Study on gas seepage-stress-damage coupling model in mining coal and rock and its application

2014 ◽  
pp. 415-420
Keyword(s):  
Coupling Model ◽  
Gas Seepage ◽  
Mining Coal ◽  
Stress Damage

scholarly journals Thermos-Solid-Gas Coupling Dynamic Model and Numerical Simulation of Coal Containing Gas

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Xiao Fukun ◽  
Meng Xin ◽  
Li Lianchong ◽  
Liu Jianfeng ◽  
Liu Gang ◽  
...  
Keyword(s):  
Principal Stress ◽  
Dynamic Model ◽  
Gas Flow ◽  
Flow Behavior ◽  
Coupling Model ◽  
Gas Pressure ◽  
Permeability Model ◽  
Gas Seepage ◽  
Coupling Dynamic ◽  
Coupling Dynamic Model

Based on gas seepage characteristics and the basic thermo-solid-gas coupling theory, the porosity model and the dynamic permeability model of coal body containing gas were derived. Based on the relationship between gas pressure, principal stress and temperature, and gas seepage, the thermo-solid-gas coupling dynamic model was established. Initial values and boundary conditions for the model were determined. Numerical simulations using this model were done to predict the gas flow behavior of a gassy coal sample. By using the thermo-solid-gas coupling model, the gas pressure, temperature, and principal stress influence, the change law of the pressure field, displacement field, stress field, temperature field, and permeability were numerically simulated. Research results show the following: (1) Gas pressure and displacement from the top to the end of the model gradually reduce, and stress from the top to the end gradually increases. The average permeability of the Y Z section of the model tends to decrease with the rise of the gas pressure, and the decrease amplitude slows down from the top of the model to the bottom. (2) When the principal stress and temperature are constant, the permeability decreases first and then flattens with the gas pressure. The permeability increases with the decrease of temperature while the gas pressure and principal stress remain unchanged.

Numerical Simulation of Gas Distribution and Mined Seepage Passage with the Pressure Relief of Short Distance Protective Coal Stratum

2011 ◽  
Vol 105-107 ◽  
pp. 1517-1520
Author(s):  
Yong Jun Zhang ◽  
Nian Jie Ma ◽  
Zi Min Zhang ◽  
Tian Rang Jia
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Gas Permeability ◽  
Process Analysis ◽  
Failure Process ◽  
Numerical Approach ◽  
Gas Seepage ◽  
Coal Rock ◽  
Rock Model ◽  
Stress Damage

With the full consideration of the heterogeneity, existing joints, and cracks in the rock, the coupled gas-rock model for investigating the failure process of coal-rock is established by introducing the related equations governing the evolution of stress, damage and gas permeability along with the deformation of coal and rock. A numerical approach of realistic failure process analysis (RFPA) to simulate the stratum movement, layer separation, the whole collapse progresses, and gas permeability changing of the protected coal seam is proposed. The numerical simulation results well displayed the whole processes of the cracks growth of gas seepage passage and the change of gas permeability for the closed distance protected coal seam. It can be seen from the distribution of acoustic emission in the space that the stratum failure is transferred from deeper to surface. By the analysis of the stress fields changing, the reasons of the gas permeability improvement of the protected coal seam are presented.

Coupling Model of Evolution of Mining Fissure Elliptic Paraboloid Zone and Methane Delivery

2013 ◽  
Vol 734-737 ◽  
pp. 546-550 ◽  
Author(s):  
Hai Fei Lin ◽  
Rui Feng Ma ◽  
Shu Gang Li ◽  
Lian Hua Cheng ◽  
Hong Yu Pan ◽  
...  
Keyword(s):  
Initial Conditions ◽  
Drainage System ◽  
Seepage Flow ◽  
Coupling Model ◽  
Gas Diffusion ◽  
Elliptic Paraboloid ◽  
Field Coupling ◽  
Deformation Equation ◽  
Gas Seepage ◽  
Mass Transfer Theory

After mining, a dynamic distribution of mining fissure elliptic paraboloid zone in the overlying stratum would be formed. Based on the rock mechanics, seepage flow mechanics, mass transfer theory and elastic-plastic theory, the coal-rock mass deformation equation, mixture gas seepage equation and gas diffusion equation of the mining fissure elliptic paraboloid zone are deduced. Combined with various boundaries, initial conditions, the multi-field coupling mathematical model of mining fissure elliptic paraboloid is obtained. The model provides a theoretical basis for numerical simulation of gas drainage system layout.

scholarly journals Electromechanical-Mode Coupling Model and Failure Prediction of CFRP under Three-Point Bending

Electronics ◽  
2021 ◽  
Vol 10 (16) ◽  
pp. 2007
Author(s):  
Ronghua Zhang ◽  
Lifu Zhang ◽  
Hongying Fang ◽  
Wuliang Yin
Keyword(s):  
Carbon Fiber ◽  
Electromechanical Coupling ◽  
Three Dimensional ◽  
Failure Prediction ◽  
Coupling Model ◽  
Polymer Materials ◽  
Three Point Bending ◽  
Conductivity Change ◽  
Electromagnetic Methods ◽  
Stress Damage

Carbon fiber reinforced polymer materials (CFRP) cause CFRP to bend or fail when subjected to external loads or impacts. In the case of static three-point bending, using the conductive properties of the carbon fiber inside the CFRP, the overall damage detection and failure prediction can be carried out by electromagnetic methods. The eddy current coil is used to realize real-time monitoring of damage, and the measured voltage value can be mapped to obtain the load of the sample. This paper conducts theoretical analysis and experimental verification, and obtains the relationship between CFRP stress damage and spatial conductivity change, and proposes a CFRP electromechanical coupling model under quasistatic three-point bending. Combined with the theory of electrically ineffective length, the CFRP three-point bending electromechanical coupling model was revised. Experimental results prove that the revised model can describe the load-conductivity change trend of three-dimensional braided CFRP more accurately, which provides a theoretical basis for monitoring the structural health of CFRP through electromagnetic methods.

scholarly journals Solid-Gas Coupling Model for Coal-Rock Mass Deformation and Pressure Relief Gas Flow in Protection Layer Mining

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Zhuohui Zhu ◽  
Tao Feng ◽  
Zhigang Yuan ◽  
Donghai Xie ◽  
Wei Chen
Keyword(s):  
Rock Mass ◽  
Gas Flow ◽  
Coupling Model ◽  
Pressure Relief ◽  
Coal Rock ◽  
Rock Mass Deformation ◽  
Protection Layer ◽  
Mining Coal ◽  
Migration Law ◽  
Mass Deformation

The solid-gas coupling model for mining coal-rock mass deformation and pressure relief gas flow in protection layer mining is the key to determine deformation of coal-rock mass and migration law of pressure relief gas of protection layer mining in outburst coal seams. Based on the physical coupling process between coal-rock mass deformation and pressure-relief gas migration, the coupling variable of mining coal-rock mass, a part of governing equations of gas seepage field and deformation field in mining coal-rock mass, is introduced. Then, a new solid-gas coupling mathematical model reflecting the coupling effects of gas adsorption/desorption, gas pressure, and coal-rock mass deformation on the mining coal-rock mass deformation and pressure relief gas flow is established combined with the corresponding definite conditions. It lays a theoretical foundation for the numerical calculation of the deformation of mining coal-rock mass and the migration law of gas under pressure relief in the outburst coal seam group.

scholarly journals The Role of the Reverse Fault on the Permeability Evolution in Mining Coal

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Rui Zhou ◽  
Yujin Qin ◽  
Yang Hu
Keyword(s):  
Coal Sample ◽  
Axial Strain ◽  
Deviatoric Stress ◽  
Reverse Fault ◽  
Permeability Evolution ◽  
Concentration Coefficient ◽  
Stress Peak ◽  
Gas Seepage ◽  
Mining Coal ◽  
Stress Concentration Coefficient

To prevent and control the coal seam gas disaster affected by the reverse fault, we performed gas seepage tests, which consider stress-loading and unloading schemes, to investigate the stress change and coal permeability of the mining coal with reverse fault. The experimental results show that the mechanical behavior and permeability change of the mining coal are related to the distance between the coal and the reverse fault. The stress concentration coefficient of the coal body gradually increases. The closer is the distance between the coal and the reverse fault, the larger are the deviatoric stress peak and strain. In comparison with the coal sample M1 that is 5 m away from the reverse fault, the deviatoric stress peak and axial strain of the coal sample M3, 35 m away from the reverse fault, increase by 40.74% and 26.73%, respectively. In this stage, the permeability of M1, M2, and M3 coal samples increases by 22.1%, 28.0%, and 36.7%, respectively. In another stage, the stress concentration coefficient of coal increases to the peak and then decreases, causing the deviatoric stress peak and strain of coal to rise first and then fall. In comparison with the coal sample M4 that is 65 m away from the reverse fault, the deviatoric stress peak and axial strain of coal sample M6, 5 m away from the reverse fault, decrease by 29.48% and 5.55%, respectively. The permeability of coal samples M4, M5, and M6 increases by 23.6%, 37.2%, and 20.8%, respectively. Based on the gas seepage test results, we established the permeability model of mining-induced coal under the influence of a reverse fault, with consideration of the volume changes of coal fractures induced by adsorption and desorption. In the model, the variations of permeability in both stages of the prepeak and postpeak were deduced, which was verified with the experimental data. The verification results demonstrate that the proposed model has the capacity to predict the permeability evolution of mining coal under the influence of a reverse fault.

Stress–damage–flow coupling model and its application to pressure relief coal bed methane in deep coal seam

2011 ◽  
Vol 86 (4) ◽  
pp. 357-366 ◽  
Author(s):  
T.H. Yang ◽  
T. Xu ◽  
H.Y. Liu ◽  
C.A. Tang ◽  
B.M. Shi ◽  
...  
Keyword(s):  
Coal Seam ◽  
Coupling Model ◽  
Coal Bed ◽  
Coal Bed Methane ◽  
Pressure Relief ◽  
Flow Coupling ◽  
Stress Damage

scholarly journals Study on Stability Control of Retained Gob-Side Entry by Blasting Fracturing Roof Technology in Thick Immediate Roof

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jingang Guo ◽  
Yaohui Li ◽  
Fulian He ◽  
GuangSheng Fu ◽  
Sheng Gao
Keyword(s):  
Longwall Mining ◽  
Stability Control ◽  
Surrounding Rock ◽  
Field Practice ◽  
Immediate Roof ◽  
Stress Environment ◽  
The Stability ◽  
Mining Coal ◽  
Stress Damage ◽  
Double Yield

A retained gob-side entry technique is popular in longwall mining coal mines, because the excavation of an entry is reduced for the next panel. However, it is influenced by multiple excavations and mining, so the stability control of the surrounding rock becomes a problem. In view of the above problems, a typical retained gob-side entry with thick immediate roof was carried out, and a blasting fracturing roof technology was used in it to improve the stress environment, reduce the deformation and damage, and ensure stability and safety. To study the fracturing roof parameters, a global model with thick immediate roof considering strain-soft and double-yield constitution was built. It found that the stress, damage range, and deformation of surrounding rock were closely related to the height and angle of fracturing roof, and an optimal case was given out. The simulation result was applied to the field practice, and a good application effect was achieved. The above technique and research method can be used as a reference for the coal mine with similar conditions.

Sign in / Sign up

Export Citation Format

Share Document