Lightning Protection of Ancient Chola Monument in South India Based on Three-Dimensional Geometric and Electro-Geometric Techniques

Abstract

Lightning is one of the most commonly occurring natural phenomena which causes irrecoverable damage toedifices which include monuments that uniquely showcase global heritage. Most monuments are usually built tall since these signify symbols of victory, whereby invariably becoming vulnerable to lightning. Though several researchers have implemented various Lightning Protection Systems (LPS) to a considerable level of success, substantial statistical variations in prospective stroke currents during lightning due to factors such as climate change,complexities in geographical topography etc., present considerable challenges in obtaining a common framework for protection of structures. Hence, this research focuses on carrying out analysis based on exhaustive case-studies for an ancient United Nations Educational, Scientific and Cultural Organization (UNESCO) monument in South India. The first objective of this research is in carrying out detailed comparison of shielding effectiveness based on 3D geometric and electro-geometric LPS strategies such as Protection Angle Method (PAM) and Rolling Sphere Method (RSM). The second aims at assessment of risk in accordance with IEC 62305 for estimation of level of risk and the role of varying lightning protection levels utilizing striking distance models to obtain the appropriate choice of the location of air terminal. The third focuses on conducting cross-validation studies to assess the adequacy of the proposed location of LPS using SESShield-3D by depicting the critical zones that necessitate additional protection. In addition, shielding failure analysis of the proposed LPS is also carried out. Inferences on unshielded zones for the three-dimensional (3D) layout models of the monuments have been summarized with appropriate recommendations.