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The geotechnical seismic isolation of historical buildings through polyurethane injections: A numerical study
Published in Renato Lancellotta, Carlo Viggiani, Alessandro Flora, Filomena de Silva, Lucia Mele, Geotechnical Engineering for the Preservation of Monuments and Historic Sites III, 2022
Seismic risk is a combination of seismic hazard, vulnerability, and exposure. Seismic hazard is the measure of the seismicity of a certain area. The vulnerability is proper of structures and is related to the adequacy of quality and quantity of materials (deteriorated or designed through aseismic building codes). Exposure depends on the population density, which governs damage associated with the occurrence of a seismic event. High-seismic-risk buildings are mainly the historic ones, because of their vulnerability. Interventions of vulnerability reduction through structural reinforcement are widespread, but in most cases, they do not protect the aesthetic conservation, especially for buildings of the artistic heritage.
Precast segmental bridge construction in seismic zones
Published in Fabio Biondini, Dan M. Frangopol, Bridge Maintenance, Safety, Management, Resilience and Sustainability, 2012
Fabio Biondini, Dan M. Frangopol
We note here the distinction between seismic risk, hazard and vulnerability. Based on (Dutta & Mander, 1998), we can define seismic risk as the probability of a structure suffering a determine damage after an earthquake. Seismic risk can be seen as a combination of seismic hazard and seismic vulnerability to the expected hazard. The seismic hazard is a characteristic of the region and depends on the probability that an earthquake occurs in a time period (Clemente, 2003). The seismic vulnerability is the susceptibility of a structure to suffer damage from an earthquake of given intensity. Vulnerability is characteristic of the structure and it is independent of the regional hazard.
Structural height, amplification and damages during the superficial earthquakes at Casamicciola, Ischia Island (2017), and Santa Venerina, Catania (2018), Italy
Published in Geomatics, Natural Hazards and Risk, 2023
Seismic Risk is the engineering measure for assessment of expected damages in buildings or other structures following a probable earthquake: it is the product of the hazard [P], exposure [E] and vulnerability [V]. [P] is the acceleration, with a fixed probability, transmitted by the earthquake to the ground: OPCM 3274/2003 (OPCM, 2003) has classified the Italian territory into four seismic categories; later, the National Institute of Geophysics and Volcanology - INGV confirmed the classification, making it more exact on the basis of geographical coordinates (NTC 2018). All the municipalities in Italy (about 8700) are located in a seismic zone. [E] is related to the importance of a construction within its social and economic fabric. There are structures whose use or operation cannot be interrupted (hospitals, schools, universities, major roads and railway lines, airports, ports, bridges-viaducts, electrical, thermal and nuclear power plants, aqueducts, gas pipelines, dams, etc.). For these constructions, the seismic risk is estimated by means of a thorough structural analysis, although there are exceptions for road networks (Costa et al. 2020; El-Maissi et al. 2020). [V] is the predisposition of a structure to suffer damage and collapse: this predisposition is related to the size (in planimetry and height), geometry, materials, design and construction types, degradation and damage mechanisms, i.e. to its box-like behavior in the presence of a seismic stress.
Seismic vulnerability and risk assessment at the urban scale using support vector machine and GIScience technology: a case study of the Lixia District in Jinan City, China
Published in Geomatics, Natural Hazards and Risk, 2023
Yaohui Liu, Xinyu Zhang, Wenyi Liu, Yu Lin, Fei Su, Jian Cui, Benyong Wei, Hao Cheng, Lutz Gross
After obtaining the seismic vulnerability index, formula (10) was used to estimate the mean seismic damage index for buildings based on different seismic intensities, and the mean seismic damage degree was then obtained. In this study, the seismic damage degree of buildings was evaluated under intensities VII, VIII, IX, and X. According to the RISK-UE method, the seismic damage degree of buildings was divided into six grades: ‘none’, ‘slight’, ‘moderate’, ‘substantial to heavy’, ‘very heavy’, and ‘destruction’. The mean seismic damage index and the classification standard for different seismic damage degrees are shown in Table 3. Many factors affect the seismic risk, such as the vibration intensity, side effects, and geological conditions. In this study, the vibration intensity factor was mainly considered. According to the calculation results, there are no damaged buildings in Lixia District at seismic intensity X and below.
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.