Seismic Emergency Research Articles

Scenario-based seismic hazard for horizontal and vertical ground motions in central Italy

We propose an innovative methodology for seismic emergency planning and earthquake risk mitigation in central Italy by integrating three prototypal earthquake scenarios. The different scenarios derive maximum earthquake magnitudes from different input data. The first scenario utilizes local rheological, geological, and geophysical conditions; the second scenario considers the study area fault characteristics, while the third scenario relies on the cluster analysis of historical and instrumental earthquake records. The magnitudes and related uncertainties are combined using a conflation method to derive the expected ground motions for a grid of sites in central Italy. The resulting scenarios include peak ground acceleration and spectral ordinates, presented as maps and spectra for two selected localities. The vertical component of ground motion is also presented, because it is essential for accurately assessing the response of short-period structures. Our methodology complements the more classic seismic hazard analyses, offering additional insights for earthquake contingency planning and loss analysis. The proposed methodology is flexible; multiple models and ongoing advancements in scenario practice (near-field effects, vertical ground motion, and the choice of ground motion models) can be easily incorporated, increasing the effectiveness of seismic scenario modeling in seismic emergency planning and risk mitigation.

Enhancing Buildings’ Energy Resilience by Dynamic Seismic Emergency Inspection and Restoration Scheduling in Multiple Systems

Buildings’ energy resilience in natural disasters is reliant on the support of the functionalities of critical infrastructure that the buildings connect to, such as highway-bridge and electric power systems. Meanwhile, as critical infrastructure systems have increasingly become interconnected and interdependent, they are more susceptible to natural hazards and less able to withstand their effects. Insufficient research has been conducted regarding computational models of effectively representing the interdependencies and interactions involved in the restoration scheduling of post-disaster critical infrastructure systems. To address this research gap, this study proposes integer programs, integrating hybrid genetic algorithms, to explicitly investigate the impact of interactions and interdependencies between electric power systems (EPSs) and highway-bridge systems (HBSs) on the energy-recovery processes of buildings. The objective is to dynamically prioritize the restoration scheduling for EPSs and HBSs while considering inspection and restoration activities. A case study based on the 2008 Wenchuan Earthquake in Sichuan province, China, is employed to validate the efficacy of the proposed method. The results of the analysis reveal that the dynamic model exhibits a substantial 6.4% improvement in building energy resilience at the seven-day mark, compared to the static model. Moreover, the proposed coupled EPS–HBS inspection–restoration joint model outperforms a disjoint EPS inspection–restoration scheduling model, yielding a remarkable 11.4% enhancement in system resilience at the seven-day mark. These findings underscore the significance of considering interdependencies and interactions within critical infrastructure systems to enhance the energy resilience of buildings in earthquake-affected areas.

Adolescents’ Responses to the 2017 Puebla Earthquake in Mexico City

This paper presents the results of a cross-sectional study on adolescents’ behavioral and emotional reactions during and immediately after the 2017 Puebla earthquake that occurred in Mexico City. Convenience sampling was used to achieve a sample size of n=362. Some of the key findings are as follows: a) some 57.0% of adolescent women and over 60.0% of men “ran out of the building” during the earthquake; only 17.4% of women and 14.2% of men took shelter. Early and late adolescent women were significantly associated with building “evacuation” immediately after the earthquake. b) Early and late adolescent men were “surprised” by the earthquake occurrence. c) The perceived vulnerability of the city (PVC) was significantly associated with men but not with women. d) Adolescents exhibited strong information-seeking behavior regarding seismic risk. The results of the study highlight a lack of adolescents’ preparedness for earthquakes in terms of the protective actions taken during the ground shaking and knowledge of the functioning of the Mexican seismic alert system. An educational program aimed at better educating and preparing adolescents for a seismic emergency should be implemented in preparatory schools.

Intelligent Recognition of Key Earthquake Emergency Chinese Information Based on the Optimized BERT-BiLSTM-CRF Algorithm

To address the problems of the text of earthquake emergency information keeps changing incrementally with the time of an earthquake’s occurrence and there being more and more information categories, thus making it difficult to identify earthquake emergency key information, this paper proposes an intelligent recognition algorithm of earthquake emergency information based on the optimized BERT-BiLSTM-CRF algorithm. Based on the historical seismic emergency information dataset of the past 10 years, first, the BIO sequence labeling method is used to classify the seismic entities, and the BERT pretraining model is constructed to represent the seismic emergency text with sentence-level feature vectors. The BiLSTM algorithm is used to obtain the contextual information of the bidirectional seismic emergency text, and we introduce the attention mechanism to enhance the recognition effect of the seismic emergency key information in the statements. Finally, we use conditional randomization to enhance the recognition of earthquake emergency key information in the utterance. The conditional randomization algorithm is applied to extract the dependency relationship between adjacent vectors and improve the accuracy identification to realize the intelligent recognition of earthquake emergency information. The experimental results show that our model can extract earthquake emergency information from online media efficiently and accurately, with better performance than other baseline models.

Securing the church of Madonna del Sole during the emergency phase of 2016 earthquake: interoperability of different actors as an instrument for reducing seismic risk of damaged built heritage

Potential damage from seismic risk is particularly high for historic buildings, as it can produce an irreversible loss of value and sense, not only concerning the material meaning but also the intangible one. Undoubtedly, the best strategy to reduce seismic risk of the built heritage consists in assessing and reducing vulnerability. In any case, it is not always possible to early intervene on historic buildings to improve seismic performance, neither it is possible to change or to completely remove some external factors (i.e., the hazard exposure due to local geotechnical features), nor to avoid that aftershocks increase the damage produced by the first event. On the contrary, it is possible to reduce the level of seismic risk for buildings also resorting to the coping capacity of a society, improving the effective reaction that authorities can oppose to a hazardous event, such as an earthquake, already during the emergency phase. This capacity, or preparedness to risk, applies also to the protection of damaged cultural heritage and particularly to churches, which constitute one of the most vulnerable typologies of historic buildings, due mainly to their shape and constructive characteristics.Recent seismic events have clearly shown that during the emergency phase which immediately follows an earthquake it is still possible to intervene on historic buildings, in order to limit the progress of damage. During a seismic emergency the protection of Cultural Heritage is in charge to public Agencies: the cooperation among them plays an essential role, as well as does the knowledge both of the buildings and of their vulnerability, or the technical ability to properly intervene in order to stop the progress of damage.This paper shows how interoperability in preparedness to risk can be effectively developed among the different actors involved in the protection of cultural heritage during the post-earthquake emergency phase. The study refers to the case of the church of “Madonna del Sole” in Capodacqua (AP), a hamlet in the heart of the Sibillini Mountains. This case study well demonstrates the importance of preparedness to risk, since a prompt reaction can effectively reduce negative consequences on the built heritage; at the same time, it shows the benefit of achieving a good interoperability of all the actors involved in the protection of cultural heritage during the emergency phase, as they can significatively increase the residual safety of damaged historic buildings.

A seismic emergency performance optimization model for infrastructure systems under demand differences: A case study in China

AbstractInfrastructure systems play a crucial role in ensuring the safety of cities and the well‐being of residents after earthquakes. Meanwhile, infrastructure systems are vulnerable to earthquakes and may fail to provide necessary services, highlighting the significant need to improve seismic emergency performance. Nevertheless, the seismic emergency performance of infrastructure systems still lacks effective enhancement strategies and optimization models, which makes it challenging to devise and benchmark appropriate emergency enhancement actions. This study proposes an emergency performance optimization model for infrastructure systems against earthquakes. The model aims at maximizing the effects of resistance actions and short‐term recovery actions on infrastructure systems with consideration of residents' expectations of infrastructure performance after earthquakes. The efficacy of the proposed model is tested by a case study in China. Experiments and results illustrate advantages of the seismic emergency performance optimization and prioritize resistance and short‐term recovery activities within constraints set by available resources.

Dynamic Identification on an Irregular Structure

This paper presents the experimental analysis on the “Municipal Headquarters” of Palagianello Town. This is a strategic building with a high complexity at planimetric and altimetric level, so it is interesting the evaluation of its structural dynamic performance in case of seismic emergency management. To this aim, environmental vibrations have been acquired in situ and accelerometers have been positioned in well-defined points. The data were analyzed with an easy and accurate process that includes the Operational Modal Analysis (OMA), to identify the natural frequencies, the mode shapes and the damping ratios with non-destructive testings. Subsequently, the experimental results were compared with those of two numerical models (with and without infill walls) defined by means of the finite element method (FEM); this allowed for better calibration of the model and to arrive at more realistic conclusions about the behavior of the structure. The paper discusses the influence of the stiffness contribution of masonry infills on the dynamic properties of the building. Moreover, it shows that the adoption of ad hoc chosen locations of the sensors could influence the accuracy of the experimental results, especially for structures characterized by irregularities.

Emotional and behavioural responses to the 19 September 2017 earthquake: the case of the occupants of three multi-storey buildings

PurposeStudies on human behaviour during a seismic emergency in tall buildings are scant. During such emergencies, occupants need to reach a safe place. The purpose of this paper is to address some of the emotional and behavioural responses of the occupants of three multi-storey buildings during the 19 September earthquake that hit Mexico City in 2017.Design/methodology/approachA cross-sectional and non-probability study was conducted using a questionnaire-based survey; the sample size was n = 352, and the study was conducted from 4 October to 20 November 2017.Findings(1) In the 11 storey-building, women, age (18–49 years old [yo]) and participants with higher education exhibited flight behaviour, and those of the six storey-building within the age category 18–49 yo also exhibited a similar behaviour; (2) Women and age (18–49 yo) in the six and 11-storey buildings were significantly associated with fear of the earthquake; (3) Women were significantly more fearful and felt more intense the tremors than men in the 11-storey building; (4) Women were significantly more fearful of the 11-storey building collapsing; (5) The taller the building, the more fearful were the occupants of the building collapsing.Research limitations/implicationsFirst, the sample considered in the study was no probability; consequently, the results should not be generalised to the existing high-rising buildings in Mexico City. Second, some of the variables considered herein were of the Likert-type scale but have been assumed as continuous; in fact, some future work could be the design of a valid and reliable questionnaire to address human behaviour during earthquakes in tall buildings.Practical implicationsThe presented results may be the great value to key decision-makers on how to address the lack of earthquake preparedness during a seismic emergency. Further, the results have shed light on the negative emotions (fear) experienced by the occupants of tall buildings.Social implicationsGaining a better understanding of human behavioural in tall buildings is essential in devising measures to mitigate the impact of earthquake disasters.Originality/valueResearch on human behaviour during a seismic emergency in high-rise buildings is scant. To gain a better understanding of human emotional and behavioural response to earthquakes in tall buildings, it becomes necessary to conduct research such as the present case study. This may help decision-makers to devise measures so that the impact of earthquake disasters may be limited.

An assessment of physical aspects for seismic response capacity in Dhaka, Bangladesh

Bangladesh's geology puts it at high risk of earthquakes. The extremely high population and building density of the capital city, Dhaka, make it especially vulnerable to earthquakes in terms of emergency risk responses such as evacuation and rescue. This study aims to analyze the physical seismic emergency response capacity in Dhaka, thereby identifying areas that lack emergency seismic response capacity and require mitigation measures. Five indicators, rescue and evacuation accessibility, emergency evacuation capacity in open space, rescue capacity by firefighters and community volunteers, availability of emergency medical facilities, and evacuation capacity of temporary shelters, are developed for the assessment. Using RAJUK's GIS data, the accessible area, which shows the ease of rescuers' accessibility and evacuation, is calculated based on road width. Furthermore, calculations are also conducted of the population coverage ratio in each grid by each emergency facility, open spaces as evacuation space, fire stations, medical facilities, and public buildings as temporary shelters. The five maps showing the risk level for each indicator are developed. These indices are combined, and the comprehensive emergency response capacity is assessed, while the comprehensive risk map is developed. The assessment shows that the western part and the northern part have high-risk areas facing emergency response difficulties. In contrast, areas in the inner part of the city are at lower risk. To verify the assessment results, a questionnaire survey was conducted to determine experts' perceptions of high-risk and low-risk areas in terms of emergency response capacity. The results of the assessment were compared to experts' perceptions. Most of the assessments were similar to the experts' perceptions, but there were some inconsistencies. Some of the inconsistencies are likely due to misconceptions by the experts, but others likely stem from our use of non-updated data and calculation methods. In conclusion, some recommendations for improving the assessment are proposed.

The value of structural health monitoring in seismic emergency management of bridges

The management of civil infrastructures in the aftermath of a seismic event is a concern for decision makers, which have to choose quickly among alternative actions with limited knowledge on the actual structural conditions. The availability of real time Structural Health Monitoring (SHM) data on the asset might be particularly useful. However, SHM data are not collected for free, and the cost of the SHM system should be compared with its associated benefit. A powerful tool to estimate such benefit is the Value of Information (VoI) from Bayesian decision theory. This paper provides a methodology to compute the VoI of SHM for seismic emergency management of roadway bridges. This methodology can be used by decision makers before the installation of a seismic SHM system to quantify the cost benefit of doing so and thus optimize the allocation of economic resources. Results show that the VoI is high when the expected costs of the decision alternatives (such as ‘keep the bridge open’ or ‘close the bridge’) evaluated without the SHM information are comparable. In this condition, which is highly dependent on the seismic hazard and on emergency management costs at stake, the SHM information provides the maximum support to decision making.

Development of quasi real-time comprehensive evaluation system for earthquake disaster

Fast acquisition of the seismic information and accurate assessment of the earthquake disaster is the key problem for emergency rescue after a destructive earthquake. In order to satisfy the requirements of the earthquake emergency response and rescue for the cities and counties, a quasi real-time comprehensive evaluation system for earthquake disaster is developed. This software system has the functions of gathering disaster information, analyzing seismic damage and estimating disaster extent. To prop up such a powerful software platform, data and algorithms are prerequisites. As a result, Micro-Electro-Mechanical System (MEMS) is developed to monitor strong motion underground, application programs for data collection by the mobile terminal are also developed to acquire the basic structural data and disaster information. Besides, based on short-distance emergency communication technology, a set of short-distance multi-modes are designed to transmit those critical data to the evaluation system. After a certain earthquake, using fragility analysis method and dynamic correction algorithm, together with the basic data, seismic disaster evaluation in the county region is finally realized in real-time to provide a scientific basis for seismic emergency command, rescue and assistant decision.

SEPM: rapid seism emergency information processing based on social media

With the development of network communication technology and the popularity of social media tools, earthquake-related information has been easily published and disseminated in social networks. This study focuses on obtaining this information and providing guidance for earthquake emergency work. A processing model is proposed to obtain earthquake information from social networks. First, a configuration-driven data acquisition module is designed to acquire earthquake information. Second, according to the characteristics of earthquake information in social media, a seismic emergency thesaurus is selected, and weight is calculated. To solve the low accuracy of inter-class classification, an improved mutual term frequency–inverse document frequency (MTF–IDF) algorithm is proposed. Finally, the thesaurus database is used to classify the acquired earthquake information. By taking the Lushan and Jiuzhaigou earthquakes as examples, the improved MTF–IDF algorithm shows a better effect on the selection of seismic keywords than the traditional TF–IDF algorithm; the F1-measure in classification has increased from 79.86 to 86.93%. The proposed model can rapidly and easily acquire and classify earthquake information according to different sources, which can provide timely information and support for disaster relief.

Mexico city’s residents emotional and behavioural reactions to the 19 September 2017 earthquake

The paper presents the results of a cross-sectional study conducted in Mexico City following the earthquake that occurred on September 19, 2017. The sample size of the study was N = 2400. The aim has been the study of people's emotional and behavioural responses during and immediately after the tremors. Some of the results and conclusions were the following: a). During the tremors, respondents coping reactions were related to escape, reaching and protecting people, and seeking shelter; b). The actions taken by the respondents immediately after the tremor were reuniting with family members, evacuation, and returning to houses; c). The emotional responses of the participants of the study were fear and surprise; d). The capital city's residents exhibited a relatively high percentage of prosocial behaviour during the seismic emergency response; e). More generally, the residents of the city should be trained on what to do during and after the tremors; moreover, key decision-makers should consider people's emotional and behavioural responses to tremors when designing plans for mass emergencies following earthquakes, such as the present case study.

Seismic emergency system evaluation: The role of seismic hazard and local effects

The emergency management system is a complex network consisting of structural components, such as buildings, infrastructure and emergency areas, and non-structural elements, such as procedures, emergency workers, information management, etc. This document describes the evaluation of only its structural components. The system was adopted at the territorial scale and is defined by a multi-municipality area extension. This paper presents a methodology for the probabilistic evaluation of operating the emergency structural system in the case of a seismic event occurrence and, in detail, it highlights the methodology for calculating the seismic hazard including seismic local effects (amplification and permanent co-seismic effects). Systemic seismic risk and associated impact were considered in a rigorous and unified way. Moreover, the importance of the interconnection and interdependence between elements at risk belonging to the same system and between different networks at urban or territorial scales is well known. The aim of the proposed methodology is to evaluate the operational losses of an emergency system considering the connections between the components of the system, contributing, in an original way, to the estimation of the seismic effects. The fundamental characteristics of this calculation are:•Estimating ground motion amplification at the territorial scale using a Vs30 from a probabilistic map obtained with the seismic microzonation national database;•Estimating shaking scenarios in terms of PGA and PGV depending on the Vs30;•Co-seismic permanent failure and deformations (landslide and liquefaction) evaluated with regression logistic methods.Finally, a case study is presented showing the application of the methodology on a real emergency system in an area of southern Italy.

Scenario-based seismic vulnerability and hazard analyses to help direct disaster risk reduction in rural Weinan, China

Seismic vulnerability and hazard analyses play a significant role in comprehensive risk mitigation and seismic emergency planning, especially for the rural Weinan prefecture in northwestern China with a complex construction infrastructure and a high population density. Traditional methods assessing potential physical seismic damage prior to an earthquake are providing an incomplete picture for seismic risk assessments and post-disaster situations, and are insufficient for local authorities to plan mitigation strategies effectively. This study presents a novel perspective on scenario-based seismic vulnerability and hazard assessment. First, an in situ survey was carried out in three villages, Helan, Zhaojia, and Dongyu Village in the plain, loess, and mountain area respectively. Then, a quantitative analysis of building vulnerability and associated human homelessness under different seismic intensities was conducted based on the RISK-UE vulnerability index method. Finally, we estimated and analyzed other seismic impact scenarios. Results showed that the mean building vulnerability index is 0.69, 0.70, and 0.76 for Helan, Zhaojia, and Dongyu Village, respectively. Considering the possible displaced populations, Dongyu Village will have the highest proportion of homeless people. If an earthquake causes intensity greater than VII, Dongyu Village would suffer landslides and isolated-communication. The residents would have to rely on self-rescue and mutual rescue. These findings can be a potential guide to decision making in disaster risk reduction in rural Weinan.

Urban Seismic Networks, Structural Health and Cultural Heritage Monitoring: The National Earthquakes Observatory (INGV, Italy) Experience

An effective reduction of seismic risk can implement through a multiscale approach to the earthquakes monitoring. Devoted monitoring network are essential to cope with the seismic emergency in urban areas, to assess the damage scenarios, which are useful for the preservation of the strategic functions and services and to improve the community resilience to earthquakes. The National Earthquake Observatory, Italian Institute for Geophysics and Volcanology (ONT-INGV, Italy), has been recently involved in several projects devoted to the reduction of seismic risk by means of the implementation of urban-scale and building-scale monitoring networks. Such systems represent a necessary support for the well-established national seismic network. All these approaches (country, urban, and building scale) could be framed within of a unique system in which each part holds different tasks, with the common final objective of the earthquake risk reduction. In this papers different approaches, experiences and potential capabilities on urban seismic networks, structural health and cultural heritage monitoring implemented in Italy by the ONT-INGV will be presented, with the ultimate goal of achieving an effective integrated multi-scale system.

The Use of UAVs for Performing Safety-Related Tasks at Post-Disaster and Non-Critical Construction Sites

Thanks to the wide diffusion of unmanned aerial vehicles (UAVs), geomatics solutions have actively contributed to the field of safety enhancement and disaster risk reduction, supporting rapid mapping and documentation activities of the damages that have occurred to heritage buildings after natural disasters (such as earthquakes) where, in this scenario it is even more important to plan and execute disaster assessment and response operations in safe conditions. In fact, the planning and execution of technical countermeasures in a seismic emergency response involve higher risks for the safety of the operators as compared with responses related to the activities performed at non-critical construction sites. After an analysis of the state of the art, this study aims to underline the possibilities offered by the use of UAVs for performing safety-related tasks, both at post-disaster and non-critical construction sites. First, a survey has been conducted concerning the main user expectations and characteristics that an ideal UAV platform should have in order to perform safety-related tasks at construction sites that are created following the initial emergency phases. The answers that were obtained have been compared with similar studies retrieved from the literature validating previously conducted research. The legislative context is also considered, as it is an important factor that influences the applicability of these platforms and technology. Along with a method for assessing and mitigating the intrinsic risk of using an UAV, the results of a survey submitted to experts in the field of safety at construction sites is also discussed, intending to identify requirements of the ideal platform and the related user expectations. The results are reported, together with a summary of considerations on the use of these strategies in the analyzed contexts.

Temporary dense seismic network during the 2016 Central Italy seismic emergency for microzonation studies

In August 2016, a magnitude 6.0 earthquake struck Central Italy, starting a devastating seismic sequence, aggravated by other two events of magnitude 5.9 and 6.5, respectively. After the first mainshock, four Italian institutions installed a dense temporary network of 50 seismic stations in an area of 260 km2. The network was registered in the International Federation of Digital Seismograph Networks with the code 3A and quoted with a Digital Object Identifier (https://doi.org/10.13127/SD/ku7Xm12Yy9). Raw data were converted into the standard binary miniSEED format, and organized in a structured archive. Then, data quality and completeness were checked, and all the relevant information was used for creating the metadata volumes. Finally, the 99 Gb of continuous seismic data and metadata were uploaded into the INGV node of the European Integrated Data Archive repository. Their use was regulated by a Memorandum of Understanding between the institutions. After an embargo period, the data are now available for many different seismological studies.

Sustainable planning of seismic emergency in historic centres through semeiotic tools: Comparison of different existing methods through real case studies

Sustainable cities have to constantly face natural catastrophes, and planning actions should be oriented to quickly manage emergency conditions. Earthquake represents one of the most critical disasters. Earthquake-induced built environment modifications (i.e. building debris) affect the urban paths network availability. Historic centres are relevant scenarios because of their specific features (i.e. Heritage vulnerability; complex and compact fabric). Predicting which paths could be used by rescuers to rapidly reach damaged inhabitants could reduce losses and improve first aid actions. Sustainable semeiotic tools are proposed to quickly esteem the paths availability combining street geometrical features and building damages. Currently, no study provides insights on methods reliability. Hence, this work critically analyses methods outcomes by implementing them, for the first time, on the same real-world sample (Italian historic centres). Rapid tools (satellite images, photographic documentation) are used to compare methods previsions with effective post-earthquake paths availability. Pros and cons of each analysed method are evidenced, underlining that the approach that combines street-building geometry, building vulnerability and earthquake severity seems to give the best results. This could help Local Authorities and Civil Protection Bodies in better developing risk-mitigation strategies concerning, e.g., emergency management (rescuers’ access routes definition) and urban planning (building retrofitting interventions).

How useful are earthquake early warnings? The case of the 2017 earthquakes in Mexico city

The paper presents the results of a cross-sectional study regarding participants' perception on the SASMEX system performance following the two earthquakes that hit Mexico City on 7 and 19 September in 2017. The approach has been the application of questionnaires to a sample size of n = 2400. The survey was conducted from 4 October-20 November 2017. The questions included in the questionnaire were based on the criteria of the effectiveness of early warning systems proposed by the United Nations-International Strategy for Disaster Reduction (UN-ISDR). Some of the key conclusions were the following: {a}. Deficiencies have been highlighted in relation to ‘risk knowledge’, ‘monitoring and warning’, ‘dissemination & communication’, and ‘response capability’ of the system; {b}. The results have highlighted the need to issue the warning time to the residents of the city (i.e., the time between the moment the siren sounds and the actual ground shaking); knowing the warning time may be of great value to people during the seismic emergency, at least for the case of Mexico City, however, this may require further research; {c}. More generally, the SASMEX and any earthquake early warning (EEW) system should be people-centred.