Mechanism Analysis of Anchor Bolt and Cable Synergistic Action in Coal Roadway Support

2014 ◽  
Vol 716-717 ◽  
pp. 735-738 ◽  
Author(s):  
Peng Cheng ◽  
Jian Zhang ◽  
Ai Qing Liu
Keyword(s):  
Simulation Method ◽  
Paper Analysis ◽  
Synergistic Action ◽  
Mechanism Analysis ◽  
Anchor Bolt ◽  
Tension Distribution ◽  
Coal Roadway ◽  
Cable Force ◽  
Roadway Support ◽  
The Stability

Aiming at the current situation of anchor bolt and cable arrangement in mine roadway support, the paper analysis the mechanical characteristics and mechanism of bolts and cables, and numerical simulation method is used to comparison and analysis of pre-tension distribution characteristics under different anchor bolt-cable arrangement. The research indicated that separate anchor bolt-cable layout in different sections, anchor bolt and cable force stable equilibrium, coordinate with each other, at this time roadway surrounding rock of shallow and deep pretension distribution more reasonable, can play a role of bolt anchor cable synergistic action, and form the best pre-tension load-bearing structure, which is helpful to keep the stability of coal roadway.

Study and Application of Three-Step Supporting Design Method in Coal Roadway

2013 ◽  
Vol 353-356 ◽  
pp. 252-257
Author(s):  
Ren Liang Shan ◽  
Xiang Song Kong ◽  
Ji Jun Zhou ◽  
Wen Feng Zhao ◽  
Yu Tao ◽  
...  
Keyword(s):  
Design Method ◽  
Surrounding Rock ◽  
Second Step ◽  
Preliminary Design ◽  
The Third ◽  
Coal Roadway ◽  
Roadway Stability ◽  
Simulation Calculation ◽  
Roadway Support ◽  
The Stability

Scientific supporting design is of great significance to ensure coal roadway stability. The three-step supporting design method is put forward for coal roadway support: The first step is preliminary design, determine the range of each supporting parameter according to the theoretical calculation and supporting experiences; the second step is numerical simulation calculation, choose the reasonable one through the comparison of schemes; the third step is field monitoring, verify the scheme applicability. After applying the three-step supporting design method to study 3# coal seam roadway in Guandi mine, the optimal supporting scheme is obtained, and good results of underground roadway are achieved, which ensure the stability of roadway surrounding rock. Meanwhile, some rules are summarized which provide references for future roadway supporting design.

Study of Anchor Bolt Support in Deep Hard Roof of Roadway of Tangshan Mine

2014 ◽  
Vol 945-949 ◽  
pp. 1163-1168 ◽  
Author(s):  
Rui Xi Zhang ◽  
Yu Kai Lv ◽  
Cong Jiang
Keyword(s):  
High Efficiency ◽  
Simulation Method ◽  
Surrounding Rock ◽  
High Yield ◽  
Anchor Bolt ◽  
Hard Roof ◽  
Mining Depth ◽  
Working Face ◽  
The Stability ◽  
Bolt Support

Traditional trellis support was mainly used in deep mining roadway of Kailuan group. With the increase of mining depth, section of roadway and deformation of surrounding rock also increased gradually. As a passive support ways of roadway, trellis support had been unable to meet the requirements of high yield and high efficiency comprehensive mechanized mining. Therefore, anchor bolt supportis in urgent need to turn passive support into active support and to ensure the safety and the stability of surrounding rock of roadway, meanwhile, the cost saving and boosting yield was made sure. This paper is based on the physical and mechanical parameters of coal seam roof and floor of working face 1357w, numerical simulation method was took, and the parameters of anchor bolt support suitable for the roadway with working face were also studied. The result of study could provide theoretical basis for later projects.

scholarly journals Out-of-plane local mechanism analysis with finite element method

2021 ◽  
Vol 8 (1) ◽  
pp. 130-136
Author(s):  
Roberto Spagnuolo
Keyword(s):  
Finite Element ◽  
Masonry Walls ◽  
Finite Element Models ◽  
Mechanism Analysis ◽  
Fem Method ◽  
Local Mechanism ◽  
Out Of Plane ◽  
Smeared Crack ◽  
The Stability ◽  
No Tension Material

Abstract The stability check of masonry structures is a debated problem in Italy that poses serious problems for its extensive use. Indeed, the danger of out of plane collapse of masonry walls, which is one of the more challenging to evaluate, is traditionally addressed not using finite element models (FEM). The power of FEM is not properly used and some simplified method are preferred. In this paper the use of the thrust surface is suggested. This concept allows to to evaluate the eccentricity of the membrane stresses using the FEM method. For this purpose a sophisticated, layered, finite element with a no-tension material is used. To model a no-tension material we used the smeared crack method as it is not mesh-dependent and it is well known since the early ’80 in an ASCE Report [1]. The described element has been implemented by the author in the program Nòlian by Softing.

scholarly journals Shock Mechanism Analysis and Simulation of High-Power Hydraulic Shock Wave Simulator

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaoqiu Xu ◽  
Han Tao ◽  
Junwei Han
Keyword(s):  
Shock Wave ◽  
High Power ◽  
Structure Optimization ◽  
Simulation Method ◽  
Mechanism Analysis ◽  
Hydraulic Shock ◽  
Characteristic Parameters ◽  
Software Simulation ◽  
Shock Mechanism ◽  
Shock Characteristic

The simulation of regular shock wave (e.g., half-sine) can be achieved by the traditional rubber shock simulator, but the practical high-power shock wave characterized by steep prepeak and gentle postpeak is hard to be realized by the same. To tackle this disadvantage, a novel high-power hydraulic shock wave simulator based on the live firing muzzle shock principle was proposed in the current work. The influence of the typical shock characteristic parameters on the shock force wave was investigated via both theoretical deduction and software simulation. According to the obtained data compared with the results, in fact, it can be concluded that the developed hydraulic shock wave simulator can be applied to simulate the real condition of the shocking system. Further, the similarity evaluation of shock wave simulation was achieved based on the curvature distance, and the results stated that the simulation method was reasonable and the structural optimization based on software simulation is also beneficial to the increase of efficiency. Finally, the combination of theoretical analysis and simulation for the development of artillery recoil tester is a comprehensive approach in the design and structure optimization of the recoil system.

Stability Prediction of Surrounding Rocks and Optimum Design of Roof-Bolt Parameters in Deep Roadway

2013 ◽  
Vol 353-356 ◽  
pp. 436-439
Author(s):  
De Sen Kong ◽  
Yong Po Chen
Keyword(s):  
Prediction Method ◽  
Simulation Method ◽  
Complex Stress ◽  
Roof Bolt ◽  
Deformation And Failure ◽  
Long Run ◽  
Research Findings ◽  
Stress Environment ◽  
Classification Prediction ◽  
The Stability

In order to forecast the stability of deep roadway and optimize the parameters of bolts, the complex stress environment and the multivariate surrounding rocks characteristics of deep roadway were analyzed. Then the classification prediction method and the numerical simulation method were simultaneously used to analysis the stability of surrounding rocks. Furthermore, the supporting parameters of bolts were also designed optimally. It was shown that the characteristics of stress distribution, deformation and failure zone of surrounding rocks are not ideal. So it is necessary to optimize the supporting parameters of deep roadway. All these research findings will provide the theory basis for bolts of deep roadway and will ensure the optimization of bolts and the stability of deep roadway in the long run.

Quasi-Periodic Motion and Hopf Bifurcation of a Two-Dimensional Aeroelastic Airfoil System in Supersonic Flow

2021 ◽  
Vol 31 (02) ◽  
pp. 2150018
Author(s):  
Wentao Huang ◽  
Chengcheng Cao ◽  
Dongping He
Keyword(s):  
Hopf Bifurcation ◽  
Sufficient Conditions ◽  
Theoretical Method ◽  
Simulation Method ◽  
Runge Kutta Method ◽  
Complex Roots ◽  
The Stability ◽  
Necessary And Sufficient ◽  
2D And 3D ◽  
Imaginary Roots

In this article, the complex dynamic behavior of a nonlinear aeroelastic airfoil model with cubic nonlinear pitching stiffness is investigated by applying a theoretical method and numerical simulation method. First, through calculating the Jacobian of the nonlinear system at equilibrium, we obtain necessary and sufficient conditions when this system has two classes of degenerated equilibria. They are described as: (1) one pair of purely imaginary roots and one pair of conjugate complex roots with negative real parts; (2) two pairs of purely imaginary roots under nonresonant conditions. Then, with the aid of center manifold and normal form theories, we not only derive the stability conditions of the initial and nonzero equilibria, but also get the explicit expressions of the critical bifurcation lines resulting in static bifurcation and Hopf bifurcation. Specifically, quasi-periodic motions on 2D and 3D tori are found in the neighborhoods of the initial and nonzero equilibria under certain parameter conditions. Finally, the numerical simulations performed by the fourth-order Runge–Kutta method provide a good agreement with the results of theoretical analysis.

Reinforcing measures of steel roadway support in rockburst prone areas / Wzmacnianie stalowych obudów chodnikowych w obszarach zagrożonych tąpnięciami

2012 ◽  
Vol 57 (1) ◽  
pp. 193-208 ◽  
Author(s):  
Petr Horyl ◽  
Richard Šňupárek
Keyword(s):  
Computer Modeling ◽  
Critical Energy ◽  
Permanent Strain ◽  
Dynamic Events ◽  
Mathematic Modeling ◽  
Mining Safety ◽  
Roadway Support ◽  
The Stability ◽  
Standard Steel ◽  
Adjacent Rock

Due to the strong impacts of rockbursts in Ostrava-Karvina coalfield, which affect especially roadways and cross-cuts of longwall panels, it is necessary to strengthen standard steel roadways and breakthroughs supports. However it is a little different task in comparison with main solved problems of mining safety (Kidybinski, 2011), the use of reinforcing complementary bolts seems to be very effective. A varieties of numbers and locations of such rockbolts have been analyzed and compared from the viewpoint of the stability under dynamic events on the base of 3D mathematic modeling. The method used for computer modeling has been FEM applied by ANSYS code. It deals with the shape and nature the following issues: the deformation of a steel support, strain and deformation of reinforcing bolts, the critical energy by which a permanent strain is caused and the influential interaction of the adjacent rock on the above mentioned characteristics. A recommendation for number and location of reinforcing complementary bolts is also contained.

scholarly journals Classification and Application of Roof Stability of Bolt Supporting Coal Roadway Based on BP Neural Network

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Heng Ren ◽  
Yongjian Zhu ◽  
Ping Wang ◽  
Peng Li ◽  
Yuqun Zhang ◽  
...  
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Site Investigation ◽  
Recognition System ◽  
Quantitative Prediction ◽  
Widespread Application ◽  
Coal Roadway ◽  
Roof Stability ◽  
Stability Classification ◽  
The Stability

In view of the frequent occurrence of roof accidents in coal roadways supported by bolts, the widespread application of bolt support technology in coal roadways has been restricted. Through on-site investigation, numerical analysis, and other research methods, 6 evaluation indicators were determined, and according to the relevant evaluation factors and four types of coal roadway roof stability, a neural network structure for roof stability prediction was constructed to realize the quantitative prediction of the roof stability of bolt-supported coal roadway. The method of adding momentum is used to improve the BP neural network algorithm. After passing the simulation test, it is applied to the field experiment of the roof stability classification. In order to facilitate on-site application, on the basis of the established BP neural network prediction model, a coal mine roof stability classification software recognition system was developed. Using the developed software system, the stability of coal roadway roof is classified into mine, coal seam, and region. According to the recognition result, the surfer software is used to draw the contour map of the stability of the roof of each coal mining roadway. The classification results are consistent with the actual situation on site.

scholarly journals Galloping Stability and Aerodynamic Characteristic of Iced Transmission Line Based on 3-DOF

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xiaohui Liu ◽  
Ming Zou ◽  
Chuan Wu ◽  
Bo Yan ◽  
Mengqi Cai
Keyword(s):  
Wind Speed ◽  
Transmission Line ◽  
Angle Of Attack ◽  
Wind Tunnel Test ◽  
Simulation Method ◽  
Theoretical Formula ◽  
Aerodynamic Load ◽  
Line System ◽  
Critical Wind Speed ◽  
The Stability

A new calculation method of critical wind speed based on three degrees of freedom (3-DOF) is proposed for galloping problem of iced transmission line. Based on the quasistatic theory, the aerodynamic load of iced transmission line is obtained, which considers the influence of transverse and torsional motion on the relative wind angle of attack. Finally, the equivalent galloping model of 3-DOF iced transmission line is established. At the initial angle of attack, the aerodynamic load is expanded by Taylor, and the unsymmetrical linear aerodynamic coefficient matrix is obtained. The Routh–Hurwitz criterion is used to judge the stability of iced transmission line system, and then the critical wind speed is calculated. The in-plane and out-plane frequencies corresponding to the first-order mode of the transmission line are solved by the analytical method and numerical simulation method. The results obtained by the two methods are compared and verified. The influence of dimensionless transmission line parameter λ on the in-plane and out-of-plane frequencies is discussed. The aerodynamic coefficients of the iced transmission line are measured by wind tunnel test and the aerodynamic characteristics are analyzed. According to the theoretical formula, the critical wind speed is calculated by MATLAB. The critical wind speed determined in this paper is compared with the critical wind speed determined by Den Hartog and Nigol theory. The influences of torsional vibration frequency, ice thickness, and ice shape on critical wind speed are analyzed. The research results of this paper have important theoretical significance for the stability judgment of iced transmission lines.

Stability Evaluation of Karst Foundation Based on Orthogonal Test

2013 ◽  
Vol 807-809 ◽  
pp. 1725-1732
Author(s):  
Yi Ping Wu ◽  
Jian Hong Zhou ◽  
Qiu Xia Zhang ◽  
Zhong Jie Zhao
Keyword(s):  
Simulation Method ◽  
Orthogonal Test ◽  
Ratio Method ◽  
Stability Evaluation ◽  
Rock Slide ◽  
Factors Influencing ◽  
Object Based ◽  
Stability Maps ◽  
The Stability ◽  
Stability Results

Many State Grid projects of China are facing a series of natural disaster threats, such as landslide, collapse, mud-rock slide, etc. This article takes the Huangshi Daye Steel Substation as research object. Based on the orthogonal test which confirmed factors influencing the stability, it adopts the Numerical Simulation Method and the Roof Thickness-to-span Ratio Method to evaluate the stability of the Huangshi Daye Steel Substations karst foundation. By doing this, karst foundation stability maps of the substation are respectively obtained. Analyzing the stability results of the two methods, it has been found that the stability evaluation results measured by the two methods are the same. And orthogonal test has advantages such as comprehensiveness, speediness, reliability and accuracy. Meanwhile, according to the stability evaluation results, specific site operation suggestions are proposed.

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