多重采动下大倾角上覆煤岩移动及地面井变形规律  

Movement of overlying rock and deformation law of surface well under multiple mining with large dip angle

作　　者：王智民 梁运培[1,2] 邹全乐[1,2] 张碧川 冉启灿 WANG Zhimin;LIANG Yunpei;ZOU Quanle;ZHANG Bichuan;RAN Qican(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044 [2]重庆大学资源与安全学院,重庆400044

出　　处：《煤炭科学技术》2023年第4期47-55,共9页Coal Science and Technology

基　　金：国家自然科学基金资助项目(52174166)。

摘　　要：地面井在煤层开采引起的采动作用下极易发生变形直至失稳破坏,这也是制约采动卸压区地面井瓦斯抽采技术应用的关键性问题。以新疆1930煤矿大倾角煤层群开采为背景,开展了大倾角煤层群开采下地面井变形的相似模拟试验,通过监测覆岩移动、煤层应力变化、地面井管道不同位置的轴向与环向变形,揭示了大倾角煤层群采动下地面井变形规律,研究表明:首先地面井在采动过程中处于剪切、挤压、拉伸的复合应力状态,但由于煤岩层倾角的存在,环向的剪切变形大多时间大于轴向的拉伸变形,即地面井受到的剪切作用占主导地位,同时采动过程中,地面井环向的剪切变形与轴向伸缩变形存在一定的负相关关系,在一定程度上说明地面井所受的剪切作用和拉压作用存在相互制约的关系;其次地面井轴向变形规律整体呈现增大趋势,但过程中出现拉缩交替的现象,与近水平煤层重复采动时的一直增大存在较大差异,而环向的剪切变形的变化趋势则与近水平煤层重复采动时较为相似,出现了反复错动的特点,但最终剪切位移的方向始终为煤层的倾斜方向;最后研究也发现在主关键层上部地面井变形规律整体呈现“增大—减小”反复三次交替,在主关键层及下部呈现“增大—减小”反复四次交替。研究成果可以为大倾角多重采动区地面井的工程应用提供一定的理论支持。Surface wells are prone to deformation and even instability under the mining action caused by coal seam mining.This is also a key issue that restricts the application of gas drainage technology in surface wells in mining pressure relief areas.Based on the mining of high-incline coal seam group in Xinjiang 1930 Coal Mine,this paper carried out similar simulation experiments of surface well deformation under high-incline coal seam group mining,by monitoring overlying rock movement,coal seamstress changes,and the axial and circumferential directions of different positions of surface well pipelines.Deformation reveals the law of deformation of surface wells under the mining of large-dip coal seams.Research shows that:first,surface wells are in a state of sheer,compression,and tension during the mining process.Most of the time,the shear deformation in the axial direction is greater than the tensile deformation in the axial direction,that is,the shearing action on the surface well is dominant.At the same time,during the mining process,the shear deformation in the circumferential direction and the axial expansion and contraction deformation of the surface well is negative to a certain extent.The correlation,to a certain extent,shows that the shearing and tensioning,and compressing effects of surface wells are mutually restrictive;secondly,the axial deformation of surface wells shows an increasing trend as a whole,but the phenomenon of tension and shrinkage alternates in the process,and there is a big difference in the constant increase in the repeated mining of the near-level coal seam,and the changing trend of the circumferential shear deformation is similar to that of the near-level coal seam.The direction of displacement is always the inclination direction of the coal seam;the final study also found that the surface well defamation law in the upper part of the main key layer showed an overall“increase-decrease”alternating three times,and“increase-decrease”in the main key layer and lower part.Repeat four times

关 键 词：大倾角煤层 多重采动 覆岩移动 地面井 井筒变形 

分 类 号：TD32[矿业工程—矿井建设]