The Experts below are selected from a list of 18267 Experts worldwide ranked by ideXlab platform
Chenyang Ma - One of the best experts on this subject based on the ideXlab platform.
-
Effect of Excavation Blasting in Underground Water-Sealed Gas Storage Cavern Under In-Situ Stress
Geotechnical and Geological Engineering, 2019Co-Authors: Yuchun Zhou, Li Wu, Chenyang MaAbstract:When underground caverns are created in deep rock masses by drilling and blasting methods, an undesirable excavation damage zone is induced. However, previous studies on effects of initial in situ stress field on blast-induced damage and Safety Criterion are few worldwide. In this study, we calculated and analyzed the dynamic response of surrounding rock during blasting excavation by the finite element software ANSYS/LS-DYNA based on field blasting tests of excavation blasting for underground gas storage caverns in Yantai, Shandong province, PR China. The numerical results indicated that tensile failure tended to occur in the middle of the curved wall. Meanwhile, the distribution and the range of surrounding rock damage under coupled static–dynamic load were obviously different with those under dynamic load alone, which showed that the influence of in situ stress on rock blast-induced damage could not be ignored. The relationship of the maximum tensile stress and peak particle velocity in the middle of the curved under in situ stress was analyzed and modeled. According to the maximum tensile strength theory and numerical calculation results, the critical vibration velocity was determined for controlling the rock damage of underground cavern, and the effects of the in situ stress on the Safety Criterion for rock damage were discussed.
Kenneth R. Posey - One of the best experts on this subject based on the ideXlab platform.
-
Induced Voltage and Current Simulations, Safety Criterion, and Mitigation for EHV Transmission Lines in Close Proximity
IEEE Transactions on Industry Applications, 2019Co-Authors: David J. Meisner, Kyle D. Stechschulte, Vinod Simha, Ronald J. Wellman, Manish Thakur, Kenneth R. Posey, Scott S. DimpflAbstract:One of the benefits of double-circuit transmission lines is that line maintenance work can be performed on a de-energized circuit while the other circuit remains energized. However, induced voltages and currents can be generated on the de-energized line due to electrostatic and/or electromagnetic coupling effects and the close proximity to energized conductors. In order to mitigate the Safety concern related to high induced voltages or currents, line discharging grounding switches (LDGS) may be installed. Since this can be an expensive solution, the magnitude of induced voltage and current is the key for defining Safety criteria to judge whether or not a costly mitigation plan is needed. This paper presents the theory of induced voltage and current and a sensitivity analysis of influential parameters that impact each. In addition, a Safety Criterion using arc reach calculation is proposed to determine when LDGS are required. A case study is included.
-
induced voltage current simulations Safety Criterion and mitigations for ehv transmission lines in close proximity
IEEE Industry Applications Society Annual Meeting, 2018Co-Authors: David J. Meisner, Kyle D. Stechschulte, Vinod Simha, Ronald J. Wellman, Manish Thakur, Kenneth R. PoseyAbstract:one of the benefits of double-circuit transmission lines is that line maintenance work can be performed on a de-energized circuit while the other circuit remains energized. However, induced voltages and currents can be generated on the de-energized line due to electrostatic and/or electromagnetic coupling effects and the close proximity to energized conductors. In order to mitigate the Safety concern related to high induced voltages or currents, line discharging grounding switches (LDGS) may be installed. Since this can be an expensive solution, the magnitude of induced voltage and current is the key for defining Safety criteria to judge whether or not a costly mitigation plan is needed. This paper presents the theory of induced voltage and current and a sensitivity analysis of influential parameters that impact each. In addition, a Safety Criterion using arc reach calculation is proposed to determine when LDGS are required. A case study is included.
-
Induced Voltage & Current Simulations, Safety Criterion, and Mitigations for EHV Transmission Lines in Close Proximity
2018 IEEE Industry Applications Society Annual Meeting (IAS), 2018Co-Authors: David J. Meisner, Kyle D. Stechschulte, Vinod Simha, Ronald J. Wellman, Manish Thakur, Kenneth R. PoseyAbstract:one of the benefits of double-circuit transmission lines is that line maintenance work can be performed on a de-energized circuit while the other circuit remains energized. However, induced voltages and currents can be generated on the de-energized line due to electrostatic and/or electromagnetic coupling effects and the close proximity to energized conductors. In order to mitigate the Safety concern related to high induced voltages or currents, line discharging grounding switches (LDGS) may be installed. Since this can be an expensive solution, the magnitude of induced voltage and current is the key for defining Safety criteria to judge whether or not a costly mitigation plan is needed. This paper presents the theory of induced voltage and current and a sensitivity analysis of influential parameters that impact each. In addition, a Safety Criterion using arc reach calculation is proposed to determine when LDGS are required. A case study is included.
Yuchun Zhou - One of the best experts on this subject based on the ideXlab platform.
-
Effect of Excavation Blasting in Underground Water-Sealed Gas Storage Cavern Under In-Situ Stress
Geotechnical and Geological Engineering, 2019Co-Authors: Yuchun Zhou, Li Wu, Chenyang MaAbstract:When underground caverns are created in deep rock masses by drilling and blasting methods, an undesirable excavation damage zone is induced. However, previous studies on effects of initial in situ stress field on blast-induced damage and Safety Criterion are few worldwide. In this study, we calculated and analyzed the dynamic response of surrounding rock during blasting excavation by the finite element software ANSYS/LS-DYNA based on field blasting tests of excavation blasting for underground gas storage caverns in Yantai, Shandong province, PR China. The numerical results indicated that tensile failure tended to occur in the middle of the curved wall. Meanwhile, the distribution and the range of surrounding rock damage under coupled static–dynamic load were obviously different with those under dynamic load alone, which showed that the influence of in situ stress on rock blast-induced damage could not be ignored. The relationship of the maximum tensile stress and peak particle velocity in the middle of the curved under in situ stress was analyzed and modeled. According to the maximum tensile strength theory and numerical calculation results, the critical vibration velocity was determined for controlling the rock damage of underground cavern, and the effects of the in situ stress on the Safety Criterion for rock damage were discussed.
David J. Meisner - One of the best experts on this subject based on the ideXlab platform.
-
Induced Voltage and Current Simulations, Safety Criterion, and Mitigation for EHV Transmission Lines in Close Proximity
IEEE Transactions on Industry Applications, 2019Co-Authors: David J. Meisner, Kyle D. Stechschulte, Vinod Simha, Ronald J. Wellman, Manish Thakur, Kenneth R. Posey, Scott S. DimpflAbstract:One of the benefits of double-circuit transmission lines is that line maintenance work can be performed on a de-energized circuit while the other circuit remains energized. However, induced voltages and currents can be generated on the de-energized line due to electrostatic and/or electromagnetic coupling effects and the close proximity to energized conductors. In order to mitigate the Safety concern related to high induced voltages or currents, line discharging grounding switches (LDGS) may be installed. Since this can be an expensive solution, the magnitude of induced voltage and current is the key for defining Safety criteria to judge whether or not a costly mitigation plan is needed. This paper presents the theory of induced voltage and current and a sensitivity analysis of influential parameters that impact each. In addition, a Safety Criterion using arc reach calculation is proposed to determine when LDGS are required. A case study is included.
-
induced voltage current simulations Safety Criterion and mitigations for ehv transmission lines in close proximity
IEEE Industry Applications Society Annual Meeting, 2018Co-Authors: David J. Meisner, Kyle D. Stechschulte, Vinod Simha, Ronald J. Wellman, Manish Thakur, Kenneth R. PoseyAbstract:one of the benefits of double-circuit transmission lines is that line maintenance work can be performed on a de-energized circuit while the other circuit remains energized. However, induced voltages and currents can be generated on the de-energized line due to electrostatic and/or electromagnetic coupling effects and the close proximity to energized conductors. In order to mitigate the Safety concern related to high induced voltages or currents, line discharging grounding switches (LDGS) may be installed. Since this can be an expensive solution, the magnitude of induced voltage and current is the key for defining Safety criteria to judge whether or not a costly mitigation plan is needed. This paper presents the theory of induced voltage and current and a sensitivity analysis of influential parameters that impact each. In addition, a Safety Criterion using arc reach calculation is proposed to determine when LDGS are required. A case study is included.
-
Induced Voltage & Current Simulations, Safety Criterion, and Mitigations for EHV Transmission Lines in Close Proximity
2018 IEEE Industry Applications Society Annual Meeting (IAS), 2018Co-Authors: David J. Meisner, Kyle D. Stechschulte, Vinod Simha, Ronald J. Wellman, Manish Thakur, Kenneth R. PoseyAbstract:one of the benefits of double-circuit transmission lines is that line maintenance work can be performed on a de-energized circuit while the other circuit remains energized. However, induced voltages and currents can be generated on the de-energized line due to electrostatic and/or electromagnetic coupling effects and the close proximity to energized conductors. In order to mitigate the Safety concern related to high induced voltages or currents, line discharging grounding switches (LDGS) may be installed. Since this can be an expensive solution, the magnitude of induced voltage and current is the key for defining Safety criteria to judge whether or not a costly mitigation plan is needed. This paper presents the theory of induced voltage and current and a sensitivity analysis of influential parameters that impact each. In addition, a Safety Criterion using arc reach calculation is proposed to determine when LDGS are required. A case study is included.
David Y. Jeong - One of the best experts on this subject based on the ideXlab platform.
-
EFFECT OF WHEEL/RAIL LOADS ON CONCRETE TIE STRESSES AND RAIL ROLLOVER
ASME 2011 Rail Transportation Division Fall Technical Conference, 2011Co-Authors: Brian Marquis, Michelle Muhlanger, David Y. JeongAbstract:As a result of vertical and lateral wheel/rail forces, high contact stresses can develop at the interface between the rail base and tie. Under certain conditions, these stresses can exceed the strength of the concrete tie and result in deterioration of the tie and ultimately derailment due to rail rollover. This failure mode has been determined to be the probable cause of at least two derailments where the ties were found to have a triangular wear pattern. Following these derailments, a field investigation revealed this pattern of failure present in an appreciable portion of concrete ties [1]. Closedform analyses have been conducted to examine combinations of wheel/rail loads and contact conditions that produce concrete tie rail seat deterioration or rail rollover. These results indicate that under certain circumstances truck-side L/V permitted by the Federal Railroad Administration (FRA) Safety Criterion on Wheel/Rail Loads can result in stresses above the AREMA specified minimum design compressive strength of concrete used in concrete ties. Furthermore the analysis indicated that under certain circumstances truck-side L/V permitted by the FRA Safety Criterion can result in rail rollover. The analyses show that rail rollover can be a problem for new concrete ties, but is more of a problem in the presence of rail seat deterioration described above. This work is sponsored by FRA Office of Research and Development under the track research program.
-
effect of wheel rail loads on concrete tie stresses and rail rollover
ASME 2011 Rail Transportation Division Fall Technical Conference, 2011Co-Authors: Brian Marquis, Michelle Muhlanger, David Y. JeongAbstract:As a result of vertical and lateral wheel/rail forces, high contact stresses can develop at the interface between the rail base and tie. Under certain conditions, these stresses can exceed the strength of the concrete tie and result in deterioration of the tie and ultimately derailment due to rail rollover. This failure mode has been determined to be the probable cause of at least two derailments where the ties were found to have a triangular wear pattern. Following these derailments, a field investigation revealed this pattern of failure present in an appreciable portion of concrete ties [1]. Closedform analyses have been conducted to examine combinations of wheel/rail loads and contact conditions that produce concrete tie rail seat deterioration or rail rollover. These results indicate that under certain circumstances truck-side L/V permitted by the Federal Railroad Administration (FRA) Safety Criterion on Wheel/Rail Loads can result in stresses above the AREMA specified minimum design compressive strength of concrete used in concrete ties. Furthermore the analysis indicated that under certain circumstances truck-side L/V permitted by the FRA Safety Criterion can result in rail rollover. The analyses show that rail rollover can be a problem for new concrete ties, but is more of a problem in the presence of rail seat deterioration described above. This work is sponsored by FRA Office of Research and Development under the track research program.
