A method for evaluating aquiclude stability in the water conservation-based mining of shallowly buried coal seams in ecologically vulnerable areas in northwest China

Authors

LI Heng, Institute of Resources and Earth Sciences, China University of Mining and Technology, Xuzhou 221116, China; Inner Mongolia Coal Exploration New Energy Development Co. LTD, Hohhot 010010, ChinaFollow
HE Tao, Institute of Mining Engineering, Inner Mongolia University of Science and Technolog, Baotou 014010, ChinaFollow
GUO Bin, Bayan Obo Iron Mine, Baotou Iron and Steel Company, Baotou 014080, China

Abstract

Water conservation and coal mining are both critical to Northwest China. Water conservation-based coal mining is an important technology for the coordinated development of coal and water resources in this region. In this technology, the evaluation of aquiclude stability is critical. Due to the shallow depth of coal seams, intense topographic cutting, and complex changes in near-surface aquifers in the ecologically vulnerable areas in Northwest China, there exist large errors between traditional methods for aquiclude evaluation and the actual hydrological observations in these areas. To address this challenge, this study develops using the 3D geological modelling combined with numerical simulation to accurately evaluate the aquiclude stability in the water preservation-based mining of shallowly buried coal seams. First, an intuitive and reliable 3D geological model is constructed based on the exploration information and topographic contour maps. The purpose is to finely characterize topographic cutting and the complex changes in shallow aquifers. Then, numerical simulations of damage to the rocks overlying coal seams are performed by selecting several typical mining faces, aiming to determine the heights of the hydraulically conductive fissure zones at various coal seam points in the 3D model. Finally, using the 3D geological block model, the differences between the heights of the hydraulically conductive fissure zones and the thicknesses of overburden rocks’ aquifers were calculated for various coal seam proof points from the full 3D angle. These differences were employed to evaluate the aquiclude stability in water conservation-based coal mining. This study investigated the Mandura coal mine in Ordos. Based on the collected stratigraphic columns of 36 boreholes in the coal mine and its topographic and geological maps, this study established a fine-scale 3D geological model and evaluated the aquiclude stability. As indicated by the comparison of the observations of two underground waterlogged areas in the Mandura coal mine, the unstable aquiclude zones calculated using traditional methods failed to accurately reflect the area filled with water on the southern mining face. In contrast, the unstable aquiclude zones calculated using the new method was more fine-scale, adequately reflecting the effects of topographic cutting, weathering, and denudation on the Quaternary aquifers. As indicated by the results of this study, compared to traditional evaluation methods, the method for evaluating the aquiclude stability of shallowly buried coal seams based on 3D geological modeling can characterize the effects of the mining of shallowly buried coal seams on aquifers more intuitively and accurately and exhibits higher adaptability. Furthermore, the new method can provide fine-scale evaluation indices for water preservation-based coal mining.

Keywords

water conservation-based coal mining, shallow buried coal seam, performance evaluation of aquiclude, 3D geological modelling, numerical simulation

DOI

10.12363/issn.1001-1986.23.04.0176

Recommended Citation

LI Heng, HE Tao, GUO Bin, et al. (2023) "A method for evaluating aquiclude stability in the water conservation-based mining of shallowly buried coal seams in ecologically vulnerable areas in northwest China," Coal Geology & Exploration: Vol. 51: Iss. 11, Article 11.
DOI: 10.12363/issn.1001-1986.23.04.0176
Available at: https://cge.researchcommons.org/journal/vol51/iss11/11

Reference

[1] 王双明,申艳军,孙强,等. 西部生态脆弱区煤炭减损开采地质保障科学问题及技术展望[J]. 采矿与岩层控制工程学报,2020,2(4):043531.

WANG Shuangming,SHEN Yanjun,SUN Qiang,et al. Scientific issues of coal detraction mining geological assurance and their technology expectations in ecologically fragile mining areas of western China[J]. Journal of Mining and Strata Control Engineering,2020,2(4):043531.

[2] 徐智敏,孙亚军,高尚,等. 干旱矿区采动顶板导水裂隙的演化规律及保水采煤意义[J]. 煤炭学报,2019,44(3):767−776.

XU Zhimin,SUN Yajun,GAO Shang,et al. Law of mining induced water conduction fissure in arid mining area and its significance in water–preserved coal mining[J]. Journal of China Coal Society,2019,44(3):767−776.

[3] 李涛. 陕北煤炭大规模开采含隔水层结构变异及水资源动态研究[D]. 徐州：中国矿业大学，2012.

LI Tao. Study on aquifer–aquifuge structure variation and water resources dynamic evolution with large scale mining in northern Shaanxi Province[D]. Xuzhou：China University of Mining and Technology，2012.

[4] 彭苏萍,毕银丽. 黄河流域煤矿区生态环境修复关键技术与战略思考[J]. 煤炭学报,2020,45(4):1211−1221.

PENG Suping,BI Yinli. Strategic consideration and core technology about environmental ecological restoration in coal mine areas in the Yellow River Basin of China[J]. Journal of China Coal Society,2020,45(4):1211−1221.

[5] 王常建,徐祝贺,赵伟,等. 浅埋高强度开采矿区生态损伤特征与减损实践[J]. 煤炭工程,2022,54(4):176−181.

WANG Changjian,XU Zhuhe,ZHAO Wei,et al. Ecological damage characteristics and alleviation in shallow–buried high–intensity mining area[J]. Coal Engineering,2022,54(4):176−181.

[6] 范立民,马雄德,蒋泽泉,等. 保水采煤研究30年回顾与展望[J]. 煤炭科学技术,2019,47(7):1−30.

FAN Limin,MA Xiongde,JIANG Zequan,et al. Review and thirty years prospect of research on water–preserved coal mining[J]. Coal Science and Technology,2019,47(7):1−30.

[7] 范立民. 保水采煤是神府东胜煤田开发可持续发展的关键[J]. 地质科技管理,1998(5):28−29.

FAN Limin. Water conservation coal mining is the key to the sustainable development of Shenfu Dongsheng coal field development[J]. Management on Geological Science and Technology,1998(5):28−29.

[8] 常金源,李文平,李涛,等. 神南矿区煤炭开采水资源漏失量评价分区[J]. 煤田地质与勘探,2011,39(5):41−45.

CHANG Jinyuan,LI Wenping,LI Tao,et al. Zonation of water resources leakage due to coal mining in Shennan mining area[J]. Coal Geology & Exploration,2011,39(5):41−45.

[9] 邓念东,杨佩,林平选,等. 榆神矿区保水采煤工程地质条件分区研究[J]. 煤炭科学技术,2017,45(9):167−174.

DENG Niandong,YANG Pei,LIN Pingxuan,et al. Study on zone chart of engineering geological conditions of protected water resources during coal mining in Yushen Mining Area[J]. Coal Science and Technology,2017,45(9):167−174.

[10] 师本强,侯忠杰. 工程地质模型在保水采煤研究中的应用[J]. 矿业研究与开发,2006,26(3):37−39.

SHI Benqiang,HOU Zhongjie. Application of engineering geological model in research of water–preserved coal mining[J]. Mining Research and Development,2006,26(3):37−39.

[11] 刘洋,张壮路. 矿井开发对水资源系统影响评价及保护措施[J]. 煤炭工程,2008(9):88−91.

LIU Yang,ZHANG Zhuanglu. Evaluation and protection measures of the impact of mine development on water resources system[J]. Coal Engineering,2008(9):88−91.

[12] 王双明，范立民，杨宏科，等. 榆神矿区保水采煤综合研究[R]. 西安：陕西省煤田地质局，2003.

[13] 赵春虎,靳德武,虎维岳. 采煤对松散含水层地下水扰动影响规律及评价指标:以神东补连塔井田为例[J]. 煤田地质与勘探,2018,46(3):79−84.

ZHAO Chunhu,JIN Dewu,HU Weiyue. Study on influence rules and evaluation criteria of groundwater affected by mining in unconsolidated aquifers in Shendong Bulianta coal mine[J]. Coal Geology & Exploration,2018,46(3):79−84.

[14] 许玉军. 榆神矿区“五图–三带–两分区”保水采煤方法研究[D]. 徐州：中国矿业大学，2019.

XU Yujun. Study on“Five Maps，Three Zones and Two Zoning Plans”water conservation mining method in Yushen mining area[D]. Xuzhou：China University of Mining and Technology，2019.

[15] 王启庆,李文平,李涛. 陕北生态脆弱区保水采煤地质条件分区类型研究[J]. 工程地质学报,2014,22(3):515−521.

WANG Qiqing,LI Wenping,LI Tao. Division types of geological conditions at mining with water protection in ecological fragile area of northern Shaanxi[J]. Journal of Engineering Geology,2014,22(3):515−521.

[16] 范立民,马雄德,蒋辉,等. 西部生态脆弱矿区矿井突水溃沙危险性分区[J]. 煤炭学报,2016,41(3):531−536.

FAN Limin,MA Xiongde,JIANG Hui,et al. Risk evaluation on water and sand inrush in ecologically fragile coal mine[J]. Journal of China Coal Society,2016,41(3):531−536.

[17] 马雄德,范立民,张晓团,等. 基于植被地下水关系的保水采煤研究[J]. 煤炭学报,2017,42(5):1277−1283.

MA Xiongde,FAN Limin,ZHANG Xiaotuan,et al. Water–preserved mining based on relationship between vegetation and groundwater[J]. Journal of China Coal Society,2017,42(5):1277−1283.

[18] 王双明,范立民,黄庆享,等. 基于生态水位保护的陕北煤炭开采条件分区[J]. 矿业安全与环保,2010,37(3):81−83.

WANG Shuangming,FAN Limin,HUANG Qingxiang,et al. Zoning of coal mining conditions in northern Shaanxi based on ecological water level protection[J]. Mining Safety & Environmental Protection,2010,37(3):81−83.

[19] 范立民,孙强,马立强,等. 论保水采煤技术体系[J]. 煤田地质与勘探,2023,51(1):196−204.

FAN Limin,SUN Qiang,MA Liqiang,et al. Technological system of water–conserving coal mining[J]. Coal Geology & Exploration,2023,51(1):196−204.

[20] 中关村绿色矿山产业联盟. 保水采煤技术规范：T/GRM 054—2022[S]. 北京：中关村绿色矿山产业联盟，2022.

[21] 国家煤炭工业局. 建筑物、水体、铁路及主要井巷煤柱留设与压煤开采规范[M]. 北京：煤炭工业出版社，2017.