摘要
煤层倾角是造成大倾角采场采动力学行为呈现复杂性、特殊性,诱发众多灾害事故的重要因素之一,为揭示煤层倾角对大倾角采场围岩控制及矿压显现特征的影响规律,采用物理相似模拟和数值计算相结合的研究方法,在综合分析了大倾角工作面顶板破断运移及矸石滑滚充填特征的基础上,利用有限元−离散元(FLAC2DPFC2D)耦合算法建立了不同倾角的大倾角采场耦合数值模型,研究了大倾角采场围岩应力分布及矸石充填特征的倾角效应。结果表明:①采动作用下,大倾角采场顶底板内围岩应力均呈非对称拱形分布,随着煤层倾角增大,拱形垂直应力释放区范围和向上部偏移程度逐渐增大,但水平应力释放区范围和应力值逐渐减小,无论是垂直应力还是水平应力都易在工作面上下端头顶板处出现应力集中,但最大集中应力会随煤层倾角的增大而减小;大倾角工作面顶底板内应力大小和传递方向均存在非对称特征,随着煤层倾角增大,工作面顶底板应力拱高逐渐降低,围岩应力的传递方向以围岩涌向采出空间为主,由初始近似竖直方向逐渐偏转趋于工作面垂向。②工作面顶板破断及矸石的滑滚充填具有时序性和分区演化特性,并随煤层倾角的改变而呈现一定的倾角效应。随着煤层倾角增大,直接顶的初次破断位置将逐渐向工作面倾向上部区域转移,同时由于重力沿工作面倾向的分力变大,矸石沿倾向的充填程度更为密实,但充填长度减小,工作面中上部区域高位岩层的破碎程度和空洞范围增大。③采空区内矸石对围岩的作用机制主要体现在提供侧向应力和竖向支撑2个方面,且受矸石重力作用影响较大,会随煤层倾角改变呈现较强的倾角效应。
The dip angle of coal seam is one of the important factors that cause the complexity and particularity of the mining dynamic behavior of the large dip angle stope and induce many disasters and accidents.characteristics of mine pressure in the large dip angle stope,the research method of physical similarity simulation and numerical calculation is adopted.Based on a comprehensive analysis of the features of roof crack and gangue sliding and rolling filling in steeply dipping working faces,a finite element discrete element(FLAC2D-PFC2D)coupling algorithm is used to establish a coupled numerical model of high angle mining areas with different inclinations.The stress distribution of surrounding rock and the inclination effect of gangue filling features in steeply dipping mining areas are studied.The results show the following points.①Under the action of mining,the stress distribution of the surrounding rock in the roof and floor of the high angle mining area is asymmetric arched.As the dip angle of the coal seam increases,the range of the arched vertical stress release zone and the degree of upward displacement gradually increase.But the range and force value of the horizontal stress release zone gradually decrease.Both vertical and horizontal stresses are prone to stress concentration at the top and bottom of the working face.But the maximum concentrated stress value will decrease with the increase of coal seam inclination angle.The stress magnitude and transmission direction inside the roof and floor of the steeply dipping working face exhibit asymmetric features.As the coal seam dip angle increases,the stress arch height of the working face roof and floor gradually decreases.The transmission direction of surrounding rock stress is mainly towards the mining space,and gradually deviates from the initial approximate vertical direction towards the vertical direction of the working face.②The roof crack of the working face and the sliding and filling of gangue exhibit temporal and regional evolution features,and exhibit a certain dip angle effect with the change of coal seam dip angle.As the inclination angle of the coal seam increases,the initial breaking position of the direct roof will gradually shift towards the upper area of the working face.At the same time,due to the increased force of gravity along the inclination direction of the working face,the filling degree of the gangue along the inclination direction will be more dense.But the filling length will decrease.As the inclination angle of the coal seam increases,the degree of crack and the range of voids in the high-level rock layers in the upper and middle areas of the working face will also increase.③The mechanism of the action of gangue on the surrounding rock in the goaf is mainly reflected in providing lateral stress and vertical support,and is greatly affected by the gravity of gangue,which will show a strong inclination effect with the change of coal seam inclination angle.
作者
高利军
晋发东
梁东宇
杨文斌
汤业鹏
王同
GAO Lijun;JIN Fadong;LIANG Dongyu;YANG Wenbin;TANG Yepeng;WANG Tong(Huating Coal Industry Group Chicheng Coal Mine Co., Ltd., Pingliang 744000, China;College of Safety and Emergency Management Engineering, Taiyuan University of Technology, Taiyuan 030024, China;College of Energy Engineering, Xi'an University of Science and Technology, Xi'an 710054, China)
出处
《工矿自动化》
CSCD
北大核心
2024年第3期142-150,共9页
Journal Of Mine Automation
基金
山西省重点研发计划项目(基于BIM的三维智能化矿井透水应急救援平台研发)。
关键词
大倾角煤层
围岩应力
矸石充填
倾角效应
采动应力
顶板破断
steeply dipping coal seam
surrounding rock stress
gangue filling
angle effect
mining induced stress
roof crack
