scholarly journals Study on Numerical Simulation of Geometric Elements of Blasting Funnel Based on PFC5.0

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Wenle Gao ◽  
Zehua Zhang ◽  
Baojie Li ◽  
Kunpeng Li
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Expansion Method ◽  
Simulation Method ◽  
Particle Flow Code ◽  
Mass Model ◽  
Guide Field ◽  
Blasting Test ◽  
Geometric Elements ◽  
Charge Mode

Based on the particle flow code (PFC2D) within the discrete element method (DEM), the rock mass model was established according to the site rock conditions and the rock mass blasting was simulated by the explosive particle expansion method. The influence of various parameters (the peak pressure action coefficient of the borehole wall, explosive particle buried depth, and charge mode) in the explosive particle expansion method on blasting effect was investigated. Furthermore, the relationship between the various parameters and the geometry size of the blasting crater was obtained. By comparing the size of blasting crater in the field blasting test and numerical simulation example, the reliability of rock mass blasting simulated by the explosive particle expansion method using PFC is verified. The result shows that this paper provides a reliable new numerical simulation method for rock mass blasting and can be used to guide field blasting.

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 of Railway Track Irregularities Based on Stochastic Expansion Method of Standard Orthogonal Bases

2012 ◽  
Vol 178-181 ◽  
pp. 1373-1378 ◽  
Author(s):  
Heng Bin Zheng ◽  
Quan Sheng Yan ◽  
Jun Liang Hu ◽  
Zhou Chen
Keyword(s):  
Numerical Simulation ◽  
Stochastic Process ◽  
Random Variables ◽  
Expansion Method ◽  
Simulation Method ◽  
New Method ◽  
Railway Track ◽  
Independent Random Variables ◽  
Orthogonal Bases ◽  
Track Irregularities

A new simulation method of stochastic process was accepted in the field of simulation for the track irregularities. This method adopted the Hartley orthogonal bases as the standard orthogonal bases. On the basis of the expansion method of stochastic process, and under the condition of ensuring accuracy, it could capture main probabilistic characters of a stochastic process with only a few independent random variables. Through the numerical simulation of the example, it testified the validity and effectiveness of the new method.

scholarly journals Collapsed Shape of Shallow Unlined Tunnels Based on Functional Catastrophe Theory

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Chengping Zhang ◽  
Kaihang Han
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Catastrophe Theory ◽  
Particle Flow ◽  
Particle Flow Code ◽  
Direct Estimate ◽  
Basic Principles ◽  
Collapse Mechanisms ◽  
Functional Catastrophe Theory ◽  
Shape Curve

This paper investigates the collapse mechanisms and possible collapsing block shapes of shallow unlined tunnels under conditions of plane strain. The analysis is performed following the framework from a branch of catastrophe theory, functional catastrophe theory. First, the basic principles of functional catastrophe theory are introduced. Then, an analytical solution for the shape curve of the collapsing block of a shallow unlined tunnel is derived using functional catastrophe theory based on the nonlinear Hoek-Brown failure criterion. The effects of the rock mass parameters of the proposed method on the shape and weight of the collapsing block are examined. Moreover, a critical cover depth expression to classify deep and shallow tunnels is proposed. The analytical results are consistent with those obtained by numerical simulation using the particle flow code, demonstrating the validity of the proposed analytical method. The obtained formulas can be used to predict the height and width of the collapsing block of a shallow unlined tunnel and to provide a direct estimate of the overburden on the tunnel lining. The obtained formulas can be easily used by tunnel engineers and researchers due to their simplicity.

Seepage Numerical Simulation Methods of Hard Fractured Rock Mass

2013 ◽  
Vol 423-426 ◽  
pp. 1330-1333
Author(s):  
Gang Lei
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Permeability Coefficient ◽  
Hard Rock ◽  
Fractured Rock ◽  
Triaxial Compression ◽  
Equivalent Plastic Strain ◽  
Simulation Method ◽  
Numerical Simulation Methods ◽  
Fissure Water

According to the seepage action of hard rock fissure water, a numerical simulation method is proposed in this paper. The basic mechanical properties for rock mass changed significantly during the process of secondary stress adjustments, and the rock deterioration constitutive model (RDM) can accurately reflect both the abruptness of the rock yield failure and the changes of mechanical parameters after yield. On the basis of RDM, the permeability coefficient with equivalent plastic strain function was introduced in this method which can update the permeability coefficient, and carried out numerical simulation on hard rock fissure water seepage action by FLAC3D. The results of the seepage triaxial compression experiment proved the rationality of the method.

scholarly journals Thermo-mechanical coupling numerical simulation method under high temperature heterogeneous rock and application in underground coal gasification

2020 ◽  
Vol 38 (4) ◽  
pp. 1118-1139
Author(s):  
Xiaopeng Liu ◽  
Guangli Guo ◽  
Huaizhan Li
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Rock Mass ◽  
High Temperature ◽  
Coal Gasification ◽  
Geotechnical Engineering ◽  
Simulation Method ◽  
Underground Coal Gasification ◽  
Strata Movement ◽  
Mechanical Coupling

The heterogeneity of a rock mass under high temperature and its thermo-mechanical coupling characteristics are difficult problems to investigate. This situation brings considerable difficulties to the study of underground coal gasification under thermo-mechanical coupling. The development of a numerical simulation method for the thermo-mechanical coupling of heterogeneity rock mass under high-temperature burnt conditions can provide an important foundation for related research. On the basis of the variation of mechanical properties of rock mass with temperature, a thermo-mechanical coupling simulation method, which considers the heterogeneity of a rock mass under high temperature, is proposed in this study. A test block experiment is implemented and then applied to the strata movement and failure of underground coal gasification. The results are as follows: (1) The proposed method can truly reflect the heterogeneity of a rock mass under high-temperature environment, providing an effective method for the numerical simulation of geotechnical engineering in high-temperature conditions. (2) The variation of mechanical properties of rock mass after an increase in temperature is the main reason for the change law of strata movement and failure of underground coal gasification. These factors should be considered in the investigation of underground gasification strata movement and failure. The present study can provide an important means for the research on geotechnical engineering in high-temperature environments.

Numerical Simulation of Damage and Deformation Characteristics of Rock Mass with Transfixion Joint

2013 ◽  
Vol 405-408 ◽  
pp. 369-372
Author(s):  
Lei Wang ◽  
Jiang Yu ◽  
Jian Xin Han
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Strain Curve ◽  
Simulation Method ◽  
Joint Surface ◽  
Deformation Characteristics ◽  
Stress Strain Curve ◽  
Deformation Parameters ◽  
Strength And Deformation ◽  
Set Up

Use FLAC3D, the interface command to define joint surface, set up rock mass models with 15 °, 30 °, 60 °, etc. different dip joint, and in accordance with the laboratory test data of rock and joint surface for a variety of strength and deformation parameters setting, carries on the numerical simulation of uniaxial compression. Got failure mode, plastic zone evolution and the stress strain curve of rock mass with different dip joint, and the result compared with the actual test has a higher similarity, to prove the feasibility of the numerical simulation method.

scholarly journals Stress wave propagation in different number of fissured rock mass based on nonlinear analysis

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaoming Lou ◽  
Mingwu Sun ◽  
Jin Yu
Keyword(s):  
Numerical Simulation ◽  
Rock Mass ◽  
Confining Pressure ◽  
Displacement Discontinuity ◽  
Stress Wave Propagation ◽  
Theoretical Derivation ◽  
Mechanics Model ◽  
Fissured Rock ◽  
Deep Rock ◽  
Theoretical Accuracy

AbstractThe fissures are ubiquitous in deep rock masses, and they are prone to instability and failure under dynamic loads. In order to study the propagation attenuation of dynamic stress waves in rock mass with different number of fractures under confining pressure, nonlinear theoretical analysis, indoor model test and numerical simulation are used respectively. The theoretical derivation is based on displacement discontinuity method and nonlinear fissure mechanics model named BB model. Using ABAQUS software to establish a numerical model to verify theoretical accuracy, and indoor model tests were carried out too. The research shows that the stress attenuation coefficient decreases with the increase of the number of fissures. The numerical simulation results and experimental results are basically consistent with the theoretical values, which verifies the rationality of the propagation equation.

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