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Preventive actions for architectural heritage against seismic risk. The Italian experience
Published in Koen Van Balen, Aziliz Vandesande, Innovative Built Heritage Models, 2018
Looking at the development of the measures set for retrofitting and strengthening of buildings located in seismic areas, we can observe that the role of prevention policies becomes important only during the emergency periods, after seismic events. Since the 1970s, legislative measures were adopted for managing the emergency after each single seismic event. During the 1980s and the 1990s new approaches were proposed in academic field. In this period, the legislative acts were more orientated to reinforced concrete (r.c.) reinforcement technologies, whilst the analysis promoted by different universities introduced new observations to the strengthening criteria (Donatelli A. 2016). Research centers, like academic laboratories or other national research poles, studied the mechanical effects of seismic events on real scale models, simulating common traditional masonry buildings repaired with different strengthening technologies (Magenes & Lagomarsino 2009).As a result, a deep critic to the lack of knowledge towards historical building technologies and their substitution with new reinforced concrete elements was addressed to the national technical board of the Ministry for Public works. Analyzing the seismic events occurred in Italy during the 20th century until nowadays, a relationship between earthquakes and the development of the main legislative acts concerning risk prevention can be draw out: – In 1908 the seismic risk mapping of the territory was started, after the earthquake that destroyed Messina and Reggio Calabria.– In 1968, the Belice Valley in Sicily was stroke by a 6.1 magnitude earthquake and in 1974 a complete legislative tool against seismic risk was set by the Ministry for Public Works, providing the technical measures for new constructions in seismic areas and for reinforcing existing buildings.– In 1976, the 6.4 magnitude earthquake demolished several towns in Friuli and four years later, in 1980, an earthquake by 6.9 magnitude hit the Irpinia area in Calabria. Since 1984, new criteria for the seismic classification of the Italian territory were introduced, looking to new international experiences, like the Japanese and the American ones.– In 1997, after the Umbria earthquake, with a magnitude of 5.9, the new results coming from the seismic microzonation were used as preventive analysis for post-earthquake interventions.– In 2002, a 5.8 magnitude earthquake hit Molise region and in 2003 the new national seismic map of the Italian territory (OPCM 3274/2003) was introduced (Fig. 3).
Experimental Analysis and Theoretical Modelling of Polyurethane Effects on 1D Wave Propagation through Sand-Polyurethane Specimens
Published in Journal of Earthquake Engineering, 2022
Michele Placido Antonio Gatto, Lorella Montrasio, Linda Zavatto
Seismic hazard is the probability that an earthquake with an intensity above a certain threshold will occur in a certain geographical area within a given time interval. It is generally quantified through the expected peak ground acceleration (PGA) and the spectral accelerations (Ahmed, Lodi, and Rafi 2019; Giardini et al. 2018; Lanzano et al. 2020; Montaldo et al. 2007; Zimmaro and Stewart 2017). The PGA depends on the seismicity of the area, the time interval of consideration, and the characteristics of the foundation soil (the so-called site effects). Recently developed models for the determination of hazard parameters consider the site effects studied with seismic microzonation (Castelli et al. 2018; Castelli, Lentini, and Grasso 2017; Cavallaro et al. 2018; Ebrahimian et al. 2019; Li et al. 2018; Shreyasvi, Venkataramana, and Chopra 2019). Seismic accelerations give rise to inertial forces on structures; depending on the structure resistance (and, therefore, their vulnerability) against these inertial forces, different consequences arise. In general, seismic risk is defined as a measure of the damage expected to occur directly to buildings and indirectly to things and people. Therefore, seismic risk depends on the seismic hazard, the site effects, the vulnerability of the structures, and the anthropisation of the area.
Integration of site condition information using geographic information system for seismic risk reduction for bridge network
Published in Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, 2022
Azarm Farzam, Marie-José Nollet, Amar Khaled
Seismic site classes and related amplification factors can be determined by measuring specific geotechnical properties (NRCC 2015; CAN/CSA-S6-19 2019). In the absence of such information, seismic risk studies and building codes often rely on microzonation information. Seismic microzonation defines an area as a function of its seismic site classes and related amplification factor. Results of different measurements, such as the mean shear-wave velocity over the top 30 m (NRCC 2015) or the resonance frequency (Ghofrani and Atkinson 2014), are subjected to geostatistical data interpolations in order to map a whole area into seismic site classes. In the absence of such measurements or regional microzonation, scoring procedures consider a conservative interpretation. This interpretation results usually in an overestimation of the seismic risk associated with the bridge. This process can lead to a disqualification of the evaluation.
Seismic microzonation and building vulnerability assessment based on site characteristic and geotechnical parameters by use of Fuzzy-AHP model (a case study for Kermanshah city)
Published in Civil Engineering and Environmental Systems, 2019
Maryam Hassaninia, Rassoul Ajalloeian, Mohammad Reza Habibi
Karimzadeh, Feizizadeh, and Matsuoka (2017) presented a hybrid model based on the shear wave velocity of Vs30 for seismic risk damage assessment and KHM model. An amplitude map of Vs30 and geology maps were developed and applied for seismic microzonation.