采动岩体多尺度变形破坏光纤测试方法与表征机制研究

There are significant multiscale characteristics of mining induced overburden stratum deformation and fracture, how to evaluate its failure under the different scale of rock deformation, establish the corresponding testing method, and reveal the space-time evolution effects of rock failure, is one of the key research directions in mining rock ground control. This program plan to simulate the whole process of mining induced rock fracture under different deformation scale by means of three dimensional physical model testing with triaxial loading. An optical fiber sensing network set up with the structural system of point-line-plane-body will be established to measure and characterize the whole process internal deformation of mining induced overburden stratum. The interaction relationship between rock mass and optical fiber in multi-scale deformation will be investigated by analyzing the Interfacial mechanical properties, the coupling mechanism of rock material and optical fiber component will be revealed eventually. The description of rock deformation and fracture with optical fiber sensing characteristic parameter will be analyzed by the three dimensional model test, the dynamic response of the optical fiber sensing system reacts to the multiscale rock deformation that express in the structure of partial rock mass, key rock stratum and whole overburden will be studied. Also, the reaction of optical fiber sensing response to the rock stratum discontinuous deformation such as the broken, separated, or the fracture evolution will be quantified studied by special two-dimensional model test experiments. Cooperating with the numerical simulation analysis, the characterization mechanism of mining induced overburden stratum multiple scale deformation and fracture will be build. This research will propose a complete set of technical systems of rock deformation test and an evaluation theoretical system of space-time evolution of the internal and multiscale rock deformation based on optical fiber sensing, which can provide a theoretical and methodological basis for the ground control technology under the new circumstances of scientific mining and accurate mining.

采动岩体变形破坏具有显著的多尺度特性，如何衡量不同尺度下的岩体变形破坏特征，建立相关测试技术方法，并揭示岩体变形破坏的时空效应，是岩层控制的重点研究方向之一。本项目拟通过三向加载的采动岩体三维物理模型试验，真实模拟采动影响下岩体不同尺度的变形破坏全过程；设计搭建“点-线-面-体”的光纤感测网络，对采动岩体内部变形破坏全过程进行测试表征。通过分析岩体与光纤的界面力学特性，探究多尺度变形破坏条件下岩体与光纤的作用关系，揭示岩石材料与光纤传感元件的耦合机理，形成采动岩体变形破坏的光纤测试方法；通过三维模型试验分析岩体变形破坏的光纤特征参量表述，研究局部岩块-关键岩层-覆岩整体的多尺度岩体变形破坏的光纤动态响应，并配合二维模型试验专项分析岩层断裂、离层、裂隙演化等非连续变形的光纤响应定量特征，利用数值模拟分析，最终建立采动岩体多尺度变形破坏特征的光纤表征机制。研究将构建基于光纤感测的岩体变形测试成套技术体系和岩体内部多尺度变形时-空演化评估理论体系，可为科学采矿和精准开采新形势下的岩层控制研究提供理论和方法基础。

岩体变形破坏区域观测网络和动态预测预报体系是当前矿业工程发展新方向之一。本项目从交叉学科基本科学问题出发，借助新型光纤智能监测方法改变了基于常规测量技术的岩体内部变形表征，捕获了岩体内部全范围、多尺度的采动岩体力学基本特征。项目研究提出了基于多尺度岩体变形破坏的光纤感测理论体系，构建了岩体变形破坏的光纤感测方法应用关键技术；提出了基于光纤感测的模型试验技术体系，研发了基于光纤感测的岩体三轴应力测试微单元；建立了采动覆岩变形分区分带光纤表征模型，揭示了岩体多尺度变形破坏的时-空演化过程，从覆岩结构分区、分带的角度阐明了采动岩体变形特征的光纤感测反演与表征机制。揭示了岩层内部变形破坏特征和运动规律，阐明了巨厚砾岩层的分组破断特征和采动应力灾变机理。提出了基于机器学习的光纤感测数据分析方法，利用特征光纤布置获得了大范围岩体变形破坏过程，提升了光纤感测方法的监测效率。验证了光纤感测方法的应用适应性和光纤感测表征模型的可靠性，并最终将其用于工程实践，解决了卸压围岩力学行为的实时监测与灾变评估。相关理论与技术体系为矿山岩体力学与岩层控制提供了方法论，对智能开采背景下的矿山建设具有重要科学意义。