In order to study stability control methods for a deep gate group under complex stresses,we conducted field investigations and analyses of reasons for damage in the Xuzhou mining district.Three reasons are proposed:de...In order to study stability control methods for a deep gate group under complex stresses,we conducted field investigations and analyses of reasons for damage in the Xuzhou mining district.Three reasons are proposed:deep high stress,improper roadway layout and support technology.The stability control countermeasures of the gate group consist of an intensive design technology and responding bolt-mesh-anchor truss support technology.Our research method has been applied at the -1000 m level gate group in Qishan Coal Mine.Suitable countermeasures have been tested by field monitoring.展开更多
Although research on a field investigation about quantification drawdown of ground water wells has hitherto been conducted with emphasis on Sana'a basin which is 3 200 km2 in area characterized by general hazard i...Although research on a field investigation about quantification drawdown of ground water wells has hitherto been conducted with emphasis on Sana'a basin which is 3 200 km2 in area characterized by general hazard in quantity and quality of water,there exist uncertainties about the size of the hazardous annual decline in the level of underground water. So the authors are trying to assess reliable hazard data on the depth of ground-water which were obtained by measuring static water level. The data set are twenty six wells from 9 regions which were selected to represent Sana'a basin and collected during the course of the 20 months groundwater monitoring survey from January 2008 to January 2009. The results show that the average drawdown during 20 months to be 3.22 m with an average 0.16 m per month and 2 m per year.展开更多
Aiming at the existing problems of safety, reliability and flexibility in the traditional coal mine belt transport system, this paper designed the mine centralized control system transmitted by CAN bus and PLC as the ...Aiming at the existing problems of safety, reliability and flexibility in the traditional coal mine belt transport system, this paper designed the mine centralized control system transmitted by CAN bus and PLC as the core, and use comparison instructions and trigger of Siemens S7-200 PLC, the article has elaborated the four level conveyor belt sequence control, realized the sequence start, reverse sequence stop and fault processing and other functions for four level conveyor belt, the compared with traditional timer control instructions scheme, the design has clear thinking, simple design program, and is easy to be extended to multilevel belt drive sequence control.展开更多
基金Projects 50490270 supported by the National Natural Science Foundation of ChinaProjects 2006CB202200 by the National Basic Research Program of ChinaProjects IRT0656 by the Innovation Term Project of the Ministry of Education of China
文摘In order to study stability control methods for a deep gate group under complex stresses,we conducted field investigations and analyses of reasons for damage in the Xuzhou mining district.Three reasons are proposed:deep high stress,improper roadway layout and support technology.The stability control countermeasures of the gate group consist of an intensive design technology and responding bolt-mesh-anchor truss support technology.Our research method has been applied at the -1000 m level gate group in Qishan Coal Mine.Suitable countermeasures have been tested by field monitoring.
文摘Although research on a field investigation about quantification drawdown of ground water wells has hitherto been conducted with emphasis on Sana'a basin which is 3 200 km2 in area characterized by general hazard in quantity and quality of water,there exist uncertainties about the size of the hazardous annual decline in the level of underground water. So the authors are trying to assess reliable hazard data on the depth of ground-water which were obtained by measuring static water level. The data set are twenty six wells from 9 regions which were selected to represent Sana'a basin and collected during the course of the 20 months groundwater monitoring survey from January 2008 to January 2009. The results show that the average drawdown during 20 months to be 3.22 m with an average 0.16 m per month and 2 m per year.
文摘Aiming at the existing problems of safety, reliability and flexibility in the traditional coal mine belt transport system, this paper designed the mine centralized control system transmitted by CAN bus and PLC as the core, and use comparison instructions and trigger of Siemens S7-200 PLC, the article has elaborated the four level conveyor belt sequence control, realized the sequence start, reverse sequence stop and fault processing and other functions for four level conveyor belt, the compared with traditional timer control instructions scheme, the design has clear thinking, simple design program, and is easy to be extended to multilevel belt drive sequence control.
