针对特厚煤层大型综放开采条件下沿空巷道顶板煤体沿水平方向发生的挤压变形与破裂问题，本项目拟采用室内试验、理论分析、数值模拟、现场实测等相结合的研究方法，基于特厚煤层综放沿空巷道顶煤经历的实际开采扰动过程，探索采动应力路径下煤体力学响应特性，构建反映煤体峰后强度非线性劣化与扩容力学特性的本构模型；探讨顶煤灾变失稳的临界力学条件及应力位移场时空演化规律，揭示顶煤由挤压→破裂→失稳的力学演化机理；探究综放沿空巷道采掘时空关系优化方法与顶煤加固准则，分析支护结构对顶煤水平方向挤压变形的控制原理，形成特厚煤层综放沿空巷道顶煤控制原理与方法。本项目研究成果集特厚煤层综放沿空巷道顶煤力学响应特性、挤压破裂机理与控制方法于一体，对于综放沿空巷道顶煤稳定性控制及其灾害防治、厚煤层资源高效开采具有重要的理论意义和广阔的应用前景。

The large-scale fully-mechanized caving mining in an extra thick coal seam may bring out roof-coal mass squeezing deformation and failure in plumb direction in a gob-side entry. A comprehensive method including laboratory tests, theory analysis, numerical simulation and field monitoring is employed in this study. Based on the practical excavation and mining disturbance process roof-coal mass underwent, mechanical response properties of coal mass under the real stress path induced by mining is investigated, and as a result, a constitutive model reflecting nonlinear deterioration law of strength and dilatancy mechanical characteristics of post-peak coal mass is built. The critical mechanical condition of catastrophe and instability of roof-coal mass is revealed, and the evolution law of stress and displacement field in roof-coal mass is also studied, thus the mechanical evolution mechanism from squeezing to failure to instability of roof-coal mass is clarified. The optimization methods of the time-space relationship of mining and excavation are investigated, and the reinforcement principles of roof-coal mass in gob-side entry are also proposed, and the control mechanism of support structure to the squeezing deformation of roof-coal mass in the plump direction is further clarified. Consequently, a control principle and approach for roof-coal mass of gob-side entry with fully-mechanized caving mining in an extra thick coal seam is set up. All these results have important theoretical significance and broad application prospect for the stability control and disaster prevention of roof-coal mass of gob-side entry and the efficient mining of thick coal seam resources.