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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.

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.

The weakness of tensile strength and high weight in masonry structures under the dynamic loads of earthquakes have always led to structural damage, financial losses, injuries and deaths. In spite of the cheap and affordable masonry materials, it has been very limited their use in constructions over the past three decades. However, common masonry materials are still found in monumental and historical structures, deteriorated texture and rural buildings. Identifying the seismic behaviour and the probability of the structural damage is vital for pre-earthquake seismic risk reduction of urban areas and the rapid post-earthquake assessment. The earthquake event occurred in Ezgeleh on 2017 November 12th with Mw=7.3 triggered the greatest damage in the Sarpol-e-zahab city at a distance of about 37 kilometres from the epicentre. Post-earthquake reconnaissance, microtremor analysis and rapid visual inventory of structural damages in different zones were performed by the research teams. In the present study, the strong ground motion, the peak ground acceleration and its corresponding intensity distribution, which are based on the site response analysis in different parts of the city, are introduced. Afterward, damage probability matrices of different types of masonry buildings, namely unreinforced masonry and confined masonry buildings, are determined for both bins of peak ground accelerations and intensities. Finally, the fragility curves of two types of masonry structures are extracted based on RISK-UE level 1 (LM1) method by assuming beta distribution to estimate the probability distribution function of the damage. These curves are useful in assessing pre-earthquake possible damages in masonry structures with similar construction methods and similar materials to reduce seismic risks.

Kermanshah is a city in Iran's Zagros seismotectonic region regarded as one of the cradles of prehistoric and historic cultures. This novel study investigates the quantitative assessment of the seismic vulnerability of historical buildings in Kermanshah using numerical modeling . This study uses the hybrid method to estimate seismic vulnerability for seven mosques in Kermanshah's historical heritage. The structures are modeled by macro-elements. The material properties for the numerical models of the mosques are calibrated through ambient vibration tests . Furthermore, the efficiency and accuracy of Italian indirect method in evaluating the damage probability in Iranian historical buildings could be determined by the comparison with the hybrid method results. Moreover, it provides the knowledge for developing these methods by the architecture and structural specifications of Iranian historical structures. In the indirect method, the aggregate effect of mosques interacting with other structures is taken into account. Finally, considering local site effects, the fragility curves of both methods are developed and compared to each other at the probable design acceleration acquired from the Iranian seismic standard. The results show the seismic vulnerability of investigated mosques and the necessity to provide some parameters for the type of ceiling and configuration of the aggregates to evaluate the Iranian historical structures by indirect method more effectively.