煤层倾角改变了围岩采动应力演化特征，使得顶板变形破坏运动特征和所形成岩体结构的力学行为等区域性特征明显，导致在大倾角煤层开采中对围岩的稳定性控制异常复杂。论文采用物理模拟实验、数值模拟、理论分析、现场实测相结合的研究手段，建立了基于靶向需求的数值计算结果数-力映射方法，分析了大倾角采场顶板采动应力三维非对称传递演化特征；研究了煤层倾角对顶板破坏包络面展布的影响机理，阐明了覆岩破坏包络面内、外岩体结构演变与耦合作用机理；实测了不同倾角条件下采空区空域展布形态，优化了大倾角工作面安全高效开采关键技术并开展了工程实践。主要研究结果如下：

(1) 主应力受采动影响在煤壁前方呈现出先增大后减小的变化规律，其应力传递路径可分为原岩应力区、应力增高区、应力降低区；应力增高区内，第一主应力在Z轴分量增加幅度最大，其方向自垂直于Y轴平面内旋转。在倾向剖面内，顶板应力的传递路径呈非对称拱形形态，沿顶板自上而下，应力偏转位置由工作面倾向中轴线左侧向其右侧迁移，上覆岩层载荷以应力偏转界线为界分别向倾向上、下侧煤体传递。随煤层倾角增大，围岩应力传递演化的非对称特性显著增大，应力偏转界线与工作面倾向中轴线间的距离逐步增大。围岩应力包络拱壳呈现壳顶在工作面倾向中上部、壳基在采场四周煤体内的非对称拱壳体形态。

(2) 工作面支架后方采空区块体呈现铰接堆砌结构，反复出现倒三角临空域。顶板破断包络面内部，块体堆砌铰接现象明显；在破坏包络面外部，倾向上部悬空顶板作为主承载结构，其变形程度较块体铰接位置处小。随煤层倾角增大，倒三角临空域范围增大，沿倾斜方向直角边增大，走向长度增大；破坏包络面外部围岩承载拱高度减小，拱顶向倾向上部偏移幅度增大，水平位移、垂直位移、合位移峰值均呈现出减小的演化趋势；工作面倾向上、下端头支承压力峰值先增大后减小，沿工作面走向，支承压力影响范围增大。

(3) 工作面顶板载荷的大小与作用位置发生改变且倾向下部形成的矸石充填区改变了基本顶的约束条件。随煤层倾角增大，基本顶挠度、弯矩等峰值减小幅度加剧，挠度峰值位置不断向工作面倾向中上部偏移；倾斜砌体失稳的主要因素在于煤层倾角的改变会影响到砌体结构的倾向堆砌角度且倾斜砌体结构重力沿工作面垂直方向分力减小；倾向合理拱轴线的非对称性显著，拱顶均位于工作面倾向中上部区域；拱顶向倾向上部偏移程度呈现出先增大后减小的趋势；耦合承载拱形态在倾向下区域存在下凹段，随着煤层倾角增大，矸石充填影响段倾向范围减小；耦合承载拱的非对称性增大，拱顶位置向倾向上部偏移，偏移幅度增大。

(4) 工程尺度上不同煤层倾角条件下大倾角工作面采空区均存在倾向下侧轮廓线为直、斜线复合状的倒三角空域。大倾角工作面支架受载不均衡特性明显，在工作面倾向下部区域，支架平均工作阻力及其离散程度小；在工作面倾向中、上部区域，支架与顶板接触方式与施载特征复杂，偏载、空载、架间咬挤等现象频发，支架平均工作阻力及其离散程度大。以工作面支架为核心进行“三机”稳定性校核，采用“固-护-调-清-扶-移-稳”的动态扶架方法可有效提高效率，并在工程实践中取得了较好的经济效益。

研究揭示了大倾角长壁采场顶板采动力学行为倾角效应，为大倾角走向长壁工作面开采顶板稳定性控制提供科学指导，具有重要的理论和实践意义。

The angle of coal seam changes the evolution characteristics of mining stress of surrounding rock, which makes the regional characteristics such as the deformation and failure movement characteristics of roof and the mechanical behavior of rock structure obvious, resulting in the abnormal complexity of the stability control of surrounding rock in the mining of steeply dipping coal seam. In this paper, by means of physical simulation experiment, numerical simulation, theoretical analysis and field measurement, the number-force mapping method of numerical calculation results based on targeted demand is established, and the three-dimensional asymmetric transfer evolution characteristics of roof mining stress in steeply dipping stope are analyzed, the influence mechanism of angle on the distribution of failure envelope surface is studied, and the evolution and coupling mechanism of internal and external rock structure of overburden failure envelope surface is clarified, the spatial distribution pattern of gob under different angles was measured, and the key technology of safe and efficient mining of steeply dipping working face was optimized and engineering practice was carried out. The main findings are as follows:

(1) The principal stress first increases and then decreases in front of the coal wall under the influence of mining, while in the middle of the mined-out area, the three all decrease and the first principal stress decreases the most. The path of the first principal stress affected by mining can be divided into three areas: Original area, increasing area, decreasing area. In the increasing area, the first principal stress increases most in the Z axis component, and its direction rotates perpendicular to the Y axis plane. In the inclined section, the transmission path of the roof stress is an asymmetrical arch shape. From top to bottom, the stress deflection position gradually shifts from the left side to the right side of the working face. The load of overburden strata transferred to the upper and lower coal seams with the stress deflection boundary as the boundary. As the angle of coal seam increases, the asymmetric characteristics of the stress transfer and evolution of sur-rounding rocks increase significantly. The distance between the stress deflection boundary and the central axis of the working face gradually increases. The surrounding rock stress envelope arch shell presents an asymmetric arch shell with the top in the middle and upper part of the working face and the base in the coal body around the stope.

(2) The block in the gob behind the support presents a hinged stacking structure, and the inverted triangle airspace appears repeatedly. Inside the failure envelope surface of roof, the block stacking hinge phenomenon is obvious. Outside the failure envelope surface, the inclined upper suspended roof to be the main bearing structure, and its deformation degree is smaller than that at the hinged position of the block. With the increase of angle, the range of the inverted triangle airspace increases, the right-angle side along the inclined direction increases, and the length of the strike increases. The height of the bearing arch of the surrounding rock outside the failure envelope surface decreases, the offset amplitude of the vault to the upper part increases, and the peak values of horizontal displacement, vertical displacement and combined displacement all show a decreasing evolution trend. The peak value of abutment pressure at the upper and lower ends of the working face increases first and then decreases. Along the direction of the working face, the influence range of abutment pressure increases.

(3) The size and position of the overburden load change and the gangue filling area formed at the lower part of the dip changes the constraint condition of the main roof. With the increase of the angle of the coal seam, the peak value of the deflection and bending moment of the main roof decreases, and the peak position of the deflection continues to shift to the middle and upper part of the working face. The main factor for the instability of inclined masonry is that the change of angle will affect the inclined stacking angle of masonry structure and the gravity of inclined masonry structure decreases along the vertical direction of working face. The asymmetry of the inclined reasonable arch axis is significant, the vault is located in the middle and upper part of the working face, and the offset degree of the vault to the upper part of the inclination shows a trend of increasing first and then decreasing. The shape of the coupling bearing arch has a concave section in the lower tendency area. With the increase of the angle of the coal seam, the tendency range of the gangue filling influence section decreases. The asymmetry of the coupling bearing arch increases, and the vault position shifts to the upper part of the dip, and the offset amplitude increases.

(4) The field measurement shows that the airspace of the steeply dipping gob under different angles shows a composite shape of straight and oblique lines on the lower side of the dip. The support resistance of working face presents the basic characteristics of the largest in the middle part, the second in the upper part and the smallest in the lower part along the tendency. In the middle and upper areas of the working face, the contact mode and loading characteristics of the support and the roof are complex, and the phenomena of partial load, no load and biting between the supports are frequent, and the average working resistance of the support and its dispersion degree are large. The dynamic support method of ' solid-protecting-adjusting-clearing-supporting-moving-stabilizing ' can effectively improve the efficiency of the working face and achieve good economic benefits in engineering practice.

The study reveals the angle effect of mining behavior of roof in longwall mining of steeply dipping coal seams, and provides scientific guidance for roof stability control in steeply dipping longwall face, which has important theoretical and practical significance.