混合结构体系高层建筑模拟地震振动台试验研究

随着现代建筑高度的不断增加,混合结构体系在超高层建筑中逐步广泛应用,因此对该结构体系在地震作用下的破坏机理和抗震性能展开深入的研究是一项有意义的工作。本文对一混合结构体系复杂超高层建筑进行1／35的模型模拟地震振动台试验,分析模型结构的动力特性和不同烈度地震作用下加速度、位移和应变反应,然后根据相似关系推算出原型结构的动力特性和反应,研究其在各水准地震作用下的破坏机理和破坏形式,最后对原型结构设计提出若干建议。     

土层平均剪切波速确定及其可靠性验证——基于钻井台阵强震动记录

震害资料显示,场地条件对地震动特性以及工程结构破坏程度影响显著。为减少因场地效应而造成的经济损失和社会影响,在进行场地地震反应分析时,需最大限度地减小因场地土层模型参数的不确定性引起的地震动评估偏差,为工程结构地震反应分析选取并生成适当的地震动输入。随着强震动观测技术的逐渐发展,大量可靠的钻井台阵记录为地震过程中场地观测点的动力反应提供了直接数据。以美国加州地区La Cienega钻井台阵强震动观测数据为基础,利用互相关函数,对不同强度地震作用下场地土层的平均剪切波速进行分析,并在此基础上,以Cyclic 1D为模拟平台,建立一维自由场地地震反应有限元分析模型。分析结果表明：通过钻井台阵地震动观测数据识别,得到场地平均剪切波速,能够反映该场地的动力特性,数值模拟计算结果和台阵地震动记录基本吻合,可为数值模型参数选取提供依据。     

Earthquake risk assessment of buildings accounting for human evacuation

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.     

展望地震监测台网的发展与应用

随着国民经济的快速发展，我国地震监测台网的发展也日新月异，设备性能、技术系统、台网密度正逐步接近发达国家的水平，同时积累了大量的观测数据。如何利用这些监测资源，更好地为经济建设和社会公共安全服务，是值得研究的重要问题。本文认为提取有用的地震前兆信息、提升地震速报能力、扩展烈度速报功能是地震监测台网为地震预报和地震应急服务的重点；整合台网资源，构筑统一标准、多用途的地震监测网络是建设公共安全服务技术平台的前提；工程、海洋、气象、环保等是地震监测资源的主要服务领域。因此，开发监测资源，加强自主创新，构筑技术平台，拓展服务领域是未来地震监测台网为社会和公共安全服务的重要发展方向。     

地震烈度与地震动峰值的转换

本文以强震记录地面水平向平均峰值为基本数据,研究了在无条件、分别或同时考虑房屋层数和场地类别的前提下,地震烈度与地震动峰值的对应关系.并依据统计结果讨论了峰值均值随烈度的变化规律,给出了把烈度转换成地面峰速度、峰加速度或设计地震反应谱的建议方案.最后还讨论了把设计地震反应谱转换成地震烈度的方法,给出了建议的转换方案.      

建筑结构监测与抗震韧性评估

建筑结构响应是有效反映结构动力特性的最直接参数,开展结构动力响应实时监测可为结构抗震韧性评估提供准确的地震动输入。本文基于非结构构件损失构建结构抗震韧性评估方法,研究确定位移敏感型和加速度敏感型非结构构件的易损性模型。选择某六层钢筋混凝土框架结构进行实时监测系统建设,基于监测数据开展结构抗震韧性评估。通过构建建筑信息模型（BIM）,并在有限元分析软件OpenSees中建立结构弹塑性分析模型,利用实时监测数据实现结构模型更新,直至监测数据与模型分析结果一致。由于实时监测数据峰值较低,结构不会发生塑性变形,因此选择10条双向非脉冲地震动模拟实时监测地震记录。根据层间位移角和楼面加速度分布,开展结构功能损失评估,得到该建筑结构的抗震韧性得分。分析表明,该结构抗震性能较好,在遭受地震破坏后,会发生非结构构件脱落,需要采取有效措施进一步提升建筑抗震韧性水平。     

宁洱6.4级地震考察研究综述

基于2007年6月3日云南宁洱6.4级地震现场近场强震与流动数字地震观测、各类建筑结构及生命线工程震害调查、政府及民众应急处置与响应调查等基础工作,结合云南多年积累的大量地震现场调查资料与认识,开展了震区各类建筑结构及生命线工程震害特征与机理、强震动观测与地震烈度分布关系、灾区恢复重建资金评估方法、政府应急处置与普通群众个体认知状况以及地壳结构、震源特性、强震动频谱与农居抗震调查等方面的综合分析与研究等工作。归纳和总结了可供我国其它多震地区在城市发展规划、工程结构抗震、地震应急管理和地震灾区恢复重建等领域参考和借鉴的技术、方法、措施和经验。     

测震学综合应用软件系统在地震监测工作中的应用

简要说明了测震学综合应用软件系统的系统特点;详细介绍了该软件系统的功能;重点分析了该软件系统在地震监测工作中的应用,如在地震编目、序列自动编目、测震台网控制震级能力评定、辅助台网布设方案设计及地震现场应急等方面的应用。用户反馈的信息表明,测震学综合应用软件系统可以在地震监测中发挥重要作用。     

基于结构台阵记录的地震响应分析

为了研究土-结构相互作用对高层建筑地震响应数值模拟的影响．选择一栋具有地震观测记录的高层建筑（结构台阵）作为研究对象．利用Abaqus有限元软件和2009年姚安地震加速度记录,并假定了水平成层和有倾角成层的2种土介质模型．进行土-结构动力反应分析。结果表明：有倾角成层土-桩-结构相互作用模型的计算结果与观测资料相比有明显的放大现象,在NS方向体现的更加明显。这说明,就高层建筑的抗震分析而言,土介质模型对计算结果影响很大,在进行地震作用下土-结构地震响应分析时．土层模型应尽可能与真实土层相符。否则其计算结果会产生较大误差。     

Prediction of response spectra via real-time earthquake measurements

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.     

东莞市区震害预测与防御对策系统建设

在地震小区划、概率设定地震和广泛收集地震地质、建(构)筑物、生命线工程、地震次生灾害源、社会环境与经济人口数据等的基础上,对东莞市区89.3 km2范围工作区开展震害预测与防御对策研究,得到不同烈度下建(构)筑物、生命线工程的震害分析结果,以及地震次生灾害影响、人员伤亡与经济损失评估结果,对工作区及东莞市的抗震能力进行...     

同高宽比弹塑性隔振建筑结构的抗震性能试验研究

研究以某同高宽比弹塑性隔振建筑结构为工程实例,采用SAP2000软件构建了同高宽比弹塑性隔振建筑结构的有限元模型,并进行了模型材料和相应参数选取;在此基础上,利用循环侧推分析隔振建筑结构中各构件的内力及变形情况,建立隔震建筑结构损失模型,同时为了提高其抗震性评估精准度,采用动力弹塑性顶层位移情况反应隔震建筑结构的抗震性能。工程实例分析结果表明,普通建筑结构主要控制层间位移响应,无论是在8度频发地震作用下还是在8度特大地震作用下,隔震建筑结构的顶部加速度响应均远远小于普通建筑结构,且仍然处于完全弹性工作状态,结构构件并未发生破坏,保证了建筑内部人们的生命财产安全,同时便于震后快速修复,相比于普通建筑结构,同高宽比弹塑性隔振建筑结构的抗震性能更优。     

地震工程的研究和应用--回顾与展望

近百年来的地震工程研究取得了长足的进展，推进了人类的防震减灾事业。当前，面临社会经济发展对公众和工程安全提出的越来越高的要求，随着材料科学、信息和计算机技术、机械工程等领域高新技术的迅速发展，地震工程研究也进入了一个新的阶段。性态抗震设计、结构振动控制和健康诊断成为推进和扩展地震工程研究的前沿领域。     

Evaluation of the measured seismic response of the Mexico City Cathedral

The seismic response of the Mexico City Cathedral built of very soft soil deposits is evaluated by using motions recorded in various parts of the structure during several moderate earthquakes. This unique set of records provides significant insight into the seismic response of this and other similar historic stone masonry structures. Free‐field ground motions are carefully compared in time and frequency domains with motions recorded at building basement. The dynamic characteristics of the structure are inferred from the earthquake records by using system identification techniques. Variation of seismic response for different seismic intensities is discussed. It is shown that, due to the soil–structure interaction, due to large differences between dominant frequencies of earthquake ground motions at the site and modal frequencies of vibration of the structure, and due to a particularly high viscous damping, seismic amplifications of ground motion in this and similar historic buildings erected on soft soil deposits are much smaller than that induced in most modern constructions. Nevertheless, earthquake records and analytical results show that several components of the structure such as its central dome and the bell towers may be subjected to local vibrations that significantly amplify ground motions. Overall, results indicate that in its present state the structure has an acceptable level of seismic safety. Copyright © 2008 John Wiley & Sons, Ltd.     

Modeling, synthetics and engineering applications of strong earthquake wave motion

State of the art in modeling, synthetics, statistical estimation, and engineering applications of strong ground motion is reported in this paper. In particular, models for earthquake wave motion are presented, in which uncertainties both in the earth medium and the seismic source are taken into consideration. These models can be used to synthesize realistic strong earthquake ground motion, specifically near-field ground motion which is quite often not well recorded in real earthquakes. Statistical estimation techniques are also presented so that the characteristics of spatially-correlated earthquake motion can be captured and consequently used in investigating the seismic response of such large scale structures as pipelines and long-span bridges. Finally, applications of synthesized strong ground motion in a variety of engineering fields are provided. Numerical examples are shown for illustration.     

地震序列专用处理软件在地震监测中的应用

简要说明地震序列专用处理软件系统的系统功能和特点;详细介绍了该软件系统在地震监测工作中的应用,主要分析了该系统在地震实时监控、台站工作、序列目录管理、地震现场及序列研究中的应用。     

Prospects for the Development and Application of the Earthquake Monitoring Network

With the rapid development of the economy in China, the seismic network has been changing rapidly, in that the capability of instruments, technological systems and network density are approaching those of developed countries and a large quantity of observation data has been accumulated. How to apply these resources to economic construction and public safety has become an important issue worth studying. In order to improve earthquake prediction and earthquake emergency response, it is suggested in this paper that extracting valuable precursor information, improving earthquake rapid reporting ability and extending rapid intensity reporting function are key issues. Integrating network resources, building unified standards and a multifunction seismic monitoring network are preconditions of establishing a public safety service platform and earthquake observation resources will contribute significantly to the fields of engineering, ocean, meteorology, and environmental protection. Thus, the future directions of the development of the seismic network are exploring monitoring resources, enhancing independent innovation, constructing a technological platform and enlarging the service field.     

MEMS地震烈度仪在结构地震反应观测中的应用

工程结构地震反应观测台阵获取常时和震时结构反应记录,是工程结构健康诊断和震害评估的重要技术手段之一。2019年,云南大理建设了一个由8个地震烈度仪测点组成的结构地震反应观测台阵,每台烈度仪内置一个3分向微电子机械系统(Micro-Electro-Mechanical System, MEMS)加速度计。通过标准振动台检测,确定台阵配备的烈度仪的幅频响应特性曲线和线性度误差符合相关行业标准的要求。该台阵于2021年5月获得了大理漾濞地震序列的多次结构地震反应记录,本文选取其中3次M_S3.0～M_S3.2级地震,分析了观测记录的加速度时程、傅里叶幅值谱和信噪比等数据,由结果可知：该台阵可较好地记录幅值≥0.5 cm/s²、频带1.0～39.0Hz的振动信号,对于近场小震具有一定的监测能力。     

From regional- to local-scale seismic hazard assessment: examples from Southern Spain

An approach that relates results from a regional seismic hazard assessment study with local-scale site-effect characterizations in an area of low-to-moderate seismic activity such as Andalusia (southern Spain), is presented. Results of a previous probabilistic seismic hazard analysis of Andalusia on rock conditions are disaggregated to infer hazard controlling earthquakes for different target motions. A collection of controlling magnitude-distance pairs and the corresponding site-specific response spectra at main capital cities of the region are obtained. These spectra are first-order approximations to expected seismic actions required in local earthquake risk assessments. In addition, results of independent, local-scale studies developed in Almeria City (SE Andalusia) are used to derive an updated seismic zonation of the city. These include predominant soil period estimates and shear-wave velocity profiles at different locations. If a local seismic risk assessment study or an earthquake-resistant structural design is to be developed, it may be recommended the use of different seismic actions on sites characterized by distinct response to seismic shaking (as derived from the seismic zonation). The seismic action related to worst-case scenarios may be modeled through a hazard-consistent response spectrum, obtained by hazard disaggregation at the spectral acceleration with period matching the prevailing resonant period of the target site or structure.     

Earthquake soil‐structure interaction of nuclear power plants,differences in response to 3‐D, 3 × 1‐D,and 1‐D excitations

In soil‐structure interaction modeling of systems subjected to earthquake motions, it is classically assumed that the incoming wave field, produced by an earthquake, is unidimensional and vertically propagating. This work explores the validity of this assumption by performing earthquake soil‐structure interaction modeling, including explicit modeling of sources, seismic wave propagation, site, and structure. The domain reduction method is used to couple seismic (near‐field) simulations with local soil‐structure interaction response. The response of a generic nuclear power plant model computed using full earthquake soil‐structure interaction simulations is compared with the current state‐of‐the‐art method of deconvolving in depth the (simulated) free‐field motions, recorded at the site of interest, and assuming that the earthquake wave field is spatially unidimensional. Results show that the 1‐D wave‐field assumption does not hold in general. It is shown that the way in which full 3‐D analysis results differ from those which assume a 1‐D wave field is dependent on fault‐to‐site geometry and motion frequency content. It is argued that this is especially important for certain classes of soil‐structure systems of which nuclear power plants subjected to near‐field earthquakes are an example.