摘要
为解决FLAC3D中锚索(cable)单元无法实现层状岩层锚杆弯曲变形问题,采用桩(pile)单元实现了无预紧力状态下的锚杆弯曲变形。在此基础上引入"节点力"和"刚性连接"元件,并采用FISH语言编程,建立了可施加预紧力的改进pile单元。通过层状顶板中锚杆受力和变形特征的分析,结果表明:在预紧力施加方面,通过改进的pile单元与软件自带的cable单元预紧力施加效果相近,锚杆轴力的大小和分布符合预紧力扩散规律,表明此方法的有效性;在工程力学响应方面,改进的pile单元中锚杆的轴力变化趋势与理论研究一致,表明此方法的合理性;通过对层状顶板不同位置处锚杆剪应力分布特征分析,提出采用增加整体刚度方法如增加锚固长度、提高整体强度的方法如提高预紧力来减小顶板剪应力影响的策略。研究工作扩展了FLAC3D中pile单元的应用范围,为研究层状岩层中锚杆的弯曲变形特征提供了新手段。
In order to solve the problem that cable element in FLAC3 Dcan not realize the bending deformation of bolt in layered rock strata,pile element was used to realize the bending deformation of bolt without pretightening force.On this basis,the node force and rigid connection elements were introduced,and the improved pile element with pretightening force was established by using FISH language.Through the analysis on the stress and deformation characteristics of the bolt in the layered roof,the results are concluded as follows.Firstly,in terms of pretightening force,the effect of pretightening force applied by the improved pile element is similar to that of cable element,and the size and distribution of anchor axial force conform to the diffusion law of pretightening force,indicating the effectiveness of this method.Secondly,in terms of engineering mechanical response,the change trend of axial force of anchor rod in the improved pile element is consistent with the theoretical research result,which proves the rationality of this method.Thirdly,through the analysis on the distribution characteristics of shear stress in different positions of layered roof,the methods of increasing the overall stiffness such as increasing the anchorage length,and the methods of improving the overall strength such as increasing the pretightening force,are proposed to reduce the influence of roof shear stress.The research can expand the application scope of pile element in FLAC3 D,and provides a new method for studying the bending deformation characteristics of bolts in layered strata.
作者
刘跃东
LIU Yuedong(CCTEG Coal Mining Research Institute,Beijing 100013,China;China Coal Research Institute,Beijing 100013,China)
出处
《矿业研究与开发》
CAS
北大核心
2020年第7期58-64,共7页
Mining Research and Development
基金
天地科技开采设计事业部“设计创新基金”(KJ-2018-TDKCZL-01)
国家重点研发计划项目(2017YFC0804205)
煤炭科学研究总院科技创新基金项目(2016ZYMS011)。
