Generalization characteristics of bearing structure in short wall fully-mechanized top-coal caving mining face of steeply inclined thick seam
WANG Hongwei,JIAO Jianqiang,WU Yongping,LIU Baoheng,ZHAO Huatao
针对厚度4~8 m的急倾斜煤层难以实现机械化开采的难题,创新性提出了水平分段短壁综放采煤法。在龙泉煤矿3-3c急倾斜厚煤层布置采掘合一“单一巷道”工作面,螺旋钻机超前采出巷旁煤柱,纵横自移式支架采出顶煤,沿空成巷形成工作面“Z”形通风。并通过理论分析、数值计算和物理相似模拟分析确定了分段高度、采放比等主要回采参数,揭示了采场顶板运动演化、底板破坏滑移及围岩承载结构泛化特征。研究结果表明:分段高度10 m、采放比2.85时工作面放煤效果较好;急倾斜水平分段采场顶板结构迁移转化形成“跨层多梯阶砌体结构”、不同区域底板发生“挤出-平移”“挤出-下压”“挤出-上推”3种模式破坏滑移,顶板、煤柱、底板相互关联形成采场“顶板-底板-煤柱”链式结构。3个分段组成阶段高度30~45 m,能有效阻断采动过程中链式结构单元间强弱链相互转换,防止煤柱失稳造成顶板大面积垮落形成的冲击灾害。以上新型采煤方法的提出与研究为该类煤层的安全高效生产提供了方法与理论基础,对新疆乃至西部煤炭可持续开发具有重要意义。
In view of the difficulty of fully-mechanized mining in steeply inclined coal seam with thickness of 4 to 8 m,the horizontal sublevel short wall fully-mechanized caving method was proposed innovatively. In the No. 3-3c steeply inclined coal seam of Longquan Coal Mine,the single roadway integrated with excavation and recovery was arranged as working face,the pillar on sides of roadway was recovered ahead by spiral drilling machine,and the top coal was recovered by the vertical and horizontal self-moving supports. The Z-type ventilation was formed by constructing a ventilation roadway along the side of gob. Through theoretical analysis,numerical calculation and physical similarity simulation,the main mining parameters,including sectional height and ratio of mining height to caving height,were determined,and the characteristics of roof movement evolution,floor failure and sliding and the generalization of surrounding rock bearing structure were revealed. The results show that the effect of coal caving is better when the section height is 10 m and the ratio of mining height to caving height is 2.85. The cross-layer inclined masonry structure with multistage ladders is formed by migration of the critical layer,and the failure and slip modes of floor are extruding-translation,extruding-underdraught and extruding-upthrust in different areas of horizontal sublevel caving stope. Roof,pillar and floor are interrelated to form the roof-pillar-floor(R-P-F) chain structure. When the height of section with three sublevels is 30 to 45 m,the mutual conversion of strong and weak chains between structural units can be cut effectively in mining process,and the impact disaster caused by the roof falling over great extent and the instability of pillar can be prevented. The new mining method proposed and studied above provides the technological and theoretical basis for the safe and efficient production of such coal seams,and is of great significance to the sustainable development of coal in Xinjiang Region and even western China.
steeply inclined seam; horizontal section; full-mechanized caving mining; gob-side entry retaining; floor failure and slip
0 引言
1 工程概况
2 水平分段短壁综放开采方法
2.1 工作面巷道布置
2.2 回采工艺
2.3 主要参数确定
3 采场围岩承载结构泛化特征
3.1 围岩变形破坏演化过程
3.2 围岩承载结构链式失稳
4 结论
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会