Investigation of lightning surge current induced in reinforced concrete buildings by direct strikes

Abstract

Direct lightning strikes to reinforced concrete buildings cause telecommunication equipment to malfunction. The lightning surge currents induced in the building should be investigated to develop the countermeasure method against these strikes. A telecommunication building was modeled by a wire-frame model which presents the beams and pillars of a building. The element of each wire-frame was calculated based on the electromagnetic theory. The induced lightning surge was calculated from the observed waveform of lightning current by using SPICE and FFT. The calculated waveforms at the pillars were compared with observed values. The result showed that a similar waveform could be obtained by the calculation. The calculated deviation of the peak values at pillars almost agreed with the observed value. The results indicate that the model can be used to estimate the tendencies of the lightning surge distribution in reinforced concrete buildings. The lightning surge distribution was calculated by this model. The results showed that the range of value among pillars decreased for the lower floors.