Numerical simulation analysis of coal-gas outburst during excavation in coal seams

Author(s):  
Feng Cai ◽  
Zegong Liu
2013 ◽  
Vol 734-737 ◽  
pp. 777-780
Author(s):  
Jian Quan Tang ◽  
Yu Ting Hou ◽  
Chao Zhang ◽  
Jian Hao

Numerical simulation analysis were done on breaking arch developing and evolving process of both single stope and coal seams mining field by FLAC3D. Results show that in single strope's advancing process, breaking arch's height would be different as strope's length changes, and breaking arch's height was decided by strope's length; in composite strope, as the coal pillar increasing, composite strope's breaking arch gradually develops from superposition state to independent state; as the strope's length changing composite strope's superposition state tend to balance


2012 ◽  
Vol 204-208 ◽  
pp. 3377-3383 ◽  
Author(s):  
Feng Cai

Coal-gas outburst is a kind of complex disaster induced by engineer operations in the process of extracting or developing in coal seams. According to the theories of gas seepage and deformation of coal or rock seams, taking consideration of the heterogeneity property of coal or rock materials in mechanics of materials as well as non-linear permeability characteristic of coal or rock materials in the process of deformation and fracture, SPH algorithm of LS-DYNA software is used to numerically simulate the coal-gas outburst induced by development in coal seams. Simulation results represent the whole process of coal-gas outburst from the growing, extending and connecting of cracks to final outburst under the impact of gas pressure, ground stress and mechanical properties of coal-rock. The nonlinear nature of the mutation of outburst induced by gradual destruction of the coal or rock materials under the influence of developing operations is revealed, including the evolution of the stress field in the rupture process of the coal or rock material. This provides a theoretical foundation for further understanding the mechanism of coal-gas outburst as well as preventing outburst technology.


2021 ◽  
pp. 014459872110238
Author(s):  
Feng Du ◽  
Yangyang Guo ◽  
Liang Wang ◽  
Chao Xu ◽  
Aitao Zhou ◽  
...  

In the process of coal-gas outburst, the gas-solid two-phase flow of pulverized coal and gas will induce large-scale damage to underground mining. In this work, in order to study the dynamic evolution law of gas-solid two-phase flow of coal-gas outburst, and clarify the short-time destructive effect of outburst dynamic phenomenon, an EDEM-FLUENT coupled model is constructed to realize the numerical simulation of coal-gas outburst two-phase flow. The simulation results show that the flow velocity of pulverized coal in a short time (tens of milliseconds) approaches to the maximum velocity rapidly, which can reach 60 m/s. The velocity of pulverized coal is inversely proportional to the particle size. The initial acceleration of particles is slow, and then the acceleration increases rapidly. The accumulation angle of pulverized coal in the outburst hole is about 21° and is far less than the natural accumulation angle of pulverized coal, which is consistent with the general phenomenon of coal-gas outbursts. The results also show that the shock wave overpressure of the coal-gas outburst of numerical simulation is similar to that of the physical simulation test, and the difference is less than 10%. And the pressure change in the roadway is completed in short time. In terms of spatial relationships, the pressure at the position closest to the outburst mouth is not the maximum, and the maximum pressure exists at a certain position away from the outburst mouth.


Author(s):  
Luan Labigalini ◽  
Ricardo Salvo ◽  
Rafael Sene de Lima ◽  
Ismael Marchi Neto ◽  
Rodrigo Corrêa da Silva

2021 ◽  
Vol 11 (11) ◽  
pp. 5283
Author(s):  
Jui-Ching Chou ◽  
Hsueh-Tusng Yang ◽  
Der-Guey Lin

Soil-liquefaction-related hazards can damage structures or lead to an extensive loss of life and property. Therefore, the stability and safety of structures against soil liquefaction are essential for evaluation in earthquake design. In practice, the simplified liquefaction analysis procedure associated with numerical simulation analysis is the most used approach for evaluating the behavior of structures or the effectiveness of mitigation plans. First, the occurrence of soil liquefaction is evaluated using the simplified procedure. If soil liquefaction occurs, the resulting structural damage or the following mitigation plan is evaluated using the numerical simulation analysis. Rational and comparable evaluation results between the simplified liquefaction analysis procedure and the numerical simulation analysis are achieved by ensuring that the liquefaction constitutive model used in the numerical simulation has a consistent liquefaction resistance with the simplified liquefaction analysis procedure. In this study, two frequently used liquefaction constitutive models (Finn model and UBCSAND model) were calibrated by fitting the liquefaction triggering curves of most used simplified liquefaction analysis procedures (NCEER, HBF, JRA96, and T-Y procedures) in Taiwan via FLAC program. In addition, the responses of two calibrated models were compared and discussed to provide guidelines for selecting an appropriate liquefaction constitutive model in future projects.


2014 ◽  
Vol 953-954 ◽  
pp. 1638-1642
Author(s):  
Ai Qing Liu ◽  
Jian Zhang ◽  
Peng Cheng ◽  
Yu Hai Zhang

Prestress is a key parameter in bolting, while the cohesive force of layers in the compound roof strata is low and prone to separation, causing the prestress proliferation very poor. With the method of numerical simulation analysis,the location of separation in compound roof to affect the performance of bolting support was researched. It is concluded the roof separation in the edge of anchorage zone, the prestress field superpose, but is away from the deep surrounding rock and shows poor stability,however the role of cable can make up for the defect of rockbolts support. It has been found the highly prestressed strength bolting system adapts to the compound roof.


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