浅埋厚基岩坚硬顶板煤层初采强来压原理分析
浅埋厚基岩坚硬顶板煤层初采强来压原理分析
张书敬,张一亮,解兴智
(天地科技股份有限公司开采设计事业部,北京100013)
[摘一要]一针对浅埋厚基岩坚硬顶板煤层初采期容易出现大面积悬顶二基本顶初次来压时矿压显现异常剧烈问题,以神府矿区石窑店煤矿为工程背景,采用岩石力学实验二钻孔窥视对顶板岩层结构进行分析,在此基础上应用数值模拟和理论分析对该类顶板初采期的致灾机理进行研究三结果表明:直接顶整体性强二强度大,其初次垮落歩距大且呈大面积垮落特征,这是初采期间容易出现飓风灾害的原因;由于上位基本顶承担大部分上覆岩层载荷,其破断距只承担自身载荷的下位基本顶破断距,导致砂岩基本顶同时破断,破断后形成的厚岩块三铰拱结构稳定性差,当工作面回采到岩梁前端断裂线位置时即发生滑落失稳,给工作面支架带来巨大冲击,这是导致浅埋厚基岩坚硬顶板煤层初采期容易产生灾害的原因三
[关键词]一浅埋厚基岩;坚硬顶板;致灾机理;初采强来压[中图分类号]TD322．1一
[文献标识码]A一
[文章编号]1006-6225(2014)06-0098-05
Analysis of Strong Weighting in Initial Mining Shallow-buried
Coal-seam under Thick Basement and Hard Roof
ZHANG Shu-jin,ZHANG Liang,XIE Xing-zhi
(Coal Mining &Designing Branch,China Coal Research Institute,Beijing 100013,China)
Abstract :A large area of hanging roof and strong underground pressure behavior easily occurred in the initial period of mining shallow-buried coal-seam under thick basement and hard roof．Applying rock mechanics experiment,bore-hole imaging to analyzing roof strata structure,roof disaster mechanism in initial mining was researched by numerical simulation and theoretical analysis．Results were showed as follows．Immediate roof had high integrality and strength and its first caving pace was large,and this was the cause of typhoon
disaster easily occurring in initial mining．Most of overlying strata load was bear by upper-basic roof and broken pace of lower-basic roof resulted into sandstone basic roof simultaneously breaking．Stability of three-hinged arch structure after breaking was bad．When mining face reached the location of front breaking line,sliding instability occurred and brought large impact on powered support,which was the cause of roof disaster in initial mining shallow-buried coal-seam under thick basement and hard roof．
Keywords :shallow-buried thick basement;hard roof;disaster mechanism;strong weight in initial mining
[收稿日期]2014-07-08
[DOI]10．13532/j．cnki．cn11-3677/td．2014．06．026[基金项目]国家自然科学青年基金项目(51304118)
[作者简介]张书敬(1973-),男,山东鱼台人,工学博士,副研究员,从事矿山压力研究和煤矿生产管理工作三
[引用格式]
张书敬,张一亮,解兴智．浅埋厚基岩坚硬顶板煤层初采强来压原理分析[J ]．煤矿开采,2014,19(6):98-102．
一一国内学者将浅埋煤层划分为2种:典型浅埋深煤层和非典型浅埋煤层三其中典型浅埋煤层是基岩比较薄二松散层厚度较大的浅埋煤层,其顶板破断为整体切落形式,易出现台阶下沉;非典型浅埋煤层是基岩厚度比较大二松散载荷层厚度较小的浅埋煤层,其矿压显现规律介于普通工作面与浅埋煤层工作面之间,表现为2组关键层,存在轻微的台阶下沉现象[1-4]三
浅埋煤层主要分布在神府二东胜矿区,近几年
随着神府东胜矿区开采强度的增大,开采 厚基岩薄松散层 型浅埋煤层矿井逐渐增多,新问题也随即出现:初采期间顶板大面积悬顶二基本顶初次来压期间矿压显现异常剧烈,其灾害表现形式为
飓风伤人二大面积压架事故三
由于国内外学者对浅埋深厚基岩坚硬顶板研究很少,对该类顶板致灾机理不明确,而神府二东胜矿区矿井对该类顶板的处理办法仍然是参照一般采深特坚硬顶板矿井的经验,而没有针对性的初采期顶板控制技术,致使该条件下初采期悬顶大面积垮落导致的顶板事故时有发生三
鉴于以上情况,本文以石窑店煤矿为工程背景,对浅埋厚基岩坚硬顶板初采期致灾机理进行研究,采用钻孔窥视二岩石力学实验分析顶板岩层结构特征,利用3dec 离散元数值模拟软件分析初采期顶板破断垮落规律,并结合关键层理论研究该类浅埋煤层初采期顶板致灾机理三
8
9第19卷第6期(总第121期)
2014年12月煤一矿一开一采
COAL MINING TECHNOLOGY
Vol．19No．6(Series No．121)
December一2014