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.

Stability Analysis of Side Slope under Normal and Rainfall Conditions

2013 ◽  
Vol 275-277 ◽  
pp. 1383-1388
Author(s):  
Cheng Liang Zhang ◽  
Lei Liu ◽  
Chun Wang
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Unstable State ◽  
Electrical Method ◽  
Rainfall Condition ◽  
Long Term Stability ◽  
Side Slope ◽  
Numerical Simulation Method ◽  
The Stability ◽  
The Impact

The paper studied a side slope engineering of highway in K29+450~K29+900 sections by making an on-site survey of landform and geological features of the side slope. By combining drilling, high-density electrical method and numerical simulation method, the depth and range of the sliding surface were determined. The stability of the side slope after an excavation in a normal and a rainfall conditions was analyzed using numerical simulation method, and simulation results show that in the normal condition the safety factor of the side slope is 1.12, and it is 1.05 in the rainfall condition; the distribution of plastic zones is wide, especially in the rainfall condition, the side slope has a large deformation and is in an unstable state. When a program of side slope reinforcement is chosen, the impact under rainfall condition should be considered in order to ensure long-term stability of side slope.

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.

Numerical Simulation Techniques for Hollow Vacuum Forming of Double-Layered Plastic Sheets

2010 ◽  
Vol 154-155 ◽  
pp. 68-73
Author(s):  
Bin Gao ◽  
Bai Zhong Wu
Keyword(s):  
Numerical Simulation ◽  
Theoretical Calculation ◽  
Temperature Variation ◽  
New Products ◽  
Simulation Method ◽  
Simulation Software ◽  
New Materials ◽  
Forming Process ◽  
Simulation Techniques ◽  
Vacuum Forming

Products made from double-layered hollow vacuum forming are widely used for their various advantages. The hollow vacuum forming process has been studied in this paper. Numerical simulation method for the hollow vacuum forming process of double-layered plastic sheets has been introduced by the simulation software Polyflow, which is suitable for viscoelasticity fluid bodies. This method can vividly and intuitively estimate the thickness, temperature variation and distribution in the double-layered vacuum forming processes. Based on this method, reliably theoretical calculation data can be provided to design the reasonable vacuum forming process for double-layered vacuum forming of new materials or new products. The proposed method has been verified to be applicable and effective by prototype fabrications.

The Parameter Optimization and Field Application of Truss Cable Support System in a Thick Fragmental Coal Seam Roadway

2012 ◽  
Vol 524-527 ◽  
pp. 382-386
Author(s):  
Xiao Kang Zhang ◽  
Hong Jun Jiang ◽  
Fu Lian He ◽  
Ming Yue Weng
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Parameter Optimization ◽  
Support System ◽  
Coal Mine ◽  
Field Application ◽  
Simulation Software ◽  
Surrounding Rock ◽  
Set Up ◽  
Main Support

For the support problem of set-up room to be 7.8m wide with thick and broken coal roof in Pangpangta coal mine, the truss cable support system is adopted to control the set-up room surrounding rock. The main support parameters, such as cable length, cable angle and distance between orifice and side of the truss cable support system are simulated and optimally designed by using numerical simulation software FLAC3D, by which the support scheme is designed reasonably. The support scheme is successfully tested at set-up room No. 10101 in Pangpangta mine. The set-up room deformation is small, and the support system is safe and reliable. This kind of support technology can be widely used in the similar set-up rooms.

scholarly journals Controlling the Deformation of a Small Coal Pillar Retaining Roadway by Non-Penetrating Directional Pre-Splitting Blasting with a Deep Hole: A Case Study in Wangzhuang Coal Mine

Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3084
Author(s):  
Shixing Cheng ◽  
Zhanguo Ma ◽  
Peng Gong ◽  
Kelong Li ◽  
Ning Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Coal Mine ◽  
High Efficiency ◽  
Longwall Mining ◽  
Coal Pillar ◽  
Field Application ◽  
Vertical Stress ◽  
Mine Pressure ◽  
Deep Hole ◽  
Fracture Length

In longwall mining of coal mines, the large deformation of small pillar retaining roadways creates difficulties for the safe and efficient retreating of the mining panel. Based on the engineering background of a small coal pillar retaining roadway in Wangzhuang coal mine, pressure relief technology for non-penetrating directional pre-splitting blasting with a deep hole ahead was proposed. The influence of the non-penetrating fracture length on the pre-splitting effect was studied by numerical simulation. The results showed that the vertical stress in the coal pillar center, the small pillar retaining roadway deformation, and the energy accumulation on the pillar decreased with an increase in the non-penetrating fracture length. The vertical stress at the working face end increased with an increase in the non-penetrating fracture length. The field application and monitoring results indicated that non-penetrating directional pre-splitting blasting could effectively control the deformation of small pillar retaining roadways. The roof-to-floor and rib-to-rib maximum convergences of the 6208 tail entry were reduced by 53.66% and 52.62%, respectively, compared to the results with no blasting. The roadway section met the demands of mining panel high-efficiency retreating, thereby demonstrating the rationality of the technical and numerical simulation results. The research results shed light on the improvement of small coal pillar retaining roadway maintenance theory and technology.

Study on Numerical Simulation of Fully Mechanized Top Coal’s Caving Property of Tang Gong Ta Coal Mine

2015 ◽  
Vol 1094 ◽  
pp. 410-414
Author(s):  
Quan Ming Liu
Keyword(s):  
Numerical Simulation ◽  
Stress Concentration ◽  
Coal Mine ◽  
Peak Stress ◽  
Simulation Method ◽  
Numerical Simulation Method ◽  
Working Face ◽  
Coal Wall

Using numerical simulation method,fully mechanized top coal’s caving property of Tang gong ta coal mine was studied.The results show at primary mining period of fully mechanized working face, there were stress concentration regions at the front and rear of coal wall,but it was not distinct in the front and top coal’s caving property was not ideal.When it advanced to 84m of the working face,there would be obvious peak stress at the front and rear of coal wall. It accelerated top coal’s caving.When it advanced to 140m of the working face,top coal was caved with coal mining.Finally it was proved on the scene. The results of the study in fully mechanized mining’s safety and efficiency has some guiding role.

Numerical Simulation Study on Technology of the Top-Down Bored Excavation with Cast-In Situ Arch

2015 ◽  
Vol 744-746 ◽  
pp. 1027-1032
Author(s):  
Zhong Ren Wang
Keyword(s):  
Numerical Simulation ◽  
Simulation Method ◽  
Practical Significance ◽  
Top Down ◽  
Optimization Analysis ◽  
Flac 3D ◽  
The Stability ◽  
Specific Project ◽  
Stability Of Structure

The top-down bored excavation with cast-in-situ arch method has many advantages, such as forming a complete and stable mechanical structure, reducing construction procedures and the frequency of structure transformation, improving the stability of structure during the construction and so on. According to the specific project of single span top-down bored excavation duct in Changchun Liberation Road station, numerical simulation method is used and finite difference software FLAC 3D is adopted in this paper to analyze and research the applicability of the top-down bored excavation with cast-in-situ arch method to this project. Then optimization analysis for excavation sequence of pilot tunnel is done and the optimum construction scheme is raised to guide the practical project. This research has certain practical significance and also provides references for similar projects.

Stability Numerical Simulation of Daping Landslide Group to Sunjiaya Tunnel

2012 ◽  
Vol 170-173 ◽  
pp. 413-417
Author(s):  
Wen She He ◽  
Long Yuan ◽  
Shuang Mei Chang
Keyword(s):  
Numerical Simulation ◽  
Limit Equilibrium ◽  
Simulation Method ◽  
Work Conditions ◽  
Sliding Surface ◽  
Tunnel Engineering ◽  
Safety Factors ◽  
Easy Method ◽  
Stability Of Slope ◽  
The Stability

The stability of two profile, with No.Ⅲ landslide of Daping landslide group near the tunnel engineering of Sunjiaya, was respectively discussed using limit equilibrium and numerical simulation method at operation one (gravity) and two (gravity+rainstorm) in this paper. The dangerous sliding surface and corresponding safety factors was calculated by limit equilibrium method, to upper and lower parts of No.Ⅲ landslide in two different work conditions. The model of two calculation profiles was established and the dangerous sliding surface and corresponding safety factors was simulated by finite difference software of FLAC3D for upper and lower parts of No.Ⅲ landslide at two operations. Compared with limit equilibrium, FLAC3D is a simple and easy method to analyze the stability of slope.

scholarly journals Study on Mechanical Characteristics of Segmental Joints of a Large-Diameter Shield Tunnel under Ultrahigh Water Pressure

Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8392
Author(s):  
Lei Kou ◽  
Zhihui Xiong ◽  
Hao Cui ◽  
Jinjie Zhao
Keyword(s):  
Numerical Simulation ◽  
Theoretical Calculation ◽  
Water Pressure ◽  
Concrete Strength ◽  
Large Diameter ◽  
Simulation Method ◽  
High Water ◽  
Calculation Model ◽  
Bending Stiffness ◽  
High Water Pressure

At present, there is no clear design standard for segmental joints of large-diameter shield tunnels under high water pressure. In this paper, a theoretical calculation model for the bending stiffness of segmental joints under high water pressure is proposed. The numerical simulation method is used to investigate the failure and crack formation processes of single-layer and double-layer lining segments under large axial forces. The effects of axial force, bolt strength, and concrete strength on the bending stiffness of joints are then studied using a theoretical calculation model of segmental joints. The results show that under extremely high water pressure, the influence of double lining on joint stiffness is limited. It is more rational and safe to compute the bending stiffness of segmental joints using this theoretical model rather than the numerical simulation method. The parameter analysis reveals that increasing the bolt strength has a minor impact on bending stiffness and deformation, whereas increasing the concrete strength has the opposite effect. The influence of ultimate bearing capacity and deformation decreases non-linearly as the axial force increases.

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