深部硬岩矿山采空区损伤演化机理及稳定性控制

发布时间：2019-05-28 01:28

【摘要】：地下开采是金属矿山开采的主要方式,长期大规模开采及处理的滞后,形成了大量的采空区,成为了矿山的重大危险源之一。由于采空区自身结构及赋存环境的复杂性,造成采空区稳定性难以判断,无法及时采取有效措施。尤其进入深部开采后,高地应力使采空区赋存环境进一步恶化。因此,采空区稳定与否是保证安全开采的关键因素之一本文以深部硬岩金属矿山采空区为研究对象,以揭示采空区损伤演化机理和稳定性特征为目标,综合采用室内力学实验、理论分析、数值模拟及现场监测等技术手段,围绕深部采空区岩体复杂路径下力学特性、采空区稳定特征及失稳机理、采空区系统稳定性控制与治理等内容展开深入理论研究。 (1)选取典型深部矿山脆性岩石进行了加卸载岩石力学试验,对复杂应力路径下脆性岩石的力学及破裂特征进行了对比分析。采用声发射监测数据,对破裂过程中能量演化特征进行了研究,在此基础上,基于最小耗能原理建立了复杂应力路径下岩石演化数学模型。 (2)在采空区精细探测数据的基础上,基于分形理论,对采空区多种分形特性进行了研究,建立了采空区复杂程度的定量表征指标体系。对单一采空区稳定性敏感特性进行了详细研究,得到了采空区复杂程度与稳定特征的定量关系式,并分别建立了不同影响因素与采空区稳定特征的函数关系。将采空区划分为狭长型与立方型,基于现场监测数据,对两种类型采空区形成全过程围岩扰动规律进行了分析,采用弹性厚板理论及固支梁理论建立了两者的采空区顶板力学模型,并基于损伤断裂理论建立了狭长型顶板断裂预测模型,该研究成果在现场得到了应用。 (3)以程潮铁矿为工程背景,建立了深部采空区卸荷失稳分析模型,引入局部能量释放率指标对采空区卸荷过程中能量演化规律进行了分析,并基于尖点突变理论建立了围岩能量失稳准则,揭示了采空区围岩卸荷失稳机制。 (4)建立了采空区系统失稳灾变链式演化模型。以能量为载体,提出了采空区失稳灾变能量链式效应理论,并建立了能量链式效应演化数学模型,划分了能量演化阶段。针对不同阶段提出了不同的控制措施,并应用在了工程实际,取得了良好的控制效果,为采空区稳定控制提供了新的理论依据。
[Abstract]:Underground mining is the main way of metal mining. The lag of large-scale mining and treatment for a long time has formed a large number of goaf and become one of the major dangerous sources of the mine. Due to the complexity of goaf structure and occurrence environment, it is difficult to judge the stability of goaf and can not take effective measures in time. Especially after entering the deep mining, the occurrence environment of goaf is further aggravated by high ground stress. Therefore, the stability of goaf is one of the key factors to ensure safe mining. In this paper, the goaf of deep hard rock metal mine is taken as the research object, and the damage evolution mechanism and stability characteristics of goaf are revealed. By means of laboratory mechanical experiment, theoretical analysis, numerical simulation and field monitoring, this paper focuses on the mechanical characteristics, stability characteristics and instability mechanism of rock mass in deep goaf under complex path. The stability control and treatment of goaf system are studied in depth. The main results are as follows: (1) the mechanical tests of brittle rocks in typical deep mines are carried out, and the mechanical and fracture characteristics of brittle rocks under complex stress paths are compared and analyzed. Based on the acoustic emission monitoring data, the characteristics of energy evolution in the process of fracture are studied. On this basis, the mathematical model of rock evolution under complex stress path is established based on the principle of minimum energy consumption. (2) based on the fine detection data of goaf, a variety of fractal characteristics of goaf are studied based on fractal theory, and the quantitative characterization index system of goaf complexity is established. The stability sensitivity of a single goaf is studied in detail, and the quantitative relationship between the complexity of goaf and the stability characteristics is obtained, and the functional relationships between different influencing factors and the stability characteristics of goaf are established respectively. The goaf is divided into narrow type and cubic type. Based on the field monitoring data, the disturbance law of surrounding rock in the whole process of the formation of the two types of goaf is analyzed. The mechanical models of goaf roof are established by using elastic thick plate theory and fixed beam theory, and the narrow roof fracture prediction model is established based on damage fracture theory. The research results have been applied in the field. (3) taking Chengchao Iron Mine as the engineering background, the analysis model of unloading instability in deep goaf is established, and the local energy release rate index is introduced to analyze the law of energy evolution in the process of unloading goaf. Based on the cusp catastrophe theory, the energy instability criterion of surrounding rock is established, and the unloading instability mechanism of surrounding rock in goaf is revealed. (4) the chain evolution model of goaf system instability is established. Taking energy as the carrier, the theory of energy chain effect of goaf instability and catastrophe is put forward, and the mathematical model of energy chain effect evolution is established, and the energy evolution stage is divided. According to different stages, different control measures are put forward and applied to engineering practice, and good control results are obtained, which provides a new theoretical basis for goaf stability control.
【学位授予单位】：北京科技大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD32

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