Fig 2 - uploaded by A. Carvalho
Content may be subject to copyright.
Source publication
Decisions to mitigate seismic risk require a consistent approach to evaluate the effects of future earthquakes on population,
on civil engineering structures and infra- structures. The mathematical and probabilistic methods that are the support to
those approaches are generally called Risk Analysis; in the particular case of seismic events and miti...
Contexts in source publication
Context 1
... geographic location of MAL in Portuguese mainland territory is presented in Fig. 2, together with its global statistics, regarding inhabitants, residential buildings and econom- ics. Characteristics of building stock and their inhabitants were surveyed in the Portuguese Censos 2001 (INE ...
Context 2
... per typological class (graph on the left), and for the total building stock (graph on the right). From the analysis of those graphs it can be concluded that: (1) unreinforced brittle masonry building structures, built before 1960 and between 1961 and 1985, representing around 22% of the total asset of MAL residential building stock (11%+11% see Fig. 2), constitute the larger risk being responsible for 36% of the total economic risk; (2) non ductile RC residential buildings, built between 1961 and 1985, representing around 34% of the total asset of MAL residential building stock (see Fig. 2) constitute the second larger risk averaging all return periods, being responsible for 20% of ...
Context 3
... 1961 and 1985, representing around 22% of the total asset of MAL residential building stock (11%+11% see Fig. 2), constitute the larger risk being responsible for 36% of the total economic risk; (2) non ductile RC residential buildings, built between 1961 and 1985, representing around 34% of the total asset of MAL residential building stock (see Fig. 2) constitute the second larger risk averaging all return periods, being responsible for 20% of the total economic risk; (3) adobe and rubble stone building structures represent only a marginal contribution to the total economic risk of MAL, because of the small exposure of this ...
Similar publications
A major challenge in deep and high stress mining is managing seismic risk associated with blasting of production stopes and drift development to access the ore zones. The location, magnitude, and frequency of occurrence of seismic events are influenced by changes in stress, lithology, structure, and mining sequence rock properties such as brittlene...
The Gulf of Corinth is considered to be one of the most active tectonic rifts around the world. The high level of seismicity and the quaternary local faulting imply that it is a key place in Europe for the study of various physical processes related to the origin of earthquakes. Mean extension rates of the gulf are significantly high in a NNE-SSW d...
The eastern margin of Tibetan Plateau is one of the most active zones of tectonic deformation and seismicity in China. To monitor strain buildup and benefit seismic risk assessment, we constructed 14 survey-mode global position system (GPS) stations throughout the northwest of Longmenshan fault. A new GPS field over 1999–2011 is derived from measur...
In the Netherlands, seismicity is induced by the reactivation of faults because of the extraction of gas. The Dutch mining law requires a seismic-risk assessment as part of the license application process. For this purpose, a risk-assessment guideline has been developed over the past decade. The guideline contains three assessment levels. At the fi...
One of the key objectives of the new EU civil protection mechanism is an enhanced understanding of risks the EU is facing. Developing a European perspective may create significant opportunities of successfully combining resources for the common objective of preventing and mitigating shared risks. Risk assessments and mapping represent the first ste...
Citations
... The regional agglomerations are exposed to a terrible seismic risk, which lead to potential economic losses and casualties (Boukri et al. 2018). It appears worth to develop the seismic risk assessment and mitigation, to employ tools of analysis and lead actions for effective preventions at human and economic levels (Costa et al. 2010;Erdik 2017a;Smerzini and Pitilakis 2018). Therefore, the regional seismic risk assessment has become a world concern and plays an important role in the disaster prevention and mitigation (Boukri et al. 2018). ...
The regional seismic risk assessment plays an important role in the disaster prevention and mitigation. The accurate time-history analysis for a region provides an important data base for regional seismic risk assessment. However, an accurate calculation method is limited, then, its accuracy still lacks validation. Meanwhile, there is also a lack of risk assessment methods and indicators applicable to the regional accurate time-history analysis, both of which hinder the seismic risk assessment. In this paper, a regional-scale time history analysis-driven method is proposed for the quantitative evaluation of regional seismic damage risk and verified with a real earthquake damage survey. First, the regional time history analysis method is introduced, including the automatic modeling, response calculating, result analysis and 3-D visualization modules. Second, a calculation method for seismic damage degrees (DD) of buildings is introduced. Subsequently, the probabilistic models of each DD under the ground motions with a specific intensity are calculated based on regional-scale nonlinear time history analysis. Next, the concept of the three-level seismic damage risk is offered, then a determining workflow of seismic damage risks is proposed based on the code-abiding three-level design requirement. Afterward, the regional seismic damage index is suggested for the quantitative evaluation of earthquake-induced damage risk. Finally, the actual seismic damage database of 192 buildings in epicenter of Ludian Earthquake is established through on-site investigations, then used to verify the regional simulation’s accuracy. Consequently, it could be an aid to accurately present seismic damage distribution assessments and effectively develop seismic risk mitigation strategies.
... Post-disaster states are often assessed at a single point in time rather than longitudinally to provide a temporal assessment of the evolution of data availability over time. One reason for this state of practice is that most studies focusing on infrastructure resilience tackle the problem either before the damage assessment, i.e. optimizing mitigation strategies (Abruzzo et al. 2006;Costa et al. 2010;Yildirim and Demir 2021), or shortly thereafter, i.e. prioritizing recovery tasks (Gonz alez et al. 2016;Rouhanizadeh et al. 2020;Ghannad et al. 2021). The former includes major uncertainty on the expected damage to structures and lifelines. ...
Assessing damage to civil infrastructure is a resource-intensive process that is critical during the response to a disaster. Various datasets facilitate this process but are often collected on an individual ad hoc basis by multiple separate entities. Consequently, there is a lack of a coordinated approach when collecting disaster data, which prevents effective data interoperability. Rather than viewing datasets individually, this paper provides a comprehensive analysis of post-disaster damage data to demonstrate the merits of a dynamic data collection process accounting for both spatial and temporal variations. Specifically, datasets from Hurricane Maria and the Indios Earthquake in Puerto Rico are used to illustrate the entities involved, resources used, and resulting datasets for this purpose. The paper analyzes the evolution of key metadata features as a function of time, including data availability, coverage, and resolution. The results show distinct stages of the data collection process and reveal challenges in collaboration between entities and a lack of data integration for disaster response. The findings also lead to recommendations about the essential metadata for increased shareability. With these outcomes, entities in the field can improve the quality of information extracted and facilitate interoperability and information integration across datasets for damage assessment.
... Several empirical and analytical studies have highlighted the high seismic vulnerability of this type of construction [6][7][8][9][10][11][12], mainly due to the low tensile strength, high specific weight, poor wall-to-wall and wall-to-slab connections, structural irregularities in height and plan, and the lack of maintenance. Most of the masonry buildings were constructed without seismic provisions or under old design codes that covered only gravity loads [13]. ...
According to the 2011 National Housing Census, masonry buildings comprise more than 50% of the Portuguese building stock. This type of construction has demonstrated a poor performance during the destructive events that struck Portugal in the last century (e.g., 1909 M6.3 Benavente, 1969 M7.8 Algarve, 1980 M6.9 Azores). While some efforts have been made towards the vulnerability assessment of individual masonry buildings or the residential building stock at the national scale, this building class has been the target of limited research. In this study, a comprehensive database of material and geometric properties of granite and limestone buildings was used to generate complex 3D numerical models. These models were subjected to nonlinear time history analysis to derive fragility curves considering the record-to-record and building-to-building variability. The structural damage was defined using two novel engineering demand parameters, and the resulting fragility functions were compared against other existing models. These results can be used directly to generate earthquake scenarios at the country scale or in probabilistic seismic risk analysis to identify regions where risk reduction measures should be prioritized.
... Secondly, the seismic vulnerability and collapse of the masonry building (Pinho et al. 2006;FEMA. 2009;Costa et al. 2010;Kassem et al. 2020;Chettri et al. 2022;Gautam 2018, Gautam et al. 2021 determines the available safety escape time (ASET). It will be estimated by structure deformations, strength, or stability under an earthquake. ...
To predict the number of casualties in dwellings when a strong earthquake occurs, this paper investigated the seismic performances of masonry buildings located in a rural town where earthquake occurs frequently with high earthquakes. The incremental dynamic analysis method was employed to estimate the available escape time and the collapse probability of building under those selected ground motions with a series of peak accelerations. Meanwhile, the required safety escape time of the building was obtained through evacuation simulation analysis. According to the safe evacuation criteria, the probability of casualties in terms of earthquake intensity measure was predicted. The results show that available escape time decreases with the increase of peak ground acceleration level. While the required safety escape time increases with the number of building layers subjoining; residents on the upper floors have a lower probability of escape. The present work implied that the residents on the higher floors must seek temporary security zones in their rooms to reduce casualties.
... This fact has led to an increase in geological hazards and a need for adequate urban planning. In this line, several authors as Campos Costa et al. (2010) and Carvalho et al. (2018) addressed their studies in the LMA from a seismic or soils liquefaction hazards point of view. Other researchers have focused on the flood risk and damage in buildings produced by extreme rainfalls episodes (Leal et al., 2019;Leal et al., 2020). ...
In this doctoral thesis, several A-DInSAR (Advanced Differential SAR Interferometry) techniques have been applied in three areas of Central Asturias (N Spain) and in the Lisbon Metropolitan Area (SW Portugal), to the main aim of detecting, modeling and monitoring of ground motion from January 2018 to February 2020. Specifically, the study areas in Asturias correspond to the Peñas Cape surrounding (including the Podes Peninsula), the Tazones Lighthouse landslide and a mountainous area located in the Central Coal Basin.
The research has involved the following methodological steps: 1) A-DInSAR processing from PSIG and P-SBAS software using three different sets of SAR images: i) 113 SAR images from the Sentinel-1A/B satellites in descending orbit from January 2018 to February 2020; ii) 109 SAR images of Sentinel-1A satellite from January 2018 to April 2020, 48 of them in ascending orbit and 61 SAR images in descending orbit; 2) Obtaining of mean deformation velocity maps in the Line-of-Sight (LOS) direction (mm year−1) and deformation time series (mm); 3) Application of A-DInSAR post-processing methodologies of Active Deformation Areas (ADA tools) to estimate the deformation Vertical - Horizontal components; 4) Integration of all the-information, with geospatial data and topographic measurements taken by total station and validation of the deformations by field campaigns in a Geographic Information System and 5) Interpretation of the results obtained from a geological point of view.
The Peñas Cape environment has shown maximum LOS velocities from −17.1 to 37.4 and −23.0 to 38.3 mm year−1, linked to ground settlements and slope instabilities. In the Tazones Lighthouse landslide, topographic measurements have shown maximum monthly displacements of some points from 1 m to more than 14 m. However, the characteristics of the movement and the nature of the terrain have not allowed to obtain good results through A-DInSAR techniques.
In the sector of the Central Coal Basin, the measured deformations presented maximum LOS velocities of −18.4 and 9.5 mm year−1. These velocities are compatible with subsidence and phreatic level recuperation in an underground coal mining environment. However, these hypotheses could not be corroborated due to the confidentiality of geological-mining data. Deformations related to surficial slope instabilities were also detected.
In the Lisbon Metropolitan Area, 4 ADAs in ascending orbit and 3 ADAs in descending orbit have been related to industrial and urban subsidence, with maximum LOS velocities of −25.5 mm year−1. The maximum measured Vertical velocity was −32.4 mm year−1. The geological and hydrological data allowed to relate this subsidence to continuos compation of alluvial and anthropic deposits.
This research is an important contribution to the knowledge of mass movements at mining and coastal areas in the case of Asturias and at urban environment in the Lisbon Metropolitan Area. Furthermore, the reliability of the P-SBAS processing for ground motion detection and monitoring at regional and local scales has been demonstrated, as well as the usefulness of using A-DInSAR data together with topographic measurements taken in situ.
... Given its location in the western Iberian Peninsula on the Atlantic Ocean, the Lisbon Metropolitan Area is susceptible to offshore earthquakes occurring on the Africa-Eurasia plate boundary, particularly in the Gorringe Bank region (Tang et al., 2012). This region has been affected by severe historical earthquakes, like the emblematic 1755 Lisbon earthquake with Mw = 8.5 − 9.0 (Costa et al., 2009). The seismic hazard in this region has also a contribution of onshore, moderate to strong intraplate earthquakes on inherited crustal fractures like the Lower Tagus Valley fault zone (Vilanova e Fonseca, 2004). ...
... Regarding previous works in LMA, several authors [30,39] have addressed their studies from the seismic hazard and liquefaction soils points of view in recent years. On the other hand, other researchers have focused on the flood risk and damage in buildings produced by extreme rainfalls episodes [34,40]. ...
The Lisbon metropolitan area (LMA, central-west of Portugal) has been severely affected by different geohazards (flooding episodes, landslides, subsidence, and earthquakes) that have generated considerable damage to properties and infrastructures, in the order of millions of euros per year. This study is focused on the analysis of subsidence, as related to urban and industrial activity. Utilizing the A-DInSAR dataset and applying active deformation areas (ADA) processing at the regional scale has allowed us to perform a detailed analysis of subsidence phenomena in the LMA. The dataset consisted of 48 ascending and 61 descending SAR IW-SLC images acquired by the Sentinel-1 A satellite between January 2018 and April 2020. The line-of-sight (LOS), mean deformation velocity (VLOS) maps (mm year−1), and deformation time series (mm) were obtained via the Geohazard Exploitation Platform service of the European Space Agency. The maximum VLOS detected, with ascending and descending datasets, were −38.0 and −32.2 mm year−1, respectively. ADA processing over the LMA allowed for 592 ascending and 560 descending ADAs to be extracted and delimited. From the VLOS measured in both trajectories, a vertical velocity with a maximum value of −32.4 mm year−1 was estimated. The analyzed subsidence was associated to four ascending and three descending ADAs and characterized by maximum VLOS of −25.5 and −25.2 mm year−1. The maximum vertical velocity associated with urban subsidence was −32.4 mm year−1. This subsidence is mainly linked to the compaction of the alluvial and anthropic deposits in the areas where urban and industrial sectors are located. The results of this work have allowed to: (1) detect and assess, from a quantitative point of view, the subsidence phenomena in populated and industrial areas of LMA; (2) establish the relationships between the subsidence phenomena and geological and hydrological characteristics.
... As stated by Costa et al. [15]; a structural system can be improved to resist seismic actions by enhancing its strength (i.e., increasing its base shear capacity), its stiffness, (potentially reducing its displacement demands) or its ductility (i.e., improving its ability to undergo higher displacement demands without collapsing). Therefore, a retrofitting intervention can modify one or a combination of these structural properties to improve the seismic performance. ...
We performed benefit-cost analysis to identify optimum retrofitting interventions for the two most vulnerable building typologies in Central America, unreinforced masonry and adobe, considering the direct costs due to building damage and the indirect costs associated with the injured and fatalities. We reviewed worldwide retrofitting techniques, selected those that could be applied in the region for these building types, and derived vulnerability functions considering the impact of each retrofitting intervention in the strength, stiffness, and ductility of the structures. Probabilistic seismic risk analyses were performed considering the original configuration of each building class, as well as the retrofitted version. We calculated average annual losses to estimate the annual savings due to the different structural interventions, and benefit cost ratios were estimated based on the associated cost of each retrofitting technique. Based on the benefit-cost analyses, for a 50-year time horizon and a 4% discount rate, retrofitting these building classes could be economically viable along the western coast of Central America.
... The importance of both direct and indirect losses in the industrial sector was assessed through seismic risk analyses of PRC industrial buildings in Portugal, following the procedures described in Fig. 1. Notwithstanding the moderate seismicity, there is a high potential of destructive seismic events in some regions in Portugal [22]. Moreover, some of the regions with the highest seismic hazard also present a high concentration of population and economic activity, namely the Metropolitan Area of Lisbon (MAL). ...
Observations from past destructive earthquakes indicate that indirect economic losses can greatly exceed the direct economic losses. However, the influence of indirect losses is often neglected in seismic risk studies due to the complexity associated with their evaluation, as well as the fact that direct losses tend to gather public attention due to human losses and the visual impact of structural damage. This issue is particularly evident in the assessment of indirect losses linked to industrial activities, which can represent a significant portion of the economy. The present study presents a comprehensive framework for the assessment of indirect economic losses based on the impact of business interruption and interdependency between the different economic sectors. The application of the proposed model to precast reinforced concrete buildings constitutes the first seismic risk study of this typology in Portugal, and highlights the critical need to pursue risk mitigation measures to address both the potential direct and indirect effects in the Portuguese economy.
... The methods for developing SLFs of the building structures are divided into two categories: system-level approach and component-level approach. The system-level approach mainly focuses on evaluating seismic losses at the regional level using pre-defined SLFs according to structural systems and heights of the building structures, and HAZUS (FEMA 2003), GEM (Crowley et al. 2013), DAT (Eguchi et al. 1997), and LNECloss (Costa et al. 2010) belong to the system-level approach. The system-level approach is effective at estimating the regional seismic loss for a specific area or a specific scenario (Canuti et al. 2019a(Canuti et al. , 2019bDeBock and Liel 2015;Esmaili, Grant Ludwig, and Zareian 2018;Karaman et al. 2008). ...
In low-to-moderate seismicity regions, seismic loss functions (SLFs) are barely established due to limited observational data, making it difficult to derive decision-making on disaster prevention and management. Herein, a Bayesian framework is developed to update the SLFs with limited observational data. The proposed point-based Bayesian method updates local probability density function parameters for damage ratios at each seismic intensity, which helps to avoid an unrealistic underestimation of damage ratios in the low-to-moderate range of seismic intensities. The feasibility of the developed framework in a low-to-moderate seismicity region is verified by the comparison between the updated SLF and post-event data.
