Linkage-based device for creep testing of coal rock

Area of Science:

• Geotechnical Engineering
• Rock Mechanics
• Materials Science

Background:

• Coal rock creep properties are well-studied under uniaxial stress.
• Limited research exists on coal rock creep and seepage under triaxial stress conditions.

Purpose of the Study:

• To propose and validate a novel linkage-based creep test device for coal rock under triaxial stress.
• To investigate coal rock creep characteristics and seepage under varying triaxial stress conditions.

Main Methods:

• A specially designed data measurement system recorded deformation, pressure, and acoustic emission signals.
• The device utilizes a connecting rod mechanism for continuous constant pressure loading.
• Theoretical calculations and finite element analysis confirmed device strength and stiffness (up to 300 kN).

Main Results:

• The device successfully analyzed sandstone creep characteristics under different confining pressures.
• Catastrophic characteristics of sandstone during creep were identified, validating the device's reliability.
• The device demonstrated effectiveness in monitoring continuous or constant pressure during sandstone creep.

Conclusions:

• The developed linkage-based creep test device is valid and reliable for studying coal rock under triaxial stress.
• This new method offers insights into coal rock creep properties and seepage under diverse stress conditions.
• The device aids in understanding the catastrophic failure mechanisms of rock formations.