scholarly journals Seismic Risk Assessment of Chania, Greece, Using an Integrated Computational Approach

2021 ◽  
Vol 11 (23) ◽  
pp. 11249
Author(s):  
Ioannis Koutsoupakis ◽  
Yiannis Tsompanakis ◽  
Pantelis Soupios ◽  
Panagiotis Kirmizakis ◽  
SanLinn Kaka ◽  
...  
Keyword(s):  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Risk Model ◽  
Soil Classification ◽  
Velocity Model ◽  
Surface Shear ◽  
Near Surface ◽  
Effective Decision Making ◽  
Ground Motion Scenarios ◽  
The City

This study develops a comprehensive seismic risk model for the city of Chania, in Greece, which is located ina highly seismic-prone region due to the occurrenceof moderate to large earthquakes because of the nearby major subduction zone between African and Eurasian tectonic plates. The main aim is to reduce the seismic risk for the study area by incorporating the spatial distribution of the near-surface shear wave velocity model and the soil classification, along with all possible seismic sources, taking into account historical events. The study incorporates and correlates various ground motion scenarios and geological fault zones as well as information on existing buildings to develop a seismic risk model using QuakeIST software, and then the seismic hazard and a realistic prediction of resulting future adverse effects are assessed. The developed model can assist the municipal authorities of Chania to be prepared for potential seismic events, as well as city planners and decisionmakers, who can use the model as an effective decision-making tool to identify the seismic vulnerability of the city buildings and infrastructure. Thus, this study enables the implementation of an appropriate and viable earthquake-related hazards strategy to mitigate damage and losses in future earthquakes.

scholarly journals Potential Seismic Damage Assessment of Residential Buildings in Imzouren City (Northern Morocco)

Buildings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 179 ◽  
Author(s):  
Seif-eddine Cherif ◽  
Mimoun Chourak ◽  
Mohamed Abed ◽  
Abdelhalim Douiri
Keyword(s):  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Residential Buildings ◽  
Site Investigation ◽  
Economic Loss ◽  
Vulnerability Index ◽  
Index Method ◽  
Vulnerability Index Method ◽  
Earthquake Scenarios ◽  
The City

The main purpose of this study is to assess seismic risk and present earthquake loss scenarios for the city of Imzouren, in northern Morocco. An empirical approach was chosen to assess the seismic vulnerability of the existing buildings, using the Vulnerability Index Method (RISK-UE), and considering two earthquake scenarios (deterministic and probabilistic). Special concern was given to the seismic vulnerability in Imzouren since the 2004 earthquake (24 February, mw = 6.4) that struck the region and caused substantial damage. A site investigation was conducted in the city targeting more than 3000 residential buildings, which had been closely examined and catalogued to assess their seismic vulnerability. The results of the seismic risk assessment in the city are represented through damage to the buildings, harm to the population and economic loss. Generally, the results obtained from the deterministic approach are in agreement with the damage caused by the 2004 earthquake.

Integrated methodologies for seismic risk mitigation in Durrës (Albania) after the seismic event of November 26th, 2019

2021 ◽  
Author(s):  
Elfrida Shehu ◽  
Klodian Skrame
Keyword(s):  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Housing Prices ◽  
Point Of View ◽  
Earthquake Ground Motion ◽  
Emergency Plans ◽  
Rapid Urbanization ◽  
The Impact ◽  
The City

<p>Albania, the small country in the western Balkan, is a disaster-prone country. It ranks as one of the countries in the world with the highest economic risk from natural hazards events. During the past several decades, in average, Albania has been hit by about one major geological event per year. The impact of disasters in Albania are significantly compounded by a relatively high degree of poverty, lack of infrastructure maintenance, unsafe building and land use practices, linked to rapid urbanization, exploitation of natural resources (overgrazing of pasture, overexploitation of forests and riverbeds, etc.) as well as some other consequences of the transition from a centralized to an open marked economy.</p><p>From a geological point of view, Albania is a young and very dynamic territory and is very vulnerable to the geological and hydro-geological hazards as: earthquakes, landslides, flooding, torrential rains, river erosion, coastal erosion and avalanches that cover almost the entire territory. Due to these conditions its average annual losses count for about 2.5% of its GDP.</p><p>The Durrës earthquakes of 2019 had a huge impact on the Albanian economy. The city of Durrës, Thumanë, Tirana, Vora, Shijak and their villages suffered considerable damage after the earthquakes of September 21<sup>st</sup>, 2019 of Mw 5.4 and November 26<sup>th</sup>, 2019 of Mw 6.2. The main event of the <sup>26th</sup> November caused the deaths of 51 persons and the damaging of hundreds of buildings. The degree of damages produced by these earthquakes has been, in some cases, significantly enhanced by the characteristics of the earthquake ground motion affected by the local subsurface soil structure and the quality of the constructions. The situations during and after the seismic events highlight the indispensable need of the seismic microzonation studies for the entire Albanian territory and emergency plans for the main cities of the country.</p><p>This paper shows the impact of the earthquake event on the housing market value by treating the data collected in the city of Durrës for the period December 2019 - September2020.</p><p>The main goal of the paper is to correlate the obtained results with the engineering-geological and geophysical conditions of the city of Durrёs and the seismic vulnerability of the building.</p><p>The findings of this study can be considered as a first step for in-depth studies aiming to calculate the impact of seismic risk and the change in the risk perception on the housing prices.</p>

Probabilistic seismic risk assessment for the Eastern Himalayas, China

2021 ◽  
pp. 875529302199905
Author(s):  
Changlong Li ◽  
Zongchao Li ◽  
Hongshan Lyu ◽  
Mengtan Gao
Keyword(s):  
Seismic Risk ◽  
Census Data ◽  
Risk Model ◽  
City Center ◽  
Eastern Himalayas ◽  
Earthquake Scenario ◽  
Vulnerability Model ◽  
Concrete Building ◽  
Average Loss ◽  
The City

We developed building taxonomy for the Eastern Himalayas and estimated the distribution of building types in each town based on a field survey and local census data. We built a structure vulnerability model and mortality vulnerability model for each building type and simulated the loss distribution based on an earthquake scenario and probabilistic seismic hazards. Our seismic risk model indicates that the Eastern Himalayas have a regional annual average loss (AAL) of approximately 19 million RMB, which accounts for 0.02% of the 2018 regional gross domestic product (GDP). The AAL of reconstruction area covers nearly 7000 m2 and the AAL of casualty is approximately 60 people. The city center of Lhasa contributes more than one-fifth of the economic AAL and 18% of the AAL of reconstruction area among the towns in this area, and the casualty risk is also the highest. Reinforced concrete building classes with less than three stories and unreinforced masonry contribute to most of the AAL in the study area. The AAL of Cuona County accounts for more than 0.35% of its annual GDP, which implies that it faces the most serious risk of damage by seismic disasters.

Seabed property estimation from ambient-noise recordings: Part 2 — Scholte-wave spectral-ratio inversion

Geophysics ◽  
2007 ◽  
Vol 72 (4) ◽  
pp. U47-U53 ◽  
Author(s):  
Everhard Muyzert
Keyword(s):  
Ambient Noise ◽  
Spectral Ratio ◽  
Shear Velocity ◽  
Velocity Model ◽  
Surface Shear ◽  
Data Set ◽  
Recording Time ◽  
Near Surface ◽  
Scholte Waves ◽  
Scholte Wave

Having knowledge of the near-surface shear-velocity model is useful for various seismic processing methods such as shear-wave static estimation, wavefield separation, and geohazard prediction. I present a new method to derive a 2D near-surface shear-velocity model from ambient-noise recordings made at the seafloor. The method relies on inverting horizontal- and vertical-amplitude spectra of Scholte waves propagating in the seafloor. I compare the commonly used horizontal-over-vertical spectral ratio with three alternative spectral-ratio definitions through modeling. The modeling shows that the vertical-over-total spectral ratio has some favorable properties for inversion. I describe a nonlinear inversion method for the vertical-to-total spectral ratio of the Scholte waves and apply it to an ambient-noise data set recorded by an ocean-bottom-cable (OBC) system. A 1D near-surface shear-velocity model is derived through a joint inversion of the spectral-ratio and phase-velocity data. A 2D shear-velocity model is obtained through a local inversion of the spectral ratios averaged over small groups of receivers and shows evidence for lateral heterogeneity. The newly developed method for deriving near-surface shear-velocity distribution by inverting the Scholte-wave spectral ratio measured from seabed noise provides great opportunities for estimating the shallow-seabed shear velocity in deep water. Another benefit of the method is that, with the OBC system, no additional hardware is needed; only additional recording time is required. In this case, half an hour is sufficient.

scholarly journals Seismic vulnerability and risk assessment of Kolkata City, India

2014 ◽  
Vol 2 (4) ◽  
pp. 3015-3063 ◽  
Author(s):  
S. K. Nath ◽  
M. D. Adhikari ◽  
N. Devaraj ◽  
S. K. Maiti
Keyword(s):  
Seismic Hazard ◽  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Model Building ◽  
Disaster Mitigation ◽  
Free Zone ◽  
Building Typology ◽  
Hazard And Risk ◽  
Risk Maps ◽  
The City

Abstract. The city of Kolkata is one of the most urbanized and densely populated regions in the world, which is a major industrial and commercial hub of the Eastern and Northeastern region of India. In order to classify the seismic risk zones of Kolkata we used seismic hazard exposures on the vulnerability components namely, landuse/landcover, population density, building typology, age and height. We microzoned seismic hazard of the City by integrating seismological, geological and geotechnical themes in GIS which in turn is integrated with the vulnerability components in a logic-tree framework to estimate both the socio-economic and structural risk of the City. In both the risk maps, three broad zones have been demarcated as "severe", "high" and "moderate". There had also been a risk-free zone in the City. The damage distribution in the City due to the 1934 Bihar-Nepal Earthquake of Mw 8.1 well matches with the risk regime. The design horizontal seismic coefficients for the City have been worked out for all the predominant periods which indicate suitability of "A", "B" and "C" type of structures. The cumulative damage probabilities in terms of "slight", "moderate", "extensive" and "complete" have also been assessed for the significant four model building types viz. RM2L, RM2M, URML and URMM for each structural seismic risk zone in the City. Both the Seismic Hazard and Risk maps are expected to play vital roles in the earthquake inflicted disaster mitigation and management of the city of Kolkata.

scholarly journals MAPPING AN URBAN CITY CENTRE FOR SEISMIC RISK ASSESSMENT: APPLICATION TO VALENCIA (SPAIN)

2020 ◽  
Vol XLIV-M-1-2020 ◽  
pp. 817-824
Author(s):  
L. Basset-Salom ◽  
A. Guardiola-Víllora
Keyword(s):  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Residential Buildings ◽  
Residential Building ◽  
Relevant Information ◽  
City Centre ◽  
Building Stock ◽  
Urban City ◽  
Historical Archive ◽  
The City

Abstract. Seismic risk in urban city centres may be high, even when the city is in low to moderate seismic areas, due to the vulnerability of the residential buildings. To assess the seismic vulnerability and estimate the expected damage in case of occurrence of an earthquake, an up-to-date detailed and comprehensive information of the residential building stock, such as number of dwellings, location, age, geometry, stiffness irregularities, structure, constructive system and practices, among others, is needed. This paper presents the authors experience, describing the step by step procedure followed to obtain the required information to classify and catalogue the residential buildings of the historical neighbourhoods of the city of Valencia into a database. Official sources, like the Cadastral Database, the website of the Urban Planning Service of the city of Valencia, the Municipal Historical Archive of Valencia, and the Historical Archive of the Valencian Architects Society, but also unexpected references are shared, pointing out the information that has been retrieved and its reliability. Additionally, relevant information must be obtained with an on-site data collection. This field work is essential not only to prove the accuracy of the abovementioned data but also to define some of the parameters related to the building vulnerability.The built database, included in a GIS system, has been used by the authors for seismic risk studies. This procedure can be implemented in future assessments at an urban scale.

scholarly journals Improvement of the consideration of seismic risks in Algerian planning and urban development instruments: application to the Boumerdés region (50km east of Algiers/Algeria)

2020 ◽  
Vol 150 ◽  
pp. 03017
Author(s):  
Mohamed Yacine Kheliouen ◽  
Abdelmadjd Bouder
Keyword(s):  
Information System ◽  
Urban Areas ◽  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Urban System ◽  
Empirical Method ◽  
Vulnerability Maps ◽  
Vulnerability Of Buildings ◽  
The City ◽  
Degree Of Isolation

The territory of both Algiers and Boumerdés departments was hit in 2003 by a violent earthquake of 6.8 (M) causing considerable human and material losses. In order to establish preventive solutions, the article recommend the seismic risk studies to be considered in national and urban planning instruments, It presents a seismic vulnerability study applied to three (03) cities located in the region that have high populations and challenges Two assessments are presented for each city: the first consists of studying the vulnerability of buildings to the earthquake using a qualitative empirical method called Risk-EU. The second assessment focuses on the unbuilt part of the city through the analysis of evacuation and rescue capacity after the earthquake. This latter is a method used in the seismic micro zoning study of the wilaya of Algiers that was jointly established by 02 Japanese and Algerian study centers. The superposition of the summary vulnerability maps of the two assessments designed using a geographic information system (GIS), shows us the location of the most vulnerable urban areas. Damage of the building is coupled with their degree of isolation that serves for evacuation and rescue in the case of an earthquake. The results of cumulative vulnerability (built and urban system) at the scale of the region studied, then at each city and districts, are shown graphically and statistically.

Seismic Risk Mitigation of Historical Masonry Towers by Means of Prestressing Devices

2010 ◽  
Vol 133-134 ◽  
pp. 843-848 ◽  
Author(s):  
Adolfo Preciado Quiroz ◽  
Silvio T. Sperbeck ◽  
Harald Budelmann ◽  
Gianni Bartoli ◽  
Elham Bazrafshan
Keyword(s):  
Seismic Risk ◽  
Seismic Vulnerability ◽  
Risk Mitigation ◽  
Numerical Models ◽  
Failure Mechanisms ◽  
Masonry Towers ◽  
Seismic Risk Mitigation ◽  
Historical Masonry ◽  
Observed Damage ◽  
And Behavior

This work presents the investigation of the efficiency of different prestressing devices as a rehabilitation measure for the seismic risk mitigation of historical masonry towers. As a first phase, the seismic vulnerability of theoretical masonry towers was assessed by means of numerical models validated with information from the literature, observed damage and behavior of these structures due to passed earthquakes (crack pattern and failure mechanisms), and mainly taking into account the engineering experience. Afterwards, the validated models were rehabilitated with different prestressing devices; analyzing the results and concluding which device or the combination of them improved in a better way the seismic performance of the masonry towers. Finally, the methodology will be applied in two historical masonry towers located in seismic areas; the medieval tower “Torre Grossa” of San Gimignano, Italy, and one of the bell towers of the Cathedral of Colima, Mexico.

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