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煤柱下底板偏应力区域特征及案例

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  • 1.河南理工大学 土木工程学院,河南 焦作 454000;2.贵州大学 喀斯特环境与地质灾害防治教育部重点实验室,贵州 贵阳 550000
许磊,男,1980年生,博士,主要从事巷道支护的相关研究工作

收稿日期: 2013-10-01

  网络出版日期: 2018-06-13

基金资助

河南理工大学博士基金(No. B2015-70);河南省教育厅科学技术研究重点项目(No. 12B560007);贵州省科技厅基金(黔科合LH字[2014]7617)。

Engineering cases and characteristics of deviatoric stress under coal pillar in regional floor

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  • 1. School of Civil Engineering, Hennan Polytechnic University, Jiaozuo, Henan 454000, China; 2. Key Laboratory of Karst Environment and Geohazard Prevention, Ministry of Education, Guizhou University, Guiyang, Guizhou 550000, China

Received date: 2013-10-01

  Online published: 2018-06-13

摘要

选取某煤矿近距离煤层为工程背景,采用FLAC3D模拟了8#煤层残余煤柱底板偏应力场分布特征。结果表明:(1)底板的偏应力呈扩散状向底板传递,距离煤柱越远扩散范围越广,煤柱边缘偏应力呈45°向底板传播;(2)煤柱较窄时,中线和边缘处偏应力影响深度浅,随煤柱宽度增加,底板偏应力变化和影响深度较大,当煤柱宽度足够大时,影响深度又变浅,中部趋于原岩应力;(3)同一水平面上,偏应力呈马鞍状分布,随煤柱宽度增加,煤柱中线处和边缘处偏应力经历了先增大后减小的过程,煤柱边缘处偏应力峰值位置变化不大;(4)同一煤柱宽度,煤柱边缘偏应力峰值向深部递减且趋势减慢,同时,峰值远离煤柱且趋势加快。在自由边界受均布载荷、底板垂直应力、水平应力、切应力解析解的基础上,推导了底板偏应力解析公式,解析与模拟结果基本吻合。具体到该工程的地质条件,9205轨道巷距离煤柱边缘20 m、9205回风巷在煤柱边缘、9205运输巷在煤柱中线处,9205轨道巷维护效果最好,证明了内错式巷道且距离煤柱足够远时,偏应力较小,宏观应力环境更适合巷道围岩自稳。

本文引用格式

许 磊 ,魏海霞 ,肖祯雁 ,李博, . 煤柱下底板偏应力区域特征及案例[J]. 岩土力学, 2015 , 36(2) : 561 -568 . DOI: 10.16285/j.rsm.2015.02.036

Abstract

A close distance coal seams in a coal mine is selected as a case. Deviatoric stress distribution under coal abandon pillars #8 is simulated with FLAC3D. Research results are as follows: (1) Deviatoric stress field in floor distributes as diffusion, the farther the distance is, the wider the range spreads; it transfers from border to floor in 45o direction; (2) When the width of pillar is narrow, the deviatoric stress influence depth at midline and border is shallow; with the width increasing; deviatoric stress at floor varies obviously and the influence depth is deeper; when the coal pillar width is wide enough, middle part is as stress of primary rock; (3) In the same horizontal plane, deviatoric stresses are distributed as saddle shape, with pillar width increasing, the pillar midline and border increase at first and then decrease; and the position of deviatoric stress peak at coal pillar border has little change; (4) as to a certain coal pillar width, deviatoric stress peak at border decreases in vertical direction and its tendency is slower; meanwhile, the peak is far away from coal pillar quickly and its tendency gets faster. Through vertical stress, horizontal stress and shear stress analytical solution, a floor deviatoric stress analytic formula is derived; the analytic solution is consistent with the simulated result. In this case, track roadway 9205 has a 20 m distance from coal pillar border (inboard-type); return airway 9205 is located in coal pillar border; transportation roadway 9205 is located in coal pillar midline, track roadway 9205 maintenance effect is the best of them, which proves that the inboard-type layout roadway with an enough distance from coal pillar bears a little deviatoric stress. Macrostress field is more suitable to the roadway surrounding rock self-stabilization.
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