综放采场采动过程中，受采动应力影响顶煤的状态经历了由相对完整逐步过渡为高度破碎的渐进劣化过程，这一过程实质上也是介质状态的转化过程。煤层松软条件下，顶煤松散破碎的介质状态易形成于支架前方，极易漏冒并诱发支架倾倒。同时，在大倾角煤层长壁综放采场，采动应力的非对称展布可能导致倾斜方向不同位置的顶煤进入松散破碎介质状态的位置产生差异，进而造成支架稳定性沿倾斜方向的区化分布特征。因此，揭示采动应力演化路径下顶煤的介质状态转化机制及介态转化临界位置，确定大倾角长壁综放采场采动应力非对称演化作用下顶煤介态转化界面展布形态，可以为解决该类采场的支架稳定性控制难题提供科学依据。 论文采用数值模拟、理论分析、现场监测、物理相似模拟实验相结合的研究方法，对大倾角软煤综放采场顶煤介态转化机制及转化界面形态进行了较为系统的研究，结果表明： 不同均质度、强度、厚度、加卸载路径下的煤体，其声发射能量释放与裂隙发育均在峰值强度之后和残余强度之前这一阶段内急剧增速，而在残余强度之后趋于消弭，宏观承载能力失效，煤体进入残余强度的时刻也是介质状态发生转化的临界时刻。煤体本身的均质度、强度、厚度与其进入介态转化临界状态所经历的时间呈正相关关系。在模拟真实的采动应力的加卸-载路径下，煤体进入介态转化临界状态所经历的时间较单轴压缩条件下较长，峰后应变软化阶段表现出较强的延性特征。 综放采场采动过程中，以顶煤宏观裂隙切割贯通的位置为界限，顶煤由完整状态至放出状态经历了由拟连续介质到非连续介质的介态转化过程，这一介态转化过程实质上就是顶煤内部损伤不断累积的过程，通过分析“顶煤位置—顶煤变形—顶煤损伤—顶煤介态”的内在联系，建立了采动应力演化路径下的顶煤渐进劣化损伤模型，实现了顶煤介态转化界面与工作面煤壁相对位置关系的量化表征。 在顶煤对支架的“降载作用”影响下大倾角综放采场相较综采采场矿压显现程度缓和，在顶煤的“强度效应”与“层厚效应”影响下，大倾角综放采场的矿压显现强度与“非对称”性都将发生改变，随着煤层强度与厚度的增加矿压显现更为剧烈，同时其非对称特征与综采采场逐步由异而趋同。支架上方顶煤最终的介质状态是影响采场矿压显现的关键因素。 采场覆岩岩体结构形式及其形成层位是采动应力演化的主控因素，会影响到顶煤的介态转化进程。大倾角综放采场覆岩“关键域”岩体结构沿走向呈“砌体梁”形式而沿倾向呈“梯阶”形式，倾斜方向任意位置综放采场“关键域”岩体结构层位高度受覆岩岩性、岩体断裂铰接形式、垮落矸石非均匀充填三个方面因素的影响，呈现出渐变迁移特征。 在“关键域”岩体结构层位渐变迁移影响下，长山子1123大倾角软煤综放工作面倾斜不同位置顶煤的介态转化界面位置存在差异，“关键域”岩体结构层位越高，这一界面位置距工作面煤壁的距离越远，反之则越近。1123工作面顶煤介态转化界面沿倾斜方向呈“非对称三角拱”形展布。 揭示了大倾角软煤综放采场顶煤介态转化界面非对称展布形态影响下的倾斜方向支架的稳定性区化机制。界面形成位置距煤壁越远支架稳定性越差，反之则越强，提出了着眼于“防”的以“增加顶煤厚度、分区控制放煤量”为关键的顶煤主动控制技术，和着眼于“治”的以“工作面伪斜布置、支架结构优化、规范移架工序”为关键的支架被动调控技术，在1123工作面取得了良好实践效果。

During the mining process of fully-mechanized caving face, the medium state of top-coal has experienced the gradually degradation process which from relatively complete to highly fragmented, and this process named the top-coal medium transforming process. When the coal is soft, the fragmented mediun state of top-coal will formed front of support, and will easly to falling and cause supports tipping. At fully-mechanized caving stope in steeply dipping soft seam, the asymmetric distribution of mining-induced stress will give rise to the fragmented top-coal formed at different location along the inclined, futher caused the secational distribution of support stability along the inclined. Therefore, the research on the top-coal medium transformation mechanism and the location of transformation interface effected by the mining-induced stress evoulation, and the distribution shape of top-coal medium transformation interface effected by the asymmetric mining-induced stress evoulation of steeply dipping seam, which was helpful to provide scientific basis for support controlling. By the integrated methods of numerical simulation, theory analysis, field monitoring,and physical similar simulation experiment, the top-coal medium transformation mechanism on fully-mechanized caving face and the distribution shape of medium transformation interface in steeply dipping seam has been reaserched, The results indicates that: Under the effects of any factors as homogeneous degree, strength, thickness and load-unload route, the acoustic emission energy release and fracture development both increase sharply at the stage from peak strength to residual strength, and the acoustic emission energy release and fracture development tend to stop after the residual strength, the macro carrying capacity of top-coal failure, when the top-coal enter into the residual strength means it has enter into the medium critical transforming state. There’s a positive correlation between the factors as homogeneous degree, strength and thickness of top-coal and the time last from original state to medium critical transforming state. Under the real load-unload route of stope, the time-period that the top-coal enter into residual strength state was longer than uniaxial compression, and the strain softening after peak strength present stronger ductile character. During mining process, take the location of top-coal macroscopic fractures perforating as boundary, the top-coal form intact to caving has experienced the medium transformation process which form similar continuous to discontinuous. And this process essentially is the process of damage accumulation inside of top-coal. By analysed the internal relations between the “location-deformation-damage-medium state” of top-coal, the progressive deterioration-damage model has been established, and finally realized the quantitative characterization about the relationship between the top-coal medium transformation interface and the coal wall. Effected by the “loading-reduce” function of top-coal the strata behaviors was more mild compared with fully-mechanized mining, and effect by strength and thickness of top-coal the asymmetric and intensity of strata behavior will both tend to change. With the increase of top-coal strength and thickness, the strata behavior will became more violent and the asymmetric characteristics gradual approached to the seam with fully-mechanized mining stope. The final medium state of top-coal above the support is the key influence factor of strata behavior on fully-mechanized caving face in steeply dipping soft seam. The rock structure and stratum horizon in overburden is the main controlling factor of mining-induced stress evolution, and will further function on the medium transformation process of top-coal. The rock structure formed as “voussoir beam” along the strike and formed as “ladder” along the inclined. Effected by the factors as overburden lithology, connecting form of rock structure, caved gangue’s nonuniform filling，the stratum horizon of “critical zone” rock structure present the character as gradually transforming. Effected by the gradually transforming of “critical zone” rock structure stratum horizon, the location of top-coal medium transformation interface along the inclined in Changshanzi mine 1123 working face expressed difference. The higher the “critical zone” rock structure stratum horizon was the farther top-coal critical medium transformation interface to the coal wall, conversely, the more nearly. The distribution shape of top-coal medium transformation interface in 1123 working face present as an “asymmetric-triangular” arch. The sectional distribution mechanism of support stability along the inclined effected by the top-coal medium transformation interface has been revealed. The farther top-coal medium transformation interface to the coal wall the worse support stability was, oppositely the better. The technology of top-coal control which take the “improving thickness”and “caving amount sectional controlling” as key points , and the technology of support stability control which take the “working face pseudo-inclined arrangement”, “optimizing support structure design” , “normalizing support moving process” as key points has been proposed.