摘要
针对近距离煤层群下行开采时重复采动引起的覆岩冲击性破断问题以及再生破碎顶板条件下工作面安全开采问题,以潘二矿11221,11223工作面为研究背景,通过物理相似模拟试验,对极近距煤层群重复采动覆岩破坏及裂隙发育规律进行了研究。结果表明,1煤工作面覆岩垮落带平均高度22 m,裂隙最大发育高度85 m,“两带”发育高度相当于采高的24.2倍;受3煤、1煤工作面联合采动影响,裂隙带相对向上发育增加15 m,覆岩采动充分垮落角基本对称,顶板破坏范围增大;随着工作面推进,煤层群顶板均经历垮落、裂隙发育、采空区冒矸被压实的演变过程,14 m厚的粗砂岩层作为关键层抑制裂隙向上发育,在回采结束后其下方产生较大离层;3煤顶板覆岩垮落形态近似呈非对称“Π”型,相对于3煤,1煤采完后,工作面呈现出“两大一小”的特征;“两带”高度发育大,垮落带和裂隙带的高度分别增加了46%、21%,顶板下沉量大,顶板垮落步距小,初次垮落步距和周期垮落步距明显减小,来压较为缓和。研究结果可为煤层群开采的围岩控制提供参考。
Aiming at the problem of overlaying rock impact failure caused by repeated mining during downward mining of closedistance coal seam group and the problem of safe mining of working face under the condition of regenerated broken roof,taking the 11221 and 11223 working faces of Pan'er Coal Mine as the research background.Through physical similarity simulation test,the law of overlying rock failure and fracture development caused by repeated mining in extremely close coal seam group were studied.The results show that the average height of overlaying rock caving zone on No.l coal working face is 22 m,the maximum development height of fracture is 85 m,and the development height of“two zones”is equivalent to 24.2 times of mining height.Affected by the combined mining of No.3 coal and No.1 coal working faces,the relative upward development of fracture zone increases by 15 m,the fully caving angle of overburden mining is basically symmetrical,and the roof damage range increases.With the advance of the working face,the roofs of the coal seam group had experienced the evolution process of caving,fracture development and compaction of the gangue in the goaf,the 14 m thick coarse sandstone layer as the key layer inhibits the upward development of fractures,and a large separation layer is generated below it after the end of mining.The caving form of overlaying rock of No.3 coal roof is approximately asymmetric“II”type,compared with No.3 coal seam,the working face of No.1 coal seam shows the characteristics of“two big and one small”after mining.The height of the“two zones”is large,the height of the caving zone and the fractured zone is increased by 46%and 21%respectively,the roof subsidence is large,the roof caving step is small,the initial caving step and the periodic caving step are obviously reduced,and the pressure is more moderate.The research results can provide a reference for the surrounding rock control of coal seam group mining.
作者
康志鹏
余国锋
罗勇
段昌瑞
赵靖
KANG Zhipeng;YU Guofeng;LUO Yong;DUAN Changrui;ZHAO jing(Huainan Mining(Group)Co.,Ltd.,Huainan,Anhui 232001,China;National Engineering&Technology Academy for Coal Mining,Huainan,Anhui 232001,China;State Key Laboratory of Deep Coal Mining&Environmental Protection,Huainan,Anhui 232001,China)
出处
《矿业研究与开发》
CAS
北大核心
2023年第5期56-62,共7页
Mining Research and Development
基金
安徽省重点研究和开发计划资助项目(201904a07020011)
安徽省自然科学基金项目(2108085ME155)。
关键词
极近距煤层群
覆岩破坏
裂隙发育
相似模拟试验
Extremely close coal seam group
Overlying rock failure
Fracture development
Similar simulation test
