含裂隙煤层底板突水规律的数值模拟与工程应用   总被引：5，自引：0，他引：5  

吕春峰  王芝银  李云鹏 《岩土力学》2003,(Z2)

本文结合淮北杨庄矿某工作面实际工程情况, 利用NCAP-2D-W对煤层底板突水进行多方案的数值模拟试验研究。主要内容包括:(1) 考虑在承压水不变的条件下,设计不同裂隙分布状态,探讨单裂隙、多裂隙、不同长度裂隙对煤层底板破坏的影响及开采矿压对裂隙顶部破坏的影响;(2) 考虑承压水的变化,分别考虑单裂隙和多裂隙两种分布状态,探讨裂隙对煤层底板破坏的影响及开采矿压对裂隙底部破坏的影响。通过分析受采动荷载、岩层结构变化、煤层底板中裂隙分布状态及承压水变化等因素影响的数值试验,获得了随开采工作面不断推进煤层底板破坏区的发展、突水导升高度的递增、突水通道的形成等相关规律。  相似文献   

济宁二号矿孤岛工作面冲击矿压危险及其控制   总被引：2，自引：0，他引：2  

何烨  才庆祥  窦林名  张卫东 《岩土力学》2003,(Z2)

孤岛工作面及其周围巷道附近应力集中程度高,顶板运动剧烈,再加上地质构造的影响,采深较大时,冲击危险程度就高,很容易引发冲击矿压。《煤矿安全规程》要求孤岛工作面按冲击矿压危险工作面来管理。孤岛工作面冲击矿压危险检测预报及控制的技术是先分析冲击危险程度,确定冲击危险指数,提出早期预报;采用电磁辐射和钻屑法进行及时预报;采用卸压爆破进行处理,并采用电磁辐射和钻屑法检验防治措施的效果。实践证明,这套技术安全、可靠、有效,能够保证工作面的安全高效生产。  相似文献   

煤层上覆地层含水不均匀性电法探测的可能性   总被引：5，自引：4，他引：5  

底青云  王妙月 《地球物理学进展》2003,18(4):707-710

煤田上覆岩层中含水直接对煤层的开采构成威胁，本文先从理论上阐述了电阻率勘探可以探测煤层上覆地层含水不均匀性的可能性，然后用简单的断层型薄层含水模型的CSAMT正演模拟结果展示出：地下900m深处，尽管只有20m厚的的含水岩层，但在电阻率剖面上该薄层的反映具有非常明显的特征，从理论上和数值模拟实例说明，一定深度内一定厚度的薄层含水性的电阻率法探测是可能的。  相似文献   

Striking liptinitic bark remains peculiar to some Late Permian Chinese coals     

N.N. Zhong  M. Smyth 《International Journal of Coal Geology》1997,33(4):333-349

An unusual liptinite coal component has been reported in the Chinese literature over the past sixty years. It has been described as a maceral in the Chinese National Standard (1991), but it has not been named internationally. In Chinese literature it is called “barkinite”, on the basis of its morphological features and because it is believed to have originated as bark tissue.“Barkinite” occurs in Late Permian, marine-influenced coals and is best represented in the Changguang, Leping and Shuicheng Basins of southern China.The material originates from plant periderm or the bark of higher plants. However, “bark” contains a variety of substances, including resin and suberin, which are recognised as the precursors of the resinite and suberinite macerals. “Barkinite” is distinguished by (i) its thickness; individual pieces can be more than ten cells thick and several centimetres long and (ii) it fluoresces strongly at 0.6% vitrinite reflectance and loses its fluorescence at about 1.1% vitrinite reflectance.The reporting of “barkinite” from only Chinese coals may be due to its origin from Lepidodendron and Psaronius flora, which was common in the Northern Hemisphere during the Carboniferous, but which was isolated to China by the Late Permian. It is proposed that the remnant flora evolved into unique forms in China by the Late Permian. Lepidodendron and Psaronius remains, coupled with a strongly marine-influenced, peat-forming environment have given rise to “barkinite” and to its restricted distribution.  相似文献   

Groundwater transformation of a low-sulfur to a high-sulfur coal, the Harlem coal of the northern Appalachian basin     

L.L. Chyi 《International Journal of Coal Geology》1997,33(4):317-331

The Harlem coal is postulated to have been deposited in raised-bog settings. It was initially deposited as low-sulfur peat, but groundwater of a later origin altered portions of it to high-sulfur coal. The total sulfur content of 172 samples from 31 locations on a moisture- and ash-free basis have a quadrimodal distribution with two major modes at 0.75% S and 2.0%S. Multiple sampling and analyses at specific mine sites indicate that the addition of sulfur of a later origin occurred either laterally adjacent to sandstone channels or vertically adjacent to faults. Significant sulfur addition also occurred above clay partings at these sites. The original low-sulfur nature is preserved where the coal bed is isolated from descending groundwater by a thick impervious layer. Trace-element analyses show high concentrations of mobile elements such as Na and Mn in the high-sulfur coals.  相似文献   

The origin and distribution of HAPs elements in relation to maceral composition of the A1 lignite bed (Paleocene, Calvert Bluff Formation, Wilcox Group), Calvert mine area, east-central Texas     

Sharon S. Crowley  Peter D. Warwick  Leslie F. Ruppert  James Pontolillo 《International Journal of Coal Geology》1997,34(3-4)

The origin and distribution of twelve potentially Hazardous Air Pollutants (HAPs; As, Be, Cd, Cr, Co, Hg, Mn, Ni, Pb, Sb, Se, and U) identified in the 1990 Clean Air Act Amendments were examined in relation to the maceral composition of the A1 bed (Paleocene, Calvert Bluff Formation, Wilcox Group) of the Calvert mine in east-central Texas. The 3.2 m-thick A1 bed was divided into nine incremental channel samples (7 lignite samples and 2 shaley coal samples) on the basis of megascopic characteristics. Results indicate that As, Cd, Cr, Ni, Pb, Sb, and U are strongly correlated with ash yield and are enriched in the shaley coal samples. We infer that these elements are associated with inorganic constituents in the coal bed and may be derived from a penecontemporaneous stream channel located several kilometers southeast of the mining block. Of the HAPs elements studied, Mn and Hg are the most poorly correlated to ash yield. We infer an organic association for Mn; Hg may be associated with pyrite. The rest of the trace elements (Be, Co, and Se) are weakly correlated with ash yield. Further analytical work is necessary to determine the mode of occurrence for these elements. Overall, concentrations of the HAPs elements are generally similar to or less than those reported in previous studies of lignites of the Wilcox Group, east-central region, Texas. Petrographic analysis indicates the following ranges in composition for the seven lignite samples: liptinites (5–8%), huminites (88–95%), and inertinites (trace amounts to 7%). Samples from the middle portion of the A1 bed contain abundant crypto-eugelinite compared to the rest of the samples; this relationship suggests that the degradation of plant material was an important process during the development of the peat mire. With the exception of Hg and Mn, relatively low levels of the HAPs elements studied are found in the samples containing abundant crypto-eugelinite. We infer that the peat-forming environment for this portion of the coal bed was very wet with minimal detrital input. Relatively high concentrations of crypto-humotelinite were found in samples from the top and base of the coal bed. The presence of abundant crypto-humotefinite in this part of the coal bed suggests the accumulation of wood-rich peat under conditions conducive to a high degree of tissue preservation in the peat mire. Although several of the trace elements (Be, Co, Ni, and Sb) exhibit enrichment in these samples, they are not necessarily chemically associated with humotelinite. We infer that these elements, with the exception of Be, are possibly associated with deposition of the roof and floor rock of the coal bed; however, further analytical work would be necessary to confirm this hypothesis. Beryllium may have an organic origin.  相似文献   

对煤中锗矿化若干问题的思考——以临沧锗矿为例   总被引：8，自引：0，他引：8  

胡瑞忠  毕献武 《矿物学报》1997,17(4):364-368

本文在综述煤中锗矿化国内外研究现状的基础上，以临沧锗矿为例，深入讨论了在煤系地层中形成超大型独立锗矿床的特殊条件。结果表明，煤是锗成矿极有利的围岩，煤能否富集锗主要取决于有无富锗流体与煤相互作用。  相似文献   

四川南部晚二叠世构造对煤类分布的影响     

袁培生 《四川地质学报》1997,(3)

深成煤化作用是川南地区煤化作用的主导因素，本文着重阐明了构造对煤类分布的影响。  相似文献   

山东淄博地区晚古生代成煤环境演替     

王嘹亮  米家榕 《吉林大学学报(地球科学版)》1996,(3)

淄博地区本溪期—石千峰期沉积环境经历了障壁岛—泻湖—台地环境，三角洲环境，曲流河环境体系的演替。相应的泥炭形成环境有不稳定的局限泻湖泥炭坪，较开阔泻湖泥炭坪，中等稳定的开阔泻湖泥炭坪，三角洲平原分流河道两侧的泥炭沼泽，洪泛平原上的泥炭沼泽。成煤植物上，本溪期以Ｃｏｒｄａｉｔｅｓ，Ｌｅｐｉｄｏｄｅｎｄｒａｌｅｓ，Ｎｅｕｒｏｐｔｅｒｉｓ为主，太原期华夏植物群发展，Ｌｅｐｉｄｏｄｅｎｄｒｏｎ，Ｃｏｒｄａｉｔｅｓ继续发育，真蕨纲和种子蕨纲占越来越重要的地位。山西期以Ｏｄｏｎｔｏｐｔｅｒｉｓｓｐ．，Ａｎｎｕｌａｒｉａｏｒｉｅｎｔａｌｉｓ，Ｐｅｃｏｐｔｅｒｉｓｏｒｉｅｎｔａｌｉｓ，Ｐ．ｎｏｒｉｎｉ为主。自煤系形成至今，本区经历了海西印支期的普遍沉降埋藏、燕山期的普遍抬升局部断陷、喜山期的剥蚀、新构造运动期的差异沉降等阶段。古构造、古气候对本区成煤环境有重要的控制作用。  相似文献   

三角洲平原上网结河的发育与聚煤作用   总被引：4，自引：4，他引：4  

陈代钊  张鹏飞 《沉积学报》1996,14(3):103-112

龙潭组上段（２４＃煤顶板到１２＃煤）是盘县地区含煤最好的层段，对该区西北部本段地层的研究表明其中发育有网结河体系。河道沉积由多层叠置的鞋带状砂体组成，湿地沉积主要由菱铁质泥质岩夹薄层板状细砂岩（决口扇沉积）和煤组成。河流的发育和聚煤作用都显示幕式性，可能主要受海平面变化的控制。网结状河道被认为是海侵期对低位下切河谷充填过程中经侧向冲裂水道并相互连通形成的；稳定、连续的厚煤层发育于河道大范围废弃后的海侵晚期，其次是高水位早期。  相似文献