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1.
Earthquake risk assessment for Istanbul metropolitan area   总被引:2,自引:2,他引:2  
The impact of earthquakes in urban centers prone to disastrous earthquakes necessitates the analysis of associated risk for rational formulation of contingency plans and mitigation strategies. In urban centers, the seismic risk is best quantified and portrayed through the preparation of “Earthquake Damage and Loss Scenarios.” The components of such scenarios are the assessment of the hazard, inventories and the vulnerabilities of elements at risk. For the development of the earthquake risk scenario in Istanbul, two independent approaches, one based on intensities and the second on spectral displacements, are utilized. This paper will present the important features of a comprehensive study, highlight the methodology, discuss the results and provide insights to future developments.  相似文献   

2.
我国地震多、强度大、分布广,强地震的现实危害和潜在威胁是我国城市安全发展所面临的重大挑战。国内外城市地震灾害惨痛经验表明,震灾预防能力建设不足的城市往往在强震中毁于一旦。实现我国城市安全可持续发展,必须高度重视和持续推进城市震灾预防能力建设,切实防控和消除地震灾害风险。本文在深入分析城市地震灾害影响因素的基础上,从震灾预防能力建设、城市地震灾害风险防控工作、法规及技术标准和评价体系等方面入手,提出了进一步加强城市震灾预防能力建设的对策建议。  相似文献   

3.
王盛泽 《华南地震》2010,30(1):82-91
从历史最大地震烈度分布图分析,可知揭阳、汕头、潮州三市位于Ⅶ~Ⅷ度高地震烈度区。该城市群地震灾害有以下特点:市区发生破坏性地震的潜在危险性大;地震时市区地震烈度高,地震灾害大,损失严重。采用宏观经济易损性的地震损失分析方法,重演该区的历史破坏性地震。分析表明:抓好该区的防震减灾工作是保持社会和经济建设持续发展的一项重要工作。  相似文献   

4.
李清亚 《地震工程学报》2018,40(6):1272-1277
传统三维城市规划模型是利用三维技术通过计算机生成模型对城市进行规划,没有考虑城市地理位置因素,不能保障城市震后应急救灾工作效率。为此,构建一种新的地震带城市规划模型。通过对城市抗震防灾空间及防灾分区定义,并对其规划原则进行分析,从而为城市防灾空间规划提供依据;以此为基础,采用风险评估方法构建出地震带城市抗震防灾空间规划的基本模型。实验结果表明,所设计模型性能极佳,考虑到了城市地理因素,在进行城市规划的同时,能够促进城市震后应急救灾工作的高效运行。  相似文献   

5.
—?The city of Florence possesses a concentration of cultural and artistic treasures which is unique in the world. In this sense it has a particularly high seismic exposure and a potentially high vulnerability. In order to better evaluate its seismic hazard and risk, we analyzed the seismic response of the urban area of Florence by performing a multidisciplinary study on the effects of earthquakes on the city. By a computer aided methodology we re-evaluated the seismic intensity reports of the May 18 and June 6, 1895 earthquakes in different parts of the city and compared these data with recent studies on surface geology, active tectonics and actual fault movements in the Florence basin. We concluded that more detailed studies of soil response are needed to form a basis for public policy.  相似文献   

6.
Potential impact of large earthquakes on urban societies can be reduced by timely and correct action after a disastrous earthquake. Modern technology permits measurements of strong ground shaking in near real-time for urban areas exposed to earthquake risk. The Istanbul Earthquake Rapid Response System equipped with 100 instruments and two data processing centers aims at the near real time estimation of earthquake damages using most recently developed methodologies and up-to-date structural and demographic inventories of Istanbul city. The methodology developed for near real time estimation of losses after a major earthquake consists of the following general steps: (1) rapid estimation of the ground motion distribution using the strong ground motion data gathered from the instruments; (2) improvement of the ground motion estimations as earthquake parameters become available and (3) estimation of building damage and casualties based on estimated ground motions and intensities. The present paper elaborates on the ground motion and damage estimation methodologies used by the Istanbul Earthquake Rapid Response System with a special emphasis on validation and verification of the different methods.  相似文献   

7.
根据对历史地震震中和山西断陷带内沉降中心的研究,发现该带内的强震震中与沉降中心有很好的对应关系。以现有的资料为基础,统计了各沉降中心内第四系与新生界的比值(Q/Kz)。结果表明,强震的发生与沉降中心的 Q/Kz值有一定的对应规律。根据这一结果,近一步讨论了512年7 1/2级地震的震中位置。  相似文献   

8.
基于粤港澳大湾区地震灾害风险评估的初步成果,分析了湾区城市群地震环境、承灾体分布和场地特点,提出了两种确定地震输入的设定地震原则,即潜在震源区设定地震原则和最大风险设定地震原则,按照这两种原则可以更加准确地进行城市群地震灾害风险评估。在前人工作的基础上,提出了考虑场地条件影响的地震灾害风险表达式,探索了适合三维模拟非一致激励地震动输入的建筑物和生命线工程灾害风险评估方法,提出了建筑物和生命线工程灾害风险评估中考虑场地影响的思路,为客观地评估城市群地震灾害和损失风险提出了可参考的建议。   相似文献   

9.
Finite Fault Modeling in a Tsunami Warning Center Context   总被引:1,自引:0,他引:1  
The US NOAA/NWS tsunami warning centers have relied on earthquake location and depth, and scalar measures of earthquake size and slowness to assess the potential for the generation of a destructive tsunami by an earthquake. Recent earthquakes, such as Peru 2001, Sumatra 2004 and the Java 2006, manifest some of the difficulties the warning centers face as they try to cope with unusual earthquakes. We have undertaken a study of a simple teleseismic waveform inverse model and applied it to the earthquakes of June 23, 2001 in Peru and of July 17, 2006 in Java. Synthetic numerical experiments suggest that the most salient features of the rupture history of an earthquake can be recovered. Furthermore the calculations can be conducted quickly enough to be useful in a warning center context. We have applied our technique to the Peru 2001 and recent Java 2006 earthquakes. Our overall results are consistent with those obtained from other studies. The results show why the Peru event initially looked slow to the US tsunami warning centers and that the Java event is a truly slow or tsunami earthquake. Clearly, the warning centers stand to benefit from an increased understanding of the earthquakes they monitor. Furthermore, better knowledge of the slip distribution along a fault will improve tsunami wave-height forecasts.  相似文献   

10.
The two-island Republic of Trinidad and Tobago in the eastern Caribbean has enjoyed increased physical and industrial development in recent years; however, these islands have been subjected to damaging earthquakes during their history and an up-to-date risk assessment is needed. We examine two approaches to quantifying this problem: (a) the risk estimated probabilistically using recent instrumental data and (b) the hazard inferred from regional tectonic movements. The probabilistic approach indicates that peak ground accelerations with a probability of exceedance of 10 per cent in 50 years could range from 0–23g in Tobago to 0–36g in North-West Trinidad. Tectonic considerations suggest that a maximum-moment earthquake occurring directly under either land mass could generate accelerations as high as 0–6g; the probability of occurrence of such an event is estimated to be about 2 per cent in 50 years for Trinidad and about a tenth this risk for Tobago. This level of hazard would be significant for critical facilities such as LNG plants.  相似文献   

11.
Eight Central American volcanoes had large eruptions during the period 1961 to 1972. The distribution of intermediate depth earthquakes which occurred during the same period is marked by eight concentrations. Seven of the eight very active volcanoes are spatially related to the concentrations of intermediate depth earthquakes. The centers of the concentrations are typically a few tens of kilometers seaward of the volcanoes. The earthquakes have focal depths of about 70 to 110 km. Directly below the active volcanoes there is little or no intermediate depth seismic activity. Partially melted areas along the deep seismic zone directly below the active volcanoes might explain this distribution. Spatial-temporal progressions relating specific intermediate depth earth-quakes to specific volcanic eruptions have not been recognized. The development of a concentration of intermediate depth earthquakes spatially related to a quiescent volcano may indicate that the volcano will soon enter a period of renewed activity.  相似文献   

12.
13.
The aim of this study is to investigate the seismicity of Central Anatolia, within the area restricted to coordinates 30–35° longitude and 38–41° latitude, by determining the “a” and “b” parameters in a Gutenberg–Richter magnitude–frequency relationship using data from earthquakes of moment magnitude (Mw)?≥?4.0 that occurred between 1900 and 2010. Based on these parameters and a Poisson model, we aim to predict the probability of other earthquakes of different magnitudes and return periods (recurrence intervals). To achieve this, the study area is divided into six seismogenic zones, using spatial distributions of earthquakes greater than Mw?≥?4.0 with active faults. For each seismogenic zone, the a and b parameters in the Gutenberg–Richter magnitude–frequency relationship were calculated by the least squares method. The probability of occurrence and return periods of various magnitude earthquakes were calculated from these statistics using the Poisson method.  相似文献   

14.
The general relationships of the structure of the Kurile-Kamchatka zone are examined. The chain of volcanoes forms a true arc with the radius of 1884 km. The focal layer of earthquakes along the whole arc extends to depth with an angle of 48° ± 5°, and is a part of the surface of a circular cone. The energy of earthquakes at intervals of depth 0–100 km, 101–300 km, and 301–650 km is on the average distributed equally along the whole arc and in time. The activity of volcanoes of the whole zone in time is also rather evenly distributed. The energy lost from the earth’s interior during the volcanic eruptions is not less than the energy emitted as elastic waves during tectonic earthquakes.  相似文献   

15.
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   

16.
首先利用最短断层法烈度衰减模型分别模拟两次地震的地震动参数空间分布,并通过与实际地震的极震区对比,验证该模型模拟地震烈度的可靠性.然后,基于模拟的地震烈度空间分布和建筑物的结构类型、层高等信息,采用结构弹塑性时程分析方法对兰州市城关区建筑物进行三维震害模拟.研究结果表明:最短断层法是一个模拟历史地震烈度空间分布较好的模...  相似文献   

17.
Bogotá, the capital city of Colombia, is mostly located on a lacustrine soil deposit surrounded by hills in a central plateau of the eastern cordillera of the Colombian Andes. This highly populated urban area is exposed to a significant seismic hazard from local and regional fault systems. In addition, the potential ground motion amplification during earthquakes due to the presence of soft soil deposits, along with the effects of the surface and subsurface topography, can strongly influence the seismic hazard and consequently the seismic risk to the city. This study aims to develop a physics‐based framework to generate synthetic ground records that can help better understand the seismic response of the basin and other amplification effects during strong earthquake shaking in the region, and to incorporate these effects into the estimation of seismic risk. To this end, a set of simulations were first conducted on Hercules, the wave propagation octree‐based finite element simulator developed by the Quake Group at Carnegie Mellon University, to identify the impacts of hypothetical strong earthquakes scenarios. Then, the results from these simulations were integrated with the exposure and vulnerability information previously developed for the main building constructions in the city to assess the seismic risk in the region under different conditions of analysis. Results from this more detailed model are compared with previously published results from simplified models. Sensitivity analyses help identify critical aspects that should be considered in the future to improve the seismic risk assessment of infrastructure.  相似文献   

18.
This study focuses on four moderate-sized earthquakes in the northern margin of the Qaidam Basin, northeastern Tibet Plateau, China, of which one occurred in 2008, and three in 2009, respectively. We obtain coseismic displacement fields of these four events using Envisat descending ASAR data and D-InSAR technology. The results show that the 2008 earthquake has only one deformation center and the 2009 earthquakes have three deformation centers in their fields. The maximum displacement of 2008 and 2009 earthquakes are 0.097m and 0.41m in the LOS(line of sight), respectively. We invert ground displacements of these earthquakes based on elastic dislocation models to estimate slip distribution on fault planes. For the 2008 event, using a one-segment fault model, the inversion reveals peak slip of about 0.47m occurring at a depth of 19km. For the 2009 earthquakes, the ground displacement pattern observed by InSAR can be fitted by a three-segment fault model with smallest RMS of residuals. The three sectional fault model is considered the most reliable.  相似文献   

19.
The Soufriere Hills volcano in the south-eastern part of Montserrat erupted pyroclast flows as recently as A. D. 1646 ± 54 years and must therefore be considered dormant, not extinct. The highly destructive nature of pyroclast flow eruptions makes it imperative that such activity should be predicted and, if the threat of eruption becomes sufficiently large, the population should be moved to a sale distance from the volcano. Sharp increases in seismic and solfataric activity occurred in 1966 and these events indicated the abnormally high risk of an eruption in the near future. A network of four short period seismographs was established in the island in May 1966 and between this date and the end of 1967, 723 local earthquakes were recorded, of which 32 were reported felt in the island. Hypocentres were determined for 189 of these earthquakes, and most of these lay in a WNW to ESE belt beneath the Soufriere Hills, at depths of less than 15 km. The average rate of seismic energy release decreased with time throughout the series but there was a strong seasonal variation with maxima in May and November–December of each year. The average depth of the earthquakes decreased from 5.2 km in April and May 1966 to a minimum of 2.8 km from July to September 1966. After September the mean focal depths increased again and by the end of the crisis in November 1967 the mean depth was 9.7 km. Measurements carried out using water-tube tiltmeters showed that the region 2–3 km south-east of the Soufriere Hills was doming upwards until January 1967, then subsided between January–March 1967 and finally rose again at a slower rate between March and September 1967. Heat flow from Galway’s Soufriere which was 3 × 105 cal/sec in 1954 increased to a maximum of 2 × 105 cal/sec in October 1966, then declined to 5 × 105 cal/sec in September 1967. The earthquake series was not the aftershock sequence of any major tectonic earthquake, and only two hypocentres were determined at depths greater than 15 km. It is concluded that magma was intruded into the upper crust beneath the Soufriere Hills volcano and that the earthquakes and other phenomena resulted from the upward migration of this magma.  相似文献   

20.
During the months of June–July 2017, the Lake Ohrid area in the southwestern Macedonia experienced a series of small to intermediate earthquakes. More than a thousand earthquakes occurred in that period, all in the epicentral area about 10 km east-northeast from Ohrid city center. The earthquakes showed characteristics of a swarm with 50 of them having magnitudes of 3 or greater and the strongest reaching magnitude M5.0. The earthquakes caused concern among the people in Ohrid and neighboring cities and villages and prompted the installation of two networks of temporary stations. One network was deployed in the epicentral area to determine in more detail the earthquakes’ depth and source parameters. The other urban network of instruments was installed to monitor the influence of the ground on the amplification of shaking and the dynamics of structures in the city of Ohrid. In this study, a selection of the urban network strong motion (SM) records was analyzed for the first time. Accelerograph records from a magnitude M3.1 earthquake recorded at eight places in the city and from the two earthquakes with magnitudes M4.2 and M5.0 recorded at the permanent seismological station Ohrid (code OHR) were used. The results of the behavior of the instrumented building were also compared with the findings of previous experiments. The differences in the spectral values on the SM records from the stations were investigated in respect to the ground conditions and location where the instruments were installed, i.e., bedrock and sediments at the sites. The power spectra and the H/V ratio of the earthquake records from the 2017 seismic sequence in the Ohrid area were also viewed in respect to the Eurocode-8. In addition to being used as part of standard engineering practice, this information about the local soil conditions can be of interest to geophysicists in seismic and geotechnical investigations, as well as in seismic risk-assessment applications.  相似文献   

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