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讨论了目前场地小区划方法中存在的问题，指出应用后验贝叶斯方法估计场地物理参数和进行随机场地地震反应分析的必要性，提出了基于随机场地的场地小区划方法。通过实际应用，表明本方法是可行实用的。 相似文献
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本文从场地地震危险性评价,地震危险性概率分析、场地地震工程地质单元划分、地震反应分析、活断层工程分类等五个方面、论述场地地震效应及其预测中基本原理和方法。根据工程地震危险性评价和分析、地震小区划等地震工程实践,对场地地震效应及其预测提供一些基本考虑和经验 相似文献
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通过统计地震小区划及一些单体工程场地地震安全性评价工程所积累的资料,对江门市城区各种土类的剪切波速进行了回归分析,得到各类土剪切波速随深度变化的统计规律,并进一步分析了场地土层其它特征,如各类土层的组合模式、厚度以及地面脉动分布特征等,最后给出了建筑场地类别的分区。 相似文献
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廖振鹏 《地震工程与工程振动》1987,(1)
地震小区划是在我国广大地震活动区内进行城市和厂矿建设面临的一个重要问题。本文系统地阐明了作者对地震小区划的苦干基本问题的观点,并对当前我国的地震小区划工作提出了建议。 相似文献
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本文回顾了中国东南沿海滨海地带几例历史大地震造成的巨大灾害;讨论了由定数法所确定的地震烈度折算成抗震设计参数的关系,以及由概率法取得的地震动参数直接作为抗震设防依据的重要性;简述了地震小区划方法;指出开展滨岸地带港口城市,开发区和重大工程场地的地震小区划工作对减轻地震灾害的深远意义。 相似文献
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基于小波包分解和模糊聚类的网格结构损伤诊断方法 总被引：4，自引：1，他引：3
本文针对网格结构的特点,利用其在快速正弦扫频激励下的动力响应,基于小波包分解频带能量分析和模糊聚类法,提出了一种适合于网格结构的损伤诊断方法。利用两个传感器损伤信息的联合诊断,有效地解决了使用一个传感器无法检测出对称损伤的难题。利用有限元模拟,应用上述方法对一单层球面网壳结构进行了损伤诊断。结果表明,对网壳杆件较小程度的损伤,子频带能量成分变化敏感,用其构造诊断向量和建立损伤样本库,并进行模糊聚类和目标识别,基本可以正确地识别出网壳杆件的损伤位置和程度。同时该方法测试时间短,使用设备少,有可靠的理论基础,具有一定的工程应用参考价值。 相似文献
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复杂观测系统下的三维波动方程叠前深度偏移 总被引：1，自引：6，他引：1
波动方程三维叠前深度偏移是近年应复杂地质构造与地震岩性成像需求而发展的一项关键技术。此项技术与集群式并行机的结合，更是将其价格性能比较低至工业生产规模应用水平，然而，波动方程三维叠前深度偏移的实用化还需要诸如地震资料网络化、并行计算负载平衡等一系列配套技术。本文针对油田实际资料，试验了其应用波动方程三维叠前深度偏移的规则化技术，并结合地震炮集数据的特点，在自组装的集群式并行机上，解决了其节点间的负载平衡问题。本项工作有助于推近复杂观测系统下的地震数据实现三维波动方程叠前深度偏移。 相似文献
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This paper presents a reassessment of the seismic intensity estimated for the 2011 Lorca (southeastern Spain) earthquake based on detailed vulnerability data and its comparison with the observed damage. Building and urban data are gathered in selected areas during a field campaign and are completed with office work. The significance of vulnerability modifiers in the final vulnerability distribution is analyzed, and their relation with observed damage trends is explored. A direct application of the vulnerability modifiers is not capable of reproducing the observed damage patterns. A significant increase of vulnerability related to the performance of buildings presenting soft story is required to reach a damage distribution consistent with intensity estimates in the study areas. Accordingly, an intensity increase in certain study zones (as compared to other areas of the city of Lorca) is suggested. Although the approach followed in this study is applied in a city of Spain, it can be extrapolated to other areas where detailed vulnerability assessment is feasible and damage data are available. 相似文献
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Earthquakes are generally clustered, both in time and space. Conventionally, each cluster is made of foreshocks, the mainshock, and aftershocks. Seismic damage can possibly accumulate because of the effects of multiple earthquakes in one cluster and/or because the structure is unrepaired between different clusters. Typically, the performance-based earthquake engineering (PBEE) framework neglects seismic damage accumulation. This is because (i) probabilistic seismic hazard analysis (PSHA) only refers to mainshocks and (ii) classical fragility curves represent the failure probability in one event, of given intensity, only. However, for life cycle assessment, it can be necessary to account for the build-up of seismic losses because of damage in multiple events. It has been already demonstrated that a Markovian model (i.e., a Markov chain), accounting for damage accumulation in multiple mainshocks, can be calibrated by maintaining PSHA from the classical PBEE framework and replacing structural fragility with a set of state-dependent fragility curves. In fact, the Markov chain also works when damage accumulates in multiple aftershocks from a single mainshock of known magnitude and location, if aftershock PSHA replaces classical PSHA. Herein, this model is extended further, developing a Markovian model that accounts, at the same time, for damage accumulation: (i) within any mainshock–aftershock seismic sequence and (ii) among multiple sequences. The model is illustrated through applications to a series of six-story reinforced concrete moment-resisting frame buildings designed for three sites with different seismic hazard levels in Italy. The time-variant reliability assessment results are compared with the classical PBEE approach and the accumulation model that only considers mainshocks, so as to address the relevance of aftershocks for life cycle assessment. 相似文献
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Post-earthquake damage data represent an invaluable source of information for the seismic vulnerability assessment of the exposed building stock, as they are a direct evidence of the actual buildings’ performance under real seismic events. This paper exploits a robust and homogeneous database of damage data collected after the 2009 L’Aquila (Italy) earthquake, to derive damage probability matrices for several building typologies representative of the Italian building stock. To this aim, the first part of the work investigates several issues related to the definition of damage to be associated with each inspected building. Different approaches and damage conversion rules are applied, pointing out advantages and weaknesses of each one. Considering the widespread seismic damage observed on masonry infill panels and partitions of reinforced concrete constructions, the impact of this type of non-structural damage on empirical damage and functional loss distributions is explored. The second part of the study proposes different possible interpretations of the repartition of the observed damage in the different damage levels, showing in some cases a bimodal trend. Two novel hybrid procedures are outlined and compared with the classical binomial approach for predicting the subdivision of damage in the different levels. The application of the proposed methodologies to the different building typologies allows the selection, for each one, of the method providing the best fit to empirical results. The parameters required for the application of the optimal approach are reported in the paper, so that results can be used for forecasting the expected seismic damage in sites with similar seismic hazard and exposed buildings. 相似文献
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A hybrid neural network model for typhoon-rainfall forecasting 总被引：2，自引：0，他引：2
A hybrid neural network model is proposed in this paper to forecast the typhoon rainfall. Two different types of artificial neural networks, the self-organizing map (SOM) and the multilayer perceptron network (MLPN), are combined to develop the proposed model. In the proposed model, a data analysis technique is developed based on the SOM, which can perform cluster analysis and discrimination analysis in one step. The MLPN is used as the nonlinear regression technique to construct the relationship between the input and output data. First, the input data are analyzed using a SOM-based data analysis technique. Through the SOM-based data analysis technique, input data with different properties are first divided into distinct clusters, which can help the multivariate nonlinear regression of each cluster. Additionally, the topological relationships among data are discovered from which more insight into the typhoon-rainfall process can be revealed. Then, for each cluster, the individual relationship between the input and output data is constructed by a specific MLPN. For evaluating the forecasting performance of the proposed model, an application is conducted. The proposed model is applied to the Tanshui River Basin to forecast the typhoon rainfall. The results show that the proposed model can forecast more precisely than the model developed by the conventional neural network approach. 相似文献
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工作状态下桥梁结构的模态参数识别是桥梁损伤识别的重要环节,考虑桥梁检测的实用性,桥梁检测一般应建立在环境激励的基础上,已有的环境激励下模态参数识别的方法对模态频率的识别的精度较高,而对位移模态的识别则误差较大。提出了一种利用移动质量块在不同位置时对桥梁的模态频率进行多次测量,用各次测得的频率值确定位移模态的新方法,使得位移模态识别的精度接近频率识别的精度,建立了该方法的初步模型,推导了频率与位移模态关系的理论公式,并通过数值模拟对该方法的有效性进行了说明。 相似文献
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2015年4月25日在尼泊尔廓尔喀县发生的8.1级地震及后续强烈余震,造成尼泊尔北部严重的人员伤亡和财产损失,灾区建筑物倒塌损失严重。本文利用现场震害调查资料和高分卫星遥感影像,开展建筑物震害遥感解译,得到各个遥感解译点的遥感震害指数,结合现场调查点评估的烈度拟合了遥感震害指数-实际震害指数转换关系,再根据遥感震害指数估计了全部解译点的震害指数及地震烈度。估计的烈度与现场调查结果对比显示出较好的一致性,研究结果为该地区今后发生地震提供了可借鉴的遥感评估震害指数转换模型。 相似文献
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震后企业停产减产损失估计方法的研究 总被引：2，自引：0，他引：2
企业停产减产损失是地震间接损失的重要组成部分，本文根据唐山地震的震害资料，提出了地震破坏后一个地区或城市因停产和减产而造成的经济损失的一个估计方法，为估计地城的时间损失提供了一个可行的途径，此法广泛适用于震后经济损失估计和震害预测工作。 相似文献