布尔台矿单轴加卸载下砂质泥岩声发射特征研究  

Study on acoustic emission characteristics of sandy mudstone under uniaxial loading and unloading of Buertai Coal Mine

作　　者：曹金钟 杨志良 王文杰 CAO Jinzhong;YANG Zhiliang;WANG Wenjie(Tashan Coal Mine,China Coal Datong Energy Co.,Ltd.,Datong 037001,China;School of Coal Engineering,Shanxi Datong University,Datong 037003,China;Jinhua Palace Mine,Jinneng Holding Coal Industry Group,Datong 037000,China)

机构地区：[1]中煤大同能源有限责任公司塔山煤矿,山西大同037001 [2]山西大同大学煤炭工程学院,山西大同037003 [3]晋能控股煤业集团晋华宫矿,山西大同037000

出　　处：《工矿自动化》2022年第6期147-153,158,共8页Journal Of Mine Automation

基　　金：山西省基础研究计划项目(20210302124355)。

摘　　要：采掘反复扰动诱导的加卸载效应是造成井巷工程岩体破坏的重要诱因,但目前缺乏对西部广泛分布的弱胶结砂质泥岩在加卸载状态下力学响应的研究。针对该问题,以国家能源集团神东布尔台煤矿钻孔BK209中砂质泥岩为研究对象,采用单轴分级加卸载试验方案(设置Ⅰ,Ⅱ,Ⅲ 3种加卸载路径,其中加卸载路径Ⅰ采用位移控制,加卸载路径Ⅱ,Ⅲ采用荷载控制),研究不同加卸载路径下砂质泥岩的力学及声发射(AE)特征。研究结果表明:(1)加卸载路径I下试样应力达到峰值后跌落较快,表现出脆性特征;加卸载路径Ⅱ下试样应力达到峰值后跌落有限,有一定残余强度;加卸载路径Ⅲ下试样应力达到峰值后分级跌落,表现出一定延性特征。(2)加卸载路径越短,卸载阶段弹性模量增加越大,主要是因为在加载过程中新生裂隙接触面因剪切滑移产生碎屑,卸载路径短,受到拉应力脱落的碎屑充分充填到附近空隙,裂隙面之间的摩擦能力变强。(3)第1次加载阶段,路径Ⅰ下AE振铃计数呈先增后减的对称变化,路径Ⅱ下AE振铃计数呈左偏峰变化,路径Ⅲ下AE振铃计数呈增减波动变化,中间波动较大;第2次加载阶段,在加载路径Ⅰ,Ⅲ下,当应力增至临近峰值,达到砂质泥岩屈服极限时,AE振铃计数陡增,出现Kaiser点;最后1次加载至峰值过程中,路径I下AE振铃计数先均匀持续发生,接着渐进式增加,路径Ⅱ,Ⅲ下AE振铃计数均先均匀持续发生,临近峰值应力呈跳跃式增长。(4)第1次加载阶段,由于应力较低,AE振铃计数较少,AE处于相对平静期;在卸载阶段,基本无振铃计数,AE处于间歇期;随着应力提高和加卸载次数增多,AE振铃计数相对增加,AE处于波动期;最后1次加载至峰值的过程中,砂质泥岩处于破坏阶段,AE振铃计数激增,AE进入活跃期。The loading-unloading effect induced by repeated mining disturbance is an important inducement to cause the rock mass failure in roadway engineering. However, there is a lack of research on the mechanical response of the widely distributed weakly cemented sandy mudstone in west China under loading and unloading conditions. In order to solve this problem, the sandy mudstone in borehole BK209 of Shendong Buertai Coal Mine of National Energy Group is taken as the research object, and the uniaxial graded loading and unloading test scheme is adopted(Ⅰ, Ⅱ and Ⅲ loading and unloading paths are set, wherein the loading and unloading path I adopts displacement control, and the loading and unloading paths Ⅱ and Ⅲ adopt load control). This paper studies the mechanical and acoustic emission(AE) characteristics of sandy mudstone under different loading and unloading paths. The result shows the following four points.(1) Under the loading and unloading path I, the stress of the sample drops rapidly after the stress peak, showing the characteristics of brittleness. Under the loading and unloading path Ⅱ, the stress drop after the peak stress of the sample is limited and the stress has a certain residual strength. Under loading and unloading path Ⅲ, the stress of the sample falls after the peak stress, showing certain ductility characteristics.(2) The shorter the loading and unloading path, the greater the increase of elastic modulus in the unloading section. The main reason is that the detritus is produced by shear slip in the interface of the new fracture during loading process. When the unloading path is shorts, the detritus falling off under tensile stress fully fills the nearby gap. Therefore, the friction capacity between the fracture surfaces becomes stronger.(3) In the first loading stage, the AE ringing count under the path I is in a symmetrical change of first increasing and then decreasing. The AE ringing count under the path Ⅱ is in a left-biased peak change. And the AE ringing count under the path Ⅲ

关 键 词：砂质泥岩 巷道围岩 单轴分级加卸载 声发射特征 AE 振铃计数 

分 类 号：TD315[矿业工程—矿井建设]