scholarly journals Study on the 2D Optimization Simulation of Complex Five-Hole Cutting Blasting under Different Lateral Pressure Coefficients

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Jing Gao ◽  
Shizhen Xie ◽  
Xiantang Zhang ◽  
Hongli Wang ◽  
Wenle Gao ◽  
...  
Keyword(s):  
Lateral Pressure ◽  
Rock Breaking ◽  
Hole Diameter ◽  
Central Hole ◽  
Crustal Stress ◽  
Breaking Effect ◽  
Evolution Law ◽  
Coal Resources ◽  
Pressure Coefficients ◽  
Optimization Simulation

With the decrease and depletion of shallow coal resources, the depth of mining is increasing. The mechanism of high crustal stress blasting is not clear, and the effect of crustal stress on blasting effect is obvious. The law of the differential detonation is similar without crustal stress. The crustal stress of rock masses increases linearly with the increase in excavation depth, and the influence of crustal stress on blasting effect is great. In order to study the rock-breaking process of complex differential blasting under deep high crustal stress, the instantaneous detonation of each model and the priority detonation of the central hole are numerically simulated. The evolution law of the blasting crack and the method of optimizing blasting effect by differential blasting and increasing the aperture of the priority detonation hole under high crustal stress are put forward. The authors proposed a study on the 2D optimization simulation of complex five-hole cutting blasting under different lateral pressure coefficients of 400 m and 800 m with software ANSYS/LS-DYNA and analyzed the evolution rules of blasting cracks and lateral pressure coefficients. The results show that setting delayed detonation and hole diameter and optimizing blasthole spacing can optimize the rock-breaking effect under high crustal stress and different lateral pressure coefficients.

Study on Rock-Breaking Simulation and Experiment of Double Disc Cutter of TBM

2016 ◽  
Vol 23 ◽  
pp. 80-88
Author(s):  
F. Lu ◽  
C. Zhang ◽  
J. Sun ◽  
J.X. Tian ◽  
M. Liu ◽  
...  
Keyword(s):  
Rock Breaking ◽  
Disc Cutter ◽  
Element Analysis ◽  
Breaking Effect ◽  
The Finite Element Analysis ◽  
Breaking Mechanism ◽  
Simulation And Experiment ◽  
Tbm Cutter ◽  
Cutter Spacing ◽  
The Impact

In order to improve working efficiency of the tunneling process and extend working life of disc cutter, explore the impact of cutter spacing and loading for the cutter rock-breaking effect. With the theory of rock crushing, Based on the finite element analysis software ABAQUS, the process of disc cutter breaking rock is simulated, considering the adjacent cutters sequential constraints, then, to make sure two cutter space with the method of SE in experiment.The simulation results showed that the optimal cutter spacings were both about 80mm in the same loading and the sequentially loading, but the rock-breaking effect of sequentially loading is better than the same loading. The experimental data showed that the minimum specific energy of rock breaking is appeared cutter spacing between 80mm and 90mm. Thus, the correctness and rationality of the simulation was verified. The study is good for understanding the rock-breaking mechanism of double disc cutter and has a certain promoting value to optimize TBM cutter system.Keywords:TBM, rock fragmentation, ABAQUS, cutter spacing, sequentially cutting

scholarly journals Study on the rock‐breaking effect of water jets generated by self‐rotatory multinozzle drilling bit

2020 ◽  
Vol 8 (7) ◽  
pp. 2457-2470 ◽  
Author(s):  
Yanbao Liu ◽  
Quanbin Ba ◽  
Lipeng He ◽  
Kai Shen ◽  
Wei Xiong
Keyword(s):  
Rock Breaking ◽  
Breaking Effect ◽  
Effect Of Water ◽  
Water Jets ◽  
Drilling Bit

Experimental Study on Rock Breaking with Impacting Water Jet by Modulation of Chaos

2012 ◽  
Vol 535-537 ◽  
pp. 1751-1754 ◽  
Author(s):  
Chang Liu Tian ◽  
Xue Li Cheng ◽  
Wei Wang
Keyword(s):  
Experimental Study ◽  
High Pressure ◽  
Mass Loss ◽  
Rock Breaking ◽  
Water Jet ◽  
Breaking Effect ◽  
Erosion Depth ◽  
Pressure Water ◽  
High Pressure Water Jet ◽  
Pump Pressure

The experiment focused on the contrast with rock breaking effect of impacting water jet by modulation of chaos and common cavitation jet. Investigated the influences of various water jet parameters and conditions on rock breaking, such as standoff distance, pump pressure, transverse speed and erosion time and the mass loss and erosion depth were measured in the experiment. The results show that the impacting water jet by modulation of chaos can efficiently use the energy of water jet and increase ability in rock-breaking, which will have a wide application prospect in high pressure water jet technology field.

Experimental Study of Rock Breaking Effect of Steel Particles

2011 ◽  
Vol 23 (2) ◽  
pp. 241-246 ◽  
Author(s):  
Meng Cui ◽  
Ying-hu Zhai ◽  
Guo-dong Ji
Keyword(s):  
Experimental Study ◽  
Rock Breaking ◽  
Breaking Effect

Crack propagation patterns and energy evolution rules of coal within slotting disturbed zone under various lateral pressure coefficients

2014 ◽  
Vol 8 (9) ◽  
pp. 6643-6654 ◽  
Author(s):  
Lin Bai-quan ◽  
Liu Ting ◽  
Zou Quan-le ◽  
Zhu Chuan-jie ◽  
Yan Fa-zhi ◽  
...  
Keyword(s):  
Crack Propagation ◽  
Lateral Pressure ◽  
Energy Evolution ◽  
Pressure Coefficients ◽  
Disturbed Zone

scholarly journals Finite element analysis of stuffing-box packing subjected to thermo-mechanical loads

2018 ◽  
Vol 1 (1) ◽  
Author(s):  
Kaoutar BAHOUM
Keyword(s):  
Finite Element ◽  
Lateral Pressure ◽  
Numerical Study ◽  
Axial Stress ◽  
Fluid Pressure ◽  
Operating Conditions ◽  
Element Analysis ◽  
Geometrical Properties ◽  
Pressure Coefficients ◽  
Valve Sealing

The principal rule for the stuffing-box packings is to ensure the stem valve sealing. The behavior of these systems is affected by the operating conditions, which are the gland axial stress, the temperature, and the fluid pressure, as well as the mechanical and geometrical properties of the various components. In this paper, a numerical study using finite element method is presented to evaluate the radial contact stresses, the axial stresses, and the lateral pressure coefficients in a stuffing box system under the tightening gland load and the temperature field.

A novel concept for a rock-breaking machine. II. Excavation techniques and experiments at larger scale

1980 ◽  
Vol 373 (1754) ◽  
pp. 353-372 ◽  
Keyword(s):  
High Efficiency ◽  
Three Dimensional ◽  
Rock Breaking ◽  
Full Scale ◽  
Hole Diameter ◽  
Reinforcing Bars ◽  
Soft Or ◽  
Model Unit ◽  
Novel Concept ◽  
Design And Testing

This is the second paper describing the ‘Max’ rock breaker. In the preceding part I, early experiments and the theory of the rock-breaking process were described. This report continues with a description of experiments made with a model unit (hole diameter 6.7 mm) to investigate the behaviour of the device in various geometries (tunnelling, stoping, and quarrying). It then describes the design and testing of two larger machines, to fit holes of 35 and 57 mm diameter, respectively. The former of these machines was intended as a hand-held unit, while the latter was boom-mounted and provided with the means of drilling its own hole. Experiments with the model showed that even if very much confined, the rock could be extracted satisfactorily, and in geometries of low confinement, this could be accomplished with high efficiency. In concrete-breaking, no problems were encountered in breaking the concrete itself but, if present in a three-dimensional array, the reinforcing bars could cause trouble. Tests with the largest machine confirmed its ability to deal with rock at full scale, whether hard, soft, or badly fissured, and suggest the possibility of making a variety of very flexible and environmentally attractive mining machines.

Determination of lateral pressure coefficients of a V-shaped seal of ANG asbestos-rubber composition

1974 ◽  
Vol 10 (5) ◽  
pp. 391-394
Author(s):  
R. S. Safarov ◽  
Kh. T. Kakhramanov ◽  
S. A. Skvirskii
Keyword(s):  
Lateral Pressure ◽  
Pressure Coefficients

scholarly journals Study on Mechanical Behavior and Failure Network of Deep Roadway under Different Lateral Pressure Coefficients

2021 ◽  
Author(s):  
Feng Luo ◽  
Yijun Guo ◽  
Peidong Xu ◽  
Yanglong Diao ◽  
Meng Li
Keyword(s):  
Numerical Simulation ◽  
Mechanical Behavior ◽  
Simulation Experiment ◽  
Lateral Pressure ◽  
Pressure Coefficient ◽  
Surrounding Rock ◽  
Deviatoric Stress ◽  
Mine Safety ◽  
Pressure Coefficients ◽  
Damaged Zone

Abstract The failure and instability of roadway is a main disaster with the highest frequency in coal mines. The development of surrounding rock control technology is an important way to ensure mine safety. In order to obtain the failure characteristics of surrounding rock and optimize the support method of the roadway, the numerical simulation and physical simulation were used to investigate the mechanical behavior of deep roadway under different lateral pressure coefficients. The evolution mechanism of meso tensile-shear cracks in excavation damaged zone (EDZ) were deeply revealed. The results show that the shear bands which are basically in the form of sliding spiral extends from the two sidewalls to the roof and floor with the increase of lateral pressure coefficient, and develop to the deep surrounding rock. The “crescent-shaped” tensile failure zones generate in the roof and floor when λ < 1, and gradually decrease with the increase of horizontal stress. When λ = 1, the failure pattern around the arch and right angle sides are different influenced by the shape of different side. Under the special stress environment of high deviatoric stress, the pattern of plastic zone will lead to butterfly-like failure mode induced by the stress relief of excavation. Judged from the curves of tangential and deviatoric stress, the surrounding rock in the two sidewalls, the roof and floor are greatly damaged under λ < 0.75 and λ > 1.5 respectively. The verification of the numerical simulation experiment is proved by the similar material simulation experiment.

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