雷电灾害风险国家标准GB/T217142-2008风险管理中,把雷击建筑物导致物理损害的概率PB作为防雷级别(LPL)的函数取值,没有考虑建筑物的尺寸等参数,较为笼统。本文利用电气-几何理论(Electro-Geometric Model,EGM),建立雷电击中建筑物的模型,研究PB与建筑高度、接闪器高度及安装位置等建筑物本身的参数关系,结合雷电流概率模型推导出更加有针对性的PB计算方法。将此方法用于实体建筑物PB值的计算,与国标给出的值进行比较。结果表明,使用EGM算法计算PB比使用国标给出的参数和方法计算的建筑物雷击风险值普遍增大。论证了这种方法的实用性意义。
PBis given as a function value of lightning protection level(LPL)in the national standard GB/T217142-2008,without considering the sizes of buildings,which is not precise.The model of the struck is established by using electrical-geometry theory.The relationship between risk and building characters is provided.The method related to the heights of buildings and lightning arresters for calculating PBis given.Compared with the old method,this method is used to calculate the PBvalue of physical buildings.The result shows that PBcalculated with the new methods is generally larger than that with the old one;the practical significance of this method is demonstrated as well.