复合顶板中锚固力扩散模型及其支护参数优化研究  

Diffusion Model of Anchoring Force and Support Parameters Optimization in Composite Roof

作　　者：杜帅 康天合[1] 张智敏[1] DU Shuai;KANG Tianhe;ZHANG Zhimin(Key Laboratory of In-situ Property-improving Mining of Ministry of Education,Taiyuan University of Technology,Taiyuan,Shanxi 030024,China)

机构地区：[1]太原理工大学原位改性采矿教育部重点实验室,山西太原030024

出　　处：《矿业研究与开发》2021年第11期112-117,共6页Mining Research and Development

基　　金：国家自然科学基金面上项目(42072203);国家自然科学基金-山西煤基低碳联合基金培育项目(U1810102)。

摘　　要：为研究复合顶板中锚杆锚固力的扩散规律,以大阳煤矿3306轨道顺槽为工程背景,采用应力扩散效应、梁弯曲理论和现场监测手段,构建复合顶板中单根锚杆锚固力扩散模型和锚杆间排距设计优化模型,并通过现场工程应用对该模型进行了验证。结果表明:锚固应力穿过复合顶板岩层界面时发生应力衰减和应力扩散角突变是导致复合顶板与均质岩层中锚固应力分布差异的本质原因;基于优化模型得到的支护方案在保证顶板安全的同时,比原方案锚杆间排距增加了180 mm;锚杆间排距随锚杆预紧力的增加呈线性规律增大,随下岩层与上岩层厚度比的增大呈对数型规律增大,随下岩层与上岩层弹性模量比的增加呈指数型规律增大;预紧力对锚杆间排距的影响最大,厚度比和弹性模量比次之,由于顶板岩层弹性模量不易改变,优化支护时优先考虑提高锚杆的预紧力;研究成果对复合顶板的支护理论和支护设计优化方案提供理论依据。In order to study the diffusion law of anchor force in composite roof,3306 track roadway of Daiyang coal mine was taken as an engineering background.Based on the stress diffusion effect,beam bending theory and in-situ monitoring method,the diffusion model of anchoring force of single bolt in composite roof was constructed,as well as the design model of bolt row spacing.Then,the models were verified by field engineering test.The results show that when the anchorage stress passes through the rock interface of composite roof,the stress attenuation and the sudden change of stress diffusion angle are the essential reasons for the difference of anchorage stress distribution between composite roof and homogeneous rock.The support scheme based on the optimization model can ensure the roof safety and increase the bolt row spacing by 180 mm compared with the original scheme.The bolt row spacing increases linearly with the increase of bolt preload,increases logarithmically with the increase of the thickness ratio of the lower and upper strata,and exponentially increases with the increase of the elastic modulus ratio of the lower and upper strata.The preload has the greatest influence on the bolt row spacing,followed by the thickness and elastic modulus ratio.Because the elastic modulus of roof rock is not easy to change,improving bolt preload is preferred in the support optimization.The research conclusions provide a theoretical basis for the support theory and support design optimization scheme of composite roof.

关 键 词：复合顶板 锚固力 应力扩散 支护优化 锚杆间排距 

分 类 号：TD353[矿业工程—矿井建设]