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Hamed Azizi-Bondarabadi Nuno Mendes Paulo B. Lourenço Neda H. Sadeghi 《Bulletin of Earthquake Engineering》2016,14(11):3195-3229
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
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The evaluation of functionality and its evolution in the aftermath of extreme events and during the restoration phase is a critical step in disaster resilience assessment. To this respect, this paper presents the ‘Functionality‐Fragility Surface’ (FFS), which is a tool for probabilistic functionality and resilience evaluation of damaged structures, infrastructure systems, and communities. FFS integrates two well‐known tools, namely Fragility Curves and Restoration Functions, to present the probability of loss of functionality of a system as a function of the extreme‐event intensity, as well as the elapsed time from the initiation of the restoration process. Because of their versatility, FFSs can be applied to components and systems belonging to different infrastructure sectors (e.g., transportation, power distribution, and telecommunication), so they provide a common rigorous paradigm for integrated resilience analyses of multiple sectors, as well as for studies on interdependencies within and across sectors. While it is shown that FFSs can be developed using available data and simple computations for different types of structures and infrastructure systems, this paper proposes also a sophisticated simulation‐based methodology to develop FFSs for individual bridges, taking into account the uncertainties involved in the response, damage, and restoration scheduling of bridges. A Multi‐Span Simply Supported Steel Girder bridge is used to showcase the application of the proposed methodology. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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提出变电站地震可恢复性等级划分方法,设立评价变电站地震可恢复性的量化指标——可恢复性指数,给出基于建筑物和高压电气设备的权重系数与震害指数的变电站可恢复性指数计算公式,确定可恢复性指数与可恢复性等级对应关系,通过变电站实际震害与恢复样本研究建立变电站可恢复性矩阵。研究结果表明:随着可恢复性指数降低,变电站可恢复性越来越差,当可恢复性指数低于0.45时,变电站达到极难恢复的阈值;变电站所处的地震烈度越高时,变电站可恢复性就越低,恢复时间也越长。在9度区,变电站可恢复性指数开始快速降低,多数变电站为可恢复和难恢复,烈度为10度及以上地区,变电站极难恢复。 相似文献
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Computation of bridge seismic fragility by large‐scale simulation for probabilistic resilience analysis 
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下载免费PDF全文 Seismic resilience of structures and infrastructure systems is a fast developing concept in the field of disaster management, promoting communities that are resistant and quickly recoverable in case of an extreme event. In this contest, probabilistic seismic demand and fragility analyses are two key elements of the seismic resilience assessment in the majority of the proposed methodologies. Several techniques are available to calculate fragility curves for different types of structures. In particular, to assess the seismic performance of the regional transportation infrastructure, methods for the fragility curve estimation for entire classes of bridges are required. These methods usually rely on a set of assumptions, partially because of the limited information. Other assumptions were introduced at the time when computational resources were inadequate for a purely numerical approach and closed‐form solutions were a convenient alternative. For instance, some of these popular assumptions are aimed at simplifying the model of the engineering demand. In this paper, a simulation‐based methodology is proposed, to take advantage of the computational resources widely available today and avoid such assumptions on the demand. The resulting increase in accuracy is estimated on a typical class of bridges (multi‐span simply supported). Most importantly, the quantitative impact of the assumptions is assessed in the context of a life‐cycle loss estimation analysis and resilience analysis. The results show that some assumptions preserve an acceptable level of accuracy, but others introduce a considerable error in the fragility curves and, in turn, in the expected resilience and life‐cycle losses of the structure. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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Eric Tabacchi Johannes Steiger Dov Corenblit Michael T. Monaghan Anne-Marie Planty-Tabacchi 《Aquatic Sciences - Research Across Boundaries》2009,71(3):279-289
The structure and function of alluvial Highly Dynamic River Systems (HDRS) are driven by highly variable hydrological disturbance
regimes, and alternate between resistant, metastable states and resilient, transitional states. These are in turn subject
to influences of feedback loops within hydrogeomorphic and biological processes. Here we consider how resistance and resilience
largely determine HDRS ecosystem trajectories and how these characteristics can be modified by natural and anthropogenic processes.
We review the mechanisms by which biodiversity can affect both resistance and resilience and introduce a conceptual framework
that incorporates some unique HDRS characteristics. We suggest that resilient and resistant patterns frequently coexist in
the active tract of these river systems, and that this coexistance promotes the return of metastable states after major disturbances.
In contrast, highly resistant and poorly resilient patterns dominate at their external boundaries. The loss of these natural
dynamics resulting from direct and indirect human impacts causes deviations to resistance and resilience patterns and therefore
to HDRS trajectory. We propose that understanding the role of interactions between biological and physical processes that
control resistance and resilience is crucial for system restoration and management. 相似文献
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A primary goal of earthquake engineering is to protect society from the possible negative consequences of future earthquakes. Conventionally, this goal has been achieved indirectly by reducing seismic damage of the built environment through better building codes, or more comprehensibly, by minimizing seismic risk. However, the effect that building damage has on occupants is not explicitly taken into account while designing infrastructure. Consequently, this paper introduces a conceptual framework and numerical algorithm to assess earthquake risk on building occupants during seismic events, considering the evacuation process of the structure. The framework combines probabilistic seismic hazard analysis, inelastic structural response analysis and damage assessment, and couples these results with the response of evacuating agents. The results are cast as probability distributions of variables that measure the overall performance of the system (e.g., evacuation times, number of injured people, and repair costs) for specific time windows. As a testbed, the framework was applied to the response of a reinforced concrete frame building that exemplifies the use of all steps of the methodology. The results suggest that this seismic risk evaluation framework of structural systems that combine the response of a physical model with human agents can be extended to a wide variety of other situations, including the assessment of mitigation actions in communities and people to improve their earthquake resilience. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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The paper presents a computationally efficient algorithm to integrate a probabilistic, non-Gaussian parameter estimation approach for nonlinear finite element models with the performance-based earthquake engineering (PBEE) framework for accurate performance evaluations of instrumented civil infrastructures. The algorithm first utilizes a minimum variance framework to fuse predictions from a numerical model of a civil infrastructure with its measured behavior during a past earthquake to update the parameters of the numerical model that is, then, used for performance prediction of the civil infrastructure during future earthquakes. A nonproduct quadrature rule, based on the conjugate unscented transformation, forms an enabling tool to drive the computationally efficient model prediction, model-data fusion, and performance evaluation. The algorithm is illustrated and validated on Meloland Road overpass, a heavily instrumented highway bridge in El Centro, CA, which experienced three moderate earthquake events in the past. The benefits of integrating measurement data into the PBEE framework are highlighted by comparing damage fragilities of and annual probabilities of damages to the bridge estimated using the presented algorithm with that estimated using the conventional PBEE approach. 相似文献
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A methodology for the performance‐based seismic risk assessment of classical columns is presented. Despite their apparent instability, classical columns are, in general, earthquake resistant, as proven from the fact that many classical monuments have survived many strong earthquakes over the centuries. Nevertheless, the quantitative assessment of their reliability and the understanding of their dynamic behavior are not easy, because of the fundamental nonlinear character and the sensitivity of their response. In this paper, a seismic risk assessment is performed for a multidrum column using Monte Carlo simulation with synthetic ground motions. The ground motions adopted contain a high‐ and low‐frequency component, combining the stochastic method, and a simple analytical pulse model to simulate the directivity pulse contained in near source ground motions. The deterministic model for the numerical analysis of the system is three‐dimensional and is based on the Discrete Element Method. Fragility curves are produced conditional on magnitude and distance from the fault and also on scalar intensity measures for two engineering demand parameters, one concerning the intensity of the response during the ground shaking and the other the residual deformation of the column. Three performance levels are assigned to each engineering demand parameter. Fragility analysis demonstrated some of the salient features of these spinal systems under near‐fault seismic excitations, as for example, their decreased vulnerability for very strong earthquakes of magnitude 7 or larger. The analysis provides useful results regarding the seismic reliability of classical monuments and decision making during restoration process. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Strong motion duration affects the cumulative damage of structures significantly. There are more than 30 different definitions of strong motion duration. This study describes numerically, the interdependency between several different definitions of strong motion duration and structural accumulated damage indices, and the aim is to determine the definitions of strong motion duration that exhibit the strongest influence on structural damages. For this purpose, 20 as-recorded accelerograms with a wide range of durations, which are modified to match a 5% damped target spectrum, are considered in this study, and several different definitions of strong motion duration, such as significant duration, bracketed duration and uniform duration are proposed for measuring these durations. On the other hand, nonlinear seismic analyses of concrete gravity dams subjected to earthquake motions with different strong motion durations are conducted according to the Concrete Damaged Plasticity (CDP) model including the strain hardening or softening behavior. Peak displacement, local damage index, global damage index and damage energy dissipation are established for characterizing the influence of strong motion duration on the dynamic response of concrete gravity dams. The degree of the interrelationship between strong motion durations and damage measures is provided by correlation coefficients. Comparison of the correlation between the different durations of the ground motion and different damage measures reveals that strong motion durations calculated from different definitions have no significant influence on damage measure based on the peak displacement response of the dam, but are positively correlated to the accumulated damage measures such as the local damage index, global damage index and damage energy dissipation for events with similar response spectrum. 相似文献
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Shang Qingxue Guo Xiaodong Li Quanwang Xu Zhen Xie Linlin Liu Chaofeng Li Jichao Wang Tao 《地震工程与工程振动(英文版)》2020,19(4):811-826
The concept of seismic resilience has received significant attention from academia and industry during the last two decades. Different frameworks have been proposed for seismic resilience assessment of engineering systems at different scales (e.g., buildings, bridges, communities, and cities). Testbeds including Centerville virtual community (CVC), Memphis testbed (MTB), and the virtual city of Turin, Italy (VC-TI) have been developed during the last decade. However, the resilience assessment results of Chinese cities still require calibration based on a unified evaluation model. Therefore, a geographic information system (GIS)-based benchmark model of a medium-sized city located in the southeastern coastal region of China was developed. The benchmark city can be used to compare existing assessment frameworks and calibrate the assessment results. The demographics, site conditions, and potential hazard exposure of the benchmark city, as well as land use and building inventory are described in this paper. Data of lifeline systems are provided, including power, transportation, water, drainage, and natural gas distribution networks, as well as the locations of hospitals, emergency shelters, and schools. Data from past earthquakes and the literature were obtained to develop seismic fragility models, consequence models, and recovery models, which can be used as basic data or calibration data in the resilience assessment process. To demonstrate the completeness of the data included in the benchmark city, a case study on the accessibility of emergency rescue after earthquakes was conducted, and the preliminary results were discussed. The ultimate goal of this benchmark city is to provide a platform for calibrating resilience assessment results and to facilitate the development of resilient cities in China.
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《地震工程与结构动力学》2018,47(5):1107-1123
Regional seismic risk assessments and quantification of portfolio losses often require simulation of spatially distributed ground motions at multiple intensity measures. For a given earthquake, distributed ground motions are characterized by spatial correlation and correlation between different intensity measures, known as cross‐correlation. This study proposes a new spatial cross‐correlation model for within‐event spectral acceleration residuals that uses a combination of principal component analysis (PCA) and geostatistics. Records from 45 earthquakes are used to investigate earthquake‐to‐earthquake trends in application of PCA to spectral acceleration residuals. Based on the findings, PCA is used to determine coefficients that linearly transform cross‐correlated residuals to independent principal components. Nested semivariogram models are then fit to empirical semivariograms to quantify the spatial correlation of principal components. The resultant PCA spatial cross‐correlation model is shown to be accurate and computationally efficient. A step‐by‐step procedure and an example are presented to illustrate the use of the predictive model for rapid simulation of spatially cross‐correlated spectral accelerations at multiple periods. 相似文献
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在对中国大陆地震活动的分析研究中发现, 在某些大地震发生前的一、 两年中, 中国大陆往往出现地震活动显著平静的低活动异常。 本文应用最近100 a(1918—2017年)间5级以上地震资料, 分析地震低活动异常与未来一、 两年中国大陆地震活动的关系。 从M≥5.0地震的年频度、 年度最大地震震级、 6级以上地震的平静等方面建立了地震低活动异常的判据指标, 并从概率增益指数β、 预测效能比α、 地震预测R值评分等方面对地震低活动异常与未来大震关系作了多参数检验。 初步研究结果显示, 地震低活动异常与未来一、 两年中国大陆地震活动有一定的关系, 主要表现为其与8级左右(M≥7.8)巨大地震具有一定的相关性, 但其关联度较低, 概率增益指数β与预测效能比α为3左右, R值评分为0.2左右。 对于M＜7.5的地震, 地震低活动异常未显示, 其概率增益β, R值评分接近于0, 似呈现为近于随机关系。 M7.5是开始显示地震低活动异常与其有一定相关性的转折点。 相似文献
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在高强度地震环境下,建筑施工场点易发生危险,传统方法运用AHP算法对建筑施工场点的危险性进行分析,但未考虑抗震约束,存在分析效果差的弊端。因此,提出一种高强度地震下建筑施工场点危险性建模分析方法。首先采用TOPSIS方法得到地震风险评估指标,构建风险评估指标的物元分析模型,基于AHP-熵权法的组合赋权获取地震风险评估指标的综合权重。然后通过贝叶斯网络来推导高强度地震下建筑施工场点危险性参数,运用地震等级的划分标准和推算方法,依据建筑施工场点危险性评估准则和接受原则APLARP,利用物元分析模型中不同危险节点的致因关系和综合权重构建施工场点风险评估模型,完成对高强度地震下建筑施工场点危险性的建模分析。实验结果表明,所设计模型可准确分析高强度地震下建筑施工场点的危险性,能够确保整体施工的安全性,具有重要的应用价值。 相似文献
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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
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概率地震危险性分析是对相关区域地震活动水平的估计,是量化地震危险性的有效手段。基于泊松分布模型获得山西地区背景地震概率,结合每个单项方法预测效能获取的指标权重,采用综合概率法得到山西地区基于多种单项预测方法的地震综合概率模型。对 1985年以来山西地区 MS ≥ 5.0地震进行回溯性检验,结果表明：异常点受控于统一应力场,震前各类（包括测震、形变、电磁以及流体学科）预测指标均存在且表现出准同步性;震级大小与异常数量呈一定正相关性,震级越大,异常指标越多,综合概率值越大。 相似文献
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“双向应变结构”是孕育和发生地震可能的供能、储能与放能的一种机制。它既能缓慢地储存弹性势能与重力势能而孕育地震,又能突然快速地释放弹性势能与重力势能而发生地震。由于地震发生时孕震体是(原应变的)应变逆转的自破裂过程,因此当初始破裂发生后,在破裂的前沿区,地震剪切应力在原有应力集中的基础上,还会再次产生一个突然快速增强(使破裂加速)到快速减弱(使破裂减速到停止)的过程,即产生“应变逆转破裂效应”。这样,不仅会大大增加地震破裂前沿区的剪切应力,而且还会大大减小破裂中的阻力,可能使地震发生中的断层强度佯谬得到解释。“双向应变结构”破裂发生地震的具体物理机制,印证了震源体断层运动的复杂性：既产生了剪切错动的破裂运动,又产生了单向的拉张与单向的压缩运动,同时还产生了整体的膨胀与整体的压缩运动。 相似文献