Mechanical and energy characteristics of coal–rock composite sample with different height ratios: a numerical study based on particle flow code

2021 ◽  
Vol 80 (8) ◽  
Author(s):  
Qing Ma ◽  
Yun-liang Tan ◽  
Xue-sheng Liu ◽  
Zeng-hui Zhao ◽  
De-yuan Fan
Keyword(s):  
Numerical Study ◽  
Particle Flow ◽  
Particle Flow Code ◽  
Composite Sample ◽  
Energy Characteristics ◽  
Coal Rock

scholarly journals Numerical Study of Damage to Rock Surrounding an Underground Coal Roadway Excavation

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Jiangbo Wei ◽  
Shuangming Wang ◽  
Zhou Zhao ◽  
Delu Li ◽  
Lipeng Guo
Keyword(s):  
Field Survey ◽  
Numerical Study ◽  
Coal Mines ◽  
Circumferential Stress ◽  
Distribution Patterns ◽  
Particle Flow ◽  
Particle Flow Code ◽  
Stress Release ◽  
Coal Roadway ◽  
Shallow Coal Seam

In coal mines, underground roadways are required to transport coal and personnel. Such tunnels can become unstable and hazardous. This study simulates deformation and damage in the rock surrounding a shallow coal seam roadway using particle flow code. A numerical model of particle flow in the surrounding rock was constructed based on field survey and drilling data. Microcharacteristic indices, including stress, displacement, and microcrack fields, were used to study deformation and damage characteristics and mechanisms in the surrounding rocks. The results show that the stress within the rock changed gradually from a vertical stress to a circumferential stress pattern. Stress release led to self-stabilizing diamond-shaped and X-shaped tensile stress distribution patterns after the excavation of the roadway. Cracking increased and eventually formed cut-through cracks as the concentrated stress transferred to greater depths at the sides, forming shear and triangular-shaped failure regions. Overall, the roof and floor were relatively stable, whereas the sidewalls gradually failed. These results provide a reference for the control of rock surrounding roadways in coal mines.

Numerical Study of Anisotropic Weakening Mechanism and Degree of Non-Persistent Open Joint Set on Rock Strength with Particle Flow Code

2020 ◽  
Vol 24 (3) ◽  
pp. 988-1009 ◽  
Author(s):  
Jie Cui ◽  
Quan Jiang ◽  
Shaojun Li ◽  
Xiating Feng ◽  
Youliang Zhang ◽  
...  
Keyword(s):  
Rock Strength ◽  
Numerical Study ◽  
Particle Flow ◽  
Particle Flow Code ◽  
Open Joint

Numerical Study on Uniaxial Compression Test of Rock Specimen with Random Holes

2011 ◽  
Vol 418-420 ◽  
pp. 848-850
Author(s):  
Bing Xie ◽  
Li Guo ◽  
Xiang Xia
Keyword(s):  
Compressive Strength ◽  
Uniaxial Compression ◽  
Uniaxial Compressive Strength ◽  
Compression Test ◽  
Rock Specimen ◽  
Numerical Study ◽  
Particle Flow ◽  
Particle Flow Code ◽  
Uniaxial Compression Test ◽  
Compression Tests

Numerical specimens with ramdom holes is established by particle flow code PFC2D and uniaxial compression tests are conducted. Studies have shown that the uniaxial compressive strength of the specimen accelerated decline while the porosity increasing uniformly. With the increasing of the porosity，the plastic of the specimen increases.

scholarly journals Research on the Rockburst Tendency and AE Characteristics of Inhomogeneous Coal-Rock Combination Bodies

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Yun-liang Tan ◽  
Wei-yao Guo ◽  
Qing-heng Gu ◽  
Tong-bin Zhao ◽  
Feng-hai Yu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Bonding Strength ◽  
Particle Flow ◽  
Particle Flow Code ◽  
Energy Evolution ◽  
Evolution Law ◽  
Coal Rock ◽  
Exponential Relation ◽  
Compressive Tests

In order to research the influence of homogeneity on the rockburst tendency and on AE characteristics of coal-rock combination body, uniaxial compressive tests of inhomogeneous coal-rock combination bodies obeyed by the Weibull distribution were simulated using particle flow code (PFC2D). Macromechanical properties, energy evolution law, and AE characteristics were analyzed. The results show that (1) the elastic modulus homogeneitymEhas an exponential relation with macroscopic modulusE, and the bonding strength homogeneitymσhas an exponential relation with uniaxial compressive strengthσc; (2) the rockburst tendency of the coal-rock combination body will increase with the increase ofmEormσ, andmσis the leading factor influencing this tendency; and (3) both the change law of AE hits and lasting time in different periods of AE characteristics are influenced bymσ, butmEjust influences the lasting time. The more inhomogeneous the coal-rock combination body is, the shorter the lasting time in booming period of AE characteristics will be. This phenomenon can be used to predict the rockburst tendency of the coal-rock combination body.

scholarly journals Analysis of Acoustic Emission Characteristics and Damage Constitutive Model of Coal-Rock Combined Body Based on Particle Flow Code

Symmetry ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1040 ◽  
Author(s):  
Wanrong Liu ◽  
Wei Yuan ◽  
Yatao Yan ◽  
Xiao Wang
Keyword(s):  
Acoustic Emission ◽  
Constitutive Model ◽  
Particle Flow ◽  
Particle Flow Code ◽  
Emission Characteristics ◽  
Damage Constitutive Model ◽  
Coal Rock ◽  
Three Stages ◽  
Two Stages ◽  
Stable Stage

In this manuscript, the numerical coal-rock combined bodies with different height ratios of rock part to coal-rock combined body (HRRC) were established by particle flow code (PFC) firstly, and then the influence of different HRRC on mechanical properties and numerical acoustic emission (AE) characteristics of coal-rock combined bodies were investigated. Finally, the damage constitutive model of the coal-rock combined body was discussed. The research results show that with the increase of the HRRC, the UCS and the elastic modulus (E) of the combined coal-rock bodies increased. The failure of coal-rock combined bodies is mainly focused on the coal body. The evolution law of AE hits of coal-rock combined bodies have three stages, named stable stage, rapid ascending stage, and rapid descending stage. The damage variable curves of coal-rock combined body have two stages, named slowly damage stage and sharply damage stage. The damage constitutive relation based on AE hits can well reflect the stress-strain relationships with a lower HRRC. However, for a higher HRRC, the damage constitutive equation is not accurately and the damage of the rock part in the coal-rock-combined body should be considered.

scholarly journals Experimental and numerical study of coal-rock bimaterial composite bodies under triaxial compression

2020 ◽  
Author(s):  
Yulong Chen ◽  
Jianping Zuo ◽  
Dejun Liu ◽  
Yingjie Li ◽  
Zhenbo Wang
Keyword(s):  
Composite Structures ◽  
Numerical Study ◽  
Triaxial Compression ◽  
Confining Pressure ◽  
Particle Flow Code ◽  
X Ray ◽  
Numerical Investigations ◽  
Compression Failure ◽  
Confining Pressures ◽  
Coal Rock

Abstract The paper presents experimental and numerical investigations on the response of rock-coal, coal-rock, and rock-coal-rock bimaterial composite structures under triaxial compression. The triaxial compression experiments are conducted under confining pressures in the range of 0–20 MPa. The resulting inside fracture networks are detected using X-ray-based computed tomography (CT). The experimentally observed data indicate that the mechanical parameters of the rock-coal-rock composites are superior to those of the rock-coal and coal-rock combinations. After compression failure, the coal-rock combination specimens are analyzed via X-ray CT. The results display that the failure of the coal-rock composite bodies primarily takes place within the coal. Further, the bursting proneness is reduced by increasing confining pressure. Subsequently, the corresponding numerical simulations of the experiments are carried out by exploiting the particle flow code (PFC). The numerical results reveal that coal is preferable with regard to energy storage and accumulation.

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