特厚煤层综放工作面煤-架受力演化特征及其承载机理_郭星辰.pdf

第 5 卷第 1 期 采矿与岩层控制工程学报 Vol.5 No.1 2023 年 2 月 JOURNAL OF MINING AND STRATA CONTROL ENGINEERING Feb.2023 013022-1 郭星辰，郭军，冯国瑞，等.特厚煤层综放工作面煤-架受力演化特征及其承载机理J.采矿与岩层控制工程学报，2023，5(1)：013022.GUO Xingchen，GUO Jun，FENG Guorui，et al.Stress evolution characteristics and bearing mechanism of coal-hydraulic support in fully-mechanized caving mining face in extra-thick coal seamJ.Journal of Mining and Strata Control Engineering，2023，5(1)：013022.特厚煤层综放工作面煤-架受力演化特征 及其承载机理 郭星辰1,2，郭 军1,2,3，冯国瑞1,2，文晓泽1,2，戚庭野1,2，白锦文1,2,3，高 瑞1,2，钱瑞鹏1,2，朱林俊1,2 (1.太原理工大学 矿业工程学院，山西 太原 030024；2.山西省绿色采矿工程技术研究中心，山西 太原 030024；3.山西焦煤集团有限责任公司，山西 太原 030024)摘 要：为了研究特厚煤层综放工作面煤-架结构及其承载机理，以塔山矿8216工作面为背景，根据煤体与支架的位置关系将其分为架前顶煤、架上顶煤和承载煤体，采用FLAC3D数值模拟软件分析了煤-架结构应力演化特征及煤体失稳破坏规律。结果表明：工作面超前支承压力峰值位于煤壁斜上方的架前顶煤中，顶煤破坏深度与超前支承压力峰值的超前距离基本相当，向控顶区侧呈“弧形”破坏形态。确定了煤-架结构对顶板来压承载能力的排序依次为架前顶煤承载煤体液压支架架上顶煤。承载煤体在围岩应力拱和顶煤的保护下破坏深度始终保持在近煤壁侧3 m内，已破坏煤体应力基本不受推进距离与支架工作阻力变化的影响。架上顶煤在顶煤冒放前后承载特性不同，进而引起整个煤-架结构承载特性的改变。放煤前后煤壁破坏深度分别为3 m和2 m，顶煤破坏深度分别为7 m和12 m。架前顶煤的失稳是发生端面冒顶的主要原因，煤壁侧承载煤体的破坏是煤壁片帮的直接原因。在围岩应力拱的作用下，顶板以架前顶煤为轴做回转运动并伴随着顶板、支架及超前煤体应力的动态变化，但煤-架结构的承载特性不会改变。研究结果可为特厚煤层综放工作面矿压灾害防控提供有益参考。关键词：综放开采；支架-围岩；支承压力；数值模拟 中图分类号：TD324 文献标志码：A 文章编号：2096-7187(2023)01-3022-14 Stress evolution characteristics and bearing mechanism of coal-hydraulic support in fully-mechanized caving mining face in extra-thick coal seam GUO Xingchen1,2，GUO Jun1,2,3，FENG Guorui1,2，WEN Xiaoze1,2，QI Tingye1,2，BAI Jinwen1,2,3，GAO Rui1,2，QIAN Ruipeng1,2，ZHU Linjun1,2(1.College of Mining Engineering，Taiyuan University of Technology，Taiyuan 030024，China；2.Research Center of Green Mining Engineering Technology in Shanxi Province，Taiyuan 030024，China；3.Shanxi Coking Coal Group Co.，Ltd.，Taiyuan 030024，China)Abstract：A numerical study was performed using FLAC3D to analyze the stress evolution characteristics of the 收稿日期：2022-05-18 修回日期：2022-07-14 责任编辑：施红霞 基金项目：国家自然科学基金资助项目(51904203)；山西省科技重大专项资助项目(20201102004)；中国博士后科学基金面上资助项目(2021M702049)作者简介：郭星辰(1997)，男，山西临汾人，硕士研究生。E-mail： 通信作者：郭军(1987)，男，山西定襄人，副研究员，博士，主要从事矿山岩体力学与煤炭开采岩层控制等方面的研究工作。E-mail： DOI:10.13532/10-1638/td.20221119.002 郭星辰等：采矿与岩层控制工程学报 Vol.5，No.1(2023)：013022 013022-2 coal-hydraulic support structure and the law of coal instability destruction.The numerical model was constructed according to the geological and engineering properties of the 8216 working face at the Tashan Coal Mine.The results show that the peak front abutment pressure of the working face is located in the top coal before support on the upper inclined side of the coal wall.The damage depth of the top coal is the same as the advanced distance of the peak front abutment pressure，showing a arc damage form to the side of the roof control area.The sequence of bearing capacity of the coal-hydraulic support structure to roof weighting is determined as the coal in the front of the support，the coal rib，the hydraulic support and top coal above the support.Under the protection of stress arch and top coal，the damage depth of the coal rib is s maintained within 3 m，and the stress of the damaged coal is not affected by the change of advancing distances and support working resistance.The bearing characteristics of top coal on support are different before and after top coal caving，which leads to the change in the bearing characteristics of the whole coal-hydraulic support structure.The damage depth of the coal rib before and after coal caving is 3 m and 2 m，respectively，and the damage depth of top coal is 7 m and 12 m，respectively.The instability of the top coal before support is the main reason for the roof caving of end face，and the damage of the bearing coal on the coal rib is the direct cause of coal spalling.Under the action of the surrounding rock stress arch，the roof takes the top coal before support as the axis to do the back movement and is accompanied by the dynamic change of the stress of the roof，the hydraulic support and the advanced coal，but the bearing characteristics of the coal-hydraulic support structure will not change.This research provides a useful reference for the prevention and control of mine pressure disasters in fully mechanized caving face of extra-thick coal seams.Key words：fully-mechanized top coal caving；support and surrounding rock；abutment pressure；numerical simulation 特厚煤层广泛分布于我国晋、陕、蒙和新疆等省、自治区的大型煤炭基地，其储量约占我国煤炭资源总储量的44%，产量占煤炭总产量的40%以上，其中大部分采用综采放顶煤开采方法1。顶板、煤壁的稳定与支架的安全承载是工作面围岩控制的核心。综放工作面采高较大、采动应力强、顶板结构复杂，影响煤壁稳定和支架稳定性的顶板范围广，作用于煤壁和支架顶板的载荷增高，煤壁发生片帮几率加大，端面失稳冒顶概率升高，严重影响工作面的安全生产。提高支架工作阻力、改变采高和采放工艺等一般措施对顶板控制效果欠佳2。因此，分析煤-架结构的相互作用关系及工作面前方煤体失稳破坏机理对工作面矿压灾害防控具有重要意义。国内外学者对支架与工作面前方煤体(也称作广义煤壁)承载特性进行了大量研究，孔德中3等通过理论分析、相似模拟与数值模拟相结合的方法建立了“煤壁-支架-顶板”力学模型，分析了支架不同工作阻力对煤壁变形破坏的影响，确定了维护煤壁稳定时的支架工作阻力；王家臣4等采用理论研究方法分析了顶板压力等对煤壁稳定的影响以及支架工作阻力在减缓煤壁压力方面的作用，得出煤壁上的顶板压力是影响其稳定的主要因素，提出了在保持煤壁稳定为前提时支架工作阻力应满足的基本准则；王国法5等采用理论分析、数值模拟方法，建立了液压支架与围岩耦合动力学模型及煤壁片帮的“拉裂滑移”力学模型，得出了控制煤壁片帮发生滑移失稳的液压支架临界护帮力；许永 祥6等在“支架围岩”强度、刚度和稳定性耦合的基础上，提出超大采高综放开采“支架围岩”结构耦合理论，讨论了液压支架结构高度对矿山压力显现强度、顶煤冒放结构和资源采出率的影响；王家臣7等采用理论分析和数值模拟手段，分析了综放开采顶煤裂隙场拓展的应力驱动机制，发现煤层开采后顶煤主应力大小和方向均发生二次分布，最大主应力与最小主应力