In order to explore the influence of different caving thicknesses on the MSS distributionand evolving characteristics of surrounding rocks in unsymmetrical disposal andfully mechanized top-coal caving (FMTC),based on ...In order to explore the influence of different caving thicknesses on the MSS distributionand evolving characteristics of surrounding rocks in unsymmetrical disposal andfully mechanized top-coal caving (FMTC),based on unsymmetrical disposal characteristics,the analyses of numerical simulation,material simulation and in-situ observation weresynthetically applied according to the geological and technical conditions of the 1151(3)working face in Xieqiao Mine.The results show that the stress peak value of the MSS-baseand the ratio of MSS-body height to caving thickness are nonlinear and inverselyproportional to the caving thickness.The MSS-base width,the MSS-body height,theMSS-base distance to working face wall and the rise distance of MSS-base beside coalpillar are nonlinear and directly proportional to the caving thickness.The characteristics ofMSS distribution and its evolving rules of surrounding rocks and the integrated cavingthickness effects are obtained.The investigations will provide lots of theoretic referencesto the surrounding rocks' stability control of the working face and roadway,roadway layout,gas extraction and exploitation,and efficiency of caving,etc.展开更多
Based on the theory of attribute identification, a weight-variable identification model was put forward on top coal caving effect in fully mechanized top coal caving face. Contribution value of all kinds of evaluation...Based on the theory of attribute identification, a weight-variable identification model was put forward on top coal caving effect in fully mechanized top coal caving face. Contribution value of all kinds of evaluation factor of the caving coal and waste were used to determine weight coefficient. And then comprehensively estimated it by the given credible degree value. This kind of method can not only classify for attribute identification, but also can classify it into sub-classification according to comprehensive score compositor that of the same attribute. The comprehensive estimate result of plane and solid caving experiments shows that the result is true, credible, simple and that is not only one of the effective method of theory study, but also can be regarded as a quantitative examine method of the top coal caving effect in scene.展开更多
The environmental changes in show caves have been concerned by the show cave managers and speleo-scientists. Most scientists have recognized the speleo-activities and tourist facilities as the main factors to force th...The environmental changes in show caves have been concerned by the show cave managers and speleo-scientists. Most scientists have recognized the speleo-activities and tourist facilities as the main factors to force the environment changes in the show caves. The show caves in carbonate rocks including the water caves and dried caves are strongly influenced by the visitor flow. Great number of visitors rushing into the show caves in a short periods causes the CO2 content and temperature rapidly increase, especially in the narrow and small passages and chambers. The maximum CO2 content was 7000 ppm （May 2, 2001） in the chamber about 20 m long, 25 m wide and 58 m high in Baiyun Cave, Hebei, after about 3000 people visited for 5 hours, the temperature increased from 16 8 ℃ to 19.6℃.In some cases, the natural factors may make great changes of the cave environment . For example, the heavy rain caused the great amount of drops in Yaolin Cave,Zhejiang.CO2 concentration was obviously increased from 490800 ppm on October 30 （before raining） to 7401580 ppm on November 14, 1997 （ after raining）. The measurement results show the temperature of drop water is 0.10.6℃ higher than the cave temperature, but it is not very clear that the temperature of cave was whether increased or not in the big chambers in Yaolin Cave. In Huangxian Cave, Hubei, in the wet season, most of 1833 rim pools were over flowing, the average CO2 content in the Rim Pool Hall on October 6,2000 was 2050 ppm, in the range of 1800 ppm and 2300 ppm; the temperature varied from 17.6℃ to 19.1℃, average temperature was 18.5℃. While on August 20, 2001, when 90% of the rim pools were dried out,it was only 950 ppm of average CO2 concentration varying from 900 ppm to 1100 ppm, and the average temperature was 17.9℃, fluctuated from 15.9℃ to 21.3℃.展开更多
基金Supported by National Basic Research Program(973)(2005cb221503)National Natural Science Foundation of China(50674003)Science and Technological Fund of Anhui Province for Outstanding Youth(08040106839)
文摘In order to explore the influence of different caving thicknesses on the MSS distributionand evolving characteristics of surrounding rocks in unsymmetrical disposal andfully mechanized top-coal caving (FMTC),based on unsymmetrical disposal characteristics,the analyses of numerical simulation,material simulation and in-situ observation weresynthetically applied according to the geological and technical conditions of the 1151(3)working face in Xieqiao Mine.The results show that the stress peak value of the MSS-baseand the ratio of MSS-body height to caving thickness are nonlinear and inverselyproportional to the caving thickness.The MSS-base width,the MSS-body height,theMSS-base distance to working face wall and the rise distance of MSS-base beside coalpillar are nonlinear and directly proportional to the caving thickness.The characteristics ofMSS distribution and its evolving rules of surrounding rocks and the integrated cavingthickness effects are obtained.The investigations will provide lots of theoretic referencesto the surrounding rocks' stability control of the working face and roadway,roadway layout,gas extraction and exploitation,and efficiency of caving,etc.
文摘Based on the theory of attribute identification, a weight-variable identification model was put forward on top coal caving effect in fully mechanized top coal caving face. Contribution value of all kinds of evaluation factor of the caving coal and waste were used to determine weight coefficient. And then comprehensively estimated it by the given credible degree value. This kind of method can not only classify for attribute identification, but also can classify it into sub-classification according to comprehensive score compositor that of the same attribute. The comprehensive estimate result of plane and solid caving experiments shows that the result is true, credible, simple and that is not only one of the effective method of theory study, but also can be regarded as a quantitative examine method of the top coal caving effect in scene.
文摘The environmental changes in show caves have been concerned by the show cave managers and speleo-scientists. Most scientists have recognized the speleo-activities and tourist facilities as the main factors to force the environment changes in the show caves. The show caves in carbonate rocks including the water caves and dried caves are strongly influenced by the visitor flow. Great number of visitors rushing into the show caves in a short periods causes the CO2 content and temperature rapidly increase, especially in the narrow and small passages and chambers. The maximum CO2 content was 7000 ppm （May 2, 2001） in the chamber about 20 m long, 25 m wide and 58 m high in Baiyun Cave, Hebei, after about 3000 people visited for 5 hours, the temperature increased from 16 8 ℃ to 19.6℃.In some cases, the natural factors may make great changes of the cave environment . For example, the heavy rain caused the great amount of drops in Yaolin Cave,Zhejiang.CO2 concentration was obviously increased from 490800 ppm on October 30 （before raining） to 7401580 ppm on November 14, 1997 （ after raining）. The measurement results show the temperature of drop water is 0.10.6℃ higher than the cave temperature, but it is not very clear that the temperature of cave was whether increased or not in the big chambers in Yaolin Cave. In Huangxian Cave, Hubei, in the wet season, most of 1833 rim pools were over flowing, the average CO2 content in the Rim Pool Hall on October 6,2000 was 2050 ppm, in the range of 1800 ppm and 2300 ppm; the temperature varied from 17.6℃ to 19.1℃, average temperature was 18.5℃. While on August 20, 2001, when 90% of the rim pools were dried out,it was only 950 ppm of average CO2 concentration varying from 900 ppm to 1100 ppm, and the average temperature was 17.9℃, fluctuated from 15.9℃ to 21.3℃.
