Numerical Research on the Floor Heave Control of Deep Roadway in Coal Mining

2012 ◽  
Vol 524-527 ◽  
pp. 446-449 ◽  
Author(s):  
Fu Kun Xiao ◽  
Chun Jie Zhang ◽  
Li Wei Gao ◽  
Yang Yang Yue
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Good Effect ◽  
Optimal Program ◽  
Anchor Cable ◽  
Geological Conditions ◽  
Floor Heave ◽  
Mine Roadway ◽  
Numerical Research ◽  
Main Factors

On the engineering background of coal mine roadway orbit, according to the destruction of its original roadway, the paper have analyzed the situation of the deformation in the roadway , using the method of numerical simulation. Besides, it also determined the stress distribution and the forces supporting of roadway in the deformation process. Geological conditions, support patterns and bad construction are considered as the main factors of roadway damage and new support method is given. Numerical simulation method is used to study mechanism about anchor rod, anchor cable and anchor mesh coupled with the surrounding, bottom corner anchor rod and grouting to determine the optimal program. The new program is applied to the practice field and monitored, indicating that the application has a very good effect.

scholarly journals Numerical Simulation of the Effect of Dynamic Stress on the Rock Surrounding a Mine Roadway

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jun-hua Xue ◽  
Ke-liang Zhan ◽  
Xuan-hong Du ◽  
Qian Ma
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Rock Burst ◽  
Dynamic Stress ◽  
Simulation Method ◽  
Mining Areas ◽  
Geological Conditions ◽  
Mine Roadway ◽  
The Stability ◽  
Two Sides

In view of the damage of dynamic stress to the rock surrounding a mine roadway during coal mining, based on the actual geological conditions of Zhuji mine in Huainan, China, a UDEC model was established to study the influences of the thickness and strength of the direct roof above the coal seam and the anchorage effect on the stability of the roadway. The failure mechanism and effect of the dynamic stress on the rock surrounding a mine roadway were revealed. Under dynamic stress, cracks appear near the side of the roadway where the stress is concentrated. These cracks rapidly expand to the two sides of coal and rock mass. At the same time, the coal and rock mass at the top of the roadway fall, and finally, the two sides of coal and rock mass were broken and ejected into the roadway, causing a rock burst. However, when the same dynamic stress is applied to the roadway after supports are installed, there is no large-deformation failure in the roadway, which shows that, under certain conditions, rock bolting can improve the stability and seismic resistance of the surrounding coal and rock mass. Furthermore, by simulating the failure of surrounding rock with different strengths and thicknesses in the immediate roof, it is found that the thinner the roof, the greater the influence of the dynamic stress on the roadway; the stronger the roof is, the more likely the rock burst will occur with greater intensity under the same dynamic stress. A numerical simulation method was used to analyze the factors influencing rock bursting. The results provide a theoretical basis for research into the causes and prevention of rock bursts in deep mining areas.

scholarly journals Numerical Simulation of The Response of An Underground Pipeline Connector With a Super-Large Section Under Complex Geological Conditions

2021 ◽  
Author(s):  
Long Ma ◽  
Ping Ai ◽  
ChuanSheng Xiong
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Simulation Method ◽  
Large Section ◽  
Simulation Accuracy ◽  
Numerical Simulation Method ◽  
Geological Conditions ◽  
The Finite Element Model

Abstract Aiming at the low simulation accuracy of the numerical simulation method of the joint response of the super-large section underground comprehensive pipeline gallery under the current complicated geological conditions, a numerical simulation method of the joint response of the super-large section underground comprehensive pipe gallery joint response under the complicated geological conditions based on the finite element model was proposed. According to the analysis process for the super-large section underground comprehensive pipe gallery, the viscous boundary of the comprehensive pipe gallery is determined. Additionally, by analyzing soil and structural parameters, the optimal combined dynamic boundary is used as the model boundary. The HSS model is used to describe the constitutive structure of the soil, and by improving the Goodman element to describe the contact surface of the model, the finite element model of the joint response of the comprehensive pipe gallery is constructed. Furthermore, based on the internal force balance and deformation coordination conditions, considering the influence of the deformation shape of the joint joints and the elongation of the prestressed tendons on the finite element model, the response model of the integrated pipe gallery joint is optimized. Experimental results show that the proposed method has higher numerical simulation accuracy.

scholarly journals Experimental and Numerical Research on the Influence of Stern Flap Mounting Angle on Double-Stepped Planing Hull Hydrodynamic Performance

2019 ◽  
Vol 7 (10) ◽  
pp. 346 ◽  
Author(s):  
Zou ◽  
Lu ◽  
Jiang ◽  
Sun ◽  
Li
Keyword(s):  
Numerical Simulation ◽  
Critical Speed ◽  
Simulation Method ◽  
Hydrodynamic Performance ◽  
Water Mixture ◽  
Mixture Flow ◽  
Resistance Reduction ◽  
Numerical Simulation Methods ◽  
Numerical Research ◽  
Resistance Performance

In the current hydrodynamic research relating to planing hulls, the stern flap and steps are generally considered to be two independent resistance reduction measures. Limited research has focused on the coupled effects of flaps and steps. Therefore, experimental and numerical simulation methods are carried out in this paper to explore the influence of the flap mounting angle coupled with the steps. A series of model towing tests were implemented for a double-stepped planing hull with 2°, 3° and 4.5° flap angles. The test results show that, as the mounting angle increased, the low speed resistance performance was improved and the porpoising critical speed was delayed, with a slight resistance cost. Based on the tests, a numerical simulation method was established with volume Froude numbers ranging from 0.88 to 5.20. The simulated hull flow field showed good agreement with the testing data. The simulation results suggest a cavity induces the negative pressure after the steps; the cavity core region is the air phase, and this expands with the air–water mixture flow. The cavity also causes wetted surface reduction and pressure distribution changes. Finally, comparisons of cavities after-steps and load coefficients of different planing surfaces among models were considered. Numerical results analysis gave distinct interpretations for the experimental phenomenon of porpoising critical speed increasing with a slight resistance increment.

Numerical Simulation Analysis of Different Coal Mine Roadway Support Effect

2013 ◽  
Vol 807-809 ◽  
pp. 2356-2360 ◽  
Author(s):  
Guang Yi Sun ◽  
Xiao Luo
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
Simulation Analysis ◽  
Support Effect ◽  
Surrounding Rock ◽  
Anchor Cable ◽  
Mine Roadway ◽  
Coal Wall ◽  
Roadway Support

The application of FLAC2D software long ditch coal mine extraction tunnel without support boltgrouting. Anchor when the anchor rope supporting and strengthening supporting state ofroadwaywere simulated and analyzed the change of roadway surrounding rock under differentsupport forms. Demonstrated the possibility that the current anchor cable anchor supporting andanalysis under the condition of the coal wall broken grouting bolt is the necessity of reinforcement.

scholarly journals Study on Numerical Simulation of Fire Danger Area Division in Mine Roadway

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Hu Wen ◽  
Yin Liu ◽  
Jun Guo ◽  
Ze Zhang ◽  
Mingyang Liu ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
High Temperature ◽  
Gas Flow ◽  
Concentration Field ◽  
Environmental Parameters ◽  
Simulation Method ◽  
Development Stage ◽  
Calculation Model ◽  
Mine Fire ◽  
Mine Roadway

High-temperature poisonous smoke produced by coal mine roadway fire seriously affects miners' lives and safety. Studying the development law of high-temperature smoke in the process of mine roadway fire and then exploring the danger of roadway are of great significance to personnel safety and post-disaster rescue. In order to study this problem, the CFD numerical simulation method is used to establish a fire calculation model based on ANSYS Fluent software in the development stage of mine fire. The high-temperature flue gas flow in the roadway during the development stage of mine fire is simulated, and the variation law of temperature field and gas concentration field with time and space position under different levels of roadway in the development stage of fire is revealed. The variation rules of environmental parameters, such as temperature, CO, and CO2, are obtained by numerical calculation. Based on these, the danger zones of smoke spread in fire development stage are divided by the critical values of high-temperature smoke and toxicity evaluation index, and the mathematical fitting analysis of the evolution of the dangerous area with time is carried out. The research results have certain theoretical guiding significance for reducing underground environmental pollution and ensuring the personal safety of workers and rescuers.

scholarly journals Study on environmental impact of artificial horizontal freezing method in subway connecting passage

2020 ◽  
Vol 198 ◽  
pp. 04023
Author(s):  
Changyi Yu ◽  
Mingyue Lu
Keyword(s):  
Numerical Simulation ◽  
Environmental Impact ◽  
Simulation Method ◽  
Simplified Model ◽  
Thermophysical Parameters ◽  
Freezing Method ◽  
Geological Conditions ◽  
Complex Boundary ◽  
Artificial Freezing ◽  
Artificial Freezing Method

When the subway is built in complex urban strata, especially when excavating near buildings, it is necessary to strictly control the freezing amount by adopting artificial freezing method. At present, the theoretical calculation is aimed at the frozen rise under ideal conditions, but for complex geological conditions, the simplified model results are difficult to meet the actual requirements. However, numerical calculation can adapt to complex strata and complex boundary conditions. Therefore, in this paper, the environmental impact of artificial horizontal freezing method in subway connecting passage is studied by numerical simulation, and the change of thermophysical parameters with the change of temperature field is considered in the simulation. The simulation method in this paper provides guidance for actual construction.

Numerical Simulation of Terminal Shock Oscillation in Over/Under Turbine-Based Combined-Cycle Inlet

2017 ◽  
Vol 0 (0) ◽  
Author(s):  
Jun Liu ◽  
Huacheng Yuan ◽  
Meng Yao ◽  
Ning Ge
Keyword(s):  
Numerical Simulation ◽  
Separation Bubble ◽  
Control Point ◽  
Simulation Method ◽  
Combined Cycle ◽  
Key Factors ◽  
Oscillation Phenomenon ◽  
Shock Oscillation ◽  
Main Factors ◽  
Unsteady Numerical Simulation

AbstractThe physical characteristics of self-sustain shock oscillation and the key factors that affect the shock oscillation in turbine-based combined-cycle(TBCC) inlet were investigated through unsteady numerical simulation method in this paper. The terminal shock oscillation in the throat was caused by the separation bubble appeared in the lower wall of the turbojet flowpath. The angle of the splitter and the offset of the diffuser were the main factors which affect the characteristics of the shock oscillation. When the angle of the splitter increased from 0 deg to 12 deg, the frequency of terminal shock increased from 100Hz to 133Hz; while when it was greater than 18 deg the terminal shock oscillation phenomenon disappeared. Different offset of the turbojet diffuser affect the motion of terminal shock in the inlet. When the y-coordinate value of the control point (y

scholarly journals Numerical simulation analysis of anchorage characteristics of constant-resistance and large-deformation anchor cable for highly weathered rock masses

2020 ◽  
Author(s):  
Tao Zhigang ◽  
Deng Fei ◽  
WANG Zhicai ◽  
QIAO Xiaobing ◽  
LI Mengnan ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Axial Force ◽  
Simulation Analysis ◽  
Shear Strain Rate ◽  
Reinforcement Effect ◽  
Anchorage Length ◽  
Reinforcement System ◽  
Anchor Cable ◽  
Geological Conditions ◽  
Calculation Results

Abstract In order to effectively maintain the stability of high and steep loose slopes around the site of the Tonglushan Ancient Copper Mine in Daye City, Hubei Province, the NPR anchor cable reinforcement system was introduced. Based on the significance of anchorage characteristics of NPR anchor cable for the whole reinforcement system, we first investigated and analyzed the engineering geological conditions of the ancient smelting site slopes, while selected a typical highly weathered section to establish a numerical simulation calculation model. Following, utilized the FLAC3D method to numerically calculate the reinforcement effect of NPR anchor cables under various anchorage lengths. Finally, based on the calculation results, we reveal the changes in displacement, as well as in stress and anchor cable axial force of the site slope, analyzing the shear strain rate and evolution characteristics of plastic zone near the potential sliding surface. The calculation results show that as the NPR anchorage length increase, the displacement gradually decrease. Moreover, the maximum axial force of the NPR anchor cable and the principal stress of the slope change slightly, while the plastic failure range gradually decrease; when the anchorage length is 20m, the safety factor reach the peak value and the reinforcement effect is optimal, which lay the theoretical and practical foundation for the reinforcement control of similar site slopes.

Numerical Analysis on Mechanical and Deformation Characteristics of Pile-Anchor Retaining Structure for Waterway Excavation

2013 ◽  
Vol 734-737 ◽  
pp. 682-685
Author(s):  
Zhi Yu He ◽  
Jiang Feng Wang ◽  
Li Fu
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Inflection Point ◽  
Horizontal Displacement ◽  
Simulation Method ◽  
Measured Data ◽  
Deformation Characteristics ◽  
Retaining Structure ◽  
Anchor Cable ◽  
Construction Procedure

Mechanical and deformation characteristics of pile-anchor retaining structure was analyzed by using numerical simulation method. The rationality of numerical model was also verified through comparing measured data in field test and numerical results. On the basis of this numerical model, Mechanical and deformation characteristics of pile-anchor retaining structure under three different construction procedures were analyzed individually. The results show that: the maximum horizontal displacement of pile is controlled effectively by applying anchoring force, and the global horizontal displacement of pile increases as well. Forced state of pile is changed from being bended on one side to being bended on both sides, and maximum moment value decreases heavily. Therefore, anchor cable reinforcement should be arranged at the head of construction procedure of pile-anchor retaining structure. The later anchoring force be applied, the closer inflection point nears the pile top.

Study on the Magnitude of the Roadway-Protection Pillar in the Isolated Face

2014 ◽  
Vol 1065-1069 ◽  
pp. 844-847
Author(s):  
Yan Wei Li ◽  
Lei Meng ◽  
Ji Ping Liu
Keyword(s):  
Numerical Simulation ◽  
Theoretical Calculation ◽  
Production Process ◽  
Coal Mine ◽  
Simulation Method ◽  
Field Application ◽  
Good Effect ◽  
Actual Production ◽  
The Stability ◽  
Protection Pillar

In the actual production process, Zhengli Coal Mine has a problem to make sure that the width of chain pillars. This paper from the view of field application with theoretical calculation and numerical simulation method to calculate and verify the stability and security of the chain pillars, It achieved good effect and finally determined the width of chain pillars.

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