scholarly journals On distribution characteristics of the temperature field and gas seepage law of coal in deep mining

2020 ◽  
Vol 24 (6 Part B) ◽  
pp. 3923-3931
Author(s):  
Ming-Qing Yang ◽  
He-Ping Xie ◽  
Ming-Zhong Gao ◽  
Zhi-Qiang He ◽  
Cong Li ◽  
...  
Keyword(s):  
Temperature Field ◽  
Stress Field ◽  
Coal Mining ◽  
Coal Mine ◽  
Temperature Fields ◽  
Seepage Field ◽  
Element Analysis ◽  
Safety Control ◽  
Working Face ◽  
Gas Seepage

The study of gas seepage under the condition of multifield coupling has always been an important topic in coal mining. Based on the theory of multifield coupling and the research method of numerical simulation, the influences of the stress and temperature fields on the seepage field under the conditions of deep coal mining are studied. With the example of the J15-31030 deep working face from mine No. 12 in the Pingdingshan Coal Mine, modeling and finite element analysis are carried out. The influences of the mining stress field and temperature field on the gas seepage field are preliminarily revealed. The results show that the closer to the working face, the greater the velocity of the seepage field is, and the greater the gradient of velocity change. There is a clear negative correlation between the mining stress field and the permeability of the seepage field. The larger the excavation length is, the greater the change gradient of the rock permeability near the working face is. The temperature field has a significant impact on the adsorbed gas in the seepage field. These research results provide the corresponding basis for the safety control and effective mining of coal mine gas.

Piezothermoelasticity and Precision Control of Piezoelectric Systems: Theory and Finite Element Analysis

1994 ◽  
Vol 116 (4) ◽  
pp. 489-495 ◽  
Author(s):  
H. S. Tzou ◽  
R. Ye
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Degrees Of Freedom ◽  
Piezoelectric Sensor ◽  
Temperature Fields ◽  
Element Analysis ◽  
Energy Functionals ◽  
System Equation ◽  
Distributed Controls ◽  
And Control

Piezothermoelastic effects of distributed piezoelectric sensor/actuator and structural systems are studied. Distributed controls (static and dynamic) of piezoelectric laminates subjected to a steady-state temperature field are investigated. Piezothermoelastic constitutive equations are defined, followed by three energy functionals for the displacement, electric, and temperature fields, respectively. A new 3-D piezothermoelastic thin hexahedron finite element with three internal degrees of freedom is formulated using a variational formulation which includes thermal, electric, and mechanical energies. A system equation for the piezoelectric continuum exposed to combined displacement, electric, and temperature fields is formulated. Distributed sensing and control equations of piezoelectric laminates in a temperature field are derived. Thermal influences on the sensing and control of piezoelectric PZT/steel laminates are investigated in case studies.

Stabality Analysis of Deep Roadway Based on Coupled Thermo-Hydro-Mechanical Behaviors

2012 ◽  
Vol 594-597 ◽  
pp. 2564-2568
Author(s):  
Qi Feng Guo ◽  
Fen Hua Ren ◽  
Zhao Cai Zhang
Keyword(s):  
Temperature Field ◽  
Numerical Model ◽  
Stress Field ◽  
Constitutive Relation ◽  
Mechanical Behaviors ◽  
Seepage Field ◽  
Mechanical Equation ◽  
Rock Temperature ◽  
Ground Stress ◽  
The Stability

In order to research the stability of excavation in deep mines under high ground stress, high rock temperature and high karst hydraulic, the interaction of stress field, seepage field and temperature field are discussed through basic constitutive relation, seepage equation, thermometer equation and coupled thermo-hydro-mechanical equation. A numerical model was built to simulate the excavation of deep roadway. The result shows that the simulated ground stress based on three fields coupled is much closer to the field measured value and the change of stress and displacement caused by the excavation are limited which is about same as the later monitoring.

Water Probe in Coal Mine Working Face

2013 ◽  
Vol 734-737 ◽  
pp. 888-891
Author(s):  
Chen Shi
Keyword(s):  
Hydraulic Conductivity ◽  
Coal Mining ◽  
Coal Mine ◽  
Mine Working ◽  
Mine Water ◽  
Theoretical Calculations ◽  
Drainage System ◽  
Water Inflow ◽  
Interference Method ◽  
Working Face

Water probe in coal mine working face is an important part of the work of Mine Water. When the mine working face close to the aquifer hydraulic conductivity faults, underground rivers, caves and hydraulic conductivity collapse columns; extractive damaging effects, water probe should be done. However, the calculation of water inflow face probe has no feasible way. This paper discussed the theoretical calculations to explore water drilling inflow well group interference method and provides the basis for provision of drainage system for the coal mining enterprises.

The Finite Element Analysis of Coupling Law of Single Phase Stress Field / Seepage Field in Permeable Stratum Medium

2011 ◽  
Vol 71-78 ◽  
pp. 3067-3070
Author(s):  
Yu Fen Mei
Keyword(s):  
Finite Element ◽  
Porous Medium ◽  
Stress Field ◽  
Single Phase ◽  
Average Stress ◽  
Seepage Field ◽  
Element Analysis ◽  
Finite Element Software ◽  
Total Displacement ◽  
Contrast Analysis

The research of reservoir fluid-solid coupling theory is hot issues in home or foreign recently, In oil, civil, environment and geology, mining and other fields with a wide application. On the basis of summarizing the predecessors' achievements，according to the basic theory of rock mechanics, fluid mechanics in porous medium, geologic mechanics, calculated mechanics and fluid-solid coupling seepage, a mathematical and numerical model of seepage field and stress field coupling is developed in porous medium and the LiuNan blocks of JiDong oilfield wells.based area single phase Stress Field / Seepage Field in solving with the method of finite element software ANSYS, Contrast analysis of LiuNan blocks Coupling around of Field / Seepage Field is the change of average stress and total displacement. As can be seen from Table 3, after coupling the value of average stress and total displacement are greater than before coupling.The results show than it is important meaning for used to solve practical engineering problems.

Finite Element Analysis of Temperature Filed and Stress Field of Reducer

2014 ◽  
Vol 881-883 ◽  
pp. 1447-1450
Author(s):  
Jing Zhang ◽  
Fei Wang
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Temperature Field ◽  
Stress Field ◽  
Residual Stress Field ◽  
Element Analysis ◽  
Welding Temperature ◽  
Stress And Deformation ◽  
Residual Stress And Deformation

Abstract.The connection mode of reducer with straight tube on both sides are the welding connection. There are two weld at the both side of reducer and there has a great influence on residual stress and deformation in the process of welding . Based on the particularity of reducer welding, the paper is focus on the residual stress and deformation in the process of welding, using large-scale finite element analysis software ANSYS .The DN500X450 reducer model is established.The welding temperature field and residual stress field is analysis and calculation and analysis the influence on temperature and stress distribution of reducer. The results show that the maximum of the temperature and the residual stress is located in the big side and reduce the welding seam, and the obvious deformation also find in the big side and reduce joint . The reducing pipe’s distribution of temperature field and residual stress field are obtained,providing the basis to establish properly and optimize of welding process.

Laser-Induced Thermal Damage to K9 Glass on Finite Element Method

2013 ◽  
Vol 444-445 ◽  
pp. 1422-1426
Author(s):  
Li Zi Chen ◽  
Chun Yuan Jing ◽  
Xiao Wei Guan
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Thermal Stress ◽  
Stress Field ◽  
Thermal Damage ◽  
Laser Damage Threshold ◽  
Element Analysis ◽  
Finite Element Software ◽  
Thermal Stress Field ◽  
K9 Glass

Based on the theory of the thermal conduction and the thermal elastic equations, does some researches in view of the thermal Damage of K9 glass by finite element analysis. The distribution of temperature field and thermal stress field of the ideal K9 glass which irradiated by 100W pulsed-Nd: YAG laser are simulated with finite element software. The result shows that the temperature of the surface of glass doesnt reach the melting and the thermal stress of it doesnt get to the requirement for fracture strength. Then, the model of K9 glass containing inclusions has be built. The simulation result indicates that inclusions may affect the distribution of temperature field and thermal stress field of the K9 glass, which makes the injected laser beams energy centralize on a small area around the inclusions owing to the existence of the strong absorbing, thus leading to K9 glass laser damage threshold reduction and easier to thermal damage.

scholarly journals Mechanism by Which Backfill Body Reduces Amount of Energy Released in Deep Coal Mining

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Wenyue Qi ◽  
Jixiong Zhang ◽  
Nan Zhou ◽  
Zhongya Wu ◽  
Jun Zhang
Keyword(s):  
Energy Density ◽  
Coal Mining ◽  
Coal Mine ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Mining Area ◽  
Filling Material ◽  
Ultrahigh Energy ◽  
Energy Density Distribution ◽  
Working Face

Deep coal mining is unavoidable, and the complex mining environments and the increasing dangers associated with ultrahigh energy accumulation and release from mining disturbances renders it extremely difficult to maintain a safe and stable stope. Solid backfilling technology directly uses coal gangue and other solid wastes in the mining area to fill the gob after mining. Support from the backfill body can inhibit the movement of overlying rock strata and significantly alleviate the influence of mining. In this study, the correlations between the deformation of gangue filling material and the characteristics of energy dissipation were examined under lateral uniaxial compression. The strain energy density distributions of backfilling and caving mining methods were simulated using numerical modeling. The results showed that the strain energy density distribution of backfilling mining was less concentrated, and its peak value was lower than that of caving mining by 51.0%, indicating that backfilling could effectively reduce the amount of energy released from mining rocks. The dense backfill mining area of the No. 9301 face in Tangkou Coal Mine was used as a case study. Measures for controlling the backfill body compaction for reducing the amount of energy released from mining rocks were proposed. These measures include optimizing the support structure and filling material formula, controlling the preroof subsidence, and ensuring an appropriate number of tamping strokes. The monitoring results of the backfilling quality, surface subsidence, and microseismic energy of No. 9301 working face in Tangkou Coal Mine showed that when the backfill body filling ratio control value was 82.28%, the total number of microseisms and the amount of energy released from the mining working face were significantly lower compared to those of the caving method. This study demonstrated that the backfill body could effectively reduce the amount of energy released from mining rocks, thereby realizing management of mine earthquake and sustainable deep coal mining.

Finite Element Analysis for the Stress Field and Seepage Field Interaction within Qingdao Submarine Tunnel Rockmass

2013 ◽  
Vol 405-408 ◽  
pp. 1278-1282
Author(s):  
Cheng Li ◽  
Tai Quan Zhou ◽  
Sha Sha Jiang ◽  
Jie Kong
Keyword(s):  
Finite Element ◽  
Rock Mass ◽  
Stress Field ◽  
Plastic Region ◽  
Tunnel Lining ◽  
Secondary Stress ◽  
Seepage Field ◽  
Element Analysis ◽  
Severe Condition ◽  
Finite Element Software

The submarine geology characteristic for Qingdao submarine tunnel is fracture and fragmentation with smash rock mass and unevenly distributed rock mass strength. The submarine tunnel is excavated in a weathered rock mass containing water. Before the tunnel lining is constructed, it is important to assure the stability and safety for the rock tunnel and tunnel lining structure during construction and operational periods. As the submarine tunnel is under severe condition, the rock mass stabilization is to a large extent to be determined by the underwater seepage effect. It is fundamental to investigate how the seawater interacts with the tunnel rock mass stress field. To investigate the interaction between the rock mass seepage field and the secondary stress field, the nonlinear finite element software ABAQUS is used to analyze the interaction behavior between the rock mass seepage effect and the tunnel secondary stress field. The rock mass seepage field, stress field are analyzed in detail using the numerical simulation method. Also, the distribution of the tunnel rock mass plastic region is obtained. The numerical analysis results provide guidance for the submarine tunnel construction.

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