Risk-Oriented, Bottom-Up Modeling of Building Portfolios With Faceted Taxonomies

Abstract

Earthquake exposure describes the assets that are exposed to seismic activity and are susceptible to be damaged. In seismic risk applications, it mostly refers to the residential and commercial building portfolios, although in general may also include transport infrastructure and lifelines. Providing an efficient description of a complex urban environment in terms of the structural characteristics of buildings related to their seismic vulnerability is challenging, considering the variety of building practices, materials and configurations. A common approach entails the use of pre-defined building typologies, but this may introduce a bias in the resulting models. Faceted taxonomies have been recently introduced to provide a standardized description of buildings using a rich set of basic attributes, but cannot be used directly for risk-related applications. We argue that a bottom-up approach to exposure modeling might prove instrumental in increasing the quality and reliability of risk assessment, and propose hereby a novel score-based methodology to define and assign building classes to unclassified buildings in a sound and transparent way. The approach can be adopted for standard building classifications as well as for original typologies that may be more efficient in capturing the specific features of the building stock. The proposed methodology efficiently decouples the collection of buildings observations, typical of surveying activities, from the assignment of risk-aimed building classes, and provides a useful tool to practitioners and engineers involved in large-scale earthquake risk assessment. The proposed methodology has been exemplified with a building portfolio collected in France near the geothermal plant of Soultz-sous-Fôrets, and is used to rapidly characterize the seismic exposure of a built environment for induced seismicity applications.

A Contribution to a UHS-Based Seismic Risk Assessment in Croatia—A Case Study for the City of Osijek

“…For the large-scale assessments, to demonstrate unambiguously the assignment of a vulnerability model to an individual building, most commonly specific risk-oriented taxonomies are applied [36]. The most prominent taxonomies are PAGER (the abbreviation for "prompt assessment of global earthquakes for response") [37], HAZUS (hazard-US) taxonomy [38], developed originally to describe the USA building stock, RESIS-II building (reducción de Riesgo sísmico en Guatemala, El Salvador y Nicaragua project) [39], EMS-98 (European macroseismic scale 1998) [40], which has been used for seismic risk assessment not only in a few European countries but also in Turkey and in several Central Asian countries.…”

“…On the other hand, more recently, so-called faceted taxonomies were introduced to provide a more standardized description of analyzed buildings based on a more comprehensive set of basic attributes [36]. However, according to Pittore et al [36], these taxonomies cannot be used directly for risk-related exposure models. According to the GEM (global earthquake model), single structures are described in detail from the functional and structural points of view.…”

Development of Seismic Vulnerability and Exposure Models—A Case Study of Croatia

“…Generally, two types of taxonomies can be employed: specific risk-oriented taxonomies or the faceted taxonomies [32] which have been recently developed. Risk-oriented taxonomies are used for large-scale assessments, and their primary goal is to unequivocally assign damage models to particular buildings.…”

“…A faceted taxonomy is made up of a set of taxonomies, and the task of each taxonomy in the set is to describe a particular domain from a different facet (aspect). This taxonomy is characterized by conceptual clarity, compactness, and scalability, the features that have been identified as deficient in the risk-oriented taxonomies [32,39].…”

Flood Vulnerability Assessment of Urban Traditional Buildings in Kuala Lumpur, Malaysia

“…Given the multiscale approach adopted for the assessment of the flood risk in Kampung Baru, data is After detailed data was taken on a small sample of buildings during the field survey which also allowed for identification of buildings' typologies, a further survey based on Google Street View (GSV) was 240 undertaken to gather additional data and cover a sample of buildings in excess of 163. This procedure was successfully used by one of the authors to survey buildings to determine vulnerability and damage in post-earthquake reconnaissance (Stone et al, 2017;Stone et al, 2018), and it is increasingly used to produce exposure databases in an expedient and economic manner (Pittore et al, 2018). In GSV, a continuous series of 360-degree panoramas, created by sewing multiple overlapping photos together to 245 display the real portrayal of a specific location, were observed according to the location and the time of when the photos were captured.…”