The regional strategy study was aimed at coal mine disaster control and prevention,which deepens and enriches the macro-strategy of coal mine disaster control andprevention,and provides an important support for the ra...The regional strategy study was aimed at coal mine disaster control and prevention,which deepens and enriches the macro-strategy of coal mine disaster control andprevention,and provides an important support for the rapid and healthy development ofthe regional coal industry.The country was divided into 4 regions:Northeast,North,Southand Xinqing.In view of the regional status of coal mine disasters,the regulation and developmenttrend of regional coal mine disasters were analyzed,the outstanding problemsand key factors were identified,and the general thoughts on regional coal mine disastercontrol and prevention were put forward.展开更多
Stability assessment is one of the most important issues in mining ground control. Mine development and/or production instability can cause production delay, loss of reserves, as well as injury to miners. Within the s...Stability assessment is one of the most important issues in mining ground control. Mine development and/or production instability can cause production delay, loss of reserves, as well as injury to miners. Within the scope of this study, a series of open stope’s instability under the influence of overlaying mined-out regions were carried out with different mining scenarios at Modi Taung gold mine which is operated by National Prosperity Gold Production Group Limited (NPGPGL) in Myanmar. NPGPGL has been developing stopes up to 150 m from the surface at Shwesin vein system, and the mining activities are going to continue to deeper levels to fulfill the ore mineral supply. Creating a new stope opening under overlaying mined-out regions is not easy considering the instability of mined-out regions can affect the stope. The instability of new stope opening is not only due to its own induced stress but also the strong influence by the mined-out regions situated on upper part of the stope. Therefore, the understandings of ground behaviors and failure mechanisms of new stope opening due to the influence of overlaying mined-out regions are paramount to be studied. This paper describes in detail the strength factor and failure zones under the overlaying mined-out regions with different mine conditions by using numerical simulations, 3D finite difference software (FLAC 3D).展开更多
Earthquake Administration of Liaoning Province, Shenyang 100031, China Based on the Morlet wavelet transform and digital data from the Fushun and Beizhen seismic stations, Liaoning Province, we put forward a new metho...Earthquake Administration of Liaoning Province, Shenyang 100031, China Based on the Morlet wavelet transform and digital data from the Fushun and Beizhen seismic stations, Liaoning Province, we put forward a new method in the paper, called time-frequency energy attenuation factor (α-value). The characteristics of the α-value and its variation with magnitude of natural and mine earthquakes are studied, and the statistic relations between the α-value and specific earthquake magnitude are obtained. From the results, some conclusions can be drawn as follows: (1) in general, the α-values of mine and natural earthquakes of the same intensity have obvious difference and the ranges of their variation do not overlap each other; (2) the α-value decreases with the increase of earthquake magnitude, and the α-value of mine earthquake decreases faster than that of natural earthquake; (3) based on the earthquake magnitude and on the relations between the α-value and earthquake magnitude, we can distinguish the mine earthquakes from the natural ones; (4) the difference in focal mechanism of mine and natural earthquakes would be the main cause for obvious difference of the α-value; (5) the α-value variation is relatively steady for mine and natural earthquakes that occur in the same region, but it has obvious regional difference. The above results are of inspirational meaning for the study of abnormal change of the α-value before strong earthquakes.展开更多
基金Supported by the National Key Technology R&D Program in 11th Five Years Plan of China(2006BAK03B07)
文摘The regional strategy study was aimed at coal mine disaster control and prevention,which deepens and enriches the macro-strategy of coal mine disaster control andprevention,and provides an important support for the rapid and healthy development ofthe regional coal industry.The country was divided into 4 regions:Northeast,North,Southand Xinqing.In view of the regional status of coal mine disasters,the regulation and developmenttrend of regional coal mine disasters were analyzed,the outstanding problemsand key factors were identified,and the general thoughts on regional coal mine disastercontrol and prevention were put forward.
文摘Stability assessment is one of the most important issues in mining ground control. Mine development and/or production instability can cause production delay, loss of reserves, as well as injury to miners. Within the scope of this study, a series of open stope’s instability under the influence of overlaying mined-out regions were carried out with different mining scenarios at Modi Taung gold mine which is operated by National Prosperity Gold Production Group Limited (NPGPGL) in Myanmar. NPGPGL has been developing stopes up to 150 m from the surface at Shwesin vein system, and the mining activities are going to continue to deeper levels to fulfill the ore mineral supply. Creating a new stope opening under overlaying mined-out regions is not easy considering the instability of mined-out regions can affect the stope. The instability of new stope opening is not only due to its own induced stress but also the strong influence by the mined-out regions situated on upper part of the stope. Therefore, the understandings of ground behaviors and failure mechanisms of new stope opening due to the influence of overlaying mined-out regions are paramount to be studied. This paper describes in detail the strength factor and failure zones under the overlaying mined-out regions with different mine conditions by using numerical simulations, 3D finite difference software (FLAC 3D).
文摘Earthquake Administration of Liaoning Province, Shenyang 100031, China Based on the Morlet wavelet transform and digital data from the Fushun and Beizhen seismic stations, Liaoning Province, we put forward a new method in the paper, called time-frequency energy attenuation factor (α-value). The characteristics of the α-value and its variation with magnitude of natural and mine earthquakes are studied, and the statistic relations between the α-value and specific earthquake magnitude are obtained. From the results, some conclusions can be drawn as follows: (1) in general, the α-values of mine and natural earthquakes of the same intensity have obvious difference and the ranges of their variation do not overlap each other; (2) the α-value decreases with the increase of earthquake magnitude, and the α-value of mine earthquake decreases faster than that of natural earthquake; (3) based on the earthquake magnitude and on the relations between the α-value and earthquake magnitude, we can distinguish the mine earthquakes from the natural ones; (4) the difference in focal mechanism of mine and natural earthquakes would be the main cause for obvious difference of the α-value; (5) the α-value variation is relatively steady for mine and natural earthquakes that occur in the same region, but it has obvious regional difference. The above results are of inspirational meaning for the study of abnormal change of the α-value before strong earthquakes.
