A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Research on Mechanisms and Precursors of Slip and Fracture of Coal–Rock Parting–Coal Structure
https://orcid.org/0000-0002-7439-8256
Abstract The bifurcation of coal seams is a universal geological structure in coal mines, and the special structure of rock parting intruded into coal can lead to a slip of discontinuities and shear failure, and even rockbursts due to the existence of discontinuities. Lateral confining stress unloading with axial loading tests was conducted on a coal–rock parting–coal structure (CRCS) to reproduce and simulate the stress conditions of increasing vertical stress and decreasing horizontal stress, similar to mining destressed effects. The stress and deformation of CRCS were comprehensively analyzed during slip and fracture. The precursors of shear slip and macrofracture were proposed based on the variations in the spectral distribution, cumulative apparent volume (CAV), and the energy index of acoustic emission (AE). Before and after advancing through the bifurcation area of the 5310 working face of the Zhaolou coal mine, the Microseismic (MS) observations were analyzed, confirming the experimental results. It was observed that a sharp decline in the energy index, a sharp rise in the CAV, and an increase in MS at a low frequency and high amplitude are the portents of rockbursts induced by slip and fracture of CRCS. Through field investigations of the 5310 working face, three stages was observed before and after the slip of the discontinuities, namely, stress accumulation (July–September), stress release (September–November), and stress redistribution and equilibrium (November–December). This study is relevant for understanding the mechanisms and precursors of rockbursts caused by the dynamic instability of the CRCS in coal mines.
Highlights The interfaces between coal and rock parting are liable to stress concentration and slip.The increasing CAV with a sudden drop of energy index can be regarded as a precursor of CRCS slip.Stress accumulation, release, and redistribution and equilibrium is found during CRCS slip.
Research on Mechanisms and Precursors of Slip and Fracture of Coal–Rock Parting–Coal Structure
https://orcid.org/0000-0002-7439-8256
Abstract The bifurcation of coal seams is a universal geological structure in coal mines, and the special structure of rock parting intruded into coal can lead to a slip of discontinuities and shear failure, and even rockbursts due to the existence of discontinuities. Lateral confining stress unloading with axial loading tests was conducted on a coal–rock parting–coal structure (CRCS) to reproduce and simulate the stress conditions of increasing vertical stress and decreasing horizontal stress, similar to mining destressed effects. The stress and deformation of CRCS were comprehensively analyzed during slip and fracture. The precursors of shear slip and macrofracture were proposed based on the variations in the spectral distribution, cumulative apparent volume (CAV), and the energy index of acoustic emission (AE). Before and after advancing through the bifurcation area of the 5310 working face of the Zhaolou coal mine, the Microseismic (MS) observations were analyzed, confirming the experimental results. It was observed that a sharp decline in the energy index, a sharp rise in the CAV, and an increase in MS at a low frequency and high amplitude are the portents of rockbursts induced by slip and fracture of CRCS. Through field investigations of the 5310 working face, three stages was observed before and after the slip of the discontinuities, namely, stress accumulation (July–September), stress release (September–November), and stress redistribution and equilibrium (November–December). This study is relevant for understanding the mechanisms and precursors of rockbursts caused by the dynamic instability of the CRCS in coal mines.
Highlights The interfaces between coal and rock parting are liable to stress concentration and slip.The increasing CAV with a sudden drop of energy index can be regarded as a precursor of CRCS slip.Stress accumulation, release, and redistribution and equilibrium is found during CRCS slip.
Research on Mechanisms and Precursors of Slip and Fracture of Coal–Rock Parting–Coal Structure
https://orcid.org/0000-0002-7439-8256
Abstract The bifurcation of coal seams is a universal geological structure in coal mines, and the special structure of rock parting intruded into coal can lead to a slip of discontinuities and shear failure, and even rockbursts due to the existence of discontinuities. Lateral confining stress unloading with axial loading tests was conducted on a coal–rock parting–coal structure (CRCS) to reproduce and simulate the stress conditions of increasing vertical stress and decreasing horizontal stress, similar to mining destressed effects. The stress and deformation of CRCS were comprehensively analyzed during slip and fracture. The precursors of shear slip and macrofracture were proposed based on the variations in the spectral distribution, cumulative apparent volume (CAV), and the energy index of acoustic emission (AE). Before and after advancing through the bifurcation area of the 5310 working face of the Zhaolou coal mine, the Microseismic (MS) observations were analyzed, confirming the experimental results. It was observed that a sharp decline in the energy index, a sharp rise in the CAV, and an increase in MS at a low frequency and high amplitude are the portents of rockbursts induced by slip and fracture of CRCS. Through field investigations of the 5310 working face, three stages was observed before and after the slip of the discontinuities, namely, stress accumulation (July–September), stress release (September–November), and stress redistribution and equilibrium (November–December). This study is relevant for understanding the mechanisms and precursors of rockbursts caused by the dynamic instability of the CRCS in coal mines.
Highlights The interfaces between coal and rock parting are liable to stress concentration and slip.The increasing CAV with a sudden drop of energy index can be regarded as a precursor of CRCS slip.Stress accumulation, release, and redistribution and equilibrium is found during CRCS slip.
Research on Mechanisms and Precursors of Slip and Fracture of Coal–Rock Parting–Coal Structure
He, Zhi-Long (author) / Lu, Cai-Ping (author) / Zhang, Xiu-Feng (author) / Guo, Ying (author) / Wang, Chao (author) / Zhang, Heng (author) / Wang, Bao-Qi (author)
2022
Article (Journal)
Electronic Resource
English
BKL:
38.58
Geomechanik
/
56.20
Ingenieurgeologie, Bodenmechanik
/
38.58$jGeomechanik
/
56.20$jIngenieurgeologie$jBodenmechanik
RVK:
ELIB41