Search

Seismic risk assessment requires fragility functions derived using non-linear time-history analysis with earthquake records compatible with the site hazard and characterised via a suitable intensity measure (IM), which poses a challenge given the wide variety of structural characteristics found in bridge inventories. Given the lack of consensus on a suitable IM, regional studies often use peak ground acceleration (PGA), which despite being recognized as a poor indicator of structural performance, has persisted in earthquake response characterisation. Average spectral acceleration (AvgSa) has recently gained popularity since it describes earthquake intensity over a range of pertinent periods of vibration; however, its suitability as an IM has not been demonstrated on real bridge inventories with a wide variety of structural characteristics. In this study, hazard-consistent records selected for both PGA and AvgSa are used to evaluate the response of a large inventory of existing bridges with varying structural characteristics, from the Italian roadway network. The results indicate that AvgSa is a more accurate IM compared to PGA when applied to the regional assessment of RC bridges. [ABSTRACT FROM AUTHOR]

The article focuses on the gender disparity in the sciences, highlighting that women make up less than 30 present of researchers worldwide and face biases that deter them from STEM fields. Topics include the promotion of gender equality through a collection of research papers on geohazards and georisks, the call for inclusive language in geoscience to address the gender gap, and advancements in seismology that incorporate site-specific data to improve hazard predictions.

A probabilistic seismic hazard analysis has been performed to compute probabilistic seismic hazard maps for the eastern Caribbean region (10° N-19° N, 59° W-64° W), which includes in the north the Leeward Islands (from Anguilla to Dominica) and in the south the Windward Islands (from Martinique to Grenada), Barbados, Trinidad, and Tobago. The analysis has been conducted using a standard logic-tree approach that allowed systematically taking into account the model-based (i.e., epistemic) uncertainty and its influence on the computed ground motion parameters. Hazard computations have been performed using a grid of sites with a space resolution of 0.025 degrees covering the territory of the considered islands. Two different computation methodologies have been adopted: the standard Cornell-McGuire approach (Cornell, 1968; McGuire, 1976) based on the definition of appropriate seismogenic zones (SZ), and the zone-free approach developed by Woo (1996), which overcomes the ambiguities related with the definition of seismic sources. The interplay and complexities between shallow crustal, intraplate, and interface subduction seismicity of the Caribbean region have been thoroughly investigated. By merging all available databases, a comprehensive and updated earthquake catalog for the region has been compiled. Also, a thorough investigation has been undertaken to identify the most suitable ground motion prediction equations to be used in the analyses. Uniform hazard spectra have been calculated for the horizontal component of ground motion (rock and level site conditions), 4 return periods (RP) (95-, 475-, 975-, and 2475-yr), and 22 spectral accelerations (SA) with structural periods ranging from 0 to 3 s. SAs at 0.2 and 1.0 s for 2475-yr RP have been calculated to allow the definition of seismic hazard in the region of study according to the International Building Code (IBC, International Code Council [ICC], 2009). [ABSTRACT FROM AUTHOR]

This paper presents a geospatial methodology for zoning the earthquake-induced soil liquefaction risk at a continental scale and set-up in a Geographic Information System (GIS) environment by coupling data-driven and knowledge-driven approaches. It is worth mentioning that liquefaction is a phenomenon of soil instability occurring at a very local spatial scale; thus, the mega-zonation of liquefaction risk at a continental scale is a hard facing challenge. Since the risk from natural disasters is the convolution of hazard, vulnerability, and exposure, the liquefaction risk mapping is based on the combination of geospatial explanatory variables, available at the continental scale, of the previously listed three assumed independent random variables. First, by applying a prediction model calibrated for Europe, the probability of liquefaction is mapped for the whole continent. Then, the Analytical Hierarchy Process (AHP) is adopted to identify areas that have a high risk of liquefaction, taking into account proxy data for exposure. The maps are computed for different levels of severity of ground shaking specified by three return periods (i.e., 475, 975, and 2475 years). A broad variety of stakeholders would benefit from the outcomes of this study, such as civil protection organizations, insurance and re-insurance companies, and infrastructure operators. [ABSTRACT FROM AUTHOR]