Study on sediment environment and rock mechanics characteristics of the delta plain of Jurassic coalfield in northern Shaanxi
摘要: 三角洲平原沉积环境是陕北侏罗纪煤田煤炭资源的主要形成环境之一，为获得不同环境煤层顶板岩石力学参数特征，进一步探究沉积环境与岩石力学特征之间的关系，首先从区域沉积环境分析入手，然后运用岩心精细描述、沉积构造分析、地球物理测井分析等技术，识别微相、划分顶板沉积微相类型及其组合特征；之后对不同沉积环境中不同位置、不同岩性的岩石进行系统地分层采样和测试分析；最后综合分析煤层顶板各沉积微相的岩石力学特征。结果表明，煤层直接顶板以泥岩、粉砂质泥岩为主，形成于三角洲平原亚相中的沼泽、湖泊沉积微相，局部见粉砂岩、细粒砂岩形成于分流河道和天然堤微相；基本顶主要以中-细粒砂岩为主，形成于分流河道沉积微相；沉积环境不仅控制煤层顶板岩性分布而且控制岩石力学参数及其含水层富水性的分布，其中，湖泊、沼泽相泥岩顶板区是顶板支护的重点部位，多期分流河道砂岩叠置顶板区是未来矿井防治水以及探放水的重点区域。Abstract: Delta plain sedimentary environment is one of the coal-forming environments of the coal resources of Jurassic coalfield in northern Shaanxi. In order to get the rock mechanics parameters and characteristics of coal seam roof in different environments and to further investigate the relationship between the sedimentary environments and the rock mechanics characteristics, firstly from the analysis of the regional sedimentary environments, then by using techniques such as accurate core description, sedimentary structural analysis, facies analysis of geophysical logging, the microfacies were recognized, the sedimentary microfacies types of roof and their combination characteristics were classified. Later, rock samples of different lithology at different position were collected by layer, tested and analyzed. Finally, the rock mechanics characteristics of different microfacies of seam roof were analyzes comprehensively. The results show that sedimentary environment not only controlled coal seam roof lithologic distribution but also controlled the rock mechanics parameters and the distribution of water yield properties of aquifer. Direct roof of coal seam in the study area dominated by mudstone and silty mudstone, was formed in the delta plain sub-facies of swamps, locally siltstone and fine-grained sandstone were formed in shunt rivers and natural embankment microfacies. The basic roof lithology is dominated by medium and fine-grained sandstone formed in the branch river and onshore natural levee sedimentary microfacies, coal seam roof stability is medium, the main roof sandstone aquifer is the major risk for mine production in the future, among them, lake and swamp mudstone roof area is the key part of roof support, multi-stage distributary channel sandstone overlapping top plate area is the key area for mine water prevention and drainage in the future.
 葛道凯,杨起,李宝芳. 沉积环境对煤系岩石强度的影响[J]. 煤田地质与勘探,1993,21(1):5-11.GE Daokai,YANG Qi,LI Baofang. The effect of depositional environments on the strength of rocks in coal measures[J]. Coal Geology & Exploration,1993,21(1):5-11.  刘洪涛,樊龙,宋高峰,等. 巷道顶板岩层沉积稳定性分析[J]. 煤矿开采,2012,17(2):54-56.LIU Hongtao,FAN Long,SONG Gaofeng,et al. Analysis of sediment stability of roof strata in roadway[J]. Coal Mining Technology,2012,17(2):54-56.  郭志飚,王炯,邓小卫,等. 深部软岩巷道围岩吸水后抗压强度变化规律研究[J]. 煤炭科学技术,2015,43(3):40-42.GUO Zhibiao,WANG Jiong,DENG Xiaowei,et al. Study on compressive strength change law of surrounding rock after water absorption in mine deep soft rock roadway[J]. Coal Science and Technology,2015,43(3):40-42.  孟召平,彭苏萍,傅继彤. 含煤岩系岩石力学性质控制因素探讨[J]. 岩石力学与工程学报,2002,21(1):102-106.MENG Zhaoping,PENG Suping,FU Jitong. Study on control factors of rock mechanics properties of coal bearing formation[J]. Chinese Journal of Rock Mechanics and Engi-neering,2002,21(1):102-106.  孟召平,彭苏萍. 煤系泥岩组分特征及其对岩石力学性质的影响[J]. 煤田地质与勘探,2004,32(2):14-16.MENG Zhaoping,PENG Suping. Mudstone composition of coal measures and its influence on the mechanical properties[J]. Coal Geology & Exploration,2004,32(2):14-16.  孟召平,彭苏萍,屈洪亮,等. 煤层顶底板岩石成分和结构与其力学性质的关系[J]. 岩石力学与工程学报,2000,19(2):136-139.MENG Zhaoping,PENG Suping,QU Hongliang,et al. Relationship between composition and texture of sedimentary rock and its mechanical properties in the roof and floor[J]. Chinese Journal of Rock Mechanics and Engineering,2000,19(2):136-139.  孟召平,陆鹏庆,贺小黑. 沉积结构面及其对岩体力学性质的影响[J]. 煤田地质与勘探,2009,37(1):33-38.MENG Zhaoping,LU Pengqing,HE Xiaohei. Depositional structure planes and their influence on the mechanical properties of sedimentary rock mass[J]. Coal Geology & Exploration,2009,37(1):33-38.  王东东,邵龙义,李智学,等. 鄂尔多斯盆地延安组层序地层格架与煤层形成[J]. 吉林大学学报(地球科学版),2013,43(6):1726-1739.WANG Dongdong,SHAO Longyi,LI Zhixue,et al. Sequence stratigraphic framework and coal formation of Yan'an Formation in Ordos basin[J]. Journal of Jilin University(Earth Science Edition),2013,43(6):1726-1739.  王双明. 鄂尔多斯盆地构造演化和构造控煤作用[J]. 地质通报,2011,30(4):544-552.WANG Shuangming. Tectonic evolution of the basin and Ordos basin coal controlling structures[J]. Geological Bulletin,2011,30(4):544-552.  王海军. 关于煤层顶板划分中岩性及厚度取值的探讨[J]. 能源与环保,2017,39(1):86-89.WANG Haijun. Discuss on division of lithology and thickness values of coal roof[J]. China Energy and Environmental Protection,2017,39(1):86-89.  王海军. 永陇矿区LYL井田2号煤层顶板沉积环境及其稳定性评价[J]. 煤田地质与勘探,2016,44(6):38-44.WANG Haijun. Sedimentary environment and stability evaluation of seam roof of No.2 seam in LYL coal mine of Yonglong coal field[J]. Coal Geology & Exploration,2016,44(6):38-44.  王海军. 煤层顶板沉积环境对其稳定性影响研究[J]. 煤炭科学技术,2017,45(2):178-184.WANG Haijun. Study on impact of sedimentary environment to stability of seam roof[J]. Coal Science and Technology,2017,45(2):178-184.
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