experimenter, which has great limitations and cannot meet the force required by many test requirements, and the weight of the weight will change due to changes in the external environment.

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