All engineering measurements carry inherent uncertainty, whether acknowledged or not. If we add a type of risk metric as well as uncertainty quantification in the procedure of establishing the SEISMIC design load applied to the structures, we will have a risk-informed approach for the resulting design load referred to as the risk-based SEISMIC design HAZARD. For example, ASCE/SEI 43-05 standard uses a risk-based approach to prepare the SEISMIC design spectra to be applied to the nuclear power plants (NPPs). This approach necessitates the propagation of uncertainty in ground motion model (i.e., the HAZARD curve), as well as probabilistic distribution of structural capacity levels (i.e., the fragility curve). The present research begins with the specifics of this approach, in particular the whole shape of the earthquake HAZARD curve and its integration with the structural fragility curve for estimating the SEISMIC design load. The aim is to identify for a probabilistic model that can estimate the uncertainty of SEISMIC design loads for a variety of engineering structures. This paper presents the estimated uncertainties of SEISMIC design loads across the Iran map using the developed probabilistic model. The uncertainty, according to the study's assumptions, is at least 45% in terms of the coefficient of variation, indicating a significant value. The estimated variability in SEISMIC design loads in the Iran region ranges from 45% to 90%.

Two recent developments have come into the forefront with reference to updating the SEISMIC design provisions for codes: (1) publication of new SEISMIC HAZARD MAPS for Canada by the Geological Survey of Canada, and (2) emergence of the concept of new spectral format outdating the conventional standardized spectral format. The fourth-generation SEISMIC HAZARD MAPS are based on enriched SEISMIC data, enhanced knowledge of regional SEISMICity and improved SEISMIC HAZARD modeling techniques. Therefore, the new MAPS are more accurate and need to incorporate into the Canadian Highway Bridge Design Code (CHBDC) for its next edition similar to its building counterpart National Building Code of Canada (NBCC). In fact, the code writers expressed similar intentions with comments in the commentary of CHBCD 2006. During the process of updating codes, NBCC, and AASHTO Guide Specifications for LRFD SEISMIC Bridge Design, American Association of State Highway and Transportation Officials, Washington (2009) lowered the probability level from 10 to 2% and 10 to 5%, respectively. This study has brought five sets of HAZARD MAPS corresponding to 2%, 5% and 10% probability of exceedance in 50 years developed by the GSC under investigation. To have a sound statistical inference, 389 Canadian cities are selected. This study shows the implications of the changes of new HAZARD MAPS on the design process (i.e., extent of magnification or reduction of the design forces).

In this paper, the well-established probabilistic SEISMIC HAZARD - Poisson occurrence model - technique is applied to estimate the SEISMIC severity of Syrian region.Syrian SEISMIC catalog, which extends from 19 AD to 2012, as well as seismotectonic features of the region have been utilized. The SEISMIC HAZARD assessment carried out using eight SEISMIC active zones based on tectonic settings and spatial distribution of the SEISMIC activity. We assessed the modified Gutenberg-Richter Model parameters and the maximum credible earthquake magnitude for each SEISMIC zone.Suitable numeric attenuation models have been used for the considered SEISMIC zones. An increment of 0.1x 0.1 degree is used. The SEISMIC HAZARD MAPS are developed for return periods (50, 100, 175, 475 and 975 years) and for the seven structural periods. Integrating PGA to PSA HAZARD MAPS have done based on site-effect factors of PSA/PGA. SEISMIC HAZARD curves are obtained for all major cities. Relatively high levels of PGA as well as PSA are found in regions: Lebanese part of DSFS, Al-Ghab region of Syria, along the border of Turkey and Bitilis zone. Remarkable SEISMICity has noticed in the eastern part of Syria.

This paper presents a probabilistic HAZARD assessment of Ilam region in Zagros mountain, western Iran.Zagros is one of the most SEISMICally active parts of Alpine-Himalayan SEISMIC belt. We got a catalogue containing historical and instrumental, complete for magnitudes greater 4. To account for SEISMICity of regions near Ilam, area under study was extended and fault map then seismotectonic map was obtained.Considering SEISMIC pattern in area, potential SEISMIC sources were detected and modeled as volume sources. Using probabilistic method and choosing attenuation relationship, we obtained peak ground acceleration on bedrock in sites for exceedence probability 64%, 10% and 2% and life time 50 years.Considering four relatively HAZARD level, we zoned Ilam to four zones as high danger part, relatively high danger, intermediate and low SEISMIC HAZARD level.

In this study, a modified “probabilistic SEISMIC HAZARD assessment” (PSHA) method is used to estimate the level of the potential SEISMIC ground motion in Firoozkouh. A problem that may be encountered in probabilistic studies of SEISMIC HAZARD for a specific site, for engineering purposes, is the selection of design earthquakes corresponding to a given HAZARD value. In order to derive a SEISMIC scenario consistent with the results of PSHA for a site and determine the relative contribution of events to the overall SEISMIC HAZARD, the concept of disaggregation was introduced. The disaggregation of SEISMIC HAZARD is an effective way to identify the scenario events that contribute to a selected SEISMIC-HAZARD level. In other words, the disaggregation process separates the contributions to the mean annual rate of exceedance (MRE) of a specific ground motion value at a site due to scenarios of given magnitude M, distance R, and the ground motion error term, e. Disaggregation results could change with the spectral ordinate and return period, thus more than one single event may dominate the HAZARD especially if multiple sources affect the HAZARD at the site. These results can provide useful information for better defining the design scenario and selecting corresponding time histories for SEISMIC design. In most cases, as the probability decreases, the HAZARD sources closer to the site dominate. Larger, more distant earthquakes contribute more significantly to HAZARD for longer periods than shorter periods. In this study, the SEISMIC HAZARD disaggregation process is performed to identify dominant scenarios in “peak ground acceleration” (PGA) and 5% damped 0.2 and 2.0 s spectral accelerations corresponding to mean return periods (MRPs) of 50 yr, and 475 yr (HAZARD levels of 63% and 10% probability of exceedance in 50 yr, respectively) in Firoozkouh city. In this regard, potential SEISMIC sources and their SEISMICity parameters have been estimated based on the concept of spatial distribution function in 34o–37oN latitudes and 52o–55o E longitudes in grid intervals of 0.1º. For each point using proper attenuation relationships, PGA, 0.2 and 2.0 s spectral acceleration values with 63% and 10% probabilities of exceedance in 50 yr have been calculated using the EZ-FRISK (version 7.43) code. The HAZARD can be simultaneously disaggregated in different types of bin. The result of SEISMIC HAZARD disaggregation are presented in terms of 1-D M, R and ε bins and 2-D M-R bins. Bins of width 0.4 in magnitude, 10 km in distance, and 0.2 in e are selected. The disaggregation results in terms of probability density function (PDF) are reported, which is obtained by dividing the probability mass function (PMF) contribution of each bin by the bin’s size, thus the PDF representation is independent of the bin’s amplitude. The results identify the distribution of the earthquake scenarios that contribute to exceedance of PGA and 5% damped 0.2 and 2. s spectral accelerations for 50 yr and 475 yr MRPs, in terms of magnitude and distance (M-R). Dominant scenarios are identified for interest HAZARD levels in Firoozkouh city.

The purpose of this work is to evaluate the regional SEISMIC HAZARD for Morocco, following the deterministic approach proposed by Costa et al [1], based on the computation of complete P-SV and SH synthetic seismograms. The input for the computations is represented by source and structural models. SEISMIC sources are parameterized using the knowledge about past SEISMICity and the tectonic regime. The regional structural model we adopted is the one proposed by Cherkaoui [2], modified in its shallower part to account for the effects of the uppermost sedimentary layers. MAPS of peak acceleration, velocity, and displacements are used for the general representation of the HAZARD. Accelerations are in good agreement with the values determined by Jimenez et al [3] with the standard probabilistic approach.

This paper was present a SEISMIC HAZARD analysis and uniform HAZARD spectra for different regions of Kerman city. A collected catalogue containing both historical and instrumental events and covering the period from 8th century AD until now within the area of 200 Km in radius were used and SEISMIC sources are modeled. Kijko method has been applied for estimating the SEISMIC parameters considering lack of suitable SEISMIC data, inaccuracy of the available information and uncertainty of magnitude in different periods. To determine the peak ground acceleration the calculations were performed by using the logic tree method. Two weighted attenuation relations were used; including Ghodrati et al, 0.6 and Zare et al, 0.4. Analysis was conducted for 13´8 grid points over Kerman region and adjacent areas with SEISRISK III software and in order to determine the SEISMIC spectra Ghodrati et al, spectral attenuation relationships was used.

The present study was conducted to determine peak ground acceleration (PGA) over bedrock in probabilistic analysis methods for the SEISMIC HAZARD and uniform HAZARD spectra at different HAZARD levels for Esfahan city. A series of statistics containing historical and instrumental SEISMIC data covering from the 8th century A.D. to the now up to a radius of 200 km was employed and SEISMIC sources were modeled up to a radius of 200 km from Esfahan city. For this purpose the method proposed by Kijko (2000) was employed considering uncertainty in magnitude and incomplete earthquake catalogue. SEISMIC HAZARD analysis is then carried out for Esfahan city by using SEISRlSK III (Bender and Perkins, 1987) program for 11×13 grid points. Four different attenuation relationships of PGA and SA with logic tree were used to determine the PGA on bedrock. The PGA can be determined for 143 points and the HAZARD spectra can be specified for 20 points of the city. Covering %2 and %10 probability of exceedance in one life cycle of 50 years are presented. Finally, the uniform HAZARD spectra was also presented with %10 and %2 of probability of exceedance in one life cycles of 50 years are presented along with New Mark and Hall Spectra.

SEISMIC HAZARD assessment is carried out for 48.5 - 51 oE and 33 – 36 N o including Markazi province (central province). To do this, seismotectonic map of the region has been provided by using geology MAPS 1:2500000, tectonic MAPS, satellite images, available reports, earthquake and minor earthquake catalogues. Five potential SEISMIC sources have been identified by analyzing geology, seismology and geophysics data in the studying area. At last, peak ground 10 iso-acceleration MAPS for return period have been displayed by probability method. Seisrisk III program in a network of dots with the distance of 0.1 degree has been utilized in SEISMIC HAZARD assessment. SEISMIC zone map of Markazi province shows peak horizontal acceleration for 10% probability in 10 years is 0.2g. Markazi province can be divided into different zone with relative risk. The quietest zone is in west. There are regions in north with high relative risk around Indes, kushk Nosrat, Khoshk rud Fault. There is the same situation for a small zone in west north which is in east north of Dorud Fault.