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1.
This paper is concerned with an investigation of the damage to residential buildings in two areas within Gilan and Zanjan provinces, Iran, caused by the Manjil-Rudbar earthquake of 20 June 1990. A statistical correlation between the observed ground motion and the damage to the residential buildings is derived for overall damaged buildings and expressed as the vulnerability function. The loss function is calculated by combining the seismic hazard with the vulnerability function.The study of vulnerability and annual seismic hazard shows that the specific annual risk for the range of motion of 0.18 to 0.5 g is equal to 0.02. This indicates that the specific risk for semi-engineered residential buildings with a lifetime of 20 years is about 33%. This study also shows that in large cities, such as Tehran, located in seismic areas, the extent of damage according to the vulnerability function will be 45 and 70% for expected maximum accelerations of 0.3 and 0.4 g, respectively.  相似文献   

2.
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   

3.
Ambient seismic noise measurements were conducted inside the Cathedral of Cologne (Germany) for assessing its frequencies of vibration and for checking whether these occur in the range where soil amplification is expected. If this is the case, damages may increase in case of an earthquake due to an increased structural response of the building. Analysis of the ratio between the horizontal and vertical components of the spectra recorded at stations located inside the building as well as the ratio between the corresponding components of the spectra recorded simultaneously inside the building and at a reference station placed in the basement of the cathedral indicated several modes of vibration. Facilitated by these results an assessment of the seismic vulnerability was attempted for a 2D ground motion scenario using the finite element method.  相似文献   

4.
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   

5.
The seismic risks to which populations are exposed should be estimated reliably for mitigation and preparation of response to disastrous earthquakes. Three parameters need to be known: Population numbers, properties of the built environment, and the seismic hazard. If we focus on large cities, we can say that at least one of these is known satisfactorily, namely the population, but not the other two. In the developing world, the numbers of buildings in a city are known only approximately, their distribution into building types (resistance to shaking) has to be assumed, and the distribution of types throughout the city is unknown. Recent verification of the world seismic hazard map has shown that it is grossly misleading: Instrumental measurements of accelerations due to six earthquakes were about three times larger, on average, than the maximum likely accelerations shown on the map; the macroseismic intensities reported for the last 60 earthquakes with M ≥ 7.5 were all significantly larger than expected, based on the hazard map (by 2.3 intensity units for the 12 deadliest earthquakes); and calculations of losses of life based on the hazard map underestimate the losses sustained in the 12 recent earthquakes with more than 1,000 fatalities by two to three orders of magnitude. This means that the seismic risk in most of the approximately 1,000 large cities at risk in the developing world is unknown. To remedy this intolerable situation, models for the built environment in cities need to be constructed, using cost-effective analyses of satellite images, and worst case scenario estimates of the losses in case of the nearest maximum credible earthquake.  相似文献   

6.

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.

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7.
This article contributes to the development and application of two latest-generation methods of seismic risk analysis in urban areas. The first method, namely vulnerability index method (VIM), considers five non-null damage states, defines the action in terms of macroseismic intensity and the seismic quality of the building by means of a vulnerability index. The estimated damage degree is measured by semi-empirical functions. The second method, namely capacity spectrum based method (CSBM), considers four no damage states, defines the seismic action in terms of response spectra and the building vulnerability by means of its capacity spectrum. In order to apply both methods to Barcelona (Spain) and compare the results, a deterministic and a probabilistic hazard scenario with soil effects are used. The deterministic one corresponds to a historic earthquake, while the probabilistic seismic ground motion has a probability of exceedence of 10% in 50 years. Detailed information on the building design has been obtained along years by collecting, arranging, improving, and completing the database of the dwellings of the city. A Geographic Information System (GIS) has been customized allowing storing, analysing, and displaying this large amount of spatial and tabular data of dwellings. The obtained results are highly consistent with the historical and modern evolution of the populated area and show the validity and strength of both methods. Although Barcelona has a low to moderate seismic hazard, its expected seismic risk is significant because of the high vulnerability of its buildings. Cities such as Barcelona, located in a low to moderate seismic hazard region, are usually not aware of the seismic risk. The detailed risk maps obtained offer a great opportunity to guide the decision making in the field of seismic risk prevention and mitigation in Barcelona, and for emergency planning in the city.  相似文献   

8.
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   

9.
Iran is one of the most seismically active countries of the world located on the Alpine-Himalayan earthquake belt. More than 180,000 people were killed due to earthquakes in Iran during the last five decades. Considering the fact that most Iranians live in masonry and non-engineered houses, having a comprehensive program for decreasing the vulnerability of society holds considerable importance. For this reason, loss estimation should be done before an earthquake strikes to prepare proper information for designing and selection of emergency plans and the retrofitting strategies prior to occurrence of earthquake. The loss estimation process consists of two principal steps of hazard analysis and vulnerability assessment. After identifying the earthquake hazard, the first step is to evaluate the vulnerability of residential buildings and lifelines and also the social and economic impacts of the earthquake scenarios. Among these, residential buildings have specific importance, because their destruction will disturb the daily life and result in casualties. Consequently, the vulnerability assessment of the buildings in Iran is important to identify the weak points in the built environment structure. The aim of this research is to prepare vulnerability curves for the residential buildings of Iran to provide a proper base for estimating probable damage features by future earthquakes. The estimation may contribute fundamentally for better seismic performance of Iranian societies. After a brief review of the vulnerability assessment methods in Iran and other countries, through the use of the European Macroseismic method, a model for evaluating the vulnerability of the Iranian buildings is proposed. This method allows the vulnerability assessment for numerous sets of buildings by defining the vulnerability curves for each building type based on the damage observations of previous earthquakes. For defining the vulnerability curves, a building typology classification is presented in this article, which is representative of Iranian building characteristics. The hazard is described in terms of the macroseismic intensity and the EMS-98 damage grades have been considered for classifying the physical damage to the buildings. The calculated vulnerability indexes and vulnerability curves show that for engineered houses there is not any notable difference between the vulnerability of Iranian and Risk-UE building types. For the non-engineered houses, the vulnerability index of brick and steel structures is less than the corresponding values of the other unreinforced masonry buildings of Iran. The vulnerability index of unreinforced and masonry buildings of Iran are larger than the values of the similar types in Risk-UE and so the Iranian buildings are more vulnerable in this regard.  相似文献   

10.
This research looks at the very nature of perception of seismic risk, an issue that is not only academically important, but also it can save lives and reduce injury and community costs. The background idea is that citizens in big cities, vulnerable to seismic hazard are living with latent and permanent concerns about a possible earthquake. We were interested in revealing significant aspects of Bucharest citizens’ orientations and tendencies in relation to the possible seismic event. Bucharest, the capital of Romania, is exposed to the greatest seismic hazard compared with other European capitals. The dimensions of study were: the anticipations of seism occurrence, the behavior during the event, evaluations of consequences, support factors, and individual vulnerability. This article is an example of the low cost approach on a sample of 190 citizens, understood as an exercise in attempting to relate population characteristics to various aspects of risk perception. The methodology used was based on a field investigation, where the research agents’ applied one questionnaire containing free/post codified/fan answers concerning: demographic variables, the buildings’ features, and perceptions about the possible earthquake event. The findings of this study showed that the hazard perception significantly associates with aspects concerning the subjects’ orientation toward institutional factors/human relations/negativism, and toward financial/material/moral support in case of disaster etc. It is hoped that this issue will serve to inspire further investigations into this very important and socially sensitive field, due to the fact that hazard analysis and mitigation would be more effective when it takes into account the human dimension of disasters.  相似文献   

11.
Probabilistic Assessment of Earthquake Insurance Rates for Turkey   总被引：2，自引：0，他引：2  
A probabilistic model is presented to obtain a realistic estimate of earthquake insurance rates for reinforced concrete buildings in Turkey. The model integrates information on seismic hazard and information on expected earthquake damage on engineering facilities in a systematic way, yielding to estimates of earthquake insurance premiums. In order to demonstrate the application of the proposed probabilistic method, earthquake insurance rates are computed for reinforced concrete buildings constructed in five cities located in different seismic zones of Turkey. The resulting rates are compared with the rates currently charged by the insurance companies. The earthquake insurance rates are observed to be sensitive to the assumptions on seismic hazard and damage probability matrices and to increase significantly with increasing violation of the code requirements.  相似文献   

12.
The Denver Region in Colorado, USA, is used as an example of the seismic vulnerability of a region that is not generally considered seismically active. The HAZUS (Hazards United States) natural hazard vulnerability program of United States and an integral geographical information system are used to create the regional distribution of Denver’s potential consequences of an earthquake. Two realistic scenario earthquakes are employed based on a detailed study of seismic activity in the region. Outcomes include casualties, displaced households, building damage by construction material type, hospital functionality, highway bridge functionality, and infrastructure recovery rates. Demographic information includes the use of public transportation, elderly population, and vulnerability based on education, income, and race. Additionally, the type and frequency of communication among key planning agencies and other organizations in the region are investigated through the use of personal interviews as well as a survey to determine the degree to which these agencies consider seismic risk in their communication and coordination planning.  相似文献   

13.
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   

14.
Social vulnerability is as much a part of risk as building damage, hazard magnitude, and economic loss. Social vulnerability refers to the capacity of a human community exposed during the impact of a natural hazard event (in this case, an earthquake) to resist, cope with, and recover from that impact. In the perspective of the 3rd millennium, we come to understand that the most efficient and accessible way to reduce the pressure of natural risks is to reduce the vulnerability level of the human communities exposed to that certain hazard. This study aims to test, in an exposed and vulnerable area, the relationship between social vulnerability and the perception of the seismic risk. The research focuses only on the first level of social vulnerability, defined as the ability of an individual within a household to recover from a natural hazard impact (Dwyer et al. 2004). A prevailing assumption was that social vulnerability influences the level of perception of the seismic risk, in an exposed, vulnerable area. To this end, two samples were used, different under the aspect of social vulnerability, in the context of the same residential area. Social vulnerability was computed as a normalized composed index that includes the poverty ratio and the demographic vulnerability ratio (depending on the age, gender, and education level indicators). The statistical processing has indicated a significant difference in the high perception level for the two samples that were compared, in the sense that in the context of an increased level of social vulnerability, people generally better acknowledge the seismic risk.
Iuliana ArmaşEmail:
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15.
Estimation of seismic hazard in Gujarat region, India   总被引：1，自引：1，他引：0  
The seismic hazard in the Gujarat region has been evaluated. The scenario hazard maps showing the spatial distribution of various parameters like peak ground acceleration, characteristics site frequency and spectral acceleration for different periods have been presented. These parameters have been extracted from the simulated earthquake strong ground motions. The expected damage to buildings from future large earthquakes in Gujarat region has been estimated. It has been observed that the seismic hazard of Kachchh region is more in comparison with Saurashtra and mainland. All the cities of Kachchh can expect peak acceleration in excess of 500?cm/s2 at surface in case of future large earthquakes from major faults in Kachchh region. The cities of Saurashtra can expect accelerations of less than 200?cm/s2 at surface. The mainland Gujarat is having the lowest seismic hazard as compared with other two regions of Gujarat. The expected accelerations are less than 50?cm/s2 at most of the places. The single- and double-story buildings in Kachchh region are at highest risk as they can expect large accelerations corresponding to natural periods of such small structures. Such structures are relatively safe in mainland region. The buildings of 3?C4 stories and tall structures that exist mostly in cities of Saurashtra and mainland can expect accelerations in excess of 100?cm/s2 during a large earthquake in Kachchh region. It has been found that a total of 0.11 million buildings in Rajkot taluka of Saurashtra are vulnerable to total damage. In Kachchh region, 0.37 million buildings are vulnerable. Most vulnerable talukas are Bhuj, Anjar, Rapar, Bhachau, and Mandvi in Kachchh district and Rajkot, Junagadh, Jamnagar, Surendernagar and Porbandar in Saurashtra. In mainland region, buildings in Bharuch taluka are more vulnerable due to proximity to active Narmada-Son geo-fracture. The scenario hazard maps presented in this study for moderate as well as large earthquakes in the region may be used to augment the information available in the probabilistic seismic hazard maps of the region.  相似文献   

16.
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   

17.
The paper focuses on automatic extraction of building stock information for quantifying physical exposure and its vulnerability from High and Very High Resolution (VHR) optical satellite imagery. We use two case studies. In Sana’a (Yemen), we use automatic techniques to extract the building stock as well as building height that is used to characterize its vulnerability. In Port-au-Prince (Haiti)—the area affected by the 2010 earthquake—we map the building stock based on a pre-disaster imagery, and we show the added value of area-based information when added to point-based damage assessment from visual change interpretation of post-disaster aerial images. This paper shows that VHR imagery can be used to locate and quantify the building stock and its height. This paper also shows that damages measured from changes detected from pre- and post-disaster imagery can in principle map and provide vulnerability information related to the structural fragility of the building stock.  相似文献   

18.
泥石流作用下建筑物易损性评价方法分析与评价   总被引：1，自引：0，他引：1  
曾超  贺拿  宋国虎 《地球科学进展》2012,27(11):1211-1220
建筑物易损度评价作为泥石流易损度评价的重要组成部分,其研究是实现城镇及居民点泥石流风险定量化和风险管理的必要环节。综述近30年来,泥石流作用下建筑物易损度研究的发展过程,并指出以统计分析方法建立的建筑物易损度曲线普适性差且力学机理不明等问题,提出数值计算和模型实验的手段获取建筑物结构易损度的机理模型。由于建筑物易损度研究问题本身的复杂性,统计分析方法仍将作为建筑物易损度研究的重要手段,力学机理明晰的研究方法则将成为今后研究的难点和热点。此外,地震、滚石、雪崩等类似灾种的易损度研究方法和成果可被借鉴到泥石流领域。针对灾害中因结构破坏引发人员伤亡的情况,建议采用时间概率和基于条件概率的事件树方法计算建筑物内人员易损度。最终形成综合结构和人员易损度研究成果的建筑物易损度评价方法。  相似文献   

19.
Although geophysical hazards like earthquakes can lead to tremendous losses, they are often neglected or not considered in risk analyses within an Alpine context. However, lately and especially in the framework of multi-risk analyses, earthquake risk studies are being increasingly implemented within an Alpine relation too. The presented study was conducted to quantitatively estimate potential consequences of earthquake events in the Austrian Province of Tyrol. The methodological study framework integrates the general risk components (i) hazard, (ii) elements at risk, and (iii) vulnerability. They are considered on a regional scale, accepting pragmatic approaches with simplified procedures and assumptions. Scenarios for different potential epicentres were calculated based on two different macroseismic hazard maps derived from punctual ground motion values of the building code and microzonation studies. The maps take into account the design event definitions of existing building code and a, thereupon based, simple and mono-causal Maximum Credible Earthquake assumption. Corresponding elements at risk and damage potentials were identified and potential losses were estimated under consideration of different vulnerability approaches. It can be shown that most scenarios based on the design event definition of the Austrian and European building codes, respectively have the potential of building and inventory losses solely of some hundred million up to approximately €4 billion. Additional, building and inventory losses of maximum credible events can lead to losses of more than €7 billion merely in connection with the primary earthquake event neglecting all other cascading effects.  相似文献   

20.
Bakir  P.G. 《Natural Hazards》2004,33(3):405-425
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   

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