槽波地震技术在大同煤田地质构造探测中的应用

Application of in-seam wave seismic technology in geological structure detection of Datong coalfield

大同煤田煤层为特厚煤层,地质条件复杂。通过整理近几年槽波地震技术在大同煤田的应用情况,详细总结大同煤田东北部煤矿二采区和三采区的地质规律和槽波地震法的探测效果。结果显示,大同煤田东北部3~5号煤煤层平均厚度约15 m,属特厚煤层,主要发育地质构造为小断层、煤厚变化和夹矸,且矸层数较多,局部区域受火成岩侵入影响;煤层槽波发育中等至良好,在夹矸和火成岩发育部位,槽波发育较为一般,槽波埃里相速度约1 000 m/s,不同工作面相速度差异不大;槽波解释物探成果以断层、煤层变薄煤厚变化、煤层破碎区及夹矸影响区为主,局部受火成岩侵入和背斜轴部影响。其中,推测断层大都落差较小,且未发现有短轴直径大于20 m的陷落柱存在。经地质资料验证,槽波技术适合在大同煤田进行地质构造探查,槽波解释成果可为该煤田安全生产提供地质保障。

The coal seam of Datong coalfield is an extra-thick coal seam with complex geological conditions.We summarize the application of in-seam wave seismic technology in Datong coalfield in recent years,and the geological laws and detection effects of in-seam wave seismic method of the second and third mining areas of the coal mines in the northeast of Datong Coalfield.The results show:The average thickness of 3~5 coal seams in northeastern Datong Coalfield is about 15 m,belonging to extremely thick coal seam.The main geological structures are small faults,coal thickness variation and many layers of dirt band.Local area is affected by igneous intrusion.In-seam wave development in Datong coalfield is medium to good.In the development position of dirt band and igneous rock,in-seam wave development is relatively general,and the in-seam wave Airy phase velocity is about 1 000 m/s with a little difference in velocity between different working faces.The results of in-seam wave interpretation of geophysical exploration in Datong coalfield are mainly fault,coal seam thinning and coal thickness change,coal seam crushing area and dirt band-affected area,and locally affected by igneous rock intrusion and anticlinal axis.Among them,most of the presumed faults have small drop,and no collapse column with short axis diameter greater than 20 m is found.It is proved by geological data that the in-seam wave technology is suitable for geological structure exploration in Datong coalfield.The results of in-seam wave interpretation can provide reliable geological guarantee for the safe production of mine.