Sensitivity analysis on blast design parameters to improve bench blasting outcomes using the Taguchi method
- Hosseini, Mostafa, Khandelwal, Manoj, Lotfi, Rahman, Eslahi, Mohsen
- Authors: Hosseini, Mostafa , Khandelwal, Manoj , Lotfi, Rahman , Eslahi, Mohsen
- Date: 2023
- Type: Text , Journal article
- Relation: Geomechanics and Geophysics for Geo-Energy and Geo-Resources Vol. 9, no. 1 (2023), p.
- Full Text:
- Reviewed:
- Description: In surface mines, bench blasting is a typical way of excavating hard rock mass. Although a significant development has taken place in explosive technology but still only a part of the energy is used to excavate and a large proportion of energy is wasted away and creates a number of nuisances. Backbreak, massive rock fragmentation, and high-intensity ground vibration are all symptoms of improper blasting. As a result, production costs increase significantly while productivity decreases. The blasting outcomes are affected by a variety of factors, which may be classified into three categories: rock properties, explosive properties, and blast geometry. Consequently, it is necessary to examine the effect of these parameters on bench blasting. So, in this study, a sensitivity analysis has been performed on various blast design parameters using the Taguchi method to study the influence of blast design parameters on blast vibration, backbreak, and rock fragmentation. A total of 32 experiments have been designed and numerical modeling was also carried out, using LS DYNA software to simulate the blast results. It was found that the blast hole diameter is the most important factor influencing the blasting outcomes. However, the number of rows in a blast affects backbreak almost slightly more than the hole diameter, but blast vibrations and the surrounding rock damage strongly depend on the hole diameter. Furthermore, rock blast geometry significantly affected rock blast vibration and damage compared to explosive properties. However, both blast geometry parameters and explosive properties play a significant role in backbreaking. © 2023, The Author(s).
- Authors: Hosseini, Mostafa , Khandelwal, Manoj , Lotfi, Rahman , Eslahi, Mohsen
- Date: 2023
- Type: Text , Journal article
- Relation: Geomechanics and Geophysics for Geo-Energy and Geo-Resources Vol. 9, no. 1 (2023), p.
- Full Text:
- Reviewed:
- Description: In surface mines, bench blasting is a typical way of excavating hard rock mass. Although a significant development has taken place in explosive technology but still only a part of the energy is used to excavate and a large proportion of energy is wasted away and creates a number of nuisances. Backbreak, massive rock fragmentation, and high-intensity ground vibration are all symptoms of improper blasting. As a result, production costs increase significantly while productivity decreases. The blasting outcomes are affected by a variety of factors, which may be classified into three categories: rock properties, explosive properties, and blast geometry. Consequently, it is necessary to examine the effect of these parameters on bench blasting. So, in this study, a sensitivity analysis has been performed on various blast design parameters using the Taguchi method to study the influence of blast design parameters on blast vibration, backbreak, and rock fragmentation. A total of 32 experiments have been designed and numerical modeling was also carried out, using LS DYNA software to simulate the blast results. It was found that the blast hole diameter is the most important factor influencing the blasting outcomes. However, the number of rows in a blast affects backbreak almost slightly more than the hole diameter, but blast vibrations and the surrounding rock damage strongly depend on the hole diameter. Furthermore, rock blast geometry significantly affected rock blast vibration and damage compared to explosive properties. However, both blast geometry parameters and explosive properties play a significant role in backbreaking. © 2023, The Author(s).
Rainfall affected stability analysis of Maddingley brown coal eastern batter using plaxis 3D
- Authors: Zhao, Lei , You, Greg
- Date: 2020
- Type: Text , Journal article
- Relation: Arabian Journal of Geosciences Vol. 13, no. 20 (2020), p.
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- Reviewed:
- Description: Rainfall is a common factor that triggers the instability of Victorian Brown Coal (VBC) open pits which facilitate some of the largest brown coal mining operations. There has been no relevant study on rainfall-induced slope instability of VBC open pits in literature. In this paper, a three-dimensional (3D) two-phase (fluid-solid) coupled finite element method (FEM) was employed to investigate the stability of Maddingley Brown Coal (MBC) eastern batter under different rainfall conditions. It was found that the batter tends to lead a circular failure path during large rainfall. With the increase in either precipitation period or rainfall intensity, the deformation, excess pore pressure and active pressure increased, while the matric suction decreased. The hydrostatic force in the confined aquifer underlying the brown coal seam increased during rainfall; meanwhile, the resisting force decreased. As a result, the shear strength decreased and thereby the stability of the batter decreased. The safety factor and the critical failure path of the eastern batter simulated in this study were consistent with the previous study on the Northern batter. This study is a strong supplement to the literature on rainfall-induced instability of VBC batters. In the meantime, it is significant to provide a reference to the application of sophisticated 3D numerical modelling for studying slope instability of brown coal and similar mineral deposits. © 2020, Saudi Society for Geosciences.
- Description: The study is supported by the Australian Research Training Program (RTP) Scholarship and Federation University Australia George Collins Memorial Scholarship
- Authors: Zhao, Lei , You, Greg
- Date: 2020
- Type: Text , Journal article
- Relation: Arabian Journal of Geosciences Vol. 13, no. 20 (2020), p.
- Full Text:
- Reviewed:
- Description: Rainfall is a common factor that triggers the instability of Victorian Brown Coal (VBC) open pits which facilitate some of the largest brown coal mining operations. There has been no relevant study on rainfall-induced slope instability of VBC open pits in literature. In this paper, a three-dimensional (3D) two-phase (fluid-solid) coupled finite element method (FEM) was employed to investigate the stability of Maddingley Brown Coal (MBC) eastern batter under different rainfall conditions. It was found that the batter tends to lead a circular failure path during large rainfall. With the increase in either precipitation period or rainfall intensity, the deformation, excess pore pressure and active pressure increased, while the matric suction decreased. The hydrostatic force in the confined aquifer underlying the brown coal seam increased during rainfall; meanwhile, the resisting force decreased. As a result, the shear strength decreased and thereby the stability of the batter decreased. The safety factor and the critical failure path of the eastern batter simulated in this study were consistent with the previous study on the Northern batter. This study is a strong supplement to the literature on rainfall-induced instability of VBC batters. In the meantime, it is significant to provide a reference to the application of sophisticated 3D numerical modelling for studying slope instability of brown coal and similar mineral deposits. © 2020, Saudi Society for Geosciences.
- Description: The study is supported by the Australian Research Training Program (RTP) Scholarship and Federation University Australia George Collins Memorial Scholarship
Three-dimensional numerical study on the batter instability mechanism of Maddingley Brown Coal Open Pit, Victoria, Australia using PLAXIS 3D
- Authors: Zhao, Lei
- Date: 2019
- Type: Text , Thesis , PhD
- Full Text:
- Description: With the increased size of excavation due to long-term open cut mining, batter instability has become a major geo-hazard in Victorian Brown Coal Open Pits where facilitate some largest brown coal mining operations in the world. Block failure is a unique failure mode in Victorian brown coal mines, which is often associated with cracks and rainfall. Maddingley Brown Coal Mine (MBC) is located in Bacchus Marsh, Victoria, Australia. Slope instability has also been a major geo-problem since the open pit mining commenced in MBC in 1940s. Making clear the cracking mechanism and the correlations between rainfall and batter instability have important implications in better understanding and predicting batter failures in Victorian brown coal mines. In this research, three-dimensional geologic models were developed to investigate the mechanism of brown coal batter instability. The finite element program encoded in Plaxis 3D was employed to conduct the complex two-phase (fluid-solid) coupled numerical simulations. The results revealed the cracking mechanism of coal batter and the effects of rainfall on batter stability. It was found that the brown coal batter with overburden tends to lead a circular critical path while the batter after overburden removal shows a trend of block sliding as interpreted by the shear and tensile strains simulated. The existence of joints and the hydrostatic water pressure in the joints could adversely affect the stability of brown coal batter towards block failure. Precipitation can increase the deformation, excess pore pressure, total pore pressure, active pressure and decrease the matric suction, and thereby decrease the shear strength, effective stress, and batter stability. The results from the three-dimensional hydro-mechanically coupled finite element study were well agreed with the field monitored data, theoretical calculations, and Victorian brown coal mining experience.
- Description: Doctor of Philosophy
- Authors: Zhao, Lei
- Date: 2019
- Type: Text , Thesis , PhD
- Full Text:
- Description: With the increased size of excavation due to long-term open cut mining, batter instability has become a major geo-hazard in Victorian Brown Coal Open Pits where facilitate some largest brown coal mining operations in the world. Block failure is a unique failure mode in Victorian brown coal mines, which is often associated with cracks and rainfall. Maddingley Brown Coal Mine (MBC) is located in Bacchus Marsh, Victoria, Australia. Slope instability has also been a major geo-problem since the open pit mining commenced in MBC in 1940s. Making clear the cracking mechanism and the correlations between rainfall and batter instability have important implications in better understanding and predicting batter failures in Victorian brown coal mines. In this research, three-dimensional geologic models were developed to investigate the mechanism of brown coal batter instability. The finite element program encoded in Plaxis 3D was employed to conduct the complex two-phase (fluid-solid) coupled numerical simulations. The results revealed the cracking mechanism of coal batter and the effects of rainfall on batter stability. It was found that the brown coal batter with overburden tends to lead a circular critical path while the batter after overburden removal shows a trend of block sliding as interpreted by the shear and tensile strains simulated. The existence of joints and the hydrostatic water pressure in the joints could adversely affect the stability of brown coal batter towards block failure. Precipitation can increase the deformation, excess pore pressure, total pore pressure, active pressure and decrease the matric suction, and thereby decrease the shear strength, effective stress, and batter stability. The results from the three-dimensional hydro-mechanically coupled finite element study were well agreed with the field monitored data, theoretical calculations, and Victorian brown coal mining experience.
- Description: Doctor of Philosophy
Three-dimensional DEM simulation of cone penetration test by using circumferential periodic boundary
- Yang, Yangchen, Deng, Yibing, Shi, Danda, Xue, Jianfeng
- Authors: Yang, Yangchen , Deng, Yibing , Shi, Danda , Xue, Jianfeng
- Date: 2016
- Type: Text , Journal article
- Relation: Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering Vol. 35, no. (2016), p. 3372-3384
- Full Text: false
- Reviewed:
- Description: In order to explore the micro-mechanism of CPT, a new circumferential periodic boundary was developed to consider the three-dimensional axisymmetric problem with 1/4 of the cylinder. To validate the method, a drained triaxial test was modeled with the proposed method and the traditional full model. The results are comparable and the proposed method is very effective. The method was further used to simulate a cone penetration test in dry Fontainebleau sand. It was found that, the variation of cone radial stress and tip resistance during penetration from the model are in good agreement with the reported test results. The micromechanical responses, such as the distributions of particle displacement, internal stress and local porosity to cone penetration are extensively studied. The evolutions of fabric anisotropy during penetration are also discussed. The relationship between stress and fabric is quantitatively described using fabric tensor, which reveals the mechanism of cone penetration capacity microscopically. The results of the work not only improve the efficiency of three-dimensional discrete element method(DEM) simulation, but also promote better understanding of CPT mechanism. © 2016, Science Press. All right reserved.
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