大倾角煤层开采顶板主应力方向分布特征及力学分析
Distribution characteristics and mechanical analysis of main stress direction of roof in steeply dipping coal seam
罗生虎 1任浩 1王同2
作者信息
- 1. 西安科技大学 理学院, 陕西 西安 710054
- 2. 西安科技大学 能源学院, 陕西 西安 710054
- 折叠
摘要
为了分析大倾角煤层开采顶板最大主应力方向旋转对顶板变形破坏的影响,以新疆焦煤集团2130 矿25221 工作面为背景,采用物理相似模拟实验、FLAC3D 数值模拟方法对大倾角煤层开采过程中顶板破坏及岩层结构演化特征、最大主应力方向等值线分布及其对顶板破坏影响进行分析,在此基础上建立顶板力学模型,讨论了顶板挠度分布特征.结果表明:随工作面推进,顶板破坏包络线上方承载拱拱体范围逐渐增大,拱顶逐渐向岩层中上部延伸;顶板的最大主应力方向等值线分布形态由"m"逐渐向"n"型演化(采空区中、上部区域顶板最大主应力方向偏转程度较大),在主应力方向偏转和最优扩展裂隙角协同作用下,促使顶板中上部发生破坏并逐步向高位岩层迁移;建立顶板力学模型,通过Python编程将顶板数据代入计算可得,在顶板岩层倾向 4/5 处出现挠度峰值.
Abstract
In order to analyze the influence of the rotation of the maximum principal stress direction of the roof on the deformation and damage of the roof,taking the 25221 working face of the 2130 Mine of Xinjiang Coking Coal Group as the background,physical similarity simulation and FLAC3D numerical simulation were carried to analyze the roof failure and rock structure evolution characteristics,the distribution of the maximum principal stress direction contour and its influence on the roof failure during the mining of steeply dipping coal seam.On this basis,the roof mechanical model was established to discuss the distribution characteristics of the roof deflection.The results show that:With the advancement of coal mining,the range of bearing arch above the roof failure envelope increases,and the arch extends to the middle and upper part of the rock stratum;The contour distribution pattern of the maximum principal stress direction of the roof gradually evolves from"m"to"n"type(the maximum principal stress direction of the roof in the middle and upper part of the goaf deflects greatly);Under the synergetic effect of the principal stress direction deflection and the optimal expansion crack angle,the middle and upper parts of the roof are damaged and migrate to the high level rock stratum,gradually.With the roof data fed into the roof mechanical model through Python programming,it shows that,the deflection peak value appears at 4/5 of the roof along the dip.
关键词
大倾角煤层/顶板承载结构/最大主应力方向/顶板破坏特征Key words
steeply dipping seam/roof bearing structure/direction of maximum principal stress/roof failure characteristics引用本文复制引用
基金项目
国家自然科学基金(51634007)
国家自然科学基金(51974227)
国家自然科学基金(51904226)
山东省重大科技创新工程项目(2019JZZY020326)
出版年
2024
NETL
NSTL
万方数据