The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using AN- SYS/...The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using AN- SYS/LS-DYNA 3D Nonlinear Dynamic Finite Element Software. In this package ANSYS is the preprocessor and LS-DYNA is the postprocessor. Numerical models in the paper to actual were l：10 and the element mesh was dissected in scanning mode utilizing the symmetry characteristics of the numerical model. Five different advance rates were studied. Parameters, such as the time required to maximum stress, the action time of the available stress, the maximum velocity of the nodes, the stress penetration time, the magnitude of the stress peak and the time duration for high stress were numerically simulated. The 2.2 m advance appeared optimum from an analysis of the simulation results. The results from numerical simulation have been validated by tests with physical models.展开更多
The Ak?akale Cave is located in the vicinity of the Arsa neighborhood within the boundaries of the Ak?akale village, Gümü?hane, Turkey. The cave is rich in cave formations(stalactite, stalagmite, cave pearl,...The Ak?akale Cave is located in the vicinity of the Arsa neighborhood within the boundaries of the Ak?akale village, Gümü?hane, Turkey. The cave is rich in cave formations(stalactite, stalagmite, cave pearl, cave flower, wall travertines). Thus, the appropriateness of opening the cave to visitors to boost tourism is of importance for the local and national economy. This study analyzes the stability of the Ak?akale Cave using a numerical analysis method. According to the results of the total displacement analysis, there are displacements in the entrance, ceiling, and sidewalls of the cave ranging from 1 mm to 48 mm. It seems that the entrance, ceiling, and sidewalls of the cave face a high risk of local or sudden collapse. According to the deformation analysis of the length section of the cave examined, local collapses may occur especially in the first 75 m from the entrance of the cave. We believe that this situation would not carry a risk for the Arsa neighborhood for now. In conclusion, the results of the stability analysis and in-situ observations showed clear evidence of former and ongoing cave-ins(collapses) and the Ak?akale Cave faces a high risk of local or sudden collapse. Thus, although the Ak?akale Cave is one of the most prominent karst caves in Turkey, it seems to be not appropriate to open the cave to tourist visits.展开更多
文摘The mechanism of stress generation and propagation by detonation loading in five separate independent advance of ore breaking patterns is discussed in the paper. An elastic numerical model was developed using AN- SYS/LS-DYNA 3D Nonlinear Dynamic Finite Element Software. In this package ANSYS is the preprocessor and LS-DYNA is the postprocessor. Numerical models in the paper to actual were l：10 and the element mesh was dissected in scanning mode utilizing the symmetry characteristics of the numerical model. Five different advance rates were studied. Parameters, such as the time required to maximum stress, the action time of the available stress, the maximum velocity of the nodes, the stress penetration time, the magnitude of the stress peak and the time duration for high stress were numerically simulated. The 2.2 m advance appeared optimum from an analysis of the simulation results. The results from numerical simulation have been validated by tests with physical models.
文摘The Ak?akale Cave is located in the vicinity of the Arsa neighborhood within the boundaries of the Ak?akale village, Gümü?hane, Turkey. The cave is rich in cave formations(stalactite, stalagmite, cave pearl, cave flower, wall travertines). Thus, the appropriateness of opening the cave to visitors to boost tourism is of importance for the local and national economy. This study analyzes the stability of the Ak?akale Cave using a numerical analysis method. According to the results of the total displacement analysis, there are displacements in the entrance, ceiling, and sidewalls of the cave ranging from 1 mm to 48 mm. It seems that the entrance, ceiling, and sidewalls of the cave face a high risk of local or sudden collapse. According to the deformation analysis of the length section of the cave examined, local collapses may occur especially in the first 75 m from the entrance of the cave. We believe that this situation would not carry a risk for the Arsa neighborhood for now. In conclusion, the results of the stability analysis and in-situ observations showed clear evidence of former and ongoing cave-ins(collapses) and the Ak?akale Cave faces a high risk of local or sudden collapse. Thus, although the Ak?akale Cave is one of the most prominent karst caves in Turkey, it seems to be not appropriate to open the cave to tourist visits.
