底板型冲击是冲击地压灾害的显现方式之一，明确底板内在冲击属性可以更好地评估底板型冲击危险性，指导底板型冲击地压灾害防治。在参照顶板岩层冲击倾向性分类及指数测定方法基础上，通过简化简支梁受力模型，借助小变形位移相等、岩梁长度相等方法，将底板岩层受力作用等效为均布载荷，基于薄板理论推导临界应力表达式，确定底板主控岩层位置和弯曲变形岩层层数，计算底板岩层弯曲能量指数，判断底板岩冲击倾向性，基于此建立底板岩层冲击倾向性分类和鉴定流程；以义马矿区跃进煤矿为例对该方法进行了验证，应用结果表明跃进煤矿2-1煤底板岩层的冲击倾向性由弱变强，更符合结合现场实际情况，证明了该方法的合理性和可行性。

Floor impact is one of the manifestations of rockburst disasters. Defining the inherent impact properties of floor can better evaluate the risk of floor impact and guide the prevention and control of floor rockburst disasters. On the basis of referring to the classification of roof rock stratum impact propensity and index determination method, by simplifying the simply supported beam stress model, with the aid of the method of equal small deformation displacement and equal rock beam length, the stress action of floor rock stratum is equivalent to a uniform load. Based on the thin plate theory, the expression of critical stress was derived to determine the location of the floor main rock stratum and the number of layers of bending deformation rock stratum, and calculate the bending energy index of floor rock stratum. Based on this, the floor rock burst tendency was judged, the classification and identification process of floor rock burst tendency were established. Taking Yuejin Coal Mine in Yima Mining Area as an example, the method was verified. The results showed that the impact tendency of 2-1 coal floor strata in Yuejin Coal Mine changed from weak to strong, which was more in line with the actual situation on the spot, and proved the rationality and feasibility of the method.