The performance-based earthquake engineering requires reliable assessment of long-period ground motion particularly for tall buildings, base-isolated structures, long bridges, and structures that are designed to deform beyond the elastic range.The important issues involved in such assessments are: Empirical and theoretical tools for prediction of displacement response spectra; Analysis and incorporation of near fault effects; Spectrum scaling for different damping ratios and; Time domain simulation of long-period ground motion. These issues are elaborated through (1) the principles for modification of design basis spectra in the long-period range; (2) guidelines for time domain simulation of long-period ground motions; and (3) rules for selecting and scaling ground motion records to address long-period effects. This paper aims to review and discuss these issues with developments on GMPRs for peak ground displacement and 10s spectral acceleration, and example applications on earthquake hazard assessment for 10s spectral accelerations and its deaggregation in the Marmara Region, Turkey.

Iran Strong Motion Network started its activities since 1973, and has recorded more than 5500 accelerograms up to September 2005, through which the maximum ground acceleration of about Ig is recorded due to Zanjiran [1994] and Barn [2003] earthquakes at Zanjiran and Barn stations respectively. At present the network consists of 1049 digital and 61 analogue accelerographs. In the first half of the year 2004, 363 accelerograms are recorded by ISMN and the maximum PGA of about 0.922g is occurred in Hassan Kief station in Kojur-Firouzabad earthquake of May 28, 2004.  

Time history analysis of structures require some carefully selected earthquake records to be employed as the input for dynamic analysis. Despite the increase in number of recorded earthquake ground motions, the need for generation of artificial accelerograms are highly demanded in some areas for some reasons. As a result, many efforts have been made to develop mathematical methods for simulating ground motions by various researchers. Since most of the methods for generation of spectrum compatible signals use relatively complex mathematical approaches, it requires engineers to make more effort and spend time to deal with these complicated methods. In order to meet engineers’ demand for generation of the above-mentioned signals while maintaining an applicable tool that is easy to utilize, a simple, numerically iterative novel procedure has been proposed which is based on linear combination of intrinsic mode functions (IMF) of recorded seismic signals evaluated by empirical mode decomposition (EMD). The proposed method requires only basics of structural dynamics and definitely all engineers are familiar with them and simply can apply the method, while it leads to results as accurate and efficient as benchmark methods such as random vibration theory and time-frequency analysis techniques. The results of this study prove the applicability of the developed approach.

Iran Strong Motion Network (ISMN) that runs under the authority of Building and Housing Research Center (BHRC) of Iran started its activity since 1973. At the date of this study this network consisted of more than 1049 digital (SSA-2) and 61 analog (SMA-1) accelerographs. The recorded earthquake accelerograms are downloaded, controlled, processed, and then added to the accelerograph comprehensive data bank, which is quite useful for scientists and engineers. Herein the recorded accelerograms and causal earthquakes are briefly explained and more detailed information is presented in Table 1 and also available on (http://www.bhrc.ac.ir).

Iran Strong Motion Network (ISMN) that runs under the authority of Building and Housing Research Center (BHRC) of Iran, start its activity since 1973. At the present day it consists of more than 1000 digital (SSA-2) and 61 analog (SMA-1) accelerographs. The recorded earthquake accelerograms are downloaded, controlled and processed and then added to the accelerograph comprehensive data bank, which is too useful for scientists and engineers. Here in the recorded accelerograms and causal earthquakes are briefly described and more detailed information is presented in Table 1 and also available on the web page of BHRC (http://www.bhrc.ac.ir).