Probabilistic Calculations of Lightning Protection for Tall Buildings

The analysis of the protection practices applied to tall buildings by using lightning rods or horizontal wires has shown a deficiency in defining the shape and the extent of the protective zone. The limitations in the application of the empirical protective zone defined by a conical shape below and around a lightning rod have motivated the development of new techniques for the protection of buildings against lightning. Starting from the transmission line protection practice, the protective effects of the basic lightning elements (vertical rods and horizontal wires) are studied analytically by means of the electrogeometric model developed mainly by Whitehead; as a result, we have developed a simplified shielding calculation practice, as well as a digital computer program based on Monte Carlo simulation technique. The concept of protection failure risk is introduced to characterize the effectiveness of lightning protection schemes.