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1.
A procedure for seismic risk assessment is applied to the Mt. Etna area (eastern Sicily, Italy) through assessment of urban system dysfunction following the occurrence of an earthquake. The tool used is based on the Disruption Index as a concept implemented in Simulator QuakeIST, which defines urban disruption following a natural disaster. The first element of the procedure is the definition of the seismic input, which is based on information about historical seismicity and seismogenic faults. The second element is computation of seismic impact on the building stock and infrastructure in the area considered. Information on urban-scale vulnerability was collected and a geographic information system was used to organise the data relating to buildings and network systems (e.g., building stock, schools, strategic structures, lifelines). The central idea underlying the definition of the Disruption Index is identification and evaluation of the impact on a target community through the physical elements that most contribute to severe disruption. The procedure applied in this study (i.e., software and data) constitutes a very useful operational tool to drive the development of strategies to minimise risks from earthquakes.  相似文献   

2.
张桂欣  孙柏涛  陈相兆 《地震》2017,37(4):69-79
生命线工程的震害及损失评估工作对于震害防御和震后地震应急工作有着极其重要的意义。 但是, 生命线工程是一个复杂庞大的网络系统, 目前对其开展的震害及损失评估研究工作存在着很大的局限性和不确定性。 本文充分利用研究较多且较系统的建筑物震害及损失评估结果, 结合历次典型历史地震震害中建筑物和生命线震害情况, 通过分析建筑物损失和生命线工程损失的数量关系, 建立二者之间的关联模型; 通过对人口、 GDP、 土地利用等公里网格数据进行分析, 给出中国大陆地区的分区分类原则, 建立分区分类的生命线工程地震直接经济损失分析模型; 基于GIS软件平台, 开发了生命线工程地震直接经济损失分析模块, 利用该模块, 得出了四川省不同地震烈度下的生命线工程直接经济损失空间分布情况。  相似文献   

3.
The city of Oran is exposed to a significant seismic hazard, as almost all the northern Algeria territory, where numerous casualties and severe damage occurred in the last decades due to several moderate to large earthquakes. A mitigation policy should include the establishment of priorities to reduce the vulnerability of existing buildings based on the knowledge of the actual urban fabrics. The complexity of vulnerability assessment requires a gradual approach from the urban scale to the building scale. The study reported in this paper corresponds to the first step of such an approach, i.e., a preliminary study of the seismic vulnerability and expected damage within an urban district of the city of Oran, based on a non-dedicated data base from a building survey previously performed for other purposes. The main goals of this study are twofold: (1) an assessment of the degree of uncertainty and robustness of such results through a comparison of the results derived from different urban vulnerability methods (GNDT 2; RISK-UE LM1; and VULNERALP 2.0) and (2) an assessment of the actual level of seismic risk in the city of Oran. Cross-method comparisons and correlations highlight a satisfactory agreement between mean damage estimates at the urban scale, despite significant scattering at the single building scale, and uncertainty levels which vary significantly from one method to the other. For a given scenario, the three methods provide damage estimates lying within half an EMS damage degree of one another, with some systematic positive bias for VULNERALP and negative bias for RISK-UE LM1, especially for masonry buildings. The expected mean damage is very important for intensities 9 and 10, with an average damage grade around 3–4 for intensity 9 and 4–5 for intensity 10. The spatial distribution of damage systematically exhibits larger values in the northern, older, commercial area, than in the southern, more recent and more residential area, in relation to the building typology and the existence of several aggravating factors. Some areas of higher vulnerability / damage can be distinguished, which should receive particular attention for retrofitting priorities or urban planning decisions, also taking into account their cultural heritage value.  相似文献   

4.
The seismic risk analysis evaluation in the Mediterranean area is one of the main tasks for the preservation of Cultural Heritage and for the sustainable development of Mediterranean cities. The Mediterranean area is characterised by a medium–high level of seismic risk, so that earthquakes are the major cause for the destruction of monuments, residential and industrial buildings. A case history regarding the seismic risk analysis for the city of Catania (Italy) is presented, since the city has been heavy damaged in the past by strong earthquakes such as the 1169 earthquake (XI MCS), the 1542 earthquake (IX MCS), the 1693 earthquake (XI MCS) and the 1818 earthquake (VIII MCS) etc., which caused several thousands of deaths. Fault modelling, attenuation laws, synthetic accelerograms, recorded accelerograms and site effects are considered for the evaluation of the seismic action. Vulnerability of physical environment, related to the presence of cavities and to seismic-induced landslides and liquefaction has been analysed, with special reference to the new modelling of such phenomena and to the application of models to given areas. Soil–structure Interaction has been analysed for some geotechnical works, such as shallow foundation and retaining wall, by means of physical and numerical modelling. The paper deals with the vulnerability of physical environment (landslides, liquefaction, etc.), while the road map continues with the analysis of vulnerability of monuments and buildings, with the aim of the estimation of the seismic resistance required to defend against the seismic action given by the scenario earthquake. For the mitigation of seismic risk, structural improvements of R.C. buildings with different methodology and techniques have been analysed, as well as the guideline for the strengthening of buildings. The work shows that the seismic risk of the city is not a summation of the seismic risk of each building, because the vulnerability of the urban system plays an important role on the seismic risk evaluation of a given city. To this aim the vulnerability of the road infrastructures, lifelines, and urban framework have been also analysed in the project.  相似文献   

5.
In June 2000, two Mw6.5 earthquakes occurred within a 4-day interval in the largest agricultural region of Iceland causing substantial damage and no loss of life. The distance between the earthquake epicentres and the fault rupture was approximately 15 km. Nearly 5000 low-rise residential buildings were affected, some of which were located between the faults and exposed to strong ground motion from both events. The post-earthquakes damage and repair costs for every residential building in the epicentral region were assessed for insurance purposes. The database is detailed and complete for the whole region and represents one of the best quality post-earthquake vulnerability datasets used for seismic loss estimation. Nonetheless, the construction of vulnerability curves from this database is hampered by the fact that the loss values represent the cumulative damage from two sequential earthquakes in some areas, and single earthquakes in others. A novel methodology based on beta regression is proposed here in order to define the geographical limits on areas where buildings sustained cumulative damage and predict the seismic losses for future sequence of events in each area. The results show that the average building loss in areas affected by a single event is below 10% of the building replacement value, whilst this increases to an average of 25% in areas affected by the two earthquakes. The proposed methodology can be used to empirically assess the vulnerability in other areas which experienced sequence of events such as Emilia-Romagna (Italy) in 2012.  相似文献   

6.
为探究山区超高墩三塔大跨斜拉桥在地震作用下各关键构件(桥塔、支座、基础和桥墩)的破坏顺序,以在建的贵州平塘特大桥为工程依托,首先基于OPEENSEES软件建立空间有限元模型,然后基于概率理论建立斜拉桥地震易损性模型,最后以混凝土应变和支座相对位移为易损性指标进行增量动力分析,得到各构件易损性曲线,并基于各构件的易损性曲线对此类桥型的构件破坏顺序进行分析。研究表明:横向地震对该斜拉桥造成的破坏程度要大于纵向地震;在纵向地震作用下桥梁结构最易发生破坏的是中塔支座和边塔基础,在横向地震作用下桥梁结构最易发生破坏的是边塔支座和过渡墩基础。  相似文献   

7.
城市抗震防灾规划中建筑物易损性评价方法的研究   总被引:7,自引:0,他引:7  
基于功能和后果的抗震设防理念,提出了城市建筑物的分类方法并根据不同类别采取不同抗震易损性评价方法,其中包括应用能力谱的理论易损性分析方法和快速群体震害预测方法等。根据这些方法和泉州市规划区内的房屋调查资料,对泉州市的房屋进行了震害预测,并通过泉州市建筑物地震易损性分析的结果,提出了针对性的抗震减灾策略。所发展的易损性评价方法和对策措施对其他城市编制抗震防灾规划也具有一定参考价值。  相似文献   

8.
School facilities in Iran, in particular masonry schools, have shown poor performance during past earthquakes and can be identified as one of the parts of the country’s infrastructure that is most vulnerable to earthquakes. Hence, in this paper a method to perform index-based damage assessment for brick masonry schools located in the province of Yazd, the central region of Iran, using a comprehensive database of school buildings, is proposed. The database was obtained from the field survey forms applied for each observed school to collect the features of and damage to the structure. The results of a vulnerability index method developed in Iran are employed as input data to obtain empirical fragility curves for the school inventory. The Macroseismic model and GNDT II level method are two empirical methods combined in this procedure. Finally, the procedure is verified using damage survey data obtained after recent earthquakes (1990 Manjil–Rudbar earthquake and 2003 Bam earthquake) that occurred in Iran.  相似文献   

9.
A damage scenario modelling is developed and compared with the damage distribution observed after the 2011 Lorca earthquake. The strong ground motion models considered include five modern ground motion prediction equations (GMPEs) amply used worldwide. Capacity and fragility curves from the Risk-UE project are utilized to model building vulnerability and expected damage. Damage estimates resulting from different combinations of GMPE and capacity/fragility curves are compared with the actual damage scenario, establishing the combination that best explains the observed damage distribution. In addition, some recommendations are proposed, including correction factors in fragility curves in order to reproduce in a better way the observed damage in masonry and reinforce concrete buildings. The lessons learned would contribute to improve the simulation of expected damages due to future earthquakes in Lorca or other regions in Spain with similar characteristics regarding attenuation and vulnerability.  相似文献   

10.
搜集自开展地震灾害直接损失评估以来,四川境内破坏性地震震害资料,统计省内藏式房屋在不同烈度不同破坏等级下的破坏比,给出易损性矩阵;采用房屋结构整体易损性分析方法,依据藏式房屋易损性矩阵,通过烈度与地震动参数的对应关系,以对数正态分布函数为模型,对藏式房屋在不同地震动参数(峰值速度)下超越毁坏、破坏、基本完好的概率曲线进行拟合,给出易损性曲线,为其他结构类型房屋的易损性研究、灾害损失评估工作及震害预测提供参考。  相似文献   

11.
Seismic risk evaluation of built-up areas involves analysis of the level of earthquake hazard of the region, building vulnerability and exposure. Within this approach that defines seismic risk, building vulnerability assessment assumes great importance, not only because of the obvious physical consequences in the eventual occurrence of a seismic event, but also because it is the one of the few potential aspects in which engineering research can intervene. In fact, rigorous vulnerability assessment of existing buildings and the implementation of appropriate retrofitting solutions can help to reduce the levels of physical damage, loss of life and the economic impact of future seismic events. Vulnerability studies of urban centres should be developed with the aim of identifying building fragilities and reducing seismic risk. As part of the rehabilitation of the historic city centre of Coimbra, a complete identification and inspection survey of old masonry buildings has been carried out. The main purpose of this research is to discuss vulnerability assessment methodologies, particularly those of the first level, through the proposal and development of a method previously used to determine the level of vulnerability, in the assessment of physical damage and its relationship with seismic intensity. Also presented and discussed are the strategy and proposed methodology adopted for the vulnerability assessment, damage and loss scenarios for the city centre of Coimbra, Portugal, using a GIS mapping application.  相似文献   

12.
结合天然地震推导水库地震的建筑物易损性   总被引:1,自引:1,他引:0       下载免费PDF全文
通过类比的方法,选择有现场调查资料并有建筑物破坏比结果的天然地震,基于地震中建筑物震害表现的一致性,以震级、震源深度和极震区烈度为标准,聚类得到与水库地震震害相似的天然地震震例。考虑到宏观经济水平与地震经济损失已有的统计模型,采用了人口密度、人均GDP和三产比例等3个宏观经济指标来反映不同地区的建筑物总体抗震水平,以加权海明(Hamming)距离来定义已知矩阵与目标矩阵的近似度,最终的加权结果即为待求地区的易损性矩阵。通过实际检验,所得的建筑物易损性关系能够反映水库地震的破坏特点,较中强天然地震的易损性要高。这种工作思路也可以用于水库地震其它方面的研究中  相似文献   

13.
A vulnerability analysis of some historical and monumental buildings in the city of Málaga is presented in this paper. More than twenty of these monuments were severely damaged or completely destroyed due to the large earthquake (I max = VIII–IX) occurred in the Málaga region in October 1680. The vulnerability index methodology has been used in this paper. This technique is based on statistical data from seismic damage caused to Italian monuments for the past 30?years. For each building, vulnerability curves have been obtained and damage grades have been estimated. A comparison has been carried out between the expected damage grades and the damage observed from past earthquakes, in order to check the feasibility of applying this methodology to Spanish monuments. This comparison has been possible due to the fact that detailed seismic damage information exists for monuments in the city of Málaga that still exist today, which is a very uncommon case in Spain. Results show a good consistency between expected and observed damage, especially for the churches type. Two seismic scenarios have been proposed for the city centre, one deterministic and one probabilistic, where 54 historical and modern buildings have been analyzed. Both scenarios show worrying results, especially for the types of churches, chapels and towers, where expected high probabilities of suffering very heavy damage or even collapse have been obtained. It is highly recommended to take the necessary measures, in the hope of trying to avoid the possible damage that can be expected from future earthquakes.  相似文献   

14.
史华 《地震工程学报》2017,39(6):1024-1028
城市所处的地震危险性环境和城市建筑物的易损性是影响复杂网络建筑物强震环境下抗毁能力的关键因素。由于现阶段对建筑物抗震抗毁能力的评定仍存在一定困难,对建筑物震害程度测评只能通过强震之后建筑物受破坏的程度进行评估,且评估结果不够精准,因此提出基于复杂网络的建筑物抗震能力的评估方法。考虑到地震中的危险性因素,以地面峰值加速度为参数对强震环境下复杂网络建筑物抗毁性进行测评和分析,在此基础上提出对复杂网络下建筑物的防震抗毁能力进行评估的相对建筑物抗震性能指数,并结合建筑物抗震能力评估标准确定其抗震能力水平;再进行仿真实验加以测量,并结合震害经验,证实该方法的有效性。  相似文献   

15.
This paper points to the need for seismic risk and vulnerability assessment of infrastructure systems, most notably tall structures and coastal facilities, in Kuwait and other Arabian Gulf countries. Building codes in the region currently lack seismic provisions, despite evidence of a potential threat from large-magnitude earthquakes originating from the southern part of the Zagros fold belt. The historical record of Iranian earthquakes that may have caused significant ground motion in the Gulf region is examined, as are reports of coastal damage from tsunamis. Various specific tasks, expected to constitute research priorities of a Joint Center for Risk Research, a cooperative research program involving Princeton and Kuwait Universities, are outlined.  相似文献   

16.
17.
Lateral force, response spectrum and step‐by‐step pushover analyses are performed and compared with the post‐earthquake survey of two Dieh‐Dou buildings seriously affected in the 1999 Chi‐Chi earthquake in Taiwan. The results show that the proposed FE model with finite translational and rotational stiffness can successfully be employed to assess the vulnerability of the frames. The fundamental period of Dieh‐Dou structures is about 1.0 s higher than that calculated by the simplified approach of the codes for regular frames; a modal analysis is, therefore, essential for this typology of structure. The elastic analysis, either lateral force or response spectrum, is shown to be reliable to assess Dieh‐Dou frames when quick results are desired. However, a non‐linear step‐by‐step pushover analysis has the advantage of greater accuracy, as it allows mapping the failure trend and indicating the critical elements. The lateral drifts are compared with the actual observed damage pattern and when the damage level is related to the peak ground acceleration on a vulnerability curve plot, it is shown that the joint failure combined with the lateral drift gives an indication of the global structural behaviour of this historic construction typology. Owing to the unique construction features of the Dieh‐Dou, the joint failure represents also a critical criterion in terms of maximum retention for conservation. Based on a damage level approach, an assessment methodology is suggested that would allow optimizing a strengthening strategy, for protection of these precious structures from future earthquakes while avoiding unnecessary interventions. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

18.
The tectonic system of the eastern flank of Mt. Etna volcano (Sicily, Italy) is the source of most of the strongest earthquakes occurring in the area over the last 205 years. A total of 12 events with epicentre intensities ≥VIII EMS have occurred at Mt. Etna, 10 of which were located on the eastern flank. This indicates a mean recurrence time of about 20 years. This area is highly urbanised, with many villages around the volcano at altitudes up to 700 m a.s.l. The southern and eastern flanks are particularly highly populated areas, with numerous villages very close to each other. The probabilistic seismic hazard due to local faults for Mt. Etna was calculated by adopting a site approach to seismic hazard assessment. Only the site histories of local volcano-tectonic earthquakes were considered, leaving out the effects due to strong regional earthquakes that occurred in north-eastern and south-eastern Sicily. The inventory used in this application refers to residential buildings. These data were extracted from the 1991 census of the Italian National Institute of Statistics, and are grouped according to the census sections. The seismic vulnerability of the elements at risk belonging to a given building typology is described by a vulnerability index, in accordance with a damage model based on macroseismic intensities. For the estimation of economic losses due to physical damage to buildings, an integrated impact indicator was used, which is equivalent to the lost building volume. The expected annualised economic earthquake losses were evaluated both in absolute and in relative terms, and were compared with the geographical distribution of seismic hazard and with similar evaluations of losses for other regions.  相似文献   

19.
The buildings’ capacity to maintain minimum structural safety levels during natural disasters, such as earthquakes, is recognisably one of the aspects that most influence urban resilience. Moreover, the public investment in risk mitigation strategies is fundamental, not only to promote social and urban and resilience, but also to limit consequent material, human and environmental losses. Despite the growing awareness of this issue, there is still a vast number of traditional masonry buildings spread throughout many European old city centres that lacks of adequate seismic resistance, requiring therefore urgent retrofitting interventions in order to both reduce their seismic vulnerability and to cope with the increased seismic requirements of recent code standards. Thus, this paper aims at contributing to mitigate the social and economic impacts of earthquake damage scenarios through the development of vulnerability-based comparative analysis of some of the most popular retrofitting techniques applied after the 1998 Azores earthquake. The influence of each technique individually and globally studied resorting to a seismic vulnerability index methodology integrated into a GIS tool and damage and loss scenarios are constructed and critically discussed. Finally, the economic balance resulting from the implementation of that techniques are also examined.  相似文献   

20.
In light of recent earthquakes, structures damaged during an initial seismic event (mainshock) may be more vulnerable to severe damage and collapse during a subsequent event (aftershock). In this paper, a framework for the development of aftershock fragilities is presented; these aftershock fragilities define the likelihood that a bridge damaged during an initial event will exhibit a given damage state following one or more subsequent events. The framework is capable of (i) quantifying the cumulative damage of unrepaired bridges subjected to mainshock–aftershock sequences (effect of multiple earthquakes) and (ii) evaluating the effectiveness of column repair schemes such as steel and fiber‐reinforced‐polymer jackets (post‐repair effect of jackets). To achieve this aim, the numerical model of repaired columns is validated using existing experimental results. A non‐seismically designed bridge is chosen as a case study and is modeled for three numerical bridge models: a damaged (but unrepaired) bridge model, and two bridge models with columns repaired with steel and fiber‐reinforced polymer jackets. A series of back‐to‐back dynamic analyses under successive earthquakes are performed for each level of existing damage. Using simulated results, failure probabilities of components for multiple limit states are computed for each bridge model and then are used to evaluate the relative vulnerability of components associated with cumulative damage and column repair. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

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