Mohamamad Reza Ghayamghamian

Mohamamad Reza Ghayamghamian
International Institute of Earthquake Engineering and Seismology | iiees · Disaster Risk mangment research center

Professor

About

47
Publications
4,840
Reads
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423
Citations
Citations since 2016
8 Research Items
210 Citations
201620172018201920202021202201020304050
201620172018201920202021202201020304050
201620172018201920202021202201020304050
201620172018201920202021202201020304050

Publications

Publications (47)
Preprint
Full-text available
In most buildings’ seismic design codes design basis peak ground acceleration (PGA DBE ) is provided by employing a uniform-hazard approach. However, a new trend in updating seismic codes is to adopt a risk-informed method to estimate the PGA DBE so-called risk-adjusted design basis peak ground acceleration (PGA RDBE ). An attempt is made here to e...
Preprint
Full-text available
In most buildings’ seismic design codes, the design basis peak ground acceleration (PGA DBE ) is provided by employing a uniform-hazard approach. However, a new trend in updating seismic codes is to adopt a risk-informed method to estimate the PGA DBE so-called risk-adjusted design basis peak ground acceleration (PGA RDBE ). An attempt is made here...
Article
The basic goal of earthquake resistant building design codes is to provide life safety in the event of extreme earthquake loading and to reduce the seismic risk in the long run. In the most building codes including Iranian building code (Standard No. 2800), design basis earthquake is defined as an earthquake with 10% probability of exceedance (PE)...
Article
Full-text available
On November 12, 2017, at 9:48 p.m. (local time), a destructive earthquake (Ml=7.3) occurred in the border region between Iraq and Iran, followed by many weak to strong aftershocks. The earthquake claimed more than 620 lives with a further 10000 injured. At least eight cities including Qasr-e Shirin, Ezgeleh, Salas-e Babajani, Gilan-e Gharb, Sarpol-...
Article
Rapid magnitude estimation relations for earthquake early warning systems in the Alborz region have been developed based on the initial first seconds of the P-wave arrival. For this purpose, a total of 717 accelerograms recorded by the Building and Housing Research Center in the Alborz region with the magnitude (Mw) range of 4.8–6.5 in the period b...
Article
Full-text available
The average of shear wave velocity of the upper 30 m has so far been one of the reliable parameters in seismic site classification in different building codes, despite the numerous weaknesses in the exact explanation of site dynamic characteristics. In this study, an empirical relationship is obtained between the average of the shear wave velocity...
Article
A lot of research on the 2D or 3D effects of large-scale basins (within several kilometers depth) have been conducted in the past. However, different 2D aspects of small-scale sedimentary basins (within tens of meters depth) remain in the developing stage. Here, an attempt is made to analyze different aspects of small-scale basins using both numeri...
Conference Paper
Full-text available
Similar to all earthquake prone regions in the world, cities of Iran are disposed to seismic threats and experienced earthquakes with large magnitudes in their history. Despite the significant development of urban areas in Iran after 1984, still some deficiencies such as population growth, improper occupancy of the land, as well as vulnerability of...
Article
Full-text available
In addition to the structural torsional effects coming from the horizontal asymmetry of the building structure one can also meet with the direct torsional ground excitations of the building. The dynamic analyses of structures have been carried out by neglecting the excitation by the rotational ground motions in engineering practice largely caused b...
Article
Determination of the priorities for improvement of vulnerable urban fabrics based on a comprehensive assessment is among the main desires of local governments in earthquake-prone countries like Iran. However, in most countries, the comprehensive and absolute estimation of seismic risk is not possible due to shortages of the required data. In this p...
Article
A new analytical methodology for computing synthetic seismograms in 3-D anelastic media is applied to the modelling of the local records of the 2003 Bam Mw 6.6 earthquake, Southeastern Iran. The method is based on the combination of the modal summation technique with the asymptotic ray theory. The 3-D models are determined by a set of vertically he...
Article
Full-text available
Tehran is located near the vicinity of active faults such as North Tehran, Ray and Mosha faults and each movement of these faults according to their distance from constructions and buildings can cause extreme loss of life and devastated areas in Tehran city. The effects of surface sediments on the characteristics of strong ground motions is one of...
Article
Online Material: Supplemental tables. The Tehran metropolis is located in an extensive area between the Alborz mountain belt to the north and the central Iranian plateau to the south. Tehran, as the political and economic capital of Iran, is considered one of the most populated cities in the world. From the point of view of vulnerability to natura...
Article
The Greater Tehran Area is the most important city of Iran and hosts about 20% of the country's population. Despite the presence of major faults and the occurrence of historical earthquakes, the seismicity is relatively low at present. Thus, it is important to estimate the ground motion for preventive, reliable seismic hazard assessment. An earthqu...
Article
Full-text available
In this study, the first step towards establishing an onsite earthquake early warning system (EWS) in the Tehran region is presented. The system uses the period parameters τpmax and τc from the first 3 s of the vertical and horizontal components of a P wave, separately and combined. Various regression relations between the magnitude and period para...
Article
Full-text available
In order to reduce the seismic risk in urban fabrics effectively, it is necessary to make a comprehensive assessment of vulnerability and seismic hazards in different parts of the urban area. This could provide essential information for city managers and decision makers for better understanding of risk mitigation priorities. Since in most cities of...
Article
Most of the recent earthquakes in Iran were associated with some types of geological hazards that were the cause of additional damage and casualties in the earthquake-affected areas. In order to reduce the impacts of geo-hazards, several policies and plans were prepared, approved, and implemented by the Iranian government during the last two decade...
Article
On 2005 February 22, the Dahuiyeh-Zarand earthquake, Mw 6.5, struck one of the most seismically active regions in south-central Iran, east of Zarand City in Kerman province, causing more than 500 fatalities. The causative fault of the 2005 Dahuiyeh-Zarand earthquake, a reverse fault, striking nearly EW and dipping to the north, was located within a...
Conference Paper
Full-text available
Most major cities in Iran are built near the vicinity of active faults, and on Quaternary sediments. Therefore, the site effects may play an important role in amplification of strong ground motions, and consequently cause severe damage to the buildings. Furthermore, the ground motion near the faults can be affected by the directivity pulse and/or f...
Article
Full-text available
Bridges are one of the main components of transportation networks. They should be functional before and after earthquake for emergency services. Therefore we need to assess seismic performance of bridges under different seismic loadings. Fragility curve is one of the popular tools in seismic evaluations. The fragility curves are conditional probabi...
Article
The site effects in East of Iran have been studied using Iranian Accelerograph Network data recorded at 50 stations. The geological and geotechnical investigations have been conducted to determine the characteristics of soil profiles in the 20 sites. The horizontal to vertical ratio (HVSR) have also been employed in order to recognize the site tran...
Conference Paper
Various interpolation techniques are applied to the data from 35 acceleration stations covered Tehran City, the capital of Iran. Data of Firozabad-Kojour (2004) and Kahak-Qom (2007) earthquakes, which recently occurred near to the Tehran City, were analyzed here. The accuracy of estimated PGA using different interpolation techniques is examined by...
Article
Full-text available
In this article, data were collected from the Chiba dense array, which consists of 44 accelerometers with interstation spacing in the range of 5-300 m that are employed to estimate the torsional ground motion. The geodetic method was used to estimate torsional motions from the translational records in the Chiba dense array. The translational and co...
Article
The site response during the 1998 Miyagiken-Nanbu earthquake was investigated using nine close downhole arrays in Sendai City, Japan. The site amplification function was calculated as a shear-wave spectral ratio of the surface record to that of the borehole record. The observed amplification functions reveal different peak frequencies and amplifica...
Conference Paper
The recent five earthquakes in Iran offered many good quality strong motion data at 242 Iranian free-field strong motion stations. These data provide a unique opportunity for site effect analysis and the study of a practical site classification system. The horizontal to vertical spectral ratio (HVSR) of S-wave was used to estimate the soil amplific...
Article
As an important step in effectively reducing seismic risk and the vulnerability of the city of Qom to earthquakes, a site effect microzonation study was conducted. Seismic hazard analysis for a return period of 475 years was carried out. Data from 160 borings was collected and analyzed, geophysical surveys were conducted and microtremor measurement...
Article
The Changureh–Avaj earthquake (M = 6.4) occurred 220km northwest of Tehran on June 22, 2002. According to the official report, 226 people were killed, 1300 injured and 33,000 houses were seriously damaged or collapsed. Two villages located in the near-fault region with a population more than 200 people were completely destroyed. The damage survey w...
Article
Seismic intensity in the epicentral area of the 2003 Bam, Iran earthquake is estimated using a questionnaire survey conducted two months after the earthquake. The estimated average seismic intensity on the Japan Meteorological Agency (JMA) scale is 6.1 (VIII to IX in the MMI scale). The peak frequency of the horizontal-to-vertical spectral ratio de...
Article
An effort is made to examine the properties of rotational (torsional and rocking) ground motions using Chiba dense array data. The Chiba array system, located 30 km east of Tokyo, Japan, is composed of 15 boreholes with separation distances varying from 5 to 320 m. This provides a unique opportunity to examine the characteristics of rotational comp...
Article
Full-text available
The 2003 December 26 Bam earthquake was an intermediate size strike-slip event that occurred beneath the Bam city, causing more than 26000 fatalities. The record of the only near-fault station (Bam station) shows a clear long-period pulse in almost fault normal direction suggesting a near-fault forward directivity effect contributing to the heavy d...
Article
The site amplification characteristics of the 2003 Bam, Iran, earthquake were investigated based on geological studies as well as geophysical, microtremor and aftershock measurements conducted by IIEES in the study area. A site effect microzonation map was prepared classifying the ground conditions of the city into five distinct categories, based o...
Article
Different aspects of spectral analysis for site response evaluation are investigated in this study. The segmental cross-spectrum is proposed in spectral analysis of earthquake ground motions. The performance of segmental cross-spectrum in contrast with the conventional methods is investigated through the mathematical modelling, numerical analysis a...
Article
An investigation is carried out on earthquake damage to 839 buildings in and around Bam City, and seismic intensities, using European Macroseismic Scale 1998 (EMS98), are estimated. The northern and eastern sides of Bam City show higher damage rates (more than 80%), than the southern and western sides (20% less). Combining the results and the vulne...
Article
Full-text available
After the devastating earthquake of 26 December 2003 in Bam, a discipline was followed to prepare a preliminary site effect microzonation map for the city. Seismic hazard studies for two return periods, geological studies accompanied by geophysical surveys and aftershock and microtremor measurements were carried out to provide site classification a...
Article
Full-text available
The post earthquake investigations of the 26 December 2003 Bam-Iran earthquake were conducted by the Joint Reconnais-sance Team of the Architectural Institute of Japan (AIJ), the Japan Society for Civil Engineers (JSCE), the Japan Association for Earthquake Engineering (JAEE) and the Ministry of Education, Culture, Sports, Science and Technology (M...
Article
Full-text available
The post-earthquake investigations of the Bam, Iran earthquake of Dec. 26, 2003 were conducted by the Joint Reconnaissance Team of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the Japan Association for Earthquake Engineering (JAEE), the Architectural Institute of Japan (AIJ) and the Japan Society for Civil Engineers (J...
Article
Soil amplification characteristics are investigated using data from the Chibaken-Toho-Oki earthquake and its aftershocks recorded at Chiba dense array in Japan. The frequency-dependent amplification function of soil is calculated using uphole-to-downhole spectral ratio analysis, considering the horizontal components of shear wave. The identified sp...
Article
Strong motion records at five vertical array sites in Japan are used to examine soil shear modulus and material damping as a function of shear strain during large earthquakes. Acceleration data from the sites are processed directly for evaluation of site shear stress-strain hysteresis curves for different time windows of the record. Results of the...
Article
Non-linear response of the soil is investigated by comparing the spectral ratios (uphole/downhole) using weak and strong motions. Data from seven vertical arrays in Japan are analysed in this study. The frequency-dependent transfer function of soil is calculated as a ratio of the spectrum at uphole to the spectrum at downhole, considering the horiz...
Article
ABSTARCT In engineering practice, the near-field ground motions are estimated assuming that the fault main parameters, such as slip time function, slip velocity, stress drop etc, are constant on the fault. However, the generation of high-frequency near-field motions indicates that the source function is complex, which is due to the heterogeneity of...

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