Post Earthquake Research Articles

Survivor detection approach for post earthquake search and rescue missions based on deep learning inspired algorithms

Rapid and reliable detection of human survivors trapped under debris is crucial for effective post-earthquake search and rescue (SAR) operations. This paper presents a novel approach to survivor detection using a snake robot equipped with deep learning (DL) based object identification algorithms. We evaluated the performance of three main algorithms: Faster R-CNN, Single Shot MultiBox Detector (SSD), and You Only Look Once (YOLO). While these algorithms are initially trained on the PASCAL VOC 2012 dataset for human identification, we address the lack of a dedicated dataset for trapped individuals by compiling a new dataset of 200 images that specifically depicts this scenario, featuring cluttered environment and occlusion. Our evaluation takes into account detection accuracy, confidence interval, and running time. The results demonstrate that the YOLOv10 algorithm achieves the 98.4 mAP@0.5, accuracy of 98.5% for inference time of 15 ms. We validate the performance of these algorithms using images of human survivors trapped under debris and subjected to various occlusions.

Seismic Performance Analysis of PEC Structures

Partially-Encased Composite Steel and Concrete Members (PEC members for short) consists of H-shaped cross-section of the main steel and concrete filling between the flange and the web, compared with the pure steel structure, the PEC structure has the advantages of high stiffness, high bearing capacity, good fire resistance and so on. The arrival of an earthquake may cause damage to building structures. The use of PEC structures can effectively improve their bearing capacity and seismic performance, and the method of post earthquake repair is relatively easier and more economical. In recent years, PEC components have been gradually popularized and applied in building structures.

Understanding post disaster prosociality: Comparing post earthquake cooperation and fairness in two Italian regions

Natural disasters put an enormous strain on communities' ability to cooperate. Community resilience, which heavily depends on individuals’ prosocial attitudes, reduces the effects of disasters, determining completely different dynamics even in neighboring regions. We designed an exploratory empirical study in which we collected empirical data on behavior in two games together with survey data in seven municipalities located in two Italian regions affected by two major earthquakes. We measured contributions in the Public Goods Game and fairness in a modified Dictator Game, with the aim of testing for the effects of damage suffered, and embeddedness in the community on prosociality. We compared two different explanations, damage suffered and embeddedness, and we concluded that, in our sample, embeddedness was not related to differences in contributions, while damage suffered by the individuals was. This study contributes to the literature on post-disaster prosociality by presenting a unique lab–in-the-field experiment, and showing the differential impact of the same disaster in neighboring regions.

Rapid damage assessment of regional beam bridges after earthquake based on simplified models and different seismic inputs

As the hub of the traffic network, the rapid damage assessment of bridges after earthquake is of great significance for post-disaster rescue. Traditional vulnerability-based method can only provide the probability of different damage states of structures under different earthquake intensity indicators, which confuses the selection of post-disaster rescue routes. Therefore, this paper proposes a post earthquake damage assessment technique for regional bridges based on nonlinear dynamic time-history response analysis. First, a simplified mechanical model for a single pier was established for a large number of beam bridges in the region, achieving standardized and batch rapid finite element model establishment. Secondly, using Kriging interpolation method and continuous wavelet transform technology, the surface seismic response of geological drilling points is calculated to obtain the seismic motion history of any bridge site in the region. Finally, using parallel computing technology, nonlinear dynamic time-history response analysis was conducted on the simplified beam bridge model, and the bridge damage status was quantitatively evaluated based on the calculation results. Eighty-five bridges in a specific area are considered as an example to verify the proposed method. The results show that the proposed method has high calculation efficiency and can consider the site characteristics and structural design parameters. Also, the calculation results can better reflect the actual earthquake damage distribution, providing strong technical support for post-disaster rescue.

Analysis of Damage Mechanism of Heihe Bridge during the Maduo Earthquake

It is of great significance to discuss the earthquake damage mechanism of the bridge. In this paper, the seismic damage mechanism of Heihe Bridge is analyzed based on the post earthquake data. Firstly, the seismic response of Heihe Bridge is analyzed based on the finite element software Midas/Civil, and the model of Heihe Bridge (upward) is established using the data of Dawu strong earthquake records near the bridge site; Then, the influence of bridge connecting plates on the seismic response of small and medium span simply supported girder bridges is studied, and the models with and without connecting plates are established. Finally, through the experimental analysis of the ground motion response, the internal force relationship between the connecting plate and the substructure of the bridge is discussed. The results show that:1)Abutment plays an important role in restraining the displacement of main beam along the bridge. Bridge connecting plate is an important seismic measure. (2) Using the three-dimensional ground motion simulation method of random finite faults, the seismic response analysis of the given USGS ground motion can better simulate the failure mechanism of the bridge. (3)The seismic response of the structural system is determined by the different layout of the bridge deck.

Finite Element Analysis of steel frames subjected to post-earthquake fire

Fire and post-earthquake fires pose a major hazard to our built environment. Industrial structures are generally steel structures and are many a times single storey. Risk of fire in an industrial building after an earthquake must be taken into consideration. Cascading combination of multiple hazards is essential to evaluate the real performance of a structure. The paper focused on the response of an unprotected steel frame subjected to post earthquake fire. Initially, the frame was analyzed for Earthquakes and Fire hazards independently. Time History analysis of the steel frame was carried out with the Base of Column subjected to Earthquake Time Histories. Frame damaged due to earthquakes was further subjected to Fire Hazard. Analysis for Gravity load was included in every type of Load case. Finite element tools have the ability to consider sequential loadings of Earthquake and then Fire. Fire analysis was performed considering the strength and stiffness reduction of carbon steel as per the IS800:2007. Bi-Linear stress–strain properties of steel were used considering the effect of temperature over them. The Beam-Column connections were considered rigid and Tie constraints were used to tie the surfaces of Beam to Column. The Joint Panel Zone was observed to suffer damage during the Earthquake Hazard, where the top of column was subjected to stress concentrations. Damage to the frame in a fire hazard was found to be very large compared to the damage due to earthquakes. The impact of these earthquakes on the Fire Ratings were observed considering the Post-Earthquake Fire Hazard.

DInSAR and Elastic Dislocation Modelling: A Case Study For The 24 January 2020 Elazig-Sivrice Earthquake

One of Turkey's most important neotectonic structures East Anatolian Fault Zone (EAFZ), has occurred many earthquakes. One of these earthquakes, the 6.8 Mw Sivrice-Elazig earthquake dated January 24, 2020, was felt in various provinces, especially in Elazig and Malatya, and caused the death of 44 people. It is critical to investigate this earthquake, which caused significant economic damage, and to identify possible hazards on the EAFZ. One of the remote sensing methods DInSAR was used in this study. By choosing two Sentinel 1A (Single Look Complex) descending datasets, dated 16/01/2020/01 and 28/01/2020/01 respectively (pre and post earthquake), the surface deformation and time series were determined. In addition, using the data obtained from the DInSAR results, Elastic Dislocation Modelling has been performed by applying linear and nonlinear inverse solutions to determine the slip amount of the fault structure, the fault surface slip distribution, and determine the strain area. According to the DInSAR results, while there is an offset of approximately 26 cm (away from the satellite direction) on the left block of the EAF, 19 cm offset (towards the satellite direction) are observed in the right block, respectively. Elastic Dislocation Modelling shows that the observed deformation pattern can be explained by the slip on a single plane fault of the Elazig earthquake. This fault plane was identified as a southwest strike-slip fault segment, which lies within the upper crustal region and extends to a depth of approximately 10 km. According to the results obtained by elastic modelling; slip amount (slip) was calculated as 1.95 m, Mw 6.75, rupture length 34.78 km, focal depth 10 km, width 7.4 km, strike 240.27°, slope 69.19°, rake 0.19°. Overall, the study reveals the strike-slip of the Sivrice-Elazığ earthquake, shows the deformation after the earthquake, and the elastic half-space fault model.

Evaluation modeling of highway collapse hazard based on rough set and support vector machine

The prediction of possibility and risk classification of collapse is an important issue in the process of highway construction in mountain area. Based on the principle of rough set and support vector machine, a landslide hazard prediction model was established. First of all, according to field investigation, an evaluation index system and a sample set of evaluation index data were established, the rough set decision table was constructed by preprocessing the original data based on the function classification of standard evaluation index, and then, the influence indexes of the collapse activity were reduced by rough set theory, and the main 9 indexes affecting the collapse activity as the key discriminant factors of support vector machine model, namely slope shape of slope, aspect of slope, slope of slope, height of slope, exposed structural face, stratum lithology, relationship between weakness face and free face, vegetation cover rate and weathering degree of rock were extracted. Then, taking the data of 13 post earthquake collapses in Yingxiu-Wolong highway of Hanchuan County measured by the authors in the field as training samples, the optimal model parameters were analyzed and calculated. When the penalty parameter C is 8 and the kernel parameter sigma is 0.5, the correct rate of cross-validation is 100%, and the model is optimal. At last, 4 other landslide data were tested, the discriminant results of the test sample data were compared with the results obtained by uncertainty measure and distance discriminant analysis. The results show that the discriminant results of the test sample data by RS-SVM were consistent with the results obtained by uncertainty measure and distance discriminant analysis, the accurate rate is 100%. The collapse hazard analysis model based on rough set and support vector machine can reduce the computation while ensuring the accuracy of evaluation, and better solve the small sample and nonlinear problems, can provide certain a good idea for collapse hazard evaluation in the future.

Prediction of Tunnel Earthquake Damage Based on a Combination Weighting Analysis Method

To reduce or evaluate the damage of tunnels in seismically active areas when earthquakes happen, it is very important to quickly predict the tunnel damage. This study proposes an anti-entropy–fuzzy analytic hierarchy process (FAHP) combination weighting method for tunnel earthquake damage prediction. The tunnel cross section is a symmetrical structure. The method uses tunnel damage data from the tunnels in a region where earthquake disasters have occurred as sample data to calculate the standard earthquake damage index. The weights of evaluation factors are determined by combining the FAHP and anti-entropy weighting. The correction coefficient of each evaluation factor is obtained by considering the degree of each evaluation factor’s influence on the average damage index. Then, the earthquake damage and the corresponding damage degree of each tunnel are obtained by weighting calculation. In this study, 55 tunnels in the Wenchuan earthquake-affected area are taken as analysis cases. In these cases, 45 cases of damage tunnels are used as sample data, and 10 random tunnels are used as training cases. The calculated results are compared with the observed results. The proposed method is confirmed simple and easy to implement, which can greatly reduce the workload of field investigation, calculation and analysis. The results is of great significance to the rapid earthquake emergency assessment and post earthquake recovery of tunnels.

Shaking table test of space double-layer cylindrical reticulated shell with three-dimensional isolation bearing

Space double-layer cylindrical reticulated shells (SDLCRS) have undergone rapid development in the four three decades. Significantly different from conventional multistory high-rise structures, such structures are very sensitive to vertical actions. As a result, conventional seismic isolation techniques that aim to reduce horizontal seismic actions are notably insufficient for this kind of structure. In this study, a new three-dimensional seismic isolation bearing was developed that can simultaneously reduce the horizontal and vertical seismic responses of an SDLCRS. To examine the actual seismic isolation effectiveness of the three-dimensional seismic isolation bearing and provide important theoretical, technical and experimental support for practical engineering applications, comparative shaking table tests were performed on isolated and non-isolated SDLCRSs with lower supporting structures. The 2013 Lsf ground motion record during Lushan earthquake and the 1954 Taft ground motion record were selected as seismic inputs. The dynamic responses including acceleration, displacement and strain of the SDLCRS under the input ground motions with different amplitudes were obtained using the shaking table tests. In addition, the seismic damage of the isolated and non-isolated structures was examined to determine the acceleration amplification effect of the structures. The effectiveness in acceleration and strain responses demonstrated that the three-dimensional seismic isolation bearing was very useful for horizontal and vertical seismic isolation. Moreover, the maximum displacement responses of the bearing were less than half of the respective design displacements, suggesting that the bearing still had considerable reserve bearing capacity and could significantly improve the safety of an SDLCRS under seismic loads. The bearing developed in this study not only has excellent seismic isolation performance and post earthquake restoration capability but can also be easily installed and maintained. Thus, this bearing holds great promise for engineering applications and is suitable for SDLCRS that require both horizontal and vertical seismic isolation.

Pattern of Medicine Prescribing in PHC Facilities before and after earthquake in Nepal

Introduction: On April and May 2015, Nepal experienced two earthquakes. Many studies have focused on acute care delivery, disease outbreaks, mental health issues, and disaster relief post-earthquakes. Few others have looked at psychiatric medication prescription and health aid distribution pattern, only one study has addressed the effects of an earthquake on medication prescribing patterns and compared them to the post earthquake setting. This paper aims to examine common health problems and prescribing practices before and after the earthquake.
 Methods: This descriptive retrospective study was conducted within seven randomly selected health posts (HPs) located in the three most earthquake-affected districts of Bhaktapur, Kathmandu and Dhading. The patient records per month from each HP were selected from the out patient department (OPD) register by systematic random sampling for three months prior and three months after the earthquake. There were 584 and 654 encounters in the pre and post earthquake period respectively. Each patient record was analysed using WHO drug use indicators and national treatment guidelines.
 Results: A significant decrease in encounters receiving antibiotics and cases receiving albendazole alone in worm infestation was found in the post-earthquake period. A significant increase in prescribing antibiotics in cases of common cold was found. 
 Conclusions: The common health problems were similar in both periods. However, prescribing practices were changed. As prescriptions related to mental health problems were lacking, there is a need for improving mental health education to the health workers.

How to ensure sustainability of economic and social activities post earthquake a case study in Lombok West Nusatenggara Indonesia

One of the serious problems caused by the Lombok earthquake on July 28, 2018 was the cessation of people's productive activities, so that their survival was threatened. The purpose of this research was to build a model of economic recovery post earthquake in Lombok, West Nusatenggara that can be used as a model for post earthquake regional economic recovery in Indonesia. The analytical methods used were SAST (Strategic Assumption Surfacing and Testing) and AHP (Analytical Hierarchy Process). The results of study showed that the mental recovery of the community after the earthquake was the most important problem before economic recovery. To recover the community's economy, the development of coconut sugar and handicraft-based home industries was the most potential productive activity to ensure the sustainability of people's lives. The conclusion of this study was mental recovery and the development of productive activities based on regional superior natural resources were the main keys to economic recovery post earthquake.

Collaborative Governace in Post Earthquake Disaster Management on The Western Island of Java

The geographical conditions of Indonesia which are on the Pacific Ring of Fire and are crossed by three world plates, the Eurasian plate, the Indo-Australian plate and the Pacific plate make Indonesia the most disaster-prone country, especially earthquakes. The large number of population in Indonesia contributes to the risk of life and social loss, physical loss, and economic loss. Based on this, the government seems to need more attention to disaster management efforts, which are multidimensional. On the other hand, disaster management in Indonesia have not yet become a national strategic issue and development goals so that resulting in disaster management in Indonesia are still not optimal due to the collaborative management processes that are not comprehensive and sustainable between the various levels of actors involved.The purpose of this study is to analyze collaborative governance in the prevention of earthquake reconstruction rehabilitation in the Western Island of Java. This study uses a post positivism approach with qualitative research methods through in-depth interviews and documentation studies.The results of this study indicate that it is needed: the objectives in post earthquake disaste management must consider providing solutions that can reach ordinary people, community independence and participation, human resources, technology, finance and legal as well as derivative rules, leader support, and collaboration between governments, non-governmental institutions, private sector, donor agencies, international agencies, universities and the community

Repair and retrofitting of buildings post earthquake

This paper discusses the damage types, repair methods and retrofitting of buildings post an earthquake. Data were taken by conducting surveys and assessment of buildings directly, both engineered and non-engineered buildings affected by the West Sumatra earthquake in 2009. Some causes of damage, among them is the detailing of reinforcement that do not follow the existing standard, soft-story effect, foundation failure, low material quality and does not meet the requirements, design and implementation of the construction do not follow the rules and technical provisions of the building earthquake resistant. Improvement and buildings retrofitting can be done after the buildings damage types or its components/parts and the quality of the building materials used were known. The structural analysis was done in order to know the cause of the building elements damaged and if the results of analysis with the latest regulations earthquake load, the building structures is able to withstand the earthquake loads and a repair is not required, but if not, the retrofitting is required.

Non destructive surveys for the protection of cultural heritage: restoration in a post earthquake context

Non-destructive techniques are fundamental tools for a thorough knowledge of the construction aspects, structural conditions and pathologies of buildings. These tools become indispensable in the investigation of the Architectural Heritage subject to protection, guaranteeing the minimum invasiveness of the surveys in compliance with the architectural constraints. This paper presents the contribution that thermographer and thermofluometry have made in the knowledge and communication of the Former Hospital S. Salvatore in L’Aquila, Italy. The building, following the damage suffered by the 2009 earthquake, has been the subject of numerous studies but the analyzes presented in this work represent an element of novelty and a fundamental step for the upcoming restoration interventions

Time History Analysis of Circular and Rectangular Elevated Water Storage Tank using Baffle Wall

In the world, there are large number of storage tanks which are used as water and oil storage facilities. Elevated water tank is one of the most important structures in earthquake event. As known from very upsetting experiences, elevated water tanks were heavily damaged or collapsed during earthquake Hence different configurations of liquid storage tanks have been constructed. Water tanks are play an important role in municipal water supply and firefighting systems. Due to post earthquake useful desires, seismic safety of water tanks is most important. In the current study time history analysis of rectangular and circular elevated water storage tank were analyzed using SAP 2000 software. In this study the concrete baffle wall was used to reduce sloshing effect of the water tank. The tank responses such as maximum nodal displacement, base shear and result were compared for empty and full tank water fill condition. From IS 11682:1985 provision when seismic loading is considered only two cases may be taken one is tank empty condition and other is tank full condition. Finally, study discloses the importance of suitable supporting baffle wall to remain withstand against heavy damages of circular and rectangular elevated water tanks during earthquake. As per IITK-GSDMA guidelines for seismic design of liquid storage tanks, hydrodynamic pressure for impulsive and convective mode was calculated.

Time History Analysis of Circular and Rectangular Elevated Water Storage Tank using Baffle Wall

In the world, there are large number of storage tanks which are used as water and oil storage facilities. Elevated water tank is one of the most important structures in earthquake event. As known from very upsetting experiences, elevated water tanks were heavily damaged or collapsed during earthquake Hence different configurations of liquid storage tanks have been constructed. Water tanks are play an important role in municipal water supply and firefighting systems. Due to post earthquake useful desires, seismic safety of water tanks is most important. In the current study time history analysis of rectangular and circular elevated water storage tank were analyzed using SAP 2000 software. In this study the concrete baffle wall was used to reduce sloshing effect of the water tank. The tank responses such as maximum nodal displacement, base shear and result were compared for empty and full tank water fill condition. From IS 11682:1985provision when seismic loading is considered only two cases may be taken one is tank empty condition and other is tank full condition. Finally, study discloses the importance of suitable supporting baffle wall to remain withstand against heavy damages of circular and rectangular elevated water tanks during earthquake. As per IITK-GSDMA guidelines for seismic design of liquid storage tanks, hydrodynamic pressure for impulsive and convective mode was calculated.

Effectiveness of the performance of the blood management agency (bpbd) in treatment of post earthquake natural disaster in lombok province nusa tenggara barat.

This study uses a performance evaluation used by the West Nusa Tenggara Provincial Disaster Management Agency to measure organizational performance after an earthquake. The research method used in this study is that qualitative research carried out in the research conducted is descriptive research that discusses the analysis of events. The unit of analysis in this study is the effectiveness of the performance evaluation of the Regional Disaster Management Agency of West Nusa Tenggara Province. The type of research used by the authors in this study is qualitative descriptive. Data collection techniques are interviews, observations and documents related to research. The data analysis technique in this study was carried out qualitatively. Objectives / goals / plans in achieving the goals, objectives, mission, organizational vision contained in the formulation of strategic planning (strategic planning) of an organization. Then, the results of the assessment that shows the results of systematic analysis and evaluation results based on performance indicators, which involve indicators of input, output, results, benefits, and changes. Performance measurement is used as a basis for achieving success and completion of implementation in accordance with the goals and objectives set in the framework of realizing the vision and mission. Stages of measuring organizational performance according to tactics starts from clarity of purpose, clarity of strategy, process of analysis and policy formulation, planning, planning programs, availability of facilities and infrastructure and a system of supervision and control. The results of this study explain the measurement system applied by the Regional Disaster Management Agency of West Nusa Tenggara Province has not been effective. Because the performance assessment carried out by the Regional Disaster Management Agency of the Province of West Nusa Tenggara is not systematically arranged and can only be accessed in the Government Agency Performance Accountability Report.

Messina: story of a town "expert" on earthquakes Via Risorgimento, a palimpsest of "anti-seismic" building systems

The tragic earthquake of 1908 affects the area of the Strait already strongly proven in previous centuries and with its destructions, first, and reconstructions, after, makes the city of Messina a field of verification of previous construction solutions and experimentation of innovative technical, new methods of calculation and ad hoc regulations. Through archival documents, technical reports, publications of the time, standards issued for reconstruction, the article analyses the pre and post earthquake situation of 1908, with particular attention to the composition of lands, sub-layers, foundations and of the structures in elevation. In particular, it lingers on the Via Risorgimento area, which has a rich palimpsest of techniques and shrewdness of that period.

Integrating and geolocating post earthquake building damage surveys: The 7.8 Mw Jama-Pedernales earthquake, Ecuador

Currently, it is fairly widespread to use smartphones or tablets on field surveys to collect and geolocate damage data. However, geolocation is not a straight forward process and may give inaccurate results such as, for example when the size of the object to be surveyed is relatively small or the coverage of the satellite constellation (e.g. GPS) is inadequate due to obstacles and shadows present in urban areas. Moreover, the pressure that surveyors and technicians suffer during and after the impact of a natural hazard may make the whole geolocation process even more difficult. In this paper, we describe a methodology to overcome the issues of inaccurate records in five damage data surveys collected after the 7.8 magnitude earthquake that struck the coast of Ecuador in April 2016, together with the three administrative sources used to interpret the damage. We started off by homogenizing the various states of damage as charted in field and aerial surveys, including satellite imagery. We then resolved geolocation inaccuracies by using a set of algorithms that take into account the spatial context and the size of the building. These algorithms also flag the quality of the sources to ultimately compute a figure of the spatial distribution of the damage suffered by residential buildings, together with harm done to productive and social infrastructure. Without these preliminary proceedings, the geolocation inaccuracies of the damage data surveys would not have allowed for adequate and detailed risk assessment.