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1.
We performed large-scale earthquake economic loss estimations for France and cost–benefit analyses for several French cities by developing a semiempirical, intensity-based approach. The proposed methodology is inexpensive and easily applicable in case of a paucity of detailed information regarding the specific regional seismic hazard and the structural characteristics of the building stock, which is of particular importance in moderate-to-low seismic hazard regions. The exposure model is derived from census datasets, and the seismic vulnerability distribution of buildings is calculated using data mining techniques. Several hypothetical, large-scale retrofit scenarios are proposed, with increasing levels of investment. These cities, in their respective reinforced states, are then subjected to a series of hazard scenarios. Seismic hazard data for different return periods are calculated from regulatory accelerations from French seismic zoning. Loss estimations for the original (non-reinforced) configuration show high levels of expected building repair and replacement costs for all time spans. Finally, the benefits in terms of damage avoidance are compared with the costs of each retrofit measure. Relatively limited strengthening investments reduce the probability of building collapse, which is the main cause of human casualties. However, the results of this study suggest that retrofitting is, on average, only cost-effective in the parts of France with the highest seismicity and over the longest time horizons. 相似文献
2.
In this paper, seismic risk scenarios for Bucharest, the capital city of Romania, are proposed and assessed. Bucharest has one of the highest seismic risk levels in Europe, and this is due to a combination of relatively high seismic hazard and a building stock built mainly before the devastating Vrancea 1977 earthquake. In this study, the seismic risk of Bucharest is assessed using the most recent information regarding the characteristics of the residential building stock. The ground motion amplitudes are evaluated starting from random fields obtained by coupling a ground motion model derived for the Vrancea intermediate-depth seismic source with a spatial correlation model. The seismic risk evaluation method applied in this study is based on the well-known macroseismic method. For several structural typologies, the vulnerability parameters are evaluated based on a damage survey performed on 18,000 buildings in Bucharest after the March 1977 earthquake. Subsequently, the risk metrics are compared with those from other studies in the literature that apply a different risk assessment methodology in order to gain a better view of the uncertainties associated with a seismic risk study at city level. Finally, the impact of several Vrancea intermediate-depth earthquake scenarios is evaluated and the results show that the earthquake which has the closest epicenter to Bucharest appears to be the most damaging.
相似文献3.
In this paper, seismic risk scenarios for Bucharest, the capital city of Romania, are proposed and assessed. Bucharest has one of the highest seismic risk levels in Europe, and this is due to a combination of relatively high seismic hazard and a building stock built mainly before the devastating Vrancea 1977 earthquake. In this study, the seismic risk of Bucharest is assessed using the most recent information regarding the characteristics of the residential building stock. The ground motion amplitudes are evaluated starting from random fields obtained by coupling a ground motion model derived for the Vrancea intermediate-depth seismic source with a spatial correlation model. The seismic risk evaluation method applied in this study is based on the well-known macroseismic method. For several structural typologies, the vulnerability parameters are evaluated based on a damage survey performed on 18,000 buildings in Bucharest after the March 1977 earthquake. Subsequently, the risk metrics are compared with those from other studies in the literature that apply a different risk assessment methodology in order to gain a better view of the uncertainties associated with a seismic risk study at city level. Finally, the impact of several Vrancea intermediate-depth earthquake scenarios is evaluated and the results show that the earthquake which has the closest epicenter to Bucharest appears to be the most damaging. 相似文献
4.
This paper describes a multi-tiered loss assessment methodology to estimate seismic monetary implications resulting from structural damage to the building population in Greater Cairo. After outlining a ground-shaking model, data on geological structures and surface soil conditions are collated using a considerable number of boreholes to produce a classification of different soil deposits. An inventory database for the existing building stock is also prepared. The seismic vulnerability of representative reinforced concrete building models, designed according to prevalent codes and construction practices, is evaluated. Capacity spectrum methods are utilised for assessing the structural performance through a multi-level damage scale. A simplified methodology for deriving fragility curves for non-ductile reinforced concrete building classes that typically constitute the building population of the city is adopted. In addition, suitable fragility functions for unreinforced masonry constructions are selected and used for completing the loss model for the study area. The results are finally used to build an event-based loss model caused by possible earthquakes in the region. 相似文献
5.
Mehani Youcef Benouar Djilali Bechtoula Hakim Kibboua Abderrahmane 《Natural Hazards》2011,59(1):529-551
Algeria is a country with a high seismic activity. During the last decade, many destructive earthquakes occurred, particularly
in the northern part, causing enormous losses in human lives, buildings, and equipments. In order to reduce this risk in the
capital and avoid serious damages to the strategic existing buildings, the government decided to invest in seismic upgrade,
strengthening, and retrofitting of these buildings. To do so, seismic vulnerability study of this category of buildings has
been considered. Structural analysis is performed based on a site investigation (inspection of the building, collecting data,
materials characteristics, general conditions of the building, etc.) and existing drawings (architectural plans, structural
design, etc.). The aim of these seismic vulnerability studies is to develop guidelines and a methodology for rehabilitation
of existing buildings. This paper presents the methodology followed in our study and summarizes the vulnerability assessment
and strengthening of one of the strategic buildings according to the new Algerian Seismic Design Code RPA 99/version 2003.
As a direct application of this methodology, both static equivalent method and nonlinear dynamic analysis are performed and
presented in this paper. 相似文献
6.
Development of Seismic Risk Scenarios Based on a Hybrid Method of Vulnerability Assessment 总被引：11，自引：5，他引：6
A hybrid methodology of vulnerability analysis is presented, involving elements from both empirical and theoretical methods. A model for correlating analytically calculated structural damage indices to loss (in monetary terms) is also proposed and calibrated against available statistical data. Probability damage matrices derived using this methodology are incorporated into a cost-benefit model tailored to the problem of estimating the feasibility of seismically rehabilitating the existing stock of reinforced concrete buildings in Thessaloniki, Greece. Losses calculated using the suggested procedure are found to be in good agreement with losses incurred during the 1978 Thessaloniki earthquake. The results of the present study also indicate that benefit/cost ratios for reinforced concrete buildings are quite low. Hence, it appears that a pre-earthquake strengthening programme is not economically justifiable. 相似文献
7.
8.
Shaghayegh Karimzadeh Aysegul Askan Murat Altug Erberik Ahmet Yakut 《Natural Hazards》2018,92(3):1371-1397
Estimation of seismic losses is a fundamental step in risk mitigation in urban regions. Structural damage patterns depend on the regional seismic properties and the local building vulnerability. In this study, a framework for seismic damage estimation is proposed where the local building fragilities are modeled based on a set of simulated ground motions in the region of interest. For this purpose, first, ground motion records are simulated for a set of scenario events using stochastic finite-fault methodology. Then, existing building stock is classified into specific building types represented with equivalent single-degree-of-freedom models. The response statistics of these models are evaluated through nonlinear time history analysis with the simulated ground motions. Fragility curves for the classified structural types are derived and discussed. The study area is Erzincan (Turkey), which is located on a pull-apart basin underlain by soft sediments in the conjunction of three active faults as right-lateral North Anatolian Fault, left-lateral North East Anatolian Fault, and left-lateral Ovacik Fault. Erzincan city center experienced devastating earthquakes in the past including the December 27, 1939 (Ms = 8.0) and the March 13, 1992 (Mw?=?6.6) events. The application of the proposed method is performed to estimate the spatial distribution of the damage after the 1992 event. The estimated results are compared against the corresponding observed damage levels yielding a reasonable match in between. After the validation exercise, a potential scenario event of Mw?=?7.0 is simulated in the study region. The corresponding damage distribution indicates a significant risk within the urban area. 相似文献
9.
Seismic risk assessment of buildings in urban areas: a case study for Denizli,Turkey 总被引：3，自引：2，他引：1
This study aims to carry out a seismic risk assessment for a typical mid-size city based on building inventory from a field
study. Contributions were made to existing loss estimation methods for buildings. In particular, a procedure was introduced
to estimate the seismic quality of buildings using a scoring scheme for the effective parameters in seismic behavior. Denizli,
a typical mid-size city in Turkey, was used as a case study. The building inventory was conducted by trained observers in
a selected region of Denizli that had the potential to be damaged from expected future earthquakes according to geological
and geotechnical studies. Parameters that are known to have some effect on the seismic performance of the buildings during
past earthquakes were collected during the inventory studies. The inventory includes data of about 3,466 buildings on 4,226
parcels. The evaluation of inventory data provided information about the distribution of building stock according to structural
system, construction year, and vertical and plan irregularities. The inventory data and the proposed procedure were used to
assess the building damage, and to determine casualty and shelter needs during the M6.3 and 7.0 scenario earthquakes, representing
the most probable and maximum earthquakes in Denizli, respectively. The damage assessment and loss studies showed that significant
casualties and economic losses can be expected in future earthquakes. Seismic risk assessment of reinforced concrete buildings
also revealed the priorities among building groups. The vulnerability in decreasing order is: (1) buildings with 6 or more
stories, (2) pre-1975 constructed buildings, and (3) buildings with 3–5 stories. The future studies for evaluating and reducing
seismic risk for buildings should follow this priority order. All data of inventory, damage, and loss estimates were assembled
in a Geographical Information System (GIS) database. 相似文献
10.
Texture Analysis of Grey-Tone Images by Mathematical Morphology: A Nondestructive Tool for the Quantitative Assessment of Stone Decay 总被引：1，自引：0，他引：1
Both a low-cost and easily handled nondestructive methodology and its validation criterion are proposed. The methodology is based on image analysis by mathematical morphology for the assessment of decayed stone surfaces in historic limestone buildings. It is adapted to follow the evolution, at macroscopic time and space scales, of stone materials used in art pieces and monument building stones. This methodology is applied to the quantitative analysis of textures of static grey-tone CCD video camera images representative of flat stone structures that cannot be handled. These structures line the walls inside an important church, Basílica da Estrela, built in the 18th century and located in the city of Lisbon. Detailed visual/tactile observation shows that these flat vertical structures are more or less damaged depending on their position inside the church. The damage is possibly associated with different environment conditions both from the atmosphere inside the church and from contact with the walls of the church. The presence of these pathologies breaks down the order and organization of sound rock textures introducing changes in the topographical and optical characteristics of the texture of the surfaces. This new methodology is based on the granulometry and covariance analysis of grey-tone images corresponding to the structures studied. The validation criterion allows the results of the proposed methodology to be compared to the results of a previous qualitative study made by experts in the field using visual assessment and monument mapping as a valid methodology to assess the degree of decay. This procedure is based on optical and topographical characteristics and type of decay of the stone surface, and the quantity of material lost from the surface of the panels during the year. As discussed in this paper, in the context of cultural heritage, the proposed methodology was validated and its results can be considered an improvement on and complementary to expert visual analysis and also to other nondestructive techniques. 相似文献
11.
While laboratory and analytical studies can provide valuable information about earthquake hazard mitigation, the most effective educator is the impact of a full-scale earthquake on a full-scale city. The recent earthquakes in Turkey showed that the governmental as well as individual attitudes towards earthquakes did not represent proportionate responses to the risk levels concerned. Turkey had weaknesses in preparing, planning, mitigating and responding to disasters in spite of the known seismic vulnerability of the country. Many steps have been taken after 1999 earthquakes in Turkey, however, the preparations largely concentrate on the response and recovery phases and a fundamental step to reform the current disaster management system and steps to rehabilitate the vulnerable building stock has not been undertaken until today. This would involve changing the present laws and regulations and de-centralising the disaster management system. The aim of this paper is to propose a national mitigation strategy for Turkey for a time-frame of 10 years. The model proposed is a very comprehensive model for earthquake risk reduction in Turkey and within this context, the legislative and technical aspects of mitigation will be discussed in detail. Strategies for mitigating and retrofitting the existing building stock will also be proposed. 相似文献
12.
Keyan Yu Philippe Rosset 《Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards》2016,10(2):164-178
In Canada, Montreal is the second city with the highest seismic risk. This is due to its relatively high seismic hazard, old infrastructures and high population density. The region is characterised by moderate seismic activity with no recent record of a major earthquake. The lack of historical strong ground motion records for the region contributes to large uncertainties in the estimation of hazards. Among the sources of uncertainty, the attenuation function is the main contributor and its effect on estimates of risks is investigated. Epistemic uncertainty was considered by obtaining damage estimates for three attenuation functions that were developed for Eastern North America. The results indicate that loss estimates are highly sensitive to the choice of the attenuation function and suggest that epistemic uncertainty should be considered both for the definition of the hazard function and in loss estimation methodologies. Seismic loss estimates are performed for a 2% in 50 years seismic threat, which corresponds to the design level earthquake in the national building code of Canada, using HAZUS-MH4 for the Montreal region over 522 census tracts. The study estimated that for the average scenario roughly 5% of the building stock would be damaged with direct economic losses evaluated at 1.4 billion dollars for such a scenario. The maximum number of casualties would result in approximately 500 people being injured or dead at a calculated time of occurrence of 2?pm. 相似文献
13.
Quantifying Storm Tide Risk in Cairns 总被引：6，自引：5，他引：6
Ken Granger 《Natural Hazards》2003,30(2):165-185
The United Nations International Decade for Natural Disaster Reduction (IDNDR)gave rise to an increasing level of attention to the risks posed by a range of naturalhazards and the development of strategies by which to reduce those risks. It waswidely recognised that in order to evaluate risk treatment strategies it was necessaryto `measure' the level of risk that already existed and the level of risk that would beencountered with the treatment strategy(s) in place.This paper outlines the methodology developed under the AGSO (now GeoscienceAustralia) Cities Project to quantify the risk associated with storm tide inundation. It includes the methodology for `measuring' the level of community exposure to storm tide hazards and the methodology for `measuring' community vulnerability. The Far North Queensland city of Cairns is used as the case study to demonstrate the application of these methods. 相似文献
14.
Iuliana Arma? 《Natural Hazards》2012,63(2):1129-1156
The expansive infrastructure, along with the high population density, makes cities highly vulnerable to the severe impacts of natural hazards. In the context of an explosive increase in value of the damage caused by natural disasters, the need for evaluating and visualizing the vulnerability of urban areas becomes a necessity in helping practitioners and stakeholders in their decision-making processes. The paper presented is a piece of exploratory research. The overall aim is to develop a spatial vulnerability approach to address earthquake risk, using a semi-quantitative model. The model uses the analytical framework of a spatial GIS-based multi-criteria analysis. For this approach, we have chosen Bucharest, the capital city of Romania, based on its high vulnerability to earthquakes due to a rapid urban growth and the advanced state of decay of the buildings (most of the building stock were built between 1940 and 1977). The spatial result reveals a circular pattern, pinpointing as hot spots the Bucharest historic centre (located on a meadow and river terrace, and with aged building stock) and peripheral areas (isolated from the emergency centers and defined by precarious social and economic conditions). In a sustainable development perspective, the example of Bucharest shows how spatial patterns shape the ??vulnerability profile?? of the city, based on which decision makers could develop proper prediction and mitigation strategies and enhance the resilience of cities against the risks resulting from the earthquake hazard. 相似文献
15.
The Municipality of Campos dos Goytacazes is located on the northern coast of Rio de Janeiro, Brazil. The city developed on a floodplain and as a consequence of this occupation it has experienced problems with the water table level, drainage system, soil carrying capacity and aquifers' contamination. The purpose of this paper was to accomplish a geological and environmental study, producing interpretive and derived geotechnical maps to analyze the degree of aptitudes or restrictions of the physical environment for urban expansion. In order to do this, the methodology of multicriterial analysis was used, combined with pedological indicators resulting in the elaboration of the Favorability Maps for Buildings (Shallow and Deep Foundations). The remote sensing tools, GIS and GPS, sped up the elaboration of the Information Plans. The maps generated in this work allow us to indicate problems in the physical environment serving as a guide to urbanization. It was verified that the city expands into unsuitable areas and it is recommended as areas for expansion those considered favorable in the outcomes of this research. 相似文献
16.
Within the framework of the performance based earthquake engineering, site specific earthquake spectra for Van province has been obtained. It is noteworthy that, in probabilistic seismic hazard assessment, as a first stage data from geological studies and records from the instrumental period were compiled to make a seismic source characterization for the study region. The probabilistic seismic hazard curves were developed based on selected appropriate attenuation relationships, at rock sites, with a probability of exceedance 2, 10 and 50% in 50 yrs period. The obtained results are compared with the spectral responses proposed for seismic evaluation and retrofit of building structure in Turkish Earthquake Code (2007), section 7. The acceleration response spectrums obtained from probabilistic seismic hazard analysis are matched to adjust earthquake accelerograms recorded during the 2011 Van earthquakes by using SeismoMatch v2.0 software. The aim of this procedure is to obtain a set of reasonable earthquake input motions for the seismic evaluation of existing buildings. 相似文献
17.
遗传模拟退火算法在边坡稳定分析中的应用 总被引：15，自引：6，他引：9
利用遗传模拟退火算法结合瑞典圆弧法,寻找最危险滑裂面进行边坡稳定分析。对构造数学模型、确定计算步骤、选取参数等方面作了一定的研究。通过实例计算,结果令人满意。 相似文献
18.
H. S. B. Duzgun M. S. Yucemen H. S. Kalaycioglu K. Celik S. Kemec K. Ertugay A. Deniz 《Natural Hazards》2011,59(2):917-947
In this paper, an integrated urban earthquake vulnerability assessment framework, which considers vulnerability of urban environment
in a holistic manner and performs the vulnerability assessment for the neighborhood scale, is proposed. The main motivation
behind this approach is the inability to implement existing vulnerability assessment methodologies for countries like Turkey,
where the required data are usually missing or inadequate for the decision-makers in prioritization their limited resources
for risk reduction in the administrative units from which they are responsible for. The methodology integrates socio-economical,
structural, coastal, ground condition, vulnerabilities (fragilities), as well as accessibility to critical services. The proposed
methodology is implemented for Eskisehir, which is one of the metropolitans of Turkey. In the implementation of the proposed
framework, geographic information system (GIS) is used. While the overall vulnerabilities obtained for neighborhoods are mapped
in GIS, the overall vulnerabilities obtained for buildings are visualized in 3D city model. The main reason behind using different
mapping and visualization tools for vulnerabilities is to provide better ways for communicating with decision-makers. The
implementation of the proposed vulnerability assessment methodology indicates that an urban area may have different vulnerability
patterns in terms of structural, socio-economical, and accessibility to critical services. When such patterns are investigated,
effective vulnerability reduction policies can be designed by the decision-makers. The proposed methodology well serves for
this purpose. 相似文献
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20.
The proposed flood mitigation measures in the Slovak Republic are subject of environmental impact assessment (EIA) process before its approval. The paper elaborates and demonstrates the application of the risk analysis method for evaluating alternatives, which is core in EIA. Risk analysis is an appropriate tool to determine the level of the risk of the proposed flood mitigation measures and through which it is possible to choose the alternative with the lowest level of risk for the environment. The article presents the application of the developed methodology based on universal matrix of risk analysis in ?iba village that is in existing flood risk. It analyses and discusses the results of the impact assessment from EIA practice in the Slovakia. The aim of the work is to improve existing qualitative and quantitative methods for assessing the impacts of proposed activities on the environment. Developed methodology stimulates creative approaches in searching of the best alternative to proposed activities (constructions) that are environmentally friendly. Innovation in this paper is presented by an implementation of universal matrix of risk analysis for flood mitigation measures (developed by the authors) for the purposes of EIA process. 相似文献