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1.
Tariq M. Nahhas 《地震工程与工程振动(英文版)》2011,10(1):99-113
This paper presents a comparison of the seismic forces generated from a Modal Response Spectrum Analysis (MRSA) by applying the provisions of two building codes, the 1997 Uniform Building Code (UBC) and the 2000-2009 International Building Code (IBC), to the most common ordinary residential buildings of standard occupancy. Considering IBC as the state of the art benchmark code, the primary concern is the safety of buildings designed using the UBC as compared to those designed using the IBC. A sample of four buildings with different layouts and heights was used for this comparison. Each of these buildings was assumed to be located at four different geographical sample locations arbitrarily selected to represent various earthquake zones on a seismic map of the USA, and was subjected to code-compliant response spectrum analyses for all sample locations and for five different soil types at each location. Response spectrum analysis was performed using the ETABS software package. For all the cases investigated, the UBC was found to be significantly more conservative than the IBC. The UBC design response spectra have higher spectral accelerations, and as a result, the response spectrum analysis provided a much higher base shear and moment in the structural members as compared to the IBC. The conclusion is that ordinary office and residential buildings designed using UBC 1997 are considered to be overdesigned, and therefore they are quite safe even according to the IBC provisions. 相似文献
2.
管道抗震设计规范有关地震作用的综述 总被引：2，自引：0，他引：2
本文通过介绍中国、日本、美国、英国、挪威的相关管道抗震规范,阐述了目前管道应变设计和性能设计的理念、方法以及对地震作用输入的要求。通过比较各国管道抗震设计规范,保证震后管道维持其服务功能的抗震设计理念已经得到了全世界范围的认可。现在的管道设计正向性能设计的方向发展,并提出了两级抗震设防的方法。其中,第二级以管道不发生泄漏为抗震设防目标,对管道的地震安全性评价工作提出了更高的要求,管道设计需要的地震动和地面永久变形参数也越来越多。在目前管道工程的地震安全性评价工作中,存在概率方法和确定性方法这两种方法并举的局面。针对管道的抗液化和滑坡设计,地面永久位移可以利用分解的地震安全性评价概率方法得到。针对管道的抗断设计,断层未来位错量的估计方法现在仍以确定性方法为主,概率方法因为断层位错量沿着破裂带的分布较为复杂仍有待进一步研究。 相似文献
3.
南京河西地区设计地震动研究 总被引：7，自引：3，他引：4
本文根据南京及周围地区的地震环境,采用概率法对南京河西地区某高层公寓工程场址进行了地震危险性分析,采用等效线性化模型考虑场地土的非线性特性的影响,并用一维波动模型进行了场址土层地震反应和场地地震动效应分析,给出了５０年超越概率６３％,１０％和３％的场址基岩和地表的水平向加速度反应谱值加速度。 相似文献
4.
抗震设计规范中的场地设计反应谱是一般工程抗震设计的依据,各国的抗震设计规范对场地设计反应谱的规定不尽相同。主要表现在反应谱的形状和谱参数的差异。本文收集了若干国家的抗震设计规范;在总结各国抗震设计规范中关于场地设计反应谱规定的基础上,对中国、美国、日本、欧洲、土耳其和智利等有代表性的国家和地区的抗震设计规范进行分析和对比研究;总结了我国抗震设计规范场地设计反应谱的演化历史和发展过程;提出了进一步开展这一领域研究工作的若干建议,本文的工作对从事场地设计反应谱研究的科技人员有重要的参考价值。 相似文献
5.
本文根据保定市及周围地区的地震地质环境，在地震危险性分析的基础上，采用等效线性一维波动方程进行土层的地震反应分析。给出50年超越概率63％、10％、2％基岩和地面的水平向峰值加速度、反应谱（场址基本烈度Ⅶ度）和地震影响系数最大值。该结果为抗震设计提供了可靠依据，具有应用价值。 相似文献
6.
ShahidA.Khan M.AliShah M.Qaisar 《地震学报(英文版)》2003,16(4):382-394
Estimation of seismic hazard for the fast developing coastal area of Pakistan is carried out using deterministic and probabilistic approaches. On the basis of seismotectonics and geology, eleven faults are recognized in five seismic provinces as potential hazard sources. Maximum magnitude potential for each of these sources is calculated. Peak ground acceleration (PGA) values at the seven coastal cities due to the maximum credible earthquake on the relevant source are also obtained. Cities of Gwadar and Ormara with acceleration values of 0.21g and 0.25g respec-tively fall in the high seismic risk area. Cities of Turbat and Karachi lie in low seismic risk area with acceleration values of less than 0.1g. The Probabilistic PGA maps with contour interval of 0.05g for 50 and 100 years return period with 90% probability of non-exceedance are also compiled. 相似文献
7.
轻轨铁路站桥结构体系抗震分析与隔震研究 总被引：5，自引：0，他引：5
本文结合地处高烈度地震区的天津轻轨工程，对轻轨铁路站桥结构体系进行抗震分析，并探索减轻其地震灾害、提高其抗震能力的隔震措施。研究结果表明，按照现行有关抗震设计规范规定的反应谱值设计的站桥结构体系的抗震安全性存在不足，设计必须按工程建设场地地震危险性评价给定的反应谱值对站桥结构体系进行时程分析，才能保证轻轨铁路的抗震安全性。通过在车站建筑与高架桥梁之间的连接部位安装新近研制的SMA复合橡胶支座隔震装置，可以有效地提高轻轨铁路站桥结构体系的抗震能力。 相似文献
8.
Probabilistic seismic hazard analysis: Early history 总被引：1，自引：0，他引：1
Robin K. McGuire 《地震工程与结构动力学》2008,37(3):329-338
Probabilistic seismic hazard analysis (PSHA) is the evaluation of annual frequencies of exceedence of ground motion levels (typically designated by peak ground acceleration or by spectral accelerations) at a site. The result of a PSHA is a seismic hazard curve (annual frequency of exceedence vs ground motion amplitude) or a uniform hazard spectrum (spectral amplitude vs structural period, for a fixed annual frequency of exceedence). Analyses of this type were first conceived in the 1960s and have become the basis for the seismic design of engineered facilities ranging from common buildings designed according to building codes to critical facilities such as nuclear power plants. This Historical Note traces the early history of PSHA. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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10.
This paper examines the potential development of a probabilistic design methodology, considering hysteretic energy demand, within the framework of performance‐based seismic design of buildings. This article does not propose specific energy‐based criteria for design guidelines, but explores how such criteria can be treated from a probabilistic design perspective. Uniform hazard spectra for normalized hysteretic energy are constructed to characterize seismic demand at a specific site. These spectra, in combination with an equivalent systems methodology, are used to estimate hysteretic energy demand on real building structures. A design checking equation for a (hypothetical) probabilistic energy‐based performance criterion is developed by accounting for the randomness of the earthquake phenomenon, the uncertainties associated with the equivalent system analysis technique, and with the site soil factor. The developed design checking equation itself is deterministic, and requires no probabilistic analysis for use. The application of the proposed equation is demonstrated by applying it to a trial design of a three‐storey steel moment frame. The design checking equation represents a first step toward the development of a performance‐based seismic design procedure based on energy criterion, and additional works needed to fully implement this are discussed in brief at the end of the paper. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
11.
Pakistan and the western Himalaya is a region of high seismic activity located at the triple junction between the Arabian, Eurasian and Indian plates. Four devastating earthquakes have resulted in significant numbers of fatalities in Pakistan and the surrounding region in the past century (Quetta, 1935; Makran, 1945; Pattan, 1974 and the recent 2005 Kashmir earthquake). It is therefore necessary to develop an understanding of the spatial distribution of seismicity and the potential seismogenic sources across the region. This forms an important basis for the calculation of seismic hazard; a crucial input in seismic design codes needed to begin to effectively mitigate the high earthquake risk in Pakistan. The development of seismogenic source zones for seismic hazard analysis is driven by both geological and seismotectonic inputs. Despite the many developments in seismic hazard in recent decades, the manner in which seismotectonic information feeds the definition of the seismic source can, in many parts of the world including Pakistan and the surrounding regions, remain a subjective process driven primarily by expert judgment. Whilst much research is ongoing to map and characterise active faults in Pakistan, knowledge of the seismogenic properties of the active faults is still incomplete in much of the region. Consequently, seismicity, both historical and instrumental, remains a primary guide to the seismogenic sources of Pakistan. This study utilises a cluster analysis approach for the purposes of identifying spatial differences in seismicity, which can be utilised to form a basis for delineating seismogenic source regions. An effort is made to examine seismicity partitioning for Pakistan with respect to earthquake database, seismic cluster analysis and seismic partitions in a seismic hazard context. A magnitude homogenous earthquake catalogue has been compiled using various available earthquake data. The earthquake catalogue covers a time span from 1930 to 2007 and an area from 23.00° to 39.00°N and 59.00° to 80.00°E. A threshold magnitude of 5.2 is considered for K-means cluster analysis. The current study uses the traditional metrics of cluster quality, in addition to a seismic hazard contextual metric to attempt to constrain the preferred number of clusters found in the data. The spatial distribution of earthquakes from the catalogue was used to define the seismic clusters for Pakistan, which can be used further in the process of defining seismogenic sources and corresponding earthquake recurrence models for estimates of seismic hazard and risk in Pakistan. Consideration of the different approaches to cluster validation in a seismic hazard context suggests that Pakistan may be divided into K?=?19 seismic clusters, including some portions of the neighbouring countries of Afghanistan, Tajikistan and India. 相似文献
12.
Newmark design spectra have been implemented in many building codes, especially in building codes for critical structures. Previous studies show that Newmark design spectra exhibit lower amplitudes at high frequencies and larger amplitudes at low frequencies in comparison with spectra developed by statistical methods. To resolve this problem, this study considers three suites of ground motions recorded at three types of sites. Using these ground motions, influences of the shear-wave velocity, earthquake magnitudes, source-to-site distances on the ratios of ground motion parameters are studied, and spectrum amplification factors are statistically calculated. Spectral bounds for combinations of three site categories and two cases of earthquake magnitudes are estimated. Site design spectrum coefficients for the three site categories considering earthquake magnitudes are established. The problems of Newmark design spectra could be resolved by using the site design spectrum coefficients to modify the spectral values of Newmark design spectra in the acceleration sensitive, velocity sensitive, and displacement sensitive regions. 相似文献
13.
Performance-based seismic design of nonstructural building components:The next frontier of earthquake engineering 总被引：1，自引：1，他引：0
With the development and implementation of performance-based earthquake engineering,harmonization of performance levels between structural and nonstructural components becomes vital. Even if the structural components of a building achieve a continuous or immediate occupancy performance level after a seismic event,failure of architectural,mechanical or electrical components can lower the performance level of the entire building system. This reduction in performance caused by the vulnerability of nonstructural components has been observed during recent earthquakes worldwide. Moreover,nonstructural damage has limited the functionality of critical facilities,such as hospitals,following major seismic events. The investment in nonstructural components and building contents is far greater than that of structural components and framing. Therefore,it is not surprising that in many past earthquakes,losses from damage to nonstructural components have exceeded losses from structural damage. Furthermore,the failure of nonstructural components can become a safety hazard or can hamper the safe movement of occupants evacuating buildings,or of rescue workers entering buildings. In comparison to structural components and systems,there is relatively limited information on the seismic design of nonstructural components. Basic research work in this area has been sparse,and the available codes and guidelines are usually,for the most part,based on past experiences,engineering judgment and intuition,rather than on objective experimental and analytical results. Often,design engineers are forced to start almost from square one after each earthquake event: to observe what went wrong and to try to prevent repetitions. This is a consequence of the empirical nature of current seismic regulations and guidelines for nonstructural components. This review paper summarizes current knowledge on the seismic design and analysis of nonstructural building components,identifying major knowledge gaps that will need to be filled by future research. Furthermore,considering recent trends in earthquake engineering,the paper explores how performance-based seismic design might be conceived for nonstructural components,drawing on recent developments made in the field of seismic design and hinting at the specific considerations required for nonstructural components. 相似文献
14.
通过对CECS160与GB50011-2001以及IBC-2003等规范的初步对比分析，就CECS160中有关基于性态设计的抗震设防概念、地震动参数取值以及抗震建筑分类等内容进行了讨论，并对CECS160在抗震设计中的具体实施提出一些看法。 相似文献
15.
Aman Mwafy 《地震工程与工程振动(英文版)》2011,10(1):115-127
To verify the seismic design response factors of high-rise buildings, five reference structures, varying in height from 20- to 60-stories, were selected and designed according to modern design codes to represent a wide range of concrete wall structures. Verified fiber-based analytical models for inelastic simulation were developed, considering the geometric nonlinearity and material inelasticity of the structural members. The ground motion uncertainty was accounted for by employing 20 earthquake records representing two seismic scenarios, consistent with the latest understanding of the tectonic setting and seismicity of the selected reference region (UAE). A large number of Inelastic Pushover Analyses (IPAs) and Incremental Dynamic Collapse Analyses (IDCAs) were deployed for the reference structures to estimate the seismic design response factors. It is concluded that the factors adopted by the design code are adequately conservative. The results of this systematic assessment of seismic design response factors apply to a wide variety of contemporary concrete wall buildings with various characteristics. 相似文献
16.
Consideration of vertical seismic design loads is important for long-span structural systems, short-period structures, and for some nonstructural components in the buildings. To this end, seismic design codes utilize alternative approaches to define vertical design spectrum at different levels of complexity: either as a fraction of horizontal design spectrum or using a separate functional form having features different than the horizontal spectrum. In all cases, a consistency between the horizontal and vertical design spectral ordinates is sought. In this paper, we consider a set of modern seismic design codes, horizontal and vertical ground-motion datasets, as well as ground-motion predictive models (GMPMs) to assess the accuracy of code-based vertical design spectrum expressions. We compute horizontal and vertical spectra for different earthquake scenarios (magnitude-distance-soil condition combinations) from the selected horizontal and vertical GMPMs for comparisons with their code-based (idealized) counterparts. Besides that, we study the vertical spectrum behavior from observed ground-motion data. Our observations suggest that the vertical design spectrum formulations by current codes do not fully explain the actual vertical spectral acceleration trends. We discuss the possible reasons behind the misrepresentation of vertical spectrum by the current code approach and introduce our own expressions to compute horizontal spectrum consistent vertical design spectrum from a comprehensive simulated dataset of correlated vertical and horizontal spectral ordinates. 相似文献
17.
Observations of damage due to the Kashmir earthquake of October 8, 2005 and study of current seismic provisions for buildings in Pakistan 总被引：5，自引：3，他引：2
On October 8, 2005 an earthquake of magnitude 7.6 (M
w) struck the Kashmir region of Pakistan causing widespread damage to buildings and infrastructure. This paper summarizes field
observations of building damage made by the Earthquake Engineering Field Investigation Team (EEFIT) after the event, where
the performance of residential, commercial and government buildings was investigated. A study of the seismic design provisions
currently in place in Pakistan is presented and compared with seismic provisions of EC8 (1998) and UBC (1997). Several problems
are identified for the implementation of the Pakistan seismic code in its current form and recommendations are made for its
improvement in order to be used for the reconstruction of affected areas. 相似文献
18.
In this study, a composite source model has been used to calculate the realistic strong ground motions in Beijing area, caused by 1679 MS8.0 earthquake in Sanhe-Pinggu. The results could provide us the useful physical parame-ters for the future seismic hazard analysis in this area. Considering the regional geological/geophysical background, we simulated the scenario earthquake with an associated ground motions in the area ranging from 39.3°N to 41.1°N in latitude and from 115.35°E to 117.55°E in longitude. Some of the key factors which could influence the characteristics of strong ground motion have been discussed, and the resultant peak ground acceleration (PGA) distribution and the peak ground velocity (PGV) distribution around Beijing area also have been made as well. A comparison of the simulated result with the results derived from the attenuation relation has been made, and a suf-ficient discussion about the advantages and disadvantages of composite source model also has been given in this study. The numerical results, such as the PGA, PGV, peak ground displacement (PGD), and the three-component time-histories developed for Beijing area, have a potential application in earthquake engineering field and building code design, especially for the evaluation of critical constructions, government decision making and the seismic hazard assessment by financial/insurance companies. 相似文献
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20.
Ruifang Yu Yisheng Song Xiangyun Guo Qianli Yang Xinjuan He Yanxiang Yu 《地震科学（英文版）》2022,35(5):314-328
Seismic hazard analyses are mainly performed using either deterministic or probabilistic methods. However, there are still some defects in these statistical model-based approaches for regional seismic risk assessment affected by the near-field of large earthquakes. Therefore, we established a deterministic seismic hazard analysis method that can characterize the entire process of ground motion propagation based on stochastic finite-fault simulation, and we chose the site of the Xiluodu dam to demonstrate the method. This method can characterize earthquake source properties more realistically than other methods and consider factors such as the path and site attenuation of seismic waves. It also has high computational efficiency and is convenient for engineering applications. We first analyzed the complexity of seismogenic structures in the Xiluodu dam site area, and then an evaluation system for ground motion parameters that considers various uncertainties is constructed based on a stochastic finite-fault simulation. Finally, we assessed the seismic hazard of the dam site area comprehensively. The proposed method was able to take into account the complexity of the seismogenic structures affecting the dam site and provide multi-level parameter evaluation results corresponding to different risk levels. These results can be used to construct a dam safety assessment system of an earthquake in advance that provides technical support for rapidly and accurately assessing the post-earthquake damage state of a dam, thus determining the influence of an earthquake on dam safety and mitigating the risk of potential secondary disasters. 相似文献