大倾角煤层长壁工作面安全高效开采基础研究

Steeply dipping seams, which are widely distributed in Chinese crucial mine areas, have already regarded as the hard excavated seam by mining domain with abundant problems including worst safe and efficient excavation settings at home and abroad. A hybrid methodology with multi-disciplines including geological engineering, mining engineering, computer science, engineering mechanics and mathematics, many key techniques including establishment of multidimensional interaction visual model and analysis of stochastic isolated-body movement and damage dynamic model, other examination and analysis. Scientific problems including mechanical characteristics and behavior of surrounding rock under the excavation, mechanism on multidimensional interaction action and destabilization of support-rock mass system, and evolution of isolated body from the formation to the movement and failure in excavation space has been considered. The internal essence of mechanical behavior and process attribute of surrounding rock under the excavation, multidimensional interaction mechanism for support-rock mass, the formation and movement mechanism of isolated body were found and revealed in mining the steeply dipping seam. Finally, regionalization identification of key strata area, stability control of support-rock mass system and safeguard method for flying gangue were totally proposed respectively. The built up on theoretical system for safe and efficient excavation of longwall face in steeply dipping seam would offer basis for innovation of excavation method, tackle of key techniques, manufacture of complete plants and equipment, and establishment of safe system.

大倾角煤层是国内外采矿界公认的复杂难采煤层，广泛分布于我国各大矿区，开采产效低、安全状况差。本项目采用地质工程、采矿工程、计算机科学、工程力学、数学等多学科联合方法，突破采动岩体多尺度可视化三维模型和随机分离体动力学模型的构建、测试与分析等关键技术，研究采动岩体力学性质、状态与行为、“支架-围岩”系统失稳致灾规律、回采空间随机分离体损（伤）害过程等科学问题，发现并揭示大倾角煤层采动岩体力学行为与过程属性的内在本质、长壁开采“支架-围岩”系统多维交互作用机理、随机分离体形成-运动机制，建立大倾角煤层长壁开采围岩关键层区划、“支架-围岩”系统稳定性控制和“飞矸”灾害判定准则，整体架构大倾角煤层长壁工作面安全高效开采理论体系，为该类煤层开采方法变革、关键技术攻关、成套装备研制、安全体系建设奠定基础。

大倾角煤层长壁综采技术改变了我国该类煤层非机械化开采历史，但系统性安全和产效问题仍制约着该类煤层开采技术水平进一步提高。课题采用理论、实验、数值仿真与现场测试相结合的综合研究方法，针对采动岩体力学性状数-力表征及对开采的控制作用、“支架-围岩”系统多维交互作用及失稳致灾机理、“飞矸”形成-运动-损害过程及防护机制等关键科学问题，开展了深入系统的研究与探索，取得的重要研究进展如下：.一是发现了层状采动煤岩体“重力-倾角”效应，构建了基于多尺度理论的采动煤岩体宏-细观尺度关联表征函数，揭示了不同开采条件下大倾角采场围岩空间采动主应力包络拱壳的宏观展布形态及其演化规律，获得了采空区垮落体非均衡充填形态、载荷-位移在层状介质体间的传递特征，明晰了层、块状结构体稳定-失稳时空演化过程和“关键层”区域迁移与岩体结构变异失稳致灾机理，提出了“关键层”区划方法。系统阐明了倾角效应下采动煤岩体力学行为及其对安全高效开采的控制作用。.二是揭示了采场顶板破断与底板滑移下垂向维度“顶板-支架-底板”动-静载荷作用机理，煤壁非对称片帮与矸石非均匀充填下走向维度“煤壁-支架-充填矸石”动-静载荷作用机理，支架空载与冲击、正常与倾倒下滑等状态下倾斜维度“支架（群）-围岩”动-静载荷作用机理，提出了多维交互“支架-围岩”稳定性控制方法。系统阐明了大倾角长壁采场“支架-围岩”系统多因素耦合-多维度交互效应和失稳致灾与控灾机制。.三是揭示了不同开采条件和回采工序中“飞矸”形成机理、不规则多面体随机形状“飞矸”生成和三维运移时空演化机制，明确了“飞矸”量变-质变过程及其致灾机理，提出了“飞矸”运动全过程威胁等级评估方法和灾害控制原则以及分阶段与全过程控制技术。系统阐明了倾斜回采空间“飞矸”形成-运动-损害机理及防护机制。.课题为大倾角等典型复杂难采煤层绿色智能安全高效开采提供了重要和系统的科学与技术基础。