摘要
相较于浅埋煤巷,深井煤巷面临高地应力与强采掘扰动等高风险因素,巷道维护难度明显增大。为探究深井煤巷围岩在不同采掘扰动影响下的变形响应机制及其控制技术,以城郊煤矿二水平西翼回风大巷为研究背景,通过现场实测分析巷道在实体煤侧单向掘进、采空区侧单向掘进、采空区侧对掘贯通的变形特征,建立巷道围岩结构力学模型,揭示采掘扰动下巷道围岩响应机制。运用FLAC3D模拟不同采掘扰动形式下巷道围岩应力集中程度、塑性区发育范围、能量集聚程度,并量化表征采掘活动响应强度。结果表明:在上述3种采掘扰动下,巷道煤帮移近量分别为46.24,120.10,147.36 mm,比值为1∶2.60∶3.19;巷道断面收缩比例分别为2.4%,12.1%,23.0%,比值为1∶5.04∶9.58;最大应力集中系数分别为1.31,3.10,3.59,比值为1∶2.37∶2.74;煤帮塑性区深度分别为2215.2,3564.4,5105.3 mm,比值为1∶1.61∶2.30;最大弹性变形能分别为159.4,355.1,458.2 kJ。在时间上,对掘工作面推进增大了工作面前方掘进稳定巷道的收缩比(最大增加10.8%),煤帮塑性区发育(最大增加712.3 mm),巷道周边围岩的应力、弹性应变能向深部转移(最远分别转移1062.8,1627.5 mm)且增大(最大分别增加3.44 MPa,70.1 kJ);在空间上,对掘贯通不同程度增大了巷道前后(120 m左右)围岩变形量、塑性区发育深度、应力和围岩能量,并使高应力和能量向深部转移。在实体煤处掘进后,巷道围岩应力和能量向两帮深部转移,巷道收缩,塑性区发展。在采空区处掘进后,护巷煤柱处应力、能量释放并向实体煤侧转移,巷道煤帮塑性区发育较深。基于对掘巷道变形特征,提出对掘贯通处支护优化方案:顶板采用锚网带支护,配合高预紧力高强锚杆、锚索及钢筋网护顶护帮强化支护,有效控制了顶板离层,并抑制了围岩变形,实现了深井煤巷围岩稳定性控制。
Compared with shallow coal roadways,deep coal roadways correspond to greater buried depths and higher risks such as high ground stress and severe mining disturbance,which lead to increasing difficulty in roadway maintenance.This study is aimed at exploring the deformation response mechanism and control technology of surrounding rock in deep coal roadways under different mining disturbances.With the return air roadway at the second level west wing in Chengjiao Coal Mine as the research background,the deformation characteristics of roadways under unidirectional excavation on the solid coal side,unidirectional excavation on the goaf side,and opposite-direction excavation and penetration on the goaf side were analyzed by onsite measurement.Additionally,a structural mechanical model for roadway surrounding rock was established to reveal the response mechanism of roadway surrounding rock under mining disturbances.The stress concentration degree,plastic zone development range,and energy accumulation of roadway surrounding rock under different mining disturbances were simulated by FLAC3D,and the response intensities of different mining-excavation activities were quantitively characterized.The following findings were obtained.Under the above three mining disturbances,the roadway coal rib displacements are 46.24,120.10,and 147.36 mm,respectively,their ratio being 1:2.60:3.19.The shrinkage ratios of the roadway section are 2.4%,12.1%,and 23.0%,respectively,their ratio being 1:5.04:9.58.The maximum stress concentration coefficients are 1.31,3.10,and 3.59,respectively,their ratio being 1:2.37:2.74.The plastic zone depths at the coal ribs are 2215.2,3564.4,and 5105.3 mm,respectively,their ratio being 1:1.61:2.30.The maximum elastic deformation energies are 159.4,355.1,and 458.2 kJ,respectively.Temporally,opposite-direction excavation brings about the following changes:the working face advancement raises the shrinkage ratio of the stable roadway in front of the working face(by 10.8% the most),promotes the plastic zone development at the coal ribs(by 712.3 mm the most),induces the transfer of the stress and elastic strain energy of roadway surrounding rock to the deeper area(by 1062.8 mm and 1627.5 mm the most),and increases these two parameters(by 3.44 MPa and 70.1 kJ the most).Spatially,opposite-direction excavation increases the deformation,the plastic zone development depth,stress and energy of roadway surrounding rock(within 120 m around)to varying degrees,and induces the transfer of high stress and energy to the deeper area.Unidirectional excavation on the solid coal side causes the transfer of the stress and energy of roadway surrounding rock to the deeper area at the coal ribs,roadway shrinkage,and plastic zone development.Unidirectional excavation on the goaf side results in the release of the stress and energy at roadway protection coal pillars and their transfer to the solid coal side,as well as the development of the plastic zone at the coal ribs to the deeper area.Based on the roadway deformation characteristics under opposite-direction excavation,an optimization scheme for the support at the penetration point was proposed.Specifically,the roof is supported by anchor mesh belts,and the roof and rib support is strengthened by high-pre-tension and high-strength anchor bolts,anchor cables,and steel meshes.The optimized support scheme succeeds in effectively controlling roof separation and suppressing the deformation of roadway surrounding rock,thereby realizing the stability control of roadway surrounding rock in deep mines.
作者
王方田
郝文华
汤天阔
何东升
向永恒
WANG Fangtian;HAO Wenhua;TANG Tiankuo;HE Dongsheng;XIANG Yongheng(School of Mines,China University of Mining and Technology,Xuzhou,Jiangsu221116,China;State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;Yongcheng Coal and Electricity Holding Group Co Ltd,Yongcheng,Henan 476600,China;Chengjiao Coal Mine,Yongcheng Coal and Electricity Holding Group Co Ltd,Yongcheng,Henan 476600,China)
出处
《采矿与安全工程学报》
北大核心
2025年第3期567-578,共12页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(52474151)
中国矿业大学研究生创新计划项目(2023WLJCRCZL033)。
关键词
深井煤巷
采掘活动
力学响应
围岩变形
控制技术
deep coal roadway
mining-excavation activities
mechanical response
surrounding rock deformation
control technology
