Design elastic input energy spectra based on Iranian earthquakes

Abstract

The goal of this paper is to propose input energy spectra applicable to seismic design of structures based on Iranian earthquakes. In terms of input energy, these spectra represent the load effects of a strong earthquake that a structure may encounter during its lifetime. For this purpose, from among 1800 existing earthquake records in Iran, 110 records were selected. By using these records and through dynamic response analyses, the design input energy spectra for four ground types, defined by the Iranian earthquake code of practice, have been derived.

Elastic and Inelastic Near-Fault Input Energy Spectra

“…Exact description of elastic and inelastic input energy spectra for recorded earthquake ground motions is theoretically obtained by integrating the equation of motion over time for a class of SDOF systems (Zahrah and Hall 1984, Uang and Bertero 1990. Design input energy spectra for elastic or inelastic systems on the other hand can be estimated by two procedures: Either by employing prediction equations based on the site and source characteristics of ground motions recorded in the past as well as the SDOF response parameters obtained under these ground motions (Chapman 1999, Chou and Uang 2000, Chou and Uang 2003, Cheng et al 2014, Alıcı and Sucuoglu 2016, or by developing practical scaling rules relating the elastic or inelastic system and energy response parameters with the intensity parameters of recorded ground motions (Akiyama 1988;Benavent-Climent et al 2002Okur and Erberik 2012;McKevitt et al 1960;Fajfar and Fischinger 1990;Fajfar et al 1992Fajfar et al , 1994Vidic et al 1994;Amiri et al 2008;Mollaioli 1998, 2001;Quinde et al 2016). In fact, the most practical approach for obtaining input energy spectra for inelastic systems with different damping values (ζ) and lateral strength ratios (R), which defines the ratio of the lateral elastic strength demand to the lateral strength capacity of the system, is applying scaling factors to a reference elastic input energy spectra derived for 5% damping.…”

The Inelastic Input Energy Spectra for Main Shock–Aftershock Sequences

“…In conventional seismic design, it is necessary to deal with the coupling between the loading effect of earthquake and the resistance of structure, which makes the seismic design quite cumbersome. A more rational seismic design approach, which aims to overcome this problem, is to interpret the loading effect of earthquake in terms of the input energy (Decanini and Mollaioli 1998, Amiri et al 2008, Benavent-Climent et al 2010, López-Almansa et al 2013. Some investigations (Hori andInoue 2002, Chai 2005) pointed out that the input energy correlate with structural cumulative damage well.…”

“…Later, several investigations (Decanini and Mollaioli 2001, Manfredi 2001, Ordaz et al 2003, Kalkan and Kunnath 2007, Dindar et al 2015 were devoted to acquire the input energy demands in simple systems, and to provide recommendations on how to use these demands in energy-based seismic design. The energy spectrum was recently incorporated in Japanese law (BSL 2005), and there are some nations, trying to implement the energy spectrum in the national building codes (Benavent-Climent et al 2002, Amiri et al 2008, Tselentis et al 2010.…”

Improvement of energy damage index bounds for circular reinforced concrete bridge piers under dynamic analysis

“…For example, sequential ground motions such as mainshock-aftershock and near-field earthquakes. [29][30][31][32][33][34][35][36][37] The total input energy of the system is determined as the total energy demand produced by earthquake ground motions. According to the energy balance equation, some part of the input energy is stored in the form of kinematic and strain energy, and the other ones are dissipated in the form of damping and hysteretic energy.…”