摘要
西部地区广泛分布弱胶结软岩,该条件下当煤层上方存在强度相对较高的厚层砾岩时,砾岩层破断对整体矿压影响显著。为解决弱胶结含厚砾岩层采场强矿压控制难题,采用现场监测、理论分析、相似材料模拟及数值模拟相结合的研究方法,获取西部弱胶结含厚砾岩层条件下采场矿压显现特征,揭示厚砾岩层对采场覆岩失稳的主控驱动作用,提出弱胶结厚砾岩层采场矿压调控技术,并进行现场应用。结果表明:(1)工作面初采阶段出现“轻微→剧烈→轻微”阶段性矿压显现趋势,结合覆岩赋存特性确定采场上方厚砾岩层为强矿压显现主控岩层;(2)建立覆岩“传递岩梁+砾岩岩板”结构力学模型,揭示砾岩层破断驱动下采场覆岩呈现空间上“基本顶→砾岩层→砾岩层上方岩层”递次联动失稳、时间上基本顶“大–小循环周期性”及砾岩层上方岩层“瞬时性”失稳特征;(3)基于分析强矿压显现影响因素提出砾岩破断位置系数ζ用于描述砾岩层破断位置向采空区转移程度,覆岩破断系数越小,对应覆岩破断位置更靠近采空区,矿压显现程度越弱;(4)提出以砾岩层破断位置调整为导向、支架初撑力及工作面推采速度优化为手段的强矿压调控关键技术,通过数值模拟及现场实际将初撑力与推采速度优化为31.8 MPa及8 m/d,现场应用效果明显。
Weakly cemented soft rock is widely distributed in the western region of China.Under this condition,when there is thick conglomerate with relatively high strength above the coal seam,the fracture of conglomerate layer has a significant impact on the overall ground pressure.In order to solve the difficult problem of strong ground pressure control,a research method of in-site monitoring,theoretical analysis,similar material simulation and numerical simulation was adopted.The main control driving role of thick gravel rock is revealed,and a mining pressure control technology for weakly cemented soft rock is proposed and applied on site.The results show that:(1)there is a gradual trend of“slight→severe→slight”ground pressure manifestation in the initial mining stage.Combined with the occurrence characteristics of overburden,the thick conglomerate layer above the stope is the main control layer of strong ground pressure manifestation.(2)The structural mechanics model of“transferring rock beam+conglomerate plate”of overburden is established,which reveals that the overburden characteristics of the stope driven by the fracture of the conglomerate layer:“basic roof→conglomerate layer→rock stratum above the conglomerate layer”progressive linkage instability in space,“large-small cycle periodicity”of the basic roof in time,and“instantaneous”instability characteristics of the rock stratum above the conglomerate layer.(3)Based on the analysis of influencing factors of strong ground pressure,the location coefficient of conglomerate fracture“ζ”is proposed It is used to describe the degree of transition from the broken position of conglomerate layer to the goaf.The smaller the overburden breaking coefficient is,the closer the corresponding broken position of overburden is to the goaf,and the weaker the rock pressure appearance is.(4)The key technology of strong ground pressure control is proposed,which is optimized by the setting load of hydraulic support and the mining speed of the working face.Through numerical simulation and field practice,the initial support force and the mining speed are optimized to 31.8 MPa and 8 m/d,and the field application effect is obvious.
作者
周凯
于凤海
谭云亮
马成甫
高学鹏
ZHOU Kai;YU Fenghai;TAN Yunliang;MA Chengfu;GAO Xuepeng(College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;State Key Laboratory of Mining Disaster Prevention and Control Co-Founded By Shandong Province and the Ministry of Science and Technology,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;Ordos Haohua Hongqingliang Mining Co.,Ltd.,Ordos,Inner Mongolia 014300,China;School of Resource and Civil Engineering,Northeastern University,Shenyang,Liaoning 110167,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2023年第8期2004-2017,共14页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(52074168,51874190)
山东省泰山学者攀登计划(tspd20210313)。
关键词
采矿工程
弱胶结软岩
联动失稳
矿压调控
推采速度
覆岩破断位置
mining engineering
weakly cemented soft rock
linkage instability
mine pressure regulation
push mining speed
overburden breaking position
作者简介
周凯(1996–),男,2018年毕业于山东科技大学采矿工程专业,现为博士研究生,主要从事于巷道支护方面的研究工作。E-mail:zhoukai0502@163.com;通讯作者:于凤海(1987–),男,现任副教授。E-mail:yufenghai2006@163.com。
