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1.
Dipendra Gautam 《Bulletin of Earthquake Engineering》2018,16(10):4661-4673
This paper outlines the seismic vulnerability of rural stone masonry buildings affected by the 2015 Gorkha earthquake sequence. Summary of field observation is presented first and empirical fragility curves are developed from the detailed damage assessment data from 603 villages in central, eastern and western Nepal. Fragility curves are developed on the basis of 665,515 building damage cases collected during the post-earthquake detailed damage assessment campaign conducted by Government of Nepal. Two sets of fragility functions are derived using peak ground acceleration and spectral acceleration at 0.3 s as the intensity measures. The sum of the results highlights that stone masonry buildings in Nepal are highly vulnerable even in the case of low to moderate ground shaking. The results further indicate that in the case of strong to major earthquakes, most of the stone masonry buildings in Nepal would sustain severe damage or collapse. 相似文献
2.
This study focuses on the evaluation of seismic safety of unreinforced masonry buildings in Turkey by using fragility curves generated for two behavior modes of load bearing walls: in-plane and out-of-plane. During generation of fragility curves, a force-based approach has been used. There exist two limit states in terms of base shear strength for in-plane behavior mode and flexural strength for out-of-plane behavior mode. To assess the seismic vulnerability of unreinforced masonry buildings in Turkey, fragility curves generated for in-plane behavior were verified by the observed damage during the 1995 Dinar (Turkey) earthquake and fragility curves generated for out-of-plane behavior were verified by the observed damage during the 2010 Elaz?? (Turkey) earthquake. The verification results reveal that the proposed fragility-based procedure can provide an alternative for the seismic safety evaluation of unreinforced masonry buildings in Turkey. Using this procedure, it becomes possible to investigate a large population of masonry buildings located in regions of high seismic risk in a short period of time. The obtained results are valuable in the sense that they can be used as a database during the development of strategies for pre-earthquake planning and risk mitigation for earthquake prone regions of Turkey. 相似文献
3.
The degree and distribution of damage to buildings subjected to earthquakes is a concern of the Chinese Government and the public.Seismic damage data indicates that seismic capacities of different types of building structures in various regions throughout mainland of China are different.Furthermore,the seismic capacities of the same type of structure in different regions may vary.The contributions of this research are summarized as follows:1)Vulnerability matrices and earthquake damage matrices of masonry structures in mainland of China were chosen as research samples.The aim was to analyze the differences in seismic capacities of sample matrices and to present general rules for categorizing seismic resistance.2)Curves relating the percentage of damaged masonry structures with different seismic resistances subjected to seismic demand in different regions of seismic intensity(VI to X)have been developed.3)A method has been proposed to build vulnerability matrices of masonry structures.The damage ratio for masonry structures under high-intensity events such as the Ms 6.1 Panzhihua earthquake in Sichuan province on 30 August2008,was calculated to verify the applicability of this method.This research offers a significant theoretical basis for predicting seismic damage and direct loss assessment of groups of buildings,as well as for earthquake disaster insurance. 相似文献
4.
Hossein Derakhshan Kevin Q. Walsh Jason M. Ingham Michael C. Griffith David P. Thambiratnam 《地震工程与结构动力学》2020,49(3):285-300
The results of an investigation of the probability of earthquake damage to nonstructural unreinforced masonry (URM) components are presented. The components include parapets, chimneys, and out-of-plane loaded facades typical of low-rise pre-1940 construction in Australia and New Zealand. The study is based on a street survey of component geometry, in situ data on material strength, and simplified mechanical models. Uncertainties in capacity and demand were quantified based on, respectively, stochastic and deterministic approaches. The damage probabilities were compared with relevant guidelines and empirical damage data from three earthquakes. The study established a link between the qualitative damage states reported in existing guidelines and the quantitative URM component damage states. While some median damage state thresholds correlated well with the data from the guidelines, a larger dispersion value was found in the current study due to the large variations in component properties. Comparisons with empirical data suggest that the developed fragility data provide a realistic estimate of nonstructural component damage that occurred in similar buildings, with a reasonable level of conservatism. The outcome is useful in rapid assessment of the seismic risks due to nonstructural component collapse in URM precincts. 相似文献
5.
The degree and distribution of damage to buildings subjected to earthquakes is a concern of the Chinese Government and the public. Seismic damage data indicates that seismic capacities of different types of building structures in various regions throughout mainland China are different. Furthermore, the seismic capacities of the same type of structure in different regions may vary. The contributions of this research are summarized as follows: 1) Vulnerability matrices and earthquake damage matrices of masonry structures in mainland China were chosen as research samples. The aim was to analyze the differences in seismic capacities of sample matrices and to present general rules for categorizing seismic resistance. 2) Curves relating the percentage of damaged masonry structures with different seismic resistances subjected to seismic demand in different regions of seismic intensity (VI to X) have been developed. 3) A method has been proposed to build vulnerability matrices of masonry structures. The damage ratio for masonry structures under high-intensity events such as the Ms 6.1 Panzhihua earthquake in Sichuan province on 30 August 2008, was calculated to verify the applicability of this method. This research offers a significant theoretical basis for predicting seismic damage and direct loss assessment of groups of buildings, as well as for earthquake disaster insurance. 相似文献
6.
M. Altuğ Erberik 《地震工程与结构动力学》2008,37(3):387-405
This study focuses on the seismic safety evaluation of masonry buildings in Turkey for in‐plane failure modes using fragility curves. Masonry buildings are classified and a set of fragility curves are generated for each class. The major structural parameters in the classification of masonry buildings are considered as the number of stories, load‐bearing wall material, regularity in plan and the arrangement of walls (required length, openings in walls, etc.), in accordance with the observations from previous earthquakes and field databases. The fragility curves are generated by using time history (for demand) and pushover (for capacity) analyses. From the generated sets of fragility curves, it is observed that the damage state probabilities are significantly influenced from the number of stories and wall material strength. In the second stage of the study, the generated fragility curves are employed to estimate the damage of masonry buildings in Dinar after the 1995 earthquake. The estimated damage by fragility information is compared with the inspected visual damage as assessed from the Damage Evaluation Form. For the quantification of fragility‐based damage, a single‐valued index, named as ‘vulnerability score’ (VS), is proposed. There seems to be a fair agreement between the two damage measures. In addition to this, decisions regarding the repair or demolition of masonry buildings in Dinar due to visual damage inspection are on comparable grounds with the relative measure obtained from VS of the same buildings. Hence, the fragility‐based procedure can provide an alternative for the seismic safety evaluation of masonry buildings in Turkey. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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Methodology for practical seismic assessment of unreinforced masonry buildings with historical value 
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下载免费PDF全文 Historical constructions are part of the world heritage, and their survival is an important priority. Comprising mostly unreinforced, load‐bearing masonry, heritage buildings may date anywhere from antiquity to the 19th and early 20th century. Being exposed to the elements over the years, they are in various states of disrepair and material degradation. Based on postearthquake reconnaissance reports, these structures occasionally behave rather poorly, even in moderate seismic events, undergoing catastrophic damage and collapse, whereas retrofitting is governed by international conventions regarding noninvasiveness and reversibility of the intervention. The complexity of their structural systems (continuous structural components, lack of diaphragm action, material brittleness, and variability) challenges the established methods of condition assessment of preretrofitted and postretrofitted heritage constructions. The most advanced state of the art in materials and analysis tools is required, far more complex than with conventional buildings. Thus, an assessment procedure specifically geared to this class of structures is urgently needed, in order to assist engineers in this endeavor. The objective of this paper is the development of a performance‐based assessment framework that is palatable to practitioners and quite accurate in seismic assessment of unreinforced masonry buildings with no diaphragm action. The underlying theoretical background of the method is illustrated with reference to first principles: global demand is obtained from the design earthquake scenario for the region, using empirical estimates for the prevailing translational period of the system; deformation demands are localized using an approximation to the translational 3‐D shape of lateral response, estimated using a uniform gravitational field in the direction of action of the earthquake; acceptance criteria are specified in terms of relative drift ratios, referring to the in‐plane and the out‐of‐plane action of the masonry piers. The quantitative accuracy of the introduced procedure is evaluated through comparison with detailed time‐history dynamic analysis results, using a real life example case study. Qualitative relevance of the results is evaluated through comparison of the location and extent of anticipated damage estimated from the proposed assessment procedure, with reported records of the building damages that occurred during a significant past earthquake event. 相似文献
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In situ experiment on retrofit of school buildings by adding sandwich columns to partition brick walls 总被引：1，自引：0，他引：1 下载免费PDF全文
下载免费PDF全文 Many significantly strong earthquakes have occurred over the years in Taiwan, which have caused tremendous damage to primary and middle school buildings; the 921 Chi‐Chi earthquake was particularly devastating. According to statistics, 786 schools (1,958 classrooms) were damaged on September 21, 1999 during this earthquake event. The devastation showed that a lack of seismic performance is a common problem for existing school buildings in Taiwan. Therefore, the retrofit of existing school buildings has become an urgent issue in the prevention of possible damage in the future. The retrofit technique of adding sandwich columns to partition brick walls is proposed in this paper, and the feasibility of the proposed method was verified by in situ pushover tests of two real school buildings, one without and one with retrofit. The experimental and analytical results show that the sandwich column itself contributes significantly to the seismic capacity of the examined school building. Moreover, the analytical results yielded conservative capacity curves when compared with the experimental results. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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汶川地震中极震区砌体结构教学楼典型震害分析 总被引：2，自引：3，他引：2
汶川8.0级大地震造成了巨大的损失,大量学校建筑遭受严重破坏,其中大部分是砌体结构教学楼。在此次地震中,极震区北川县擂鼓镇城区内的初中、小学和幼儿园等砌体结构教学楼的破坏极其严重,结构特征和震害现象十分典型。本文详细地介绍了擂鼓镇城区内5栋砌体结构教学楼的结构构造特点和震害现象特征,同时,总结归纳了砌体结构教学楼的典型震害并分析了震害原因;讨论并分析了建筑含墙率、开间大小、高宽比等因素对建筑的抗震能力的影响;通过结构易损性分析方法对教学楼在不同烈度下的破坏状态进行了计算,并与实际震害进行了对比分析;最后,为灾后教学楼的重建工作提出了建议。 相似文献
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2021年5月21日云南漾濞发生6.4级地震,成为继2014年6.5级鲁甸地震和6.6级景谷地震之后云南省内时隔7年的又一次震级大于6级的破坏性地震。漾濞地震虽然与鲁甸地震在震级、震源深度和震源机制等方面均较相似,但漾濞地震震中附近的地面运动强度远不及鲁甸地震,且漾濞县的抗震设防烈度远高于鲁甸;相应地,漾濞地震对抗震设防建筑造成的破坏也远轻于后者。本文首先通过比较这三次地震震中附近的强震记录的反应谱,并结合公共建筑的震后应急评估结果,说明漾濞地震和鲁甸地震中公共建筑破坏程度的显著差异。进而以位于漾濞县城的两栋钢筋混凝土公共建筑为例,介绍此次地震中砌体填充墙和吊顶等典型非结构构件的震害。 相似文献
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Masonry buildings are primarily constructed out of bricks and mortar which become discrete pieces and cannot sustain horizontal forces created by a strong earthquake.The collapse of masonry walls may cause significant human casualties and economic losses.To maintain their integrity,several methods have been developed to retrofit existing masonry buildings,such as the constructional RC frame which has been extensively used in China.In this study,a new method using precast steel reinforced concrete(PSRC)panels is developed.To demonstrate its effectiveness,numerical studies are conducted to investigate and compare the collapse behavior of a structure without retrofitting,retrofitted with a constructional RC frame,and retrofitted with external PSRC walls(PSRCW).Sophisticated finite element models(FEM)were developed and nonlinear time history analyses were carried out.The results show that the existing masonry building is severely damaged under occasional earthquakes,and totally collapsed under rare earthquakes.Both retrofitting techniques improve the seismic performance of existing masonry buildings.However,it is found that several occasional earthquakes caused collapse or partial collapse of the building retrofitted with the constructional RC frame,while the one retrofitted by the proposed PSRC wall system survives even under rare earthquakes.The effectiveness of the proposed retrofitting method on existing masonry buildings is thus fully demonstrated. 相似文献
12.
Carlo Del Gaudio Mariano Di Domenico Paolo Ricci Gerardo Mario Verderame 《Bulletin of Earthquake Engineering》2018,16(10):4607-4637
On August 21st, 2017, an earthquake with duration magnitude Md?=?4.0 and epicentre in Casamicciola Terme hit Ischia island, in the South of Italy. This event caused two fatalities and dozens of injured people. Moreover, despite the low magnitude, the earthquake produced significant damages to masonry and reinforced concrete (RC) buildings, with some partial or complete collapse of structures, in a very limited area close to the epicentre, while even at small distance from the most damaged zone the earthquake was just felt by local people and tourists. In the days after the event, discussions concerning the destructive effects of such an earthquake arose in the scientific community—as also reported by local and national media. In this paper, the seismic history of Ischia island is recalled to show and explain the peculiarity of the August 21st earthquake, which is also described in terms of ground motion and response spectra characteristics. The results of the first surveys carried out in Casamicciola Terme are reported, together with appropriate pictures, to introduce and explain the observed damage state of masonry and RC buildings in the epicentral zone. Then, data from the 15th general census of the population and dwellings (ISTAT) is used to define vulnerability classes according to the classification of the European Macrosismic Scale (EMS-98) (Grünthal, 1998). Seismic damage scenarios are then evaluated combining macro-seismic intensity values obtained using an interpolation method starting from QUEST macro-seismic survey data (Azzaro et al., 2017 ) and fragility curves for A-to-D vulnerability classes and for five damage states, from DS0 (no damage) to DS5 (collapse) trough a Monte Carlo simulation technique. The distributions of Usable, Temporarily or Partially Unusable, and Unusable buildings, which are obtained by using relationships between damage and usability judgments obtained through post-earthquake damage data collected after past seismic events, result in very good accordance with those published in September 1st, 2017 by the Department of Civil Protection, regarding a dataset of about 600 buildings. 相似文献
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This study presents a seismic fragility analysis and ultimate spectral displacement assessment of regular low-rise masonry infilled (MI) reinforced concrete (RC) buildings using a coefficient-based method. The coefficient-based method does not require a complicated finite element analysis; instead, it is a simplified procedure for assessing the spectral acceleration and displacement of buildings subjected to earthquakes. A regression analysis was first performed to obtain the best-fitting equations for the inter-story drift ratio (IDR) and period shift factor of low-rise MI RC buildings in response to the peak ground acceleration of earthquakes using published results obtained from shaking table tests. Both spectral acceleration-and spectral displacement-based fragility curves under various damage states (in terms of IDR) were then constructed using the coefficient-based method. Finally, the spectral displacements of low-rise MI RC buildings at the ultimate (or near-collapse) state obtained from this paper and the literature were compared. The simulation results indicate that the fragility curves obtained from this study and other previous work correspond well. Furthermore, most of the spectral displacements of low-rise MI RC buildings at the ultimate state from the literature fall within the bounded spectral displacements predicted by the coefficient-based method. 相似文献
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单体建筑无筋砌体结构的抗震韧性较差,在地震中容易发生严重破坏和倒塌。为此,以抗震韧性为参数指标,对单体无筋砌体结构进行加固并分析,研究其在地震作用下的抗震能力。以某实际工程作为研究对象,运用ANSYS软件建立单体建筑无筋砌体加固有限元模型,选取中国汶川地震波、日本阪神大地震波、美国克恩县地震波、中国台湾集集地震波及人工地震波作为地震动输入,利用韧性指数法和韧性等级法,从无筋砌体加固体系在震后的修复费用、修复时间及人员伤亡等方面进行分析,得到抗震韧性评估结果。研究表明：(1)在罕遇地震、设防地震和多遇地震的情况下,单体建筑无筋砌体结构的层间位移、层间剪应力、破坏程度均大于单体建筑无筋砌体加固体系;(2)在受到地震强弱因素影响下,无筋砌体结构的抗震韧性指数最高为0.877,而其加固体系的抗震韧性指数最低为0.908;(3)在经历不同地震波后,无筋砌体结构受到较大损害等级占比较高,人员伤亡较重,需要花费较长的时间和较多的费用完成灾后重建;而经过加固后的无筋砌体结构,加固体系受到较小损害等级占比较高,人员伤亡较轻,且能够用较短的时间和较少的费用完成灾后重建。 相似文献
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The Himalayan region is one of the major seismic areas in the world. However, similar to many other seismically active locations, there are substantial numbers of unreinforced masonry(URM) buildings; the majority of which have not been designed for seismic loads. Past seismic events have shown that such buildings are highly vulnerable to earthquakes. Retrofitting of these URM buildings is an important concern in earthquake mitigation programs. Most government school buildings in rural areas of northern India are constructed of unreinforced masonry. These school buildings are socially important structures and serve as a crucial resource for rehabilitation during any disaster. The effectiveness of ferrocement(FC) to create a URM-FC composite is described in this study by estimating the performance and fragility of a URM school building before and after a retrofit. Analytical models, based on the equivalent frame method, are developed and used for nonlinear static analysis to estimate the enhancement in capacity. The capacity enhancement due to retrofitting is presented in terms of the maximum PGA sustained and damage probabilities at the expected level of earthquake hazard. 相似文献
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砌体建筑群在地震中往往破坏严重损失巨大,合理评估地震作用对不同种类砌体结构造成破坏的风险变得至关重要。传统基于后验概率的地震危险性分析方法忽略了砌体建筑个体差异性的影响,未深入考虑多种震害因子的耦合作用。本文以华南地区砌体建筑群为例,开发了一种集成概率方法来对城市砌体结构的破坏风险进行建模,考虑建筑年代、层数、使用用途和墙厚四类震害因子的耦合影响,采用(Kolmogorov-Smirnov)K-S检验,在设定地震动参数下选取Gaussian分布、Log-Normal分布、Gumbel分布和Beta分布四种概率分布对该地区砌体建筑物的破坏状态概率分布参数进行拟合。通过均方根误差(Root Mean Square Error)RMSE进行拟合优度评价,最终建立基于Gaussian分布和Log-Normal分布的砌体建筑物破坏联合概率模型。最后,以华南地区三个城市典型砌体建筑物为例进行实例对比验证,将基于本文建立的建筑破坏概率模型推算出的砌体建筑群震害矩阵与基于单体结构分析得到的震害矩阵进行对比,与理论值最大偏差为0.033 3。研究表明：本文构建的集成概率方法能够获得更加合理的城市砌体建筑... 相似文献
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当前地震记录法检测中强震下砌体结构损伤时,基于已知砌体结构地震动记录实施损伤检测存在较高的局限性。提出新的中强震下砌体结构损伤检测方法,利用DASP动态测试分析仪和891型的压电式位移传感器,检测拟静力试验后的砌体结构模型,采用参数互补校正方法得到受损砌体结构的自振频率和振型检测,通过有限元分析获取砌体结构位移,依据频率和位移采用信号匹配方法检测砌体结构损伤情况,根据墙体刚度变化检测中强震下砌体结构的损伤程度。实验证明所提方法可对中强震下砌体结构损伤情况进行准确检测。 相似文献
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Empirical seismic fragility for the precast RC industrial buildings damaged by the 2012 Emilia (Italy) earthquakes 总被引：1，自引：0，他引：1 下载免费PDF全文
下载免费PDF全文 Nicola Buratti Fabio Minghini Elena Ongaretto Marco Savoia Nerio Tullini 《地震工程与结构动力学》2017,46(14):2317-2335
The paper analyses the seismic fragility of precast reinforced concrete buildings using observational damage data gathered after the 2012 Emilia earthquakes that struck Northern Italy. The damage level in 1890 buildings was collected, classified and examined. Damage matrices were then evaluated, and finally, empirical fragility curves were fitted using Bayesian regression. Building damage was classified using a six‐level scale derived from EMS‐98. The completeness of the database and the spatial distribution of the buildings investigated were analysed using cadastral data as a reference. The intensity of the ground motion was quantified by the maximum horizontal peak ground acceleration, which was obtained from ShakeMaps. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献