大倾角煤层属难采煤层，在我国西部地区赋存广泛，此类煤炭资源的开发对区域经济发展起到了重要支柱作用。受煤层赋存条件制约，大倾角煤层的岩层运动机理复杂，作业空间受限，综合机械化开采难度大。自20世纪80年代起我国学者及一线工程技术人员便开始针对大倾角煤层的开采方法、岩层控制理论、关键技术装备展开研究。发展至今，已在理论、技术、装备等方面取得了较大进展，构架了较为完整的研究体系。从大倾角煤层长壁综采的进展、实践、科学问题3个方面系统梳理了已经取得的研究成果、积累的实践经验以及未来需要突破的关键科学问题。提炼出以下主要观点:① 我国首次定义了大倾角煤层的概念(煤层倾角35°～55°)并给出了工程解释，但随着近年来装备水平与开采方法的不断提升革新，大倾角煤层倾角涵盖范围的工程解释应有所外延。自20世纪90年代起至今，在大倾角煤层长壁开采岩层控制基本理论与关键技术、工作面动力灾害防护方法、工作面主要装备研发等领域的研究与试验取得了较大进展。② 在工程实践方面，除大倾角中厚煤层综采技术已趋于成熟外，大倾角厚煤层大采高综采、特厚煤层综放开采和薄煤层伪俯斜综采技术均有所突破并取得了一定效果，但仍存在诸多“瓶颈问题”亟需从科学层面予以解答。③ 仍需进一步加强复杂采动煤岩体力学性状与量化表征、复杂采动煤岩体力学行为及其对工作面灾变的控制作用、长壁采场“支架-围岩”系统多维交互动力学与多目标非稳态控制方法、非规则回采空间随机分离体形成-运动-损害过程及防护机制等科学问题研究，并以此为前提发明颠覆性开采方法、研发关键技术与装备，最终实现大倾角煤层安全高效与绿色开采。

The steeply dipping coal seam belongs to the coal seams with complex mining conditions,which is wide- spread in western China. Its development plays an important role in regional economic development. Due to the strata movement is complex and the working space is limited,it makes the fully mechanized mining difficult under the occur- rence condition in steeply dipping coal seams. Some scholars and engineers have studied the mining methods,ground control theories and equipment of the steeply dipping coal seam since the 1980s in China. Up to now,it has made great improvement in theories,technologies and equipment,and has built a relatively complete research system. This paper systematically reviewed the state of art,field experiences and key scientific problems that need to be solved in the fu- ture from three aspects. In this study,following main conclusions can be drawn:① China first proposed the concept of steeply dipping coal seam (inclination ranging from 35 to 55 degrees) and its engineering interpretation. However,the inclination range of steeply dipping coal seam should be extended with the increase of equipment ability and mining methods in recent years. Since the 1990s,a lot of breakthroughs were made on ground control theories and key technol- ogies,a great progression was made on protective methods for dynamic hazard and mining equipment was developed for inclined working face,etc. ② Except for the fully mechanized mining technology gradually matures in medium thick- ness coal seam,the fully mechanized mining technology in the thick coal seam with large mining height,and the fully mechanized caving mining in extra thickness coal seams,the fully mechanized mining technology using pseudo-inclined working face in thin coal seams also have made some breakthroughs in field. However,there are still many “bottleneck problems” that need to be solved from a scientific perspective in the future. ③ Although there are good feedbacks,the study also needs to be strengthen on the following aspects in the future:mechanical properties and quantitative charac- terization of overburden after coal mining,the influence of surrounding rocks mechanical behaviors after coal excava- tion on working face and its control,multi-dimensional interaction and multiple objective stability control for “support- surrounding” rocks system in longwall face,and the generation,motion and damage of separated blocks in working face and corresponding protective principles. Finally,some revolutionary mining methods,new technol-ogies and equipment should to be proposed to achieve a safe and green mining in the steeply dipping coal seam mining.

1 大倾角煤层长壁综采理论技术进展

   1.1 大倾角煤层长壁综采理论研究进展

   1.2 大倾角煤层长壁综采技术研究进展

2 大倾角煤层长壁综采装备研发进展

3 大倾角煤层长壁综采(放)工程实践

4 大倾角煤层长壁开采科学问题

5 结语