Input energy power for near- fault and far - fault ground motions

Abstract

In energy based seismic design (EBSD) approach, effect of ground motions on structures is considered as an energy input to structures (EI). The usage of energy spectra is an effective tool in energy based seismic design (EBSD) methods, such as the use of design acceleration spectra in force-based and displacement-based methods. The obtaining of input energy spectra offers an important advantage to determine the energy input to structures with the effect of ground motions. On the other side, near-fault seismic ground motions are frequently characterised by intense velocity and displacement pulses of relatively long periods that clearly distinguish them from typical far-field ground motions. Intense velocity pulse motions can adversely affect the seismic performance of structures. Based on new parameters previously defined called “Input Energy Power” (IEP) and “Energy Spectral Intensity” (ESI) a comparison between ground motions pulse-like and vibratory-like is established. Is seen that records near-fault reach higher Input Energy Spectrum (IES) than far-fault records but when they are compared by the IEP or ESI the differences are much greater.