Aiming at the safety distance between coal mining working face and natural gas wells in the cross-mining area of multiple mineral resources, the cross- mining area of gas and coal resources in the Ordos Basin is taken...Aiming at the safety distance between coal mining working face and natural gas wells in the cross-mining area of multiple mineral resources, the cross- mining area of gas and coal resources in the Ordos Basin is taken as the engineering background. An anti-collision early warning technology method based on vibration wave propagation attenuation monitoring is proposed to prevent collision accidents between road headers and natural gas wells. Through the steel pipe and steel pipe concrete knocking vibration test and underground digging vibration test, the research results show that: The exponential decay coefficients of the vibration wave in steel pipe, steel pipe concrete and coal rock respectively are 0.1, 0.1140 and 0.03, which are all in accordance with the exponential decay law, and the vibration wave firstly decays sharply and then decays slowly;the formula for the distance from the road header to the natural gas well was derived based on the vibration attenuation formula, to provide a new method for realizing the problem of precise and coordinated extraction by surface monitoring of the distance from down hole road headers to gas wells, collision prevention prediction and warning and prevention of collision of extraction equipment with gas wells.展开更多
The regional lithospheric chemical heterogeneity in-ers that the East Qinling and its adjacent cratonic re-ions,as suggested by some authors,belong to twoeotectonic units,the North China subdomain includinghe North Ch...The regional lithospheric chemical heterogeneity in-ers that the East Qinling and its adjacent cratonic re-ions,as suggested by some authors,belong to twoeotectonic units,the North China subdomain includinghe North China Craton and its southern continentalhargin(the North Qinling Belt),and the Yangtzeanubdomain comprising the Yangtze Craton and itsorthern continental margin(the South Qinling Belt).In the North Qinling Belt the metamorphosedolcanic rocks and graywackes of the Early Paleozoicanfeng Group south of the Early Proterozoic QinlingGroup show geochemical characteristics resemblinghose of the are volcanies and are graywackes,espectively.The Early Paleozoic granites intruding in hehe Qinling Group also show similar geochemical fea-tures and similar compositional polarities to theare-type granites.The Erlangping Group north ofthe Qinling Group is a volcanic-sedimentary sequenceproduced in an Early Paleozoic back-are basin basedon geochemical evidence.It is therefore believed thatthe North Qinling展开更多
文摘Aiming at the safety distance between coal mining working face and natural gas wells in the cross-mining area of multiple mineral resources, the cross- mining area of gas and coal resources in the Ordos Basin is taken as the engineering background. An anti-collision early warning technology method based on vibration wave propagation attenuation monitoring is proposed to prevent collision accidents between road headers and natural gas wells. Through the steel pipe and steel pipe concrete knocking vibration test and underground digging vibration test, the research results show that: The exponential decay coefficients of the vibration wave in steel pipe, steel pipe concrete and coal rock respectively are 0.1, 0.1140 and 0.03, which are all in accordance with the exponential decay law, and the vibration wave firstly decays sharply and then decays slowly;the formula for the distance from the road header to the natural gas well was derived based on the vibration attenuation formula, to provide a new method for realizing the problem of precise and coordinated extraction by surface monitoring of the distance from down hole road headers to gas wells, collision prevention prediction and warning and prevention of collision of extraction equipment with gas wells.
文摘The regional lithospheric chemical heterogeneity in-ers that the East Qinling and its adjacent cratonic re-ions,as suggested by some authors,belong to twoeotectonic units,the North China subdomain includinghe North China Craton and its southern continentalhargin(the North Qinling Belt),and the Yangtzeanubdomain comprising the Yangtze Craton and itsorthern continental margin(the South Qinling Belt).In the North Qinling Belt the metamorphosedolcanic rocks and graywackes of the Early Paleozoicanfeng Group south of the Early Proterozoic QinlingGroup show geochemical characteristics resemblinghose of the are volcanies and are graywackes,espectively.The Early Paleozoic granites intruding in hehe Qinling Group also show similar geochemical fea-tures and similar compositional polarities to theare-type granites.The Erlangping Group north ofthe Qinling Group is a volcanic-sedimentary sequenceproduced in an Early Paleozoic back-are basin basedon geochemical evidence.It is therefore believed thatthe North Qinling
