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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.
Seismic risk assessment for the North Eastern Region of India by integrating seismic hazard and social vulnerability
Published in Sustainable and Resilient Infrastructure, 2023
Navdeep Agrawal, Laxmi Gupta, Jagabandhu Dixit, Sujit Kumar Dash
The calculated PGA values for some important cities in the region are also compared with those from previous studies, as shown in Table 6. The calculated PGA values in the present study are relatively lower than those reported by Nath & Thingbaijam (2012) and are on the higher side compared to other studies (Table 6). However, in the case of Aizawl, Imphal, and Kohima, the PGA values for low probability of exceedance (return period = 475 years) are comparable with that of (NDMA, 2010) as mentioned in Table 6. In contrast, at Aizawl and Imphal, the calculated PGA values are less than that reported by Sharma & Malik (2006) and higher than that by Sil et al. (2013). At Guwahati and Shillong, the calculated PGA values are in a higher range than that reported by Ghione et al. (2021) and comparable with Bahuguna & Sil (2020) for a higher return period. Such variations can be attributed to the selection of different seismic source zones and ground motion attenuation models, which can be considered a limitation of the PSHA method. The predicted seismic hazard maps in the present study can act as an input in sustainable infrastructure planning, urban planning, and risk mitigation and disaster preparedness plans.
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.
Analysis of the Site Effects in the North East Region of India Using the Recorded Strong Ground Motions from Moderate Earthquakes
Published in Journal of Earthquake Engineering, 2022
Manisha Sandhu, Babita Sharma, Himanshu Mittal, Prasantha Chingtham
The estimated and amplification at are shown in Figure 8. Also, the amplification between different frequency ranges is shown in Figure 9. Figure 9(a) depicts the spatial distribution of estimated site amplification corresponding to 3–10 story buildings (1–3 Hz) and similarly 9 (b) shows the spatial distribution of site amplification corresponding to 1–3 story buildings (3–10 Hz). These amplification levels are useful for the evaluation of seismic hazard to different-story buildings in the region. The spectral amplification levels for the low story buildings are high toward the eastern side and in small pockets in between as well. A high level of amplification is especially near station Tejpur, Kohima, Jorhat, Tinsukia which lies within the Brahmaputra valley region. For tall buildings (like residential and commercial towers), the spectral amplification levels are higher in small pockets towards northern and eastern sides especially in Tejpur, Jorhat, Itanagar, and Tinsukia regions and decrease towards the south of this region. These maps are useful for evaluating the seismic hazard for various types of buildings in the study region and also for the construction engineers to design new buildings.