冲击地压的煤岩动力学物理模拟相似原理

Physical similarity principles of coal-rock dynamics simulation for coal burst

  • 摘要: 冲击地压是一种在动、静载荷叠加作用下发生的突发性动力灾害,具有破坏过程剧烈、能量释放集中、发生机制复杂等特点,对矿井安全生产构成严重威胁。为在实验室中真实再现冲击地压的破坏过程并揭示其动力学本质,仅依赖现有静力学相似原理的物理模拟方法难以全面揭示冲击地压的动力学特征。为此,以冲击地压的动力致灾机理为研究对象,提出了一种以加速度相似比为核心的煤岩动力学相似准则体系,旨在构建可真实反映冲击地压动力学响应特征的物理模拟理论框架。通过量纲分析的方法,对冲击地压过程中的关键指标进行了系统分析。以加速度相似比作为核心控制参数,推导建立了冲击地压动力学相似准则的理论方程组,构建了包含应力相似比、弹性模量相似比、时间相似比及应变率相似比在内的动力学相似准则系数体系。通过引入动力学相似准则系数,分析了其与各相似比之间的耦合关系与约束条件,形成了物理模型的冲击倾向性相似判据体系。结合相似理论推导结果,对不同几何相似比条件下的模型强度曲线演化规律进行了归纳分析,明确了动力学相似准则的适用范围与参数取值区间。研究表明:动力学相似准则系数是控制动力学相似关系的关键参数,其取值直接决定模型惯性响应与能量传递的相似性,确定了动力学相似准则适用的最优几何相似比与物理模型的波速相似比。提出的冲击地压煤岩动力学相似原理突破了传统静力学相似理论的局限,实现了对惯性效应和能量释放行为的量化描述,为冲击地压动力学物理模拟试验提供了理论依据。

     

    Abstract: Coal burst is a sudden dynamic disaster that occurs under the superposition of dynamic and static loads, characterized by a violent failure process, concentrated energy release, and complex occurrence mechanism, posing a serious threat to mine safety. To reproduce the failure process of coal burst and reveal its dynamic essence in laboratory conditions, conventional physical simulation methods based on static similarity principles are inadequate to fully capture its dynamic characteristics. Therefore, with the dynamic disaster mechanism of coal burst as the research focus, a coal-rock dynamic similarity criterion system centered on the acceleration similarity ratio is proposed, aiming to establish a theoretical framework for physical simulation that can realistically reflect the dynamic response characteristics of coal burst. Through dimensional analysis, the key parameters involved in the coal burst process were systematically analyzed. Using the acceleration similarity ratio as the primary control parameter, a theoretical equation set of dynamic similarity criteria for coal burst was derived, and a system of dynamic similarity coefficients was constructed, including the stress similarity ratio, elastic modulus similarity ratio, time similarity ratio, and strain rate similarity ratio. By introducing the dynamic similarity coefficient, the coupling relationships and constraint conditions among various similarity ratios were analyzed, and a similarity criterion system describing the impact tendency of physical models was established. Furthermore, based on the derived theoretical relationships, the evolution laws of model strength curves under different geometric similarity ratios were summarized, and the applicable range and parameter intervals of the dynamic similarity criteria were clarified. The results show that the dynamic similarity coefficient is the key parameter governing dynamic similarity relationships, and its value directly determines the similarity of inertia response and energy transfer between the model and the prototype. The optimal geometric similarity ratio and wave velocity similarity ratio for the dynamic similarity criteria were determined. The proposed coal-rock dynamic similarity principle for coal burst breaks through the limitations of traditional static similarity theory, achieves quantitative characterization of inertia effects and energy release behavior, and provides an operable theoretical basis for dynamic physical simulation experiments of coal burst.

     

/

返回文章
返回