Gravity⁃dip effect is a main factor leading to the deflection and non⁃equilibrium transfer of stress in the me⁃ so⁃layered coal⁃rock mass and the interlayer contact area，the directional offset of dominant fracture in the mesoscopic layered mining model， regional migration of key strata and the variation of rock structure in the macro⁃layered in the mining of steeply dipping coal seam. The research result shows that the gravity⁃dip effects are particularly obvi⁃ ous in the coal seam with dip angle above 35° including 1 the characteristics of non⁃equilibrium stress transmission at the interface of coal⁃rock combined body are obviously and the stress transmission near the interface is deflected and the amount of deflection increases gradually. The failure of coal mass is transformed from compression⁃shear to shear slip nearly parallel to the interface，and the strength and elastic modulus of coal⁃rock mass also decrease accord⁃ ingly. 2 The evolution law of the mining stress path in the stope has been changed，and the damage deformation and failure movement of the roof driven by the stress have obvious regional and time sequence. 3 It leads to the migration and transformation of roof structure，the asymmetric failure of floor slipping，and the partial⁃total failure of the coal pil⁃ lar or coal wall in the section in the steeply dipping coal seam. The instability of the surrounding rock above has a multi⁃scale chain spatiotemporal correlation and the key rock blocks in the stope that cause surrounding rock catas⁃ trophes are changeable，which results in the dissimilation and generalization of the bearing structure of the surrounding rock in the stope. Multi⁃dimension and multi⁃scale are the essential characteristics of strata control in the steeply dip⁃ ping coal seam under the action of gravity⁃dip effect. Breaking through the bottleneck of traditional mining methods and technologies，and developing new complete sets of equipment are effective ways to achieve the safe and effi⁃ cient mining of steeply dipping coal seam.

1 倾角效应下煤岩体力学行为

   1.1 煤岩体三维力学模型

   1.2 三向压缩状态下煤岩体主应力偏转特征

   1.3 煤岩体非均衡变形与破坏特征

2 大倾角采场顶板采动应力传递时空演化规律

   2.1 顶板采动应力环境

   2.2 顶板主应力大小渐变演化规律

   2.3 顶板主应力方向偏转演化规律

3 大倾角采场“ 关键层” 区域迁移、结构异化和泛化

   3.1 采场围岩变形破坏时空规律

   3.2 采场围岩空间结构异化和泛化

4 大倾角采场多维多尺度岩层控制

   4.1 采场围岩多维协同控制

   4.2 围岩与装备多维协同控制

5 结论