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 (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).      

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 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.  

Nowadays, various types of passive control systems are being used as an effective solution to reduce the seismic responses of structures. One type of these systems, the Tuned Liquid Column Damper (TLCD), suppresses the input seismic energy by a combined action, including the movement of liquid mass in the container, a restoring force on the liquid, due to gravity loads, and the damping, due to liquid movement through the orifices. In this paper, the possible effects of seismic excitation characteristics, such as frequency content and soil condition, on the seismic performance of TLCDs, are investigated, using nonlinear time-history analyses. For this purpose, a ten-story building was Modeled as an elastic MDOF structure and used for numerical analyses. For the time-history analyses, among the past Strong Ground Motion records of Iran, 16 records with different characteristics were selected. The results of this study show that these characteristics play a substantial role in the performance of TLCDs and they should be, accordingly, considered in the designing of TLCDs. In some cases, TLCD is able to reduce structural displacement up to 50%, while, in most cases, the effectiveness of TLCD in reducing structural acceleration is not significant. However, it should be mentioned that, in real applications, de-tuning may occur, due to the inelastic behavior of structures, which can reduce effectiveness. This study also shows that the displacement reduction capacity of TLCDs is highly dependent on excitation characteristics, while the acceleration reduction capacity is not that sensitive.

Historical backGround attention to seismic events in the near-field Ground Motion goes back to the Parkfield (1966) and San Fernando (1971) earthquakes. In fact, the occurrence of earthquakes and the concentrated presence of population centers in earthquake- stricken areas have further clarified the destructive nature of seismic events in near-fault area for structural and earthquake engineers. Recognition and collection of recorded data from earthquakes in the near-fault area that have different effects can be effective in reducing damage to structures and can also be used in seismological studies and engineering research; therefore, forming a Database of  the near-field Ground Motions is necessary and vital. The most important effects of Strong Ground Motion in the near-field are   long-period pulses due to the rupture directivity effect in the vicinity of the earthquake source, which appears   mainly in the direction perpendicular to the fault and in a short time, apply a lot of energy to the structure.In this study, the near-field records of Iranian earthquakes to evaluate the status of pulses long-period have been investigated. The studied seismic database includes 450 events of recorded earthquakes in Iran, which have been recorded and stored since the establishment of the Iran Strong Motion network until 2014.All of the selected earthquakes have characteristics of magnitude, epicentral distance, geological characteristics (soil type), location of accelerometer, date and time of event, focal depth, maximum Ground surface acceleration, maximum Ground surface velocity, and maximum Ground surface displacement. It should be noted that the moment magnitude of all selected events is equal to a value between 5 and 7, and their epicentral distance is less than 30 km from the event location.Near-field records have been separated from other data due to their Forward Directivity and pulses long-period, and a total of 77 records of near-fault Strong Ground Motion were identified with Forward Directivity.The selected data have the special characteristics of near-fault records that have pulses in the acceleration or velocity time history record, and their characteristics include a short period of Strong Ground Motion, rupture directivity effects, and low-frequency pulses in velocity time history. The selected data in this study have the characteristics and values that have been mentioned, so it is possible that there are other data that have the characteristics of near-fault records and have long-period pulses in the earthquake record and at a distance of more than 30 km or outside from the moment magnitude range of 5-7.In general, the result of this research has led to the preparation of the database of the near-fault with the country's pulse-like records from the beginning of its establishment (in 1973 using the SMA1 analog accelerometer) until 2014 of the Iran Strong Motion network of the research center of the Ministry of Roads and Urban Development. The database collected in 60 stations (77 records) has provided comprehensive and reliable information about parameters such as moment magnitude, epicenter distance, focal depth, soil type, Predominant Period (Tp), Endurance Time. This database can be used as a reference to be used in projects, reports and researches of students at different levels of education, technical and engineering offices and companies, seismic hazard analysis studies, earthquake engineering projects and researches that require the use of near-field Ground Motion in Iran. The use of this refined database for the design of important structures in addition to the development of earthquake engineering knowledge is very important

Due to the inelasticity of the Ground and geometric expansion, seismic waves are reduced by moving away from the center of wave propagation, which is called the attenuation of seismic waves. Therefore, the Ground Motions that occur at the site of the structures are different from the Ground Motions that are emitted from the source. The upcoming study investigates the attenuation of seismic waves in the geographical area of Iran based on the accelerogram data of Iran. In this study, a new Ground Motion Model (GMM) for Iran is developed to estimate peak Ground acceleration (PGA), pseudo-acceleration spectral values (PSA) in 2, 5, and 10 percent damping, and displacement spectral values (Sd) at 21 oscillator periods ranging from 0.04 s to 4 s. The displacement spectra considered in this research are those with a constant resistance-to-weight ratio, which includes both elastic and inelastic displacement types. Also, the considered resistance-to-weight ratios include five ratios from 0.05 to 0.3. The database of this study consists of 659 records of 115 shallow crustal mainshocks that occurred in Iran from 1976 to 2022 with a magnitude range of 5≤Mw≤7.4 and an epicentral distance range of 0 to 200 km. Random-effect coefficients were defined in the mixed-effect regression Model for regional differences among the five regions of the Iranian plateau, and no statistical differences were detected among these regions. The effects of the site soil's nonlinear response are considered in the developed GMM using the VS30 parameter (average shear wave velocity in the upper 30 meters of the soil profile). The residuals of the proposed GMM are decomposed into three between-event, site-to-site, and event-site-corrected components, and their distributions are examined against the predictor variables. The distribution of residuals obtained showed no significant bias for the developed GMM. The output of this research is a GMM for Iran, which can be used to estimate the spectrum of pseudo-elastic acceleration and the spectrum of elastic and inelastic displacement.

Time history analyses as crucial means in many earthquake engineering applications are highly dependent to characteristics of the seismic excitation record so that the resulting responses may vary from case to case. Strong Ground Motion scaling is a known codified solution to reduce such a dependency and increase reliability of time history analyses. The well-known code practice may result in highly non-economic designs due to considerable error in the spectra scaled to match the target code spectrum. This problem is formulated here in an optimization framework with the scaling coefficients as the design variables. Harmony search as a recent meta-heuristic algorithm is utilized to solve the problem and is applied to the treated examples. Using a variety of target period ranges the scaling error is evaluated and studied after more unified via optimization. The effect of base structural period and interval variation on the scaling error is then studied in addition to considerable error decrease with respect to traditional code-based procedure. The results also show dependency of spectral matching error to the period-interval elongation/variation, the base-structural period and more error sensitivity for narrow-band resonance with the filtered records on softer soil types.