摘要
为研究长边煤柱(采空)条件下基本顶板结构的破断规律及工程价值,构建考虑长边煤柱宽度及承载能力与实体煤弹塑性软化特性的基本顶板结构力学模型,全面计算探究该条件下基本顶板在长边煤柱区及实体煤区的断裂位置、顺序及形态,并从6个层面、3个区域与传统模型对比,阐述模型所得新结论及意义。结论如下:①长边煤柱宽度与承载能力可显著影响实体煤区基本顶主弯矩大小及初次破断顺序,但是对实体煤区基本顶破断线所处区位(弹性区、塑性区、弹塑性分界区)影响小,长边煤柱也可显著改变基本顶在煤柱区的破断位态(3类),且随基本顶的弹性模量E及基本顶厚度h增大,长边煤柱的支撑系数k_(cm)、宽度L_(cm),实体煤的塑化范围L_(t-s)、塑化程度k_(s-0)、弹性煤体基础系数k_(tt)及工作面跨度L_(d)减小,其演变模式为:1条连续“长直线+两端短弧线”型(CM-N式)→2条临接对称“直线+短弧线”型(CM-L式)→2条大间距对称“短弧线”型(CM-D式);②实体煤的长边与短边区基本顶破断线的区位特征有5类,且随着E及h增大,L_(t-s),k_(s-0),k_(tt)及L_(d)减小时的演变规律为:长、短边破断线均处于塑化煤体区→长边破断线在煤体弹塑性分界区、短边破断线在塑化煤体区→长边破断线在弹性煤体区、短边破断线在塑化煤体区→长边破断线在弹性煤体区、短边破断线在弹塑性分界区→长边与短边破断线均在煤体弹性区;③基本顶的整体破断模式有3类,且随E及h增大,k_(cm),L_(cm),L_(t-s),k_(s-0),L_(d)及k_(tt)减小时的演变模式为:闭合断裂圈非对称“■-X”型→临接闭合断裂圈非对称“■-X”型→开口局部断裂圈非对称“■-X”型。针对研究长边煤柱(采空)基本顶板结构破断的3类力学模型,从6个层面对比了模型的重要区别,从3个区域(长边煤柱区、短边区、长边区)阐明了其工程价值。
In order to study the fracture law and engineering value of the main roof plate structure under the condition of long side coal pillar(goaf),the main roof plate structure mechanical model considering the width and bearing capacity of long side coal pillar and the elastic-plastic softening characteristics of solid coal is constructed.The fracture position,sequence and shape of the main roof above the long side coal pillar area and solid coal area are comprehensively calculated and investigated.Compared with the traditional model from six levels and three regions,this paper expounds the new conclusions and significance of this model.The conclusions are as follows.①The width and bearing capacity of the long side coal pillar can significantly affect the principal bending moment and the fist fracture sequence of the main roof above the solid coal area,but have little impact on the location of the main roof fracture line above the solid coal area(elastic zone,plastic zone and elastic-plastic boundary zone).The long side coal pillar can also significantly change the fracture position state of the main roof above the coal pillar area(three types),and with the increase of E and h of the main roof,the support coefficient kcm and width Lcm of the long side coal pillar,the plasticization range L_(t-s),plasticization degree k_(s-0),solid coal foundation coefficient k_(tt) of solid coal and working face width L_(d) decrease.Its evolution mode is that one continuous“long straight line+short arc at both ends”type(CM-N)→two adjacent symmetrical“straight line+short arc”type(CM-L)→two large spacing symmetrical“short arc”type(CM-D).②There are five types of location characteristics of the main roof fracture line above the long side and short side areas of solid coal.With the increase of E and h,when L_(t-s),k_(s-0),k_(tt) and L_(d) decrease,the evolution law is as follows:the long side and short side fracture lines are above the plasticized coal body area→the long side fracture line is above the elastic-plastic boundary area of coal body,and the short side fracture line is above the plasticized coal body area→the long side fracture line is above the elastic coal body area,the short side fracture line is above the plasticized coal body area→the long side fracture line is above the elastic coal body area,and the short side fracture line is above the elastic-plastic boundary area→both the long side and the short side fracture lines are above the elastic coal body area.③There are three types of overall fracture modes of main roof,and with the increase of E and h,and with the decrease of k_(cm),L_(cm),L_(t-s),k_(s-0),L_(d) and k_(tt),the evolution mode is as follows:Asymmetric“■-X”type of→asymmetric“■-X”→asymmetric“■-X”type.Aiming at the three kinds of mechanical models for studying the fracture of the main roof plate structure with long side coal pillar(goaf),the key differences of the models are compared from six levels,and its engineering value is expounded from three areas(long coal pillar area,short side area and long side area).
作者
陈冬冬
郭方方
武毅艺
谢生荣
何富连
刘瑞鹏
吴朝文
CHEN Dongdong;GUO Fangfang;WU Yiyi;XIE Shengrong;HE Fulian;LIU Ruipeng;WU Chaowen(School of Energy and Mining Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2022年第4期1473-1489,共17页
Journal of China Coal Society
基金
国家自然科学基金资助项目(52004286,51974317,52074296)。
关键词
基本顶
长边煤柱
一侧采空
弹-塑性基础
初次破断
板结构
main roof
long side coal pillar
one side gob
elastic-plastic foundation
the first fracture
plate structure
