浅埋煤层沟道采动裂缝发育特征及治理方法

Development characteristics and treatment methods of mining surface cracks in shallow buried coal seam gully

  • 摘要: 黄土沟壑区浅埋煤层开采诱发的地表裂缝灾害相对严重,特别是在沟道底部等煤层埋深极浅区域易与覆岩内部裂隙贯通形成导水通道,致使地表水溃入井下威胁生产安全。为研究黄土沟壑区浅埋煤层回采造成的沟道地表裂缝发育特征及其引发的地表溃水水害防治方法,笔者以陕西省安山煤矿125203工作面菜沟段为研究对象,采用无人机遥感技术和现场实测相结合的方法对沟底裂缝进行填图和动态监测,揭示了采动地表裂缝的平面展布规律、动态发育规律及其与工作面生产进度之间的关系。在此基础上通过实地调查沟道地质条件,提出了沟道地表裂缝不同区域的分区治理方式,并进行了现场实践应用。研究表明:① 沟底平行开切眼裂缝多以“台阶状”发育,宽度在5 cm以内的地表裂缝占64%,宽度在5~10 cm的地表裂缝占20%,宽度在10~20 cm的地表裂缝占10%,宽度超过20 cm的地表裂缝占6%;② 沟底平行开切眼裂缝初始发育位置与回采位置基本一致,超前或滞后回采位置不足6 m,裂缝角近似垂直;③ 随着工作面推进,正向坡裂缝呈现出“开裂—稳定”的动态变化特征,反向坡裂缝呈现出“开裂—闭合—稳定”的动态变化特征,平均动态变化时间为3.70 d;沟底平行开切眼裂缝呈现出“开裂—闭(半闭)合—再开裂—稳定”的动态变化特征,平均动态变化时间为5.25 d,有一定的自愈合能力;④ 基于沟底地形地貌和地表裂缝发育特征及土地利用方式划分了4种治理区域,并针对性地提出了不同区域沟道溃水水害防治方法;⑤ 工程实践应用结果表明本文提出的分区治理方法能够有效预防沟道地表裂缝溃水水害。

     

    Abstract: The surface crack induced by the mining of shallow coal seams is a kind of serious hazards in the Loess Gully area.In the shallow coal seams buried under the surface trench bottom,the trench where coal seams are buried shallow,the surface cracks will connect to the cracks in the rocks above the coal seam easily.The water channel may cause the surface water flowing down into underground coal mine.In order to study the characteristics of the surface cracks caused by the mining in shallow buried coal seams in the Loess Gully Region and the prevention methods of the ground water hazard,the Caigou section of the 125203 working face of Anshan Coal Mine was taken as the research object.Remote sensing technology and the field survey were adopted to study the plane distribution law and dynamic development law,and analyze its relationship with the production progress of the working face.Then,a zonal treatment method for different areas of the surface cracks in the trenches was proposed and applied on site by investigating the geological conditions of the trenches.The research shows that the cracks with parallel cuts at the bottom of the trenches are mostly developed in a “stepped” manner.The parallel cuts of surface cracks with a width of less than 5 cm account for 64%,surface cracks with a width of 5-10 cm account for 20%,and surface cracks with a width of 10-20 cm account for 10%.Surface cracks with a width of more than 20 cm account for 6%.Besides,the dynamic surface cracks at the forefront develop at the stop line in mining.The leading or lagging mining location is less than 6 m,and the cracks angle is approximately vertical to horizontal plane of coal roof.With the advance of working surface,the cracks on the forward slope show the dynamic characteristics of “cracking-stability”,and the cracks on the reverse slope show the dynamic characteristics of “cracking-closing-stable”,with an average dynamic change time of 3.7 days.The trench bottom cracks appear following the development trend of cracking-partially closed-partially cracked-stable and average development time is about 5.25 days,indicating that the surface crack development process in the shallow coal seam area has a certain self-healing ability.Based on the topography and geomorphological characteristics of the trench bottom,the characteristics of surface crack with parallel cuts development and land use methods,the regional governance areas can be divided into four types,and the targeted prevention and control methods for channel water damage in different areas were proposed.Additionally,the application results of engineering practice show that the zoning treatment method proposed in this paper can prevent the water damage caused by ground surface cracks in the trenches feasibly and effectively.

     

/

返回文章
返回