辛体系下采场上覆岩层运动空间的地质结构逻辑模型研究

The overburden strata space in working face is a spatial range which is caused by the surrounding rock movement and the change of the stress field followed by movement, deformation, failure, and then affecting to the ground surface due to the coal seam extraction. Most fatal accidents in coal mines occur directly or indirectly affected by the surrounding rock movement and the change of stress field in the range of overburden. According to the characteristics of overburden strata space in working face, this project will propose and establish the three-dimensional logical model of geologic structure based on the definitions of basic concepts such as geologic unit of logical structure and boundary surface, introducing the concept of "event", defining the events of sedimentation, erosion and excavation, abstracting the mechanical behavior of rock mass as the "state" is "transfered" when an event occurred in in the framework of symplectic dual system. Meanwhile, the model of DFN (Discreted Fracture Network) and SRM ( Synthetic Rock Mass) will be introduced to describe the fractured zone and implemented by the TIN model of boundary surface under the criteria of boundary surface, giving the output of the calculation model to be verified and visualization model with in-situ data. The project will be used the unified methods of sympletic system combining with different methods of different consititutive models in the past, which is more reasonable, more accurate to describe the state of the overburden in the four-dimensional space, expanding the cross-over study of mining and new theoretical system further.

采场上覆岩层空间是由煤层采出引起围岩运动和应力场变化，依次运动、变形和破坏，进而影响到地表的空间范围。煤矿重大事故多数都在该空间范围内受采动围岩运动和应力场变化因素的影响直接或间接地发生。本项目针对采场上覆岩层空间的特点，提出并建立煤矿三维地质结构逻辑模型，在定义逻辑结构地质单元、边界面等基本概念的基础上，引入"事件"概念，完成沉积、侵蚀和采动事件的定义，在辛对偶体系下将岩体力学行为特征抽象为事件发生后"状态"的"转移"。同时，采用离散裂隙网DFN和合成岩体SRM模型描述采动裂隙带，通过边界面判断准则形成TIN模型表述下的边界面，结合现场数据完成计算模型验证和可视化表达模型的输出。本项目的研究将以往不同本构模型下的不同方法统一在辛体系下的统一方法，将更合理、更精确地描述上覆岩层在四维空间上的状态及其变化，拓展采矿学科和新理论体系更深层次的交叉研究。

采场上覆岩层空间是由煤层采出引起围岩运动和应力场变化，依次运动、变形和破坏，进而影响到地表的空间范围。煤矿重大事故多数都在该空间范围内受采动围岩运动和应力场变化因素的影响直接或间接地发生。本项目针对采场上覆岩层空间连续与非连续力学的特点，在辛空间对偶体系下使用统一、理性和适合离散的方法解决了采场顶板初次来压薄板问题不同边界下连续介质力学的精确解析；利用GIS和FLAC3D的耦合定义了上覆岩层空间采动裂隙带边界面函数，用以区分连续与非连续空间的分界面；使用PFC颗粒流模型描述上覆岩层采动裂隙演化过程，并对如何进行细观参数和宏观参数标定的难点问题提出了可行的方案；针对上覆岩层空间地表开采沉陷无法精确计算任意工作面的不足，利用非结构化三角形单元作为基准沉陷单元，改进了规范中只能适用矩形工作面的计算公式，提出并实现了任意形状工作面开采沉陷预测的概率积分精确算法。本项目的研究成果以地质结构逻辑模型完整地描述了上覆岩层运动空间中的主要问题，通过辛数学理论和数值模型，耦合GIS精细地揭示了上覆岩层运动空间连续介质和非连续介质力学下的运动规律，定义并给出了数值模型下两者的分界面，为今后拓展采矿学科的新理论体系奠定了理论和数值计算的基础。