Structural Dynamic Characteristics of Ancient Egyptian Obelisks and Their Responses to Earthquake Loads

Abstract

Ancient Egyptian obelisks have existed for several millennia and have withstood numerous natural disasters. This study investigated the structural dynamic characteristics and the responses of several obelisks to earthquakes using a two-staged approach. The first involved a series of tests to study the mechanical properties of the Red Aswan granite of which the obelisks were made, whereas the second incorporated the test results in modeling the obelisks using finite-element software. An eigenvalue modal analysis was performed to generate the natural periods and corresponding modes of vibration of each of the structures. These natural periods were compared to the dominant periods of earthquakes to analyze the response of each obelisk to loading and its degree of resonance. Next, a time-history analysis was performed in which each obelisk was subjected to an earthquake signal. The results show that the obelisks vary in their responses to seismic loads.