复合顶板锚杆力学特征分析  

Mechanical characteristics analysis of the bolt in composite roof

作　　者：王建伟[1,2,3] 展勤建 WANG Jianwei;ZHAN Qinjian(State Key Laboratory of the Gas Disaster Detecting,Preventing and Emergency Controlling,Chongqing 400037,China;China Coal Technology and Engineering Group Chongqing Research Institute,Chongqing 400037,China;Taiyuan University of Technology,Taiyuan 030024,China;Guangdong University of Petrochemical Technology,Maoming 525000,China)

机构地区：[1]瓦斯灾害监控与应急技术国家重点实验室,重庆400037 [2]中煤科工集团重庆研究院有限公司,重庆400037 [3]太原理工大学,山西太原030024 [4]广东石油化工学院,广东茂名525000

出　　处：《中国矿业》2021年第8期125-132,共8页China Mining Magazine

基　　金：国家自然科学基金项目资助(编号:51574226);广东省自然科学基金项目资助(编号:2018A0303130162);茂名市科技创新专项资金项目资助(编号:917319)。

摘　　要：由于各分层间物理性能差异化分布,复合顶板内锚杆力学特征存在其独特的复杂性,但相关文献却较为鲜见。本文建立、推导了复合顶板内锚杆力学模型,进行了锚固段内锚杆的力学特征分析,有效预测了巷道两侧及顶板内的锚杆位移,为提高巷道支护效果提供支撑,研究手段及结论为复合顶板内锚杆的力学特征分析及支护设计提供一种有效的新途径。本文借鉴桩基础平衡理论的研究成果,通过理论推导、工程案例的MATLAB解析计算及FLAC 3D模拟对比分析,验证了复合顶板内锚杆力学模型的正确性。研究结果表明:复合顶板内锚杆位移、轴力及胶结面上切应力分布形式为分段的指数函数,分段边界为分层交界面位置,轴力在此出现拐点,切应力在此突变;切应力主要出现在两个位置:其一为自由段与锚固段的交界处附近(端锚形式),或为锚杆根部(全锚),其二为剪切模量相对较大的分层下边界位置;随着分层剪切模量增大,其内锚杆胶结面上切应力增大,自上边界至下边界方向,响应程度逐渐增强,同时其他分层内切应力逐渐减小,相对于该分层距离愈大,减小的幅值及幅度愈小。Due to the differential distribution of physical properties between strata,the mechanical characteristics of bolt in composite roof have complexity,but the relevant literature is rarely reported.This paper establishes and deduces the mechanical model in the composite roof,and analyzes the mechanical characteristics of the bolt anchorage section which can effectively predict the bolt displacement on both sides of the roadway and in the roof,and provides support for improving the supporting effect of the roadway.The research methods and conclusions provide an effective new way for the mechanical characteristics analysis and support design of the bolt in the composite roof.Based on the theory of Pile Foundation Balance,through theoretical derivation,MATLAB analytical calculation of project case and FLAC 3D simulation comparative analysis,the correctness of mechanical model of bolt in composite roof is verified.The results show that the distribution forms of bolt displacement,axial force and shear stress on the cementing surface are piecewise exponential functions,and piecewise boundaries are the position of the rock boundaries,anchor bolt axial force appears infection point at these positions,shear stress breaks out at these locations;shear stress peak value mainly occurs at two locations:one is near the junction of the free section and the anchorage section(when the anchorage is in the form of end anchor),or the root of the bolt(when the anchorage is in the form of full anchor),the other is the bottom edge of rocks with relatively large shear modulus.With the increase of the shear modulus,the shear stress on the bonding surface of the bolt increases,and the response degree gradually increases from the upper boundary to the lower boundary.The internal shear stress of other layers decreases gradually,and the larger the distance,the smaller the amplitude and amplitude.

关 键 词：复合顶板 力学模型 数值模拟 锚杆轴力 分布形态 

分 类 号：TD353[矿业工程—矿井建设]