Search

Seismic codes were developed to reduce the structural vulnerability and risk associated with earthquakes in earthquake-prone regions of the world. The effectiveness of the code in preventing damage is dependent on the performance level defined and the construction technology employed. The seismic fragility curves for two recent versions of the seismic code of Iran are determined by using the hybrid method. The probability of damage levels is visualized by these curves. To develop these curves, only the assumptions of the code are taken into account. These curves are compared with the empirical fragility of the recent devastating earthquake in Iran. The results indicate that, despite a similar probability of damage to the different seismic-resistant systems, steel-braced frames pose a greater risk of collapse. Concerning earthquake damage, the steel and RC moment-resisting frames have shown higher damage probability than expected from the code. [ABSTRACT FROM AUTHOR]

This study provides the seismic scenario-based risk map of the small mountain city of Kerend-e-gharb. It evaluates the existing methods and formulations for the effects of a devastating earthquake using empirical fragility curves. A seismic vulnerability map is developed at the urban block-scale using a Geographic Information System for a variety of steel, reinforced concrete, confined masonry, unreinforced masonry, and adobe residential buildings. The estimated seismic damages are validated by comparing them with the building damages surveyed after the Sarpol-e-zahab earthquake. Moreover, the damages to the population, including the probability of homelessness, death, severe injuries that need immediate hospital treatment, moderate injuries that require hospital treatment, and light injuries, without hospitalization, are assessed. The estimation of debris, and the economic losses deriving from this natural hazard, are also investigated. Finally, the map of the mean damage index is presented. The mean damage index is reduced by the renovation and retrofitting interventions in high damaged buildings, while this index is increased in moderately damaged buildings that are not structurally upgraded. The results of this study are consistent with the earthquake damage distribution. In addition, and even with the reduction in vulnerability of buildings after seismic interventions, some blocks of the northeastern part of the city are still at high seismic risk. The results of this study can be used in seismic crisis management planning to achieve a sustainable city. [ABSTRACT FROM AUTHOR]

This study investigates the damage data after November 12, 2017, Iran earthquake (Mw 7.3), collected on 440 steel and reinforced concrete residential buildings. Structures have low-to-medium height and are located in Sarpol-e-zahab city, as well as in the west and northwest parts of Kermanshah province, Iran. The peak ground acceleration demands are determined according to data of the micro-shakemap of Sarpol-e-zahab city and the shakemap of Kermanshah province, while the mean values of intensities are determined from the existing empirical relationship between PGA and intensity. The investigated buildings are engineered steel and RC structures nominally erected according to the second and third editions of the Iranian code for earthquake-resistant buildings, but mostly under careless supervision and with low-quality materials. Damage probability matrix, vulnerability index and empirical fragility curves are presented for three subgroups of steel and RC structures on the basis of (i) structural materials and seismic resistant systems (i.e. braced, moment and combination of braced and moment steel frames, as well as moment and combination of moment and shear wall RC frames), without considering the height of structures; (ii) structural materials and height of structures, without considering the seismic resistant systems (i.e. low and medium-height steel and RC structures); (iii) structural materials, without considering the seismic resistant systems and height of structures (i.e. total data for steel and RC frames). The proposed fragility curves are compared with other fragility curves for steel and RC buildings from previous studies. Finally, since this earthquake was the first seismic event in Iran affecting a considerable number of steel and RC engineered buildings, the proposed empirical fragility curves are definitely unique and crucial for realistic damage and vulnerability assessment of similar buildings in future earthquake scenarios, as well as for developing rapid seismic loss assessment after damaging earthquakes. [ABSTRACT FROM AUTHOR]

• AVTs are performed on eight historical masonry mosques. • Natural periods of the mosques are calculated and numerical models are calibrated. • Fundamental frequency and dynamic characteristics of the ground are identified. • Empirical relation is presented for the natural periods of the mosques. Eight historical mosques of Kermanshah constructed in 18th or 19th century CE are investigated with ambient vibration tests on their sites and buildings. Conventional peak picking technique is used for determination of structures' fundamental frequencies and spectral ratio of horizontal to vertical components along with ellipticity inversion of Rayleigh waves are considered to identify the natural frequency of ground and shear wave velocity profile to define the site conditions according to the national codes of Iran and Italy. The recorded motions on the buildings are used to calculate the fundamental frequencies of the structure. Afterward, buildings are modeled by macro-element method and material properties are tuned in the way that the fundamental frequencies from the modal analyses match with the measured values from AVTs. Finally, more modal analyses are performed by the calibrated models to present an empirical relation between the natural period of the mosques, the geometrical characteristics of the buildings, and the mechanical properties of the construction materials. The results show that the natural periods of the masonry buildings of the mosques are different from the values of empirical relations in the national codes. Meanwhile, the proposed empirical relation presents the natural periods of the buildings of this study reasonably well and can be used for other masonry buildings of similar architecture and materials. [ABSTRACT FROM AUTHOR]