Estimating the overall floor stability in a coal mine using deterministic methods which require complex engineering properties of floor strata is desirable, but generally it is impractical due to the difficulty of gathering essential input data. However, applying a quantitative methodology to describe floor quality with a single number provides a practical estimate for preliminary assessment of floor stability. The coal mine floor rating (CMFR) system, developed by the University of New South Wales (UNSW), is a rock- mass classification system that provides an indicator for the competence of floor strata. The most significant components of the CMFR are uniaxial compressive strength and discontinuity intensity of floor strata. In addition to the competence of the floor, depth of cover and stress notch angle are input parameters used to assess the preliminary floor stability. In this study, CMFR methodology was applied to a Central Appalachian Coal Mine that intermittently experienced floor heave. Exploratory drill core data, overburden maps, and mine plans were utilized for the study. Additionally, qualitative data (failure/non-failure) on floor conditions of the mine entries near the core holes was collected and analyzed so that the floor quality and its relation to entry stability could be estimated by statistical methods. It was found that the current CMFR classification system is not directly applicable in assessing the floor stability of the Central Appalachian Coal Mine. In order to extend the applicability of the CMFR classification system, the methodology was modified. A calculation procedure of one of the CMFR classification system’s components, the horizontal stress rating (HSR), was changed and new parameters were added to the HSR.

使用需要底板地层复杂工程特性的确定性方法估计煤矿的整体底板稳定性是可取的，但由于难以收集必要的输入数据，通常不切实际。然而，应用定量方法来用单个数字描述地板质量为地板稳定性的初步评估提供了实用的估计。新南威尔士大学 (UNSW) 开发的煤矿底板等级 (CMFR) 系统是一种岩体分类系统，为底板地层的能力提供了一个指标。CMFR 最重要的组成部分是地层的单轴抗压强度和不连续强度。除了楼层的能力，覆盖层深度和应力缺口角是用于评估初步地板稳定性的输入参数。在这项研究中，CMFR 方法应用于间歇性地经历底鼓的中阿巴拉契亚煤矿。该研究利用了勘探钻芯数据、覆盖层图和矿山计划。此外，还收集并分析了核心孔附近矿山入口底板条件的定性数据（失败/非失败），以便可以通过统计方法估计底板质量及其与入口稳定性的关系。发现当前的 CMFR 分类系统并不直接适用于评估中阿巴拉契亚煤矿的底板稳定性。为了扩展 CMFR 分类系统的适用性，对方法进行了修改。