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1.
This study conducts coupled simulation of strong motion and tsunami using stochastically generated earthquake source models. It is focused upon the 2011 Tohoku, Japan earthquake. The ground motion time-histories are simulated using the multiple-event stochastic finite-fault method, which takes into account multiple local rupture processes in strong motion generation areas. For tsunami simulation, multiple realizations of wave profiles are generated by evaluating nonlinear shallow water equations with run-up. Key objectives of this research are: (i) to investigate the sensitivity of strong motion and tsunami hazard parameters to asperities and strong motion generation areas, and (ii) to quantify the spatial variability and dependency of strong motion and tsunami predictions due to common earthquake sources. The investigations provide valuable insights in understanding the temporal and spatial impact of cascading earthquake hazards. Importantly, the study also develops an integrated strong motion and tsunami simulator, which is capable of capturing earthquake source uncertainty. Such an advanced numerical tool is necessary for assessing the performance of buildings and infrastructure that are subjected to cascading earthquake–tsunami hazards.  相似文献   

2.
A detailed numerical simulation of the ground motion and a site response analysis for two towns in the Marche Region (Treia and Cagli) is carried out on the basis of structural models deduced from available geological and geophysical data. In both cases, the reference event is an M = 5.7 earthquake associated with a normal fault located beneath each town. The ground motion is computed using the 2D spectral element method (SPEM 2D). The method solves the propagation of the seismic field through complex geological structures and enables an estimate of the effects of deep crustal structure, superficial geology, and topography on ground motion. Numerical simulations of the seismic field are performed along 2D vertical planes containing the seismic source. Strong ground motion has not been yet recorded in the two towns; therefore, the numerical simulation of ground motion represents a way to overcome the lack of instrumental data. The simulations carried out for Treia show that ground motion is influenced by both source mechanism and effects due to propagation through the geological structure, while ground motion in Cagli features strong local effects, caused by the presence of alluvial deposits under a large area of the town.  相似文献   

3.
邢台地区设定地震事件烈度影响   总被引:1,自引:1,他引:0  
通过邢台地区历史地震烈度资料分析,得到该地区烈度—频率灾害曲线及地震风险。以地震地质资料理论为基础,结合河北省城市活断层探测成果、地壳结构等资料,确定2个设定地震事件。采用复合震源模型,模拟合成强地面运动,并基于强地面运动模拟结果,分析邢台地区地震影响烈度,为今后该地区建筑物抗震设防、避难场所选址、震后救援以及地震保险风险评估提供参考依据。  相似文献   

4.
油气储运系统钢结构设备地震火灾效应研究   总被引:3,自引:0,他引:3  
预防和减轻油气储运系统地震火灾危险性是防震减灾中的重要课题。本文论述了油气储运系统的地震火灾特征及防火要求,对钢结构的防火涂料在遭到破坏和平时情况下的抗火性能进行了对比分析,并应用有限元法对油气储运系统中典型钢结构设备在地震火灾荷载作用下的抗火性能进行了数值模拟。研究结果表明,防火涂料遭到强地震荷载破坏后,钢结构的抗火性能大大降低。  相似文献   

5.
Ground motion prediction is important for earthquake early warning systems, because the region’s peak ground motion indicates the potential disaster. In order to predict the peak ground motion quickly and precisely with limited station wave records, we propose a real-time numerical shake prediction and updating method. Our method first predicts the ground motion based on the ground motion prediction equation after P waves detection of several stations, denoted as the initial prediction. In order to correct the prediction error of the initial prediction, an updating scheme based on real-time simulation of wave propagation is designed. Data assimilation technique is incorporated to predict the distribution of seismic wave energy precisely. Radiative transfer theory and Monte Carlo simulation are used for modeling wave propagation in 2-D space, and the peak ground motion is calculated as quickly as possible. Our method has potential to predict shakemap, making the potential disaster be predicted before the real disaster happens. 2008 M S8.0 Wenchuan earthquake is studied as an example to show the validity of the proposed method.  相似文献   

6.
利用多方收集到的地震灾害资料,对2019年全球地震活动性及地震灾害进行了整理,绘制了全球灾害地震分布图,描述了造成人员伤亡的地震信息及灾害情况,对重大地震灾害事件进行了详细描述与分析,并总结了2019年地震灾害的主要特征。2019年全球地震与往年相比,其活动性较弱,且强震的发生率大大降低;2019年地震灾害造成的伤亡较小、但灾害呈现频度高、范围广等特征,针对此情况,提出了相应的地震灾害预防措施及建议,强调了未来的地震监测防御工作仍然任重道远。   相似文献   

7.
The development and implementation of an earthquake early warning system (EEWS), both in regional or on-site configurations can help to mitigate the losses due to the occurrence of moderate-to-large earthquakes in densely populated and/or industrialized areas. The capability of an EEWS to provide real-time estimates of source parameters (location and magnitude) can be used to take some countermeasures during the earthquake occurrence and before the arriving of the most destructive waves at the site of interest. However, some critical issues are peculiar of EEWS and need further investigation: (1) the uncertainties on earthquake magnitude and location estimates based on the measurements of some observed quantities in the very early portion of the recorded signals; (2) the selection of the most appropriate parameter to be used to predict the ground motion amplitude both in near- and far-source ranges; (3) the use of the estimates provided by the EEWS for structural engineering and risk mitigation applications.In the present study, the issues above are discussed using the Campania–Lucania region (Southern Apennines) in Italy, as test-site area. In this region a prototype system for earthquake early warning, and more generally for seismic alert management, is under development. The system is based on a dense, wide dynamic accelerometric network deployed in the area where the moderate-to-large earthquake causative fault systems are located.The uncertainty analysis is performed through a real-time probabilistic seismic hazard analysis by using two different approaches. The first is the Bayesian approach that implicitly integrate both the time evolving estimate of earthquake parameters, the probability density functions and the variability of ground motion propagation providing the most complete information. The second is a classical point estimate approach which does not account for the probability density function of the magnitude and only uses the average of the estimates performed at each seismic station.Both the approaches are applied to two main towns located in the area of interest, Napoli and Avellino, for which a missed and false alarm analysis is presented by means of a scenario earthquake: an M 7.0 seismic event located at the centre of the seismic network.Concerning the ground motion prediction, attention is focused on the response spectra as the most appropriate function to characterize the ground motion for earthquake engineering applications of EEWS.  相似文献   

8.
The Menyuan area is an important transportation hub in the Hexi Corridor. The Menyuan MS6.9 earthquake that occurred on January 8, 2022 had a major impact on the local infrastructure and transportation of this region. Due to the high possibility of similar strong earthquakes occurring in this area in the future, preliminary assessment of the seismic intensity characteristics of destructive earthquakes in this region is essential for effective disaster control. This paper uses the empirical Green′s function (EGF) method as a numerical simulation tool to predict the ground motion intensity of Datong Autonomous County under the action of the scenario earthquake (MS7.5). Seismic records of aftershocks of the 2016 Menyuan MS6.4 earthquake were used as Green’s functions for this simulation. The uncertainties associated with various source parameters were considered, and 36 possible earthquake scenarios were simulated to obtain 72 sets of horizontal ground motions in Datong County. The obtained peak ground acceleration (PGA) vs. time histories of the horizontal ground motion were screened using the attenuation relationships provided by the fifth-edition of China's Seismic Ground Motion Parameter Zoning Map and the NGA-West2 dataset. Ultimately, 32 possible acceleration-time histories were selected for further analysis. The screened PGA values ranged from 78.8 to 153 cm/s2. The uncertainty associated with the initial rupture point was found to greatly affect the results of the earthquake simulation. The average acceleration spectrum of the selected acceleration-time history exceeded the expected spectrum of a intermediate earthquake, which means that buildings in Datong County might sustain some damage should the scenario earthquake occur. This research can provide reliable ground motion input for urban earthquake damage simulation and seismic design in Datong County. Growing the dataset of small earthquakes recorded in this region will facilitate the large-scale simulation of ground motions under different earthquake scenarios.  相似文献   

9.
EarthquakelosestimationbyusingGrosDomesticProductandpopulationdataQI-FUCHEN1)(陈棋福)YONGCHEN1)(陈禺页)LINGCHEN2)(陈凌)1)CenterforAn...  相似文献   

10.
破坏性地震强度预测可用于工程领域抗震设防以及地震危险性分析评估,是防震减灾中一项很重要的基础工作.为了再现九寨沟地震的地震动强度,评估缺失强震记录的九寨章扎台站的地震动强度,本文用经验格林函数法对九寨沟地震进行了数值模拟.选取了震源周边地震动峰值加速度超过10 Gal的10个强震台站进行模拟.因未得到九寨沟地震的余震,初次尝试将汶川地震和定西地震的余震作为格林函数模拟九寨沟地震.模拟结果整体上可以反映各台站地震动的强度特征,尤其是地震动高频成份拟合较好.模拟值的地震动峰值加速度、时程数据、反应谱等与观测值拟合较好.预测结果显示漳扎镇的地震动峰值加速度值约为180~200 Gal.预测结果也表明在缺少大震的余震记录时,经验格林函数法使用其他大震的余震同样可以再现目标地震的强度特征.本研究也为经验格林函数方法在缺乏小震记录地区的使用积累了经验.最后总结了格林函数的选取标准,为经验格林函数方法来预测未来强震动特征积累了经验.  相似文献   

11.
2022年3月16日在日本福岛县东部海域发生7.4级地震,本文基于近实时震害评估系统RED-ACT对此次地震进行了快速评估,包括强震动记录分析、区域地震破坏力震害评估结果和典型桥梁破坏,并结合实际震害对比了该系统评估结果以及其他主要震害快速评估系统的分析结果,结果表明:(1)此次地震造成的地面运动强度较大,多数台站记录PGA较2021年福岛7.3级地震更强,反应谱在0.5~1.3s区间呈现远高于2021年福岛地震的趋势。(2)RED-ACT的震害评估结果相较于日本NIED-CRS系统和美国USGS-PAGER系统与实际震害更为接近,在强震动记录较为密集的地区,开展基于强震动时程和建筑非线性分析的震害评估能够得到更为准确的震害评估结果。(3)此次地震对白石市附近桥梁造成了一定的破坏,桥梁破坏附近处的强震动会对典型桥梁结构造成一定程度的破坏。  相似文献   

12.
利用多方收集到的地震灾害资料,对2020年全球地震活动及地震灾害进行了整理,绘制了近20年全球灾害地震频度与伤亡情况变化曲线及2020年灾害地震分布图,描述了造成人员伤亡的地震信息及灾害情况,对重大地震灾害事件做了详细分析,并总结了2020年地震灾害的主要特征。与往年全球地震相比,2020年全球地震活动性较弱,6级以上强震发生频次大幅减少;2020年地震灾害造成的伤亡为本世纪最低,且灾害地震呈现频度低、伤亡小、重大灾害线性分布等特征。针对地震频度低、伤亡集中情况,本文提出了相应的地震灾害预防措施及建议,强调了未来的监测预报与震害防御工作至关重要。   相似文献   

13.
地震现场灾情信息反馈途径和集成软件   总被引:2,自引:0,他引:2  
在破坏性地震作用下,可导致人员伤亡、建筑物及基础设施破坏、财产损失、社会与经济秩序的混乱及生产系统停止运行等,现场灾情信息是地震现场应急指挥决策的重要依据,迅速、全面对这些信息进行采集与集成是非常重要的。分析了当前地震应急指挥技术系统建设中在该方面存在的一些问题,阐述了地震现场灾情信息分类,同时就其收集反馈途径和集成技术实现进行了研究,并以青岛市地震应急指挥决策软件系统为例,说明了该方法的实用性。  相似文献   

14.
A method to combine probabilistic seismic hazard analysis and stochastic earthquake motion models is presented. A set of parameters characterizing stochastic earthquake motion models is determined on a consistent probabilistic basis. The method proposed herein consists of two steps. First, the ground motion intensity is determined in the context of the conventional hazard curve technique. Next, other ground motion parameters such as duration, predominant frequency and spectral shape parameters are determined as conditional means corresponding to the annual probability of exceedance for the ground motion intensity. Some example applications are presented.  相似文献   

15.
Three studies of site amplification factors, based on the recorded aftershocks, and one study based on strong motion data, are compared one with another and with the observed distribution of damage from the Northridge, CA, earthquake of 17 January 1994 (ML=6.4). In the epicentral area, when the peak ground velocities are larger than vm≈15 cm/s, nonlinear response of soil begins to distort the amplification factors determined from small amplitude (linear) wave motion. Moving into the area of near-field and strong ground motion (vm>30 cm/s), the site response becomes progressively more affected by the nonlinear soil response. Based on the published results, it is concluded that site amplification factors determined from small amplitude waves (aftershocks, small earthquakes, coda waves) and their transfer-function representation may be useful for small and distant earthquake motions, where soils and structures respond to earthquake waves in a linear manner. However in San Fernando Valley, during the Northridge earthquake, the observed distribution of damage did not correlate with site amplification determined from spectra of recorded weak motions. Mapping geographical distribution of site amplification using other than very strong motion data, therefore appears to be of little use for seismic hazard analyses.  相似文献   

16.
It is clear that the basic countermeasure against earthquake strong motion is to reinforce buildings and other structures. Realtime earthquake disaster prevention is a countermeasure during the earthquake itself and is different from realtime seismology. An EEW, earthquake early warning system, is required to trigger realtime earthquake disaster prevention. It is important to avoid too much trust in EEW for the disaster prevention. This paper describes the concept of an EEW and gives a brief history, which eventually led to the development of the UrEDAS, the urgent earthquake detection and alarm system, the first operational P-wave early warning system. A real-world example of disaster prevention by this system is described. Finally, the role of national or public organizations in earthquake disaster prevention will be discussed, with special emphasis on the situation in Japan.  相似文献   

17.
加强高土石坝抗震研究的现实意义及工作展望   总被引:13,自引:0,他引:13  
围绕西部大开发和南水北调战略的需要,对高土石坝抗震研究的现实意义和若干关键问题及研究现状进行了论述。并针对高土石坝震害资料获取与整理、坝料动力特性研究、多耦合非线性动力分析理论和方法、动力破损特征与地震灾害机理、地震安全评价与震害预测的基本理论、抗震设计及抗震措施、震灾机理和抗震理论的动力模型试验等研究提出了工作设想和展望,并提出了建立土石坝地震安全评价及防灾对策专家系统的基本思路。  相似文献   

18.
为了及时、准确、可靠地发出地震预警信息,本文提出了一种基于贝叶斯理论的地震P波双参数预警方法.选取中国地震台网中心记录的四川地区的355条地震数据,统计P波触发后前3 s的P波平均周期τc和位移幅值Pd,结合贝叶斯理论建立震级和峰值加速度的预测模型,并以震级M4.5和峰值加速度为120 cm/s2为预警阈值,建立了地震...  相似文献   

19.
A smoothness priors-time varying autoregressive (AR) coefficient model method for the modelling of earthquake ground motion is shown. The method yields the instantaneous smoothed values of the AR coefficients and the instantaneous smoothed values of the innovations variance. These results in turn yield estimates of the instantaneous spectral density, the time varying covariance function and a simulation model for the ground motion data. An example of the application of the method to the analysis of an accelogram from the February 1971 San Fernando, California earthquake is shown.  相似文献   

20.
中强地震活动区地震动衰减关系的确定   总被引:3,自引:0,他引:3  
地震动衰减关系是影响地震安全性评价特别是地震区划结果的重要因素.我国现行的地震动衰减关系主要是依据6级以上地震的地面运动资料得到的,并没有考虑中强地震的衰减特性.为此,文中利用现有的烈度资料和其他可供参考的研究成果来建立我国中强地震活动区的地震动衰减关系.收集了我国华中、华南、东北等地区的51次地震的烈度等震线资料,运用单随机变量加权最小二乘回归法得到中强地震活动区烈度衰减关系.然后以美国西部地区为参考地区,运用缺乏地震动参数的地震动估计方法-地震对映射法得到中强地震活动区峰值加速度和有效峰值加速度衰减关系.最后,通过与我国强地震区和中强地震区已有的烈度衰减关系和地震动衰减关系的对比,验证了得出的我国中强地震活动区烈度衰减关系和地震动衰减关系的合理性.  相似文献   

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