摘要
为有效获取特厚煤层综放开采采空区侧向支承压力演化全过程,在相邻工作面巷道内利用煤层应力监测系统及电磁波CT探测设备,对采空区侧向支承压力动态演化和静态分布及扩展过程进行了实测分析。通过连续4个月动态监测数据分析发现:自工作面前方110m位置开始,采空区侧向15m范围内煤体支承压力随工作面推进持续发生变化,至采空区内120m趋于稳定;工作面侧向煤体垂直应力依次经历了稳定期、首次增长期、降低期、二次增长期及最终稳定期5个阶段;上覆岩层的破断和煤体塑性破坏2种因素的交叉,造成了采空区侧向不同位置应力峰值拐点时间的同步性及差异性,并以此分析了侧向支承压力动态演化机制。电磁波CT支承压力静态探测分析表明:由于上覆岩层破断的周期性及回转的不均衡性,采动影响范围内,采空区侧向支承压力沿走向方向呈现间隔局部承载的不连续性,分布形态是以某区域为承载中心向煤柱未破坏区近似弧形辐射分布,距离承载中心越远,支承压力越小。该研究结论对煤柱宽度的优化、临空巷道掘进时机的确定具有重要的参考意义。
In order to obtain goaf lateral abutment pressure dynamic evolution process of fully mechanized top coal mining in extra thick coal seam,and then coal seam strain monitoring system and electromagnet wave CT detection equipment were applied at next working face roadway,then goaf lateral abutment pressure dynamic evolution,static distribution and development process was analyzed in practical,after dynamic data analysis in four months,form position 110 m ahead working face,goaf lateral coal body abutment pressure range 15 m scope changed continued with working face advanced,then stable within 120 m of working face,working face lateral coal vertical stress experienced the following 5 phases sequence,stable phase,first growth phase,decrease phase,second growth phase and the last stable phase. two different factors overlapped,which included overburden broken and coal seam plastic broken,and then goaf lateral stress peak value inflection point time in different position was synchronization and difference,so dynamic evolution principle of lateral abutment pressure was analyzed. The results of abutment pressure static exploration with electromagnet wave CT showed that as unbalance of overburden broken periodicity and rotation,within mining influence scope,goaf lateral abutment pressure appeared local loading discontinuity along strike direction,its distribution state like approximate arc distribution to unbroken area of coal pillar form loading center,abutment pressure became smaller with distance larger to loading center,the conclusions could reference for coal pillar width optimized,goaf side roadway excavation time determined and so on.
引文
[1]许兴亮,魏灏,田素川,等.综放工作面煤柱尺寸对顶板破断结构及裂隙发育的影响规律[J].煤炭学报,2015,40(4):850-855.
[2]郝海金,吴健,张勇,等.大采高开采上位岩层平衡结构及其对采场矿压显现的影响[J].煤炭学报,2004,29(2):137-141.
[3]弓培林,靳钟铭.大采高采场覆岩结构特征及运动规律研究[J].煤炭学报,2004,29(1):7-11.
[4]付玉平,宋选民,邢平伟,等.大采高采场顶板断裂关键块稳定性分析[J].煤炭学报,2009,34(8):1027-1031.
[5]弓培林,靳钟铭.大采高综采采场顶板控制力学模型研究[J].岩石力学与工程学报,2008,27(1):193-198.
[6]刘金海,姜福兴,王乃国,等.深井特厚煤层综放工作面支承压力分布特征的实测研究[J].煤炭学报,2011,36(S1):18-22.
[7]赵同彬,张洪海,陈云娟,等.支承压力分布演化规律及对煤岩体破坏的影响[J].辽宁工程技术大学学报(自然科学版),2010,29(3):420-423.
[8]姜福兴,马其华.深部长壁工作面动态支承压力极值点的求解[J].煤炭学报,2002,27(3):273-275.
[9]王书文,毛德兵,潘俊锋,等.采空区侧向支承压力演化及微震活动全过程实测研究[J].煤炭学报,2015,40(12):2772-2779.
[10]谢广祥,杨科,刘全明.综放面倾向煤柱支承压力分布规律研究[J].岩石力学与工程学报,2006,25(3):545-549.
[11]朱亚军,龙昌东,杨道煌.井间电磁波CT技术在地下孤石探测中的应用[J].工程地球物理学报,2015,12(6):721-725.
[12]文学宽.CT探测覆岩破坏高度的试验研究[J].煤炭学报,1998,23(3):300-304.
[13]程久龙,于师建.工作面电磁波高精度层析成像及其应用[J].煤田地质与勘探,1999,27(8):62-64.