Coal and gas outbursts in footwalls of reverse faults
Coal and gas outbursts in footwalls of reverse faults
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DOI：
10.1016/s0166-5162(01)00037-4
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发表时间：
2001-12-01
影响因子：
5.6
通讯作者：
Glick, DC
中科院分区：
文献类型：
--
作者：
Cao, YX;He, DD;Glick, DC
煤矿中的瞬时突出涉及煤和大量气体的灾难性和强有力的排出，产生重大的采矿灾害。其他研究者研究了煤突出与许多地质因素的关系，如煤层厚度、煤阶、煤层年龄、现今埋深和距岩体的距离，由于成因机制的复杂性，不同煤田和地区得出不同的结论。煤突出几乎总是与地质构造有密切的关系，本研究旨在确定与逆断层有关的特定危险区的位置和特征。与逆断层有关的煤和瓦斯突出几乎总是发生在下盘。另外，还利用了四川省两个矿井和河南省一个矿井的数据，对地质构造现象的第一个重要观察是，逆断层下盘的煤层比上盘的煤层经历了更大的构造变形。煤失去了它的带状特征，并被物理转化为微观结构改变的形式，分类为碎裂煤，粒状煤和糜棱岩煤。突出总是发生在断层周围的构造蚀变煤带内。第二，构造蚀变带在下盘比在上盘延伸更远的断层。第三，在与逆断层相关的地方，煤层气含量较高的区域几乎总是发生在下盘。这三个因素是与逆断层有关的煤与瓦斯突出的主要控制因素。通过应用，煤矿安全专家可以将预测的突出危险区缩小到更小的区域。(C)2001 Elsevier Science B.V.保留所有权利。
Instantaneous outbursts in coal mines involve catastrophic and forceful expulsion of coal and large quantities of gas, creating a major mining hazard. Other researchers have studied relationships between coal outbursts and many geological factors, such as coal seam thickness, coal rank, coal seam age, current burial depth, and distance to plutons, with different conclusions for different coal fields and regions because of the complexity of the causative mechanisms. Coal outbursts nearly always have a close relationship to geologic structures; the present research was designed to determine the location and characteristics of specific danger zones associated with reverse faults.Four coal mines in the Pingdingshan coal field, Henan Province, China were investigated in detail. Coal and gas outbursts associated with reverse faults nearly always occurred in the footwalls. Additional data were also used from two mines in Sichuan Province and one in Henan Province.The first important observation of the geological structural phenomena was that coal seams in the footwalls of the reverse faults underwent greater tectonic deformation than those in the hanging walls. Coal lost its banded character and was physically transformed into microstructurally altered forms categorized as cataclastic coal, granular coal and mylonitic coal. Outbursts always occurred within a zone of this tectonically altered coal surrounding the fault. Second, the zone of tectonic alteration in the footwalls extended farther from the fault than that in the hanging walls. Third, where present in association with reverse faults, zones of higher coalbed methane content nearly always occurred in the footwalls. These three factors are the principal controls on coal and gas outbursts associated with reverse faults. Through their application, coal safety experts can narrow the predicted outburst danger zone to a smaller area. (C) 2001 Elsevier Science B.V. All rights reserved.