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不同地区地震活动的强度和频率是不同的.基于地震危险性分析的地震滑坡危险研究在综合了地震烈度、位置、复发时间等因素的基础上,考虑了地震动峰值加速度时空分布的特点,可以有效地应用于潜在地震滑坡危险区区划.以汶川地震灾区为研究对象,根据研究区的地质构造、地震活动特点等划分出灾区的潜在震源区,对该区进行地震危险性分析,并在此基础上采用综合指标法做出基于地震危险性分析的地震滑坡危险性区划.所得地震滑坡危险性区划按照滑坡危险程度分为高危险、较高危险、较低危险和低危险四级,表示未来一段时间内研究区在遭受一定超越概率水平的地震动作用下,不同地区地震滑坡发生的可能程度. 本文给出的地震滑坡危险性区划结果中,汶川地震滑坡崩塌较发育的汶川、北川、茂县等部分区域均处于高危险或较高危险区域;在对具有较高DEM精度的北川擂鼓镇地区所作的地震滑坡危险性区划中,汶川地震中实际发生的地震滑坡灾害与地震滑坡危险区划结果表现出较好的一致性.对区域范围而言,基于地震危险性分析的地震滑坡区划,可为初期阶段的土地规划使用及重大工程选址提供参考. 相似文献
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重要性不同的现有结构抗震加固设计地震动参数研究 总被引：1，自引：0，他引：1
提出了重要性不同的现有结构抗震加固设计基准期取值原则,给出了现有结构抗震加固设防水准的定义。基于地震危险性特征分区,利用地震动参数的危险性曲线公式对重要性不同的现有结构抗震加固设计地震动参数进行了分析。同时,为了便于工程设计人员使用,给出了现有结构设计地震动参数取值的简化方法。最后,通过算例解释了理论方法和简化计算方法中抗震加固设计地震动参数的取值方法和步骤。 相似文献
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Andrea C. Riao Juan C. Reyes Luis E. Yamín Jacobo Bielak Ricardo Taborda Doriam Restrepo 《地震工程与结构动力学》2021,50(1):155-176
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
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川滇地区是我国地震危险性较高的地区之一.本文基于对特大强震的风险性考虑,使用全球地震模型OpenQuake软件,建立了川滇地区地震危险性预测新模型.首先根据构造特征划分多个震源分区,并整理出这些震源分区内断层活动特征与滑动速率;基于震源分区和断层模型,使用GPS应变率转换成的锥形古登堡-里克特关系作为整个区域的地震积累率,并允许超过历史最大震级的特大地震的出现,结合活动断层滑动速率所积累的地震发生率,给出震源分区内断层地震源和背景地震源的地震发生率的比率分配关系;在活动断层分段上,保留了大型断裂或其主要部分,没有根据小的阶区来对断层进行详细分段,以便分配特大地震发生率;并使用地震率平滑方法分配背景地震发生率.最后在OpenQuake中加入地震动预测方程,计算出了川滇地区的PGA分布图,为区域地震危险性提供科学依据. 相似文献
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Influence of the nonlinear behavior of viscous dampers on the seismic demand hazard of building frames 总被引：1，自引：0，他引：1 
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下载免费PDF全文 This paper analyzes the influence of damper properties on the probabilistic seismic performance of building frames equipped with viscous dampers. In particular, a probabilistic methodology is employed to evaluate the influence of the damper nonlinearity, measured by the damper exponent, on the performance of structural and nonstructural components of building frames, as described by the response hazard curves of the relevant engineering demand parameters. The performance variations due to changes in the damper nonlinearity level are evaluated and highlighted by considering two realistic design scenarios and by comparing the results of a set of cases involving dampers with different exponents designed to provide the same deterministic performance. By this way, it is possible to evaluate the influence of the nonlinear response and of its dispersion on the demand hazard. It is shown that the damper nonlinearity level strongly affects the seismic performance and different trends are observed for the demand parameters of interest. A comparison with code provisions shows that further investigation is necessary to provide more reliable design formulas accounting for the damping nonlinearity level. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Depths of earthquake occurrence and large slip distribution are critical for seismic hazard assessment.Numerous examples show that earthquakes with similar magnitudes,however,can result in significantly different ground shaking and damage.One of the critical factors is that whether the large slip was generated near the ground surface.In this article,we reviewed two aspects that are important on this regard,shallow slip deficit and nucleation depth.Understanding how shallow future earthquakes may nucleate in particular regions,such as shale gas fields,is critical for hazard assessment.Whether or not a strong earthquake may slip significantly at shallow depths(less than 3 km)plays crucial rules in seismic hazard preparation and should be further investigated by integrating high-resolution fault zone observations,dynamic rupture simulation,and fault zone properties.Moreover,precisely resolving shallow depth and slip distribution of earthquakes demands InSAR and/or other image data that can better capture the near-fault deformation to constrain the source parameters of earthquakes. 相似文献
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利用中国西部古地震和历史地震资料建立了特征地震模型并与分档泊松模型结合组成混合地震模型。研究了青藏高原东南缘的重要地震带鲜水河－小江断裂地区的地震危险性,并与1990年出版的中国地震区划图结果进行了比较,表明在1786年曾经发生过73／4级地震的康定地区（离浙时间为213a,地震复地周期为320a）的地震概率大于后,Ⅷ度区面积同样是前大于后。这说明地震离逝时间与地震复发周期关系对地震危险性计算是有影响的,特征地震与混合地震模型的引入解决了泊松模型无记忆性的缺陷,使计算的结果更科学、合理。 相似文献
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Brendon A. Bradley 《地震工程与结构动力学》2013,42(15):2235-2253
This paper compares the seismic demands obtained from an intensity‐based assessment, as conventionally considered in seismic design guidelines, with the seismic demand hazard. Intensity‐based assessments utilize the distribution of seismic demand from ground motions that have a specific value of some conditioning intensity measure, and the mean of this distribution is conventionally used in design verification. The seismic demand hazard provides the rate of exceedance of various seismic demand values and is obtained by integrating the distribution of seismic demand at multiple intensity levels with the seismic hazard curve. The seismic demand hazard is a more robust metric for quantifying seismic performance, because seismic demands from an intensity‐based assessment: (i) are not unique, with different values obtained using different conditioning intensity measures; and (ii) do not consider the possibility that demand values could be exceeded from different intensity ground motions. Empirical results, for a bridge‐foundation‐soil system, illustrate that the mean seismic demand from an intensity‐based assessment almost always underestimates the demand hazard value for the exceedance rate considered, on average by 17% and with a large variability. Furthermore, modification factors based on approximate theory are found to be unreliable. Adopting the maximum of the mean values from multiple intensity‐based assessments, with different conditional intensity measures, provides a less biased prediction of the seismic demand hazard value, but with still a large variability, and a proportional increase the required number of analyses. For an equivalent number of analyses, direct computation of the seismic demand hazard is a more logical choice and provides additional performance insight. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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新版地震区划图地震活动性模型与参数确定 总被引：11，自引：4，他引：7
地震活动性模型和地震动预测模型是概率地震危险性分析的两个核心。在新版地震区划图中,依据板内地震活动空间不均匀性分布的特点,在概率地震危险性分析方法(CPSHA)中采用了由地震统计区、背景潜在震源区和构造潜在震源区构成的三级层次性潜在震源区模型,并构建了相应的地震活动性模型。本文在论述CPSHA方法及其地震活动性模型基本概念的基础上,重点介绍了新版地震区划图地震活动性模型的三级潜在震源区模型的构成、地震活动性假定和基本特点,同时,也对新版地震区划图地震活动性模型的重要参数确定思路、方法与结果进行了介绍。本文将为更好地认识与理解我国新版地震动参数区划图提供有益的参考。 相似文献
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First Order Seismic Microzonation of Haldia, Bengal Basin (India) Using a GIS Platform 总被引：2，自引：0，他引：2
The seismic microzonation of the Bengal Basin, Haldia region, India is carried out using the Analytical Hierarchy Process
(AHP) on the Geographic Information System (GIS). Three themes are used for the seismic microzonation, namely Peak Ground
Acceleration (PGA), predominant frequency and elevation map. An analysis of the maximum magnitude (m
max) and the b value is carried out after preparing the earthquake catalogue from various sources. On the basis of the tectonic
set up and seismicity of the region, five seismic zones are delineated which can be a threat to Haldia. They are broadly classified
as Zone 1: Arakan-Yoma Zone (AYZ), Zone 2: Himalayan Zone (HZ), Zone 3: Shillong Plateau Zone (SPZ), Zone 4: Bay of Bengal
Zone (BBZ) and Zone 5: Shield Zone (SZ). The m
max for Zones 1, 2, 3, 4 and 5 are 8.30 ± 0.51, 9.09 ± 0.58, 9.20 ± 0.51, 6.62 ± 0.43 and 6.61 ± 0.43, respectively. The PGA
value is computed for Haldia following the attenuation relationship taking the m
max of each source zone. The expected PGA at Haldia varies from 0.09–0.19 g. The predominant frequency of Haldia is also calculated
using the H/V ratio with a frequency ranging from 0.1–3.0 Hz. The elevation map of Haldia is also generated using the Shuttle
Radar Topography Mission (STRM) data. A first-order seismic microzonation map of Haldia is prepared in which four zones of
hazard have been broadly classified for Haldia as very high seismic hazard zone, high seismic hazard zone, moderate seismic
hazard zone and less seismic hazard zone. The very high seismic hazard zone is observed along the southern part of Haldia
where there are major industrial and port facilities. The PGA for the four hazard zones are: 0.09–0.13 g for low hazard zone,
> 0.13–0.15 g for moderate hazard zone, > 0.15–0.16 g for high hazard zone and > 0.16–0.19 g for very high hazard zone. 相似文献
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R. Secanell D. Bertil C. Martin X. Goula T. Susagna M. Tapia P. Dominique D. Carbon J. Fleta 《Journal of Seismology》2008,12(3):323-341
A unified probabilistic seismic hazard assessment (PSHA) for the Pyrenean region has been performed by an international team
composed of experts from Spain and France during the Interreg IIIA ISARD project. It is motivated by incoherencies between
the seismic hazard zonations of the design codes of France and Spain and by the need for input data to be used to define earthquake
scenarios. A great effort was invested in the homogenisation of the input data. All existing seismic data are collected in
a database and lead to a unified catalogue using a local magnitude scale. PSHA has been performed using logic trees combined
with Monte Carlo simulations to account for both epistemic and aleatory uncertainties. As an alternative to hazard calculation
based on seismic sources zone models, a zoneless method is also used to produce a hazard map less dependant on zone boundaries.
Two seismogenic source models were defined to take into account the different interpretations existing among specialists.
A new regional ground-motion prediction equation based on regional data has been proposed. It was used in combination with
published ground-motion prediction equations derived using European and Mediterranean data. The application of this methodology
leads to the definition of seismic hazard maps for 475- and 1,975-year return periods for spectral accelerations at periods
of 0 (corresponding to peak ground acceleration), 0.1, 0.3, 0.6, 1 and 2 s. Median and percentiles 15% and 85% acceleration
contour lines are represented. Finally, the seismic catalogue is used to produce a map of the maximum acceleration expected
for comparison with the probabilistic hazard maps. The hazard maps are produced using a grid of 0.1°. The results obtained
may be useful for civil protection and risk prevention purposes in France, Spain and Andorra. 相似文献
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Modelling Seismic Hazard in Earthquake Loss Models with Spatially Distributed Exposure 总被引：1，自引：0，他引：1
The prediction of possible future losses from earthquakes, which in many cases affect structures that are spatially distributed over a wide area, is of importance to national authorities, local governments, and the insurance and reinsurance industries. Generally, it is necessary to estimate the effects of many, or even all, potential earthquake scenarios that could impact upon these urban areas. In such cases, the purpose of the loss calculations is to estimate the annual frequency of exceedance (or the return period) of different levels of loss due to earthquakes: so-called loss exceedance curves. An attractive option for generating loss exceedance curves is to perform independent probabilistic seismic hazard assessment calculations at several locations simultaneously and to combine the losses at each site for each annual frequency of exceedance. An alternative method involves the use of multiple earthquake scenarios to generate ground motions at all sites of interest, defined through Monte–Carlo simulations based on the seismicity model. The latter procedure is conceptually sounder but considerably more time-consuming. Both procedures are applied to a case study loss model and the loss exceedance curves and average annual losses are compared to ascertain the influence of using a more theoretically robust, though computationally intensive, procedure to represent the seismic hazard in loss modelling.An erratum to this article can be found at 相似文献
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Spatial sensitivity of seismic hazard results to different models with respect to background seismic activity and earthquake occurrence in time is investigated. For the contribution of background seismic activity to seismic hazard, background area source with uniform seismicity and spatially smoothed seismicity models are taken into consideration. For the contribution of faults, through characteristic earthquakes, both the memoryless Poisson and the time dependent renewal models are utilized. A case study, involving the assessment of seismic hazard for the Bursa province in Turkey, is conducted in order to examine quantitatively the influence of these models on seismic hazard results. The spatial variation of the difference in Peak Ground Acceleration (PGA) values obtained from these different models is presented in the form of difference maps for return periods of 475 and 2475 years. Best estimate seismic hazard maps for PGA and Spectral Accelerations (SA) at 0.2 and 1.0 s are obtained by using the logic tree method. 相似文献
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Mehdi Zar&# Seyed-Ahmad Hashemi Roya Ebadi Sahar Amirnejad-Mojdehi Roya Rahmani Ali Sardar 《地震科学（英文版）》2012,25(4):299-305
Iran is located in one of the seismically active regions of the world. Due to the high probability of earthquakes throughout the country and the potential for tsunami inundation along the coasts and offshore, comprehensive studies on the interaction of these natural phenomena are necessary. In this study, the most conservative scenarios are determined for possible earthquakes within the Khark zone (Persian Gulf) based on experimental relations between the fault length, magnitude and displacement, which are parameters for determining tsunamigenic sources. Subsequently, the maximum height of tsunami waves are calculated based on the specifications of the seismic source and its distance from the shore as well as the coastal slope. A zoning map of tsunami hazard is finally presented. 相似文献
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Vladimir Sokolov Klaus-Peter Bonjer Friedemann Wenzel 《Soil Dynamics and Earthquake Engineering》2004,24(12):929-947
The paper presents recent achievements in evaluations of site-dependent seismic hazard in Romania and the capital city of Bucharest caused by the Vrancea focal zone (SE-Carpathians). The zone is characterized by a high rate of occurrence of large earthquakes in a narrow focal volume at depths 60–170 km. The database that was used for the hazard evaluation includes parameters of seismicity, ground-motion source scaling and attenuation models (Fourier amplitude spectra), and site-dependent spectral amplification functions. Ground-motion characteristics were evaluated on the basis of several hundred records from more than 120 small magnitude (M 3.5–5) earthquakes occurred in 1996–2001 and a few tens of acceleration records obtained during four large (M 7.4, 7.2, 6.9 and 6.3) earthquakes. The data provide a basis for probabilistic seismic hazard assessment in terms of peak ground acceleration, peak spectral acceleration and MSK intensity using Fourier amplitude spectra for various exceedance probabilities or average return periods. It has been shown that the influence of geological factors plays very important role in distribution of earthquake ground-motion parameters along the territory of Romania. 相似文献
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总结和分析了中国地震带划分的研究历史、目的和用途、划分原则、表现形式以及基本特点，指出地震带是以地震活动性区域划分研究为目的，它不同于概率地震危险性方法中的地震统计区的概念．文中对地震统计区概念及其演化历史进行了分析和论述，认为地震统计区与地震带在统计意义、物理内涵、层次性、划分规模的要求、对空间重叠的排斥性以及划分目的和用途等方面，均存在较大差异．现行工作中将两者不加区分地使用是不合适的， 一方面造成地震统计区未形成自身的适应概率地震危险性分析方法的划分理论，另一方面也造成以地震活动特征和地震孕育发生环境、机制研究为目的的地震带划分研究的停滞不前．文中最后指出，地震统计区划分是以地震带划分研究为基础，它产生并服务于考虑地震活动时空不均匀性的概率地震危险性分析方法，应将其与地震带概念加以明确区分，并加强其划分原则、理论和方法的研究． 相似文献
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建筑结构在地震中的损坏程度是人员伤亡和经济损失预测的基础,也是城市地震经济损失的主要组成部分。本文结合某中等城市市区六种典型建筑在地震作用下的受力特点和破坏机理,分别采用了相应的易损性分析方法,建立了市区震害矩阵。预测结果真实可靠,为进一步进行抗震规划和统计震害损失提供依据。 相似文献
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Seismotectonic zonation studies in the Tell Atlas of Algeria, a branch of the Africa-Eurasia plate boundary, provide a valuable input for deterministic seismic hazard calculations. We delineate a number of seismogenic zones from causal relationships established between geological structures and earthquakes and compile a working seismic catalogue mainly from readily available sources. To this catalogue, for a most rational and best-justified hazard analysis, we add estimates of earthquake size translated from active faulting characteristics. We assess the regional seismic hazard using a deterministic procedure based on the computation of complete synthetic seismograms (up to 1 Hz) by the modal summation technique. As a result, we generate seismic hazard maps of maximum velocity, maximum displacement, and design ground acceleration that blend information from geology, historical seismicity and observational seismology, leading to better estimates of the earthquake hazard throughout northern Algeria. Our analysis and the resulting maps illustrate how different the estimate of seismic hazard is based primarily on combined geologic and seismological data with respect to the one for which only information from earthquake catalogues has been used. 相似文献