不同厚度岩层破断模式实验研究.

左建平,于美鲁,胡顺银,等.不同厚度岩层破断模式实验研究[J].采矿与岩层控制工程学报,2019,1(1):013007.

ZUO Jianping,YU Meilu,HU Shunyin,et al.Experimental investigation on fracture mode of different thick rock strata[J]．Journal of Min-

ing and Strata Control Engineering,2019,1(1):013007.

不同厚度岩层破断模式实验研究

左建平1,2,于美鲁1,2,胡顺银1,2,宋洪强1,2,魏㊀旭1,2,史㊀月1,2,左书豪1,2

(1．中国矿业大学(北京)力学与建筑工程学院,北京㊀100083;2．中国矿业大学(北京)煤炭资源与安全开采国家重点实验室,北京㊀100083)

摘㊀要:顶板破断是采场矿压显现的根本原因,现有很多成果是基于梁或薄板模型而来,而顶板的厚度直接影响了顶板的破断行为㊂自主研制了采空区顶板破断模拟实验装置,在均布载荷作用下对四边固支不同厚度顶板进行了破坏实验研究㊂实验结果验证了薄板基本以沿长边的 O -X 型断裂模式为主,而厚板不仅有沿长边的 O -X 型和沿短边的 O -X 型断裂模式,还有 O -❋ 型的断裂方式㊂研究结果表明:薄板破断主要受到最大弯曲应力的影响㊂随着板厚度增加,横向剪切力的作用在加强,此时厚板的破坏主要受到弯曲和剪切耦合作用,导致其破坏行为更为复杂㊂关键词:厚板;实验研究;初次破断;基本顶

中图分类号:TD315㊀㊀㊀文献标志码:A㊀㊀㊀文章编号:2096-7187(2019)01-3007-09

收稿日期:2019-04-18㊀㊀修回日期:2019-05-17㊀㊀责任编辑:李㊀青

㊀㊀基金项目:国家自然科学基金优秀青年基金资助项目(51622404);国家自然科学基金面上资助项目(11572343);北京卓越青年科学家资助项

目;中国矿业大学(北京)越崎杰出学者资助项目

㊀㊀作者简介:左建平(1978 ),男,江西高安人,教授,博士生导师,博士㊂E -mail:zjp@

Experimental investigation on fracture mode of different thick rock strata

ZUO Jianping 1,2,YU Meilu 1,2,HU Shunyin 1,2,SONG Hongqiang 1,2,WEI Xu 1,2,SHI Yue 1,2,ZUO Shuhao 1,2

(1.School of Mechanics &Civil Engineering ,China University of Mining &Technology (Beijing ),Beijing ㊀100083,China ;2.State Key Laboratory of Coal Re-sources and Safe Mining ,China University of Mining &Technology (Beijing ),Beijing ㊀100083,China )

Abstract :Roof breaking behavior is the fundamental reason for the occurrence of stope strata pressure.Many existing research results are typically based on the beam or thin plate model,however,the thickness of roof can directly affect

the roof breaking behavior.In this paper a simulation experiment device for roof breakage of the goaf is independently developed.The experimental study on roof failure of strata with different thickness but fixed on four sides is carried out under the uniform load.The results indicate that the thin plate is mainly characterized by O -X fracture mode along

the long side,while the thick plate has not only O -X fracture mode along the both long side and short side,but it al-so shows a O -❋ fracture mode.We believe that the fracture of thin plate is mainly affected by the maximum bending stress.With the increase of plate thickness,the effect of transverse shear force is strengthened.At this time,the failure of thick plate is mainly affected by the coupling effect of bending and shear,which leads to more complex failure be-

haviors.

Key words :thick plate;experimental study;first breaking;main roof ㊀㊀煤炭开采引起上覆岩层移动㊁破断,并伴随着一

系列特殊的力学现象,从而影响生产安全和生态环境[1-2]㊂统计资料也表明,工作面冒顶等顶板事故大

多发生在基本顶初次来压和周期来压期间,尤其在初次来压期间,其强度往往最大,矿压显现最为剧烈,对巷道稳定性及采场安全影响颇大[3],导致工作面来压成为采场矿山压力控制的重要内容㊂确定基本顶初次来压步距和周期来压步距是控制矿山压力的关键㊂因此,探索岩层移动破断规律是科学采矿的基础㊂

学者们在过去的研究中提出大量的假说,最有代表性的假说可分为两类:一类是以拱为承载结构的假

㊀第1卷第1期

采矿与岩层控制工程学报

Vol.1㊀No.1㊀㊀2019年11月

JOURNAL OF MINING AND STRATA CONTROL ENGINEERING

Nov.㊀2019㊀