Critical Excitation Methods in Earthquake Engineering

During the last three decades critical excitation problems in earthquake engineering have been studied extensively, and have formed a new research discipline in applied mechanics and structural engineering. These investigations have been motivated by the fact that uncertainties in the occurrence of earthquakes, the fault rupture mechanism, the wave propagation mechanism, the ground properties, etc. cause much difficulty in defining reasonable design ground motions especially for important buildings. In the past, once a big earthquake occurred, some building codes were upgraded. However, it is true that this repetition never resolves all the issues and new damage problems occur even recently. In order to overcome this problem, a new paradigm has to be posed. To the authors knowledge, the concept of critical excitation and the structural design based upon this concept can become one of such new paradigms. In the seismic resistant design of building structures, the concept of performance-based design has become a new paradigm guaranteeing the maximum satisfaction of building owners. The quality and reliability of the performance-based design certainly depend on the scientific rationality of design ground motions. The most critical issue in the seismic resistant design is the resonance. The promising approaches are to shift the natural period of a building through seismic control and to add damping in the building. However it is also true that the seismic control is under development and more sufficient time is necessary to respond to uncertain ground motions. This book introduces a new probabilistic and energy-based critical excitation approach to overcome several problems in the scientific and rational modeling of ground motions. The author hopes that this book will help the development of new seismic-resistant design methods of buildings for such unpredicted or unpredictable ground motions.Takewaki, Izuru is the author of 'Critical Excitation Methods in Earthquake Engineering ', published 2007 under ISBN 9780080453095 and ISBN 0080453090.