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
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.
- 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
- 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
- «
- ‹
- 1
- ›
- »