煤田地质与勘探2023，Vol.51Issue(11)：92-98,7.DOI:10.12363/issn.1001-1986.23.04.0176
西北生态脆弱区浅埋煤层保水开采隔水层稳定性评价方法
A method for evaluating aquiclude stability in the water conservation-based mining of shallowly buried coal seams in ecologically vulnerable areas in northwest China
摘要
Abstract
Water conservation and coal mining are both critical to Northwest China.Water conservation-based coal min-ing is an important technology for the coordinated development of coal and water resources in this region.In this techno-logy,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 ac-curately 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,nu-merical 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 mod-el.Finally,using the 3D geological block model,the differences between the heights of the hydraulically conductive fis-sure 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 min-ing.This study investigated the Mandura coal mine in Ordos.Based on the collected stratigraphic columns of 36 bore-holes 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 water-logged areas in the Mandura coal mine,the unstable aquiclude zones calculated using traditional methods failed to accur-ately 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 de-nudation on the Quaternary aquifers.As indicated by the results of this study,compared to traditional evaluation meth-ods,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 preserva-tion-based coal mining.关键词
保水开采/浅埋煤层/隔水性能评价/三维地质建模/数值模拟Key words
water conservation-based coal mining/shallow buried coal seam/performance evaluation of aquiclude/3D geological modelling/numerical simulation分类
矿业与冶金引用本文复制引用
李恒,何滔,郭宾..西北生态脆弱区浅埋煤层保水开采隔水层稳定性评价方法[J].煤田地质与勘探,2023,51(11):92-98,7.基金项目
中国石油天然气股份有限公司"十四五"重大科技项目(2021DJ2303) （2021DJ2303）
中央引导地方科技发展资金项目(2022ZY0018) （2022ZY0018）
