Force and Displacement Based Vulnerability Assessment for Traditional Buildings

Vulnerability assessment for historic buildings is usually carried out using capacity based approaches and prediction of losses is obtained by using normal or lognormal distributions for expected levels of macro seismic intensity or peak ground accelerations. Several authors have outlined the limitations of such approach. The paper presents a method to correlate analysis of seismic vulnerability using a failure mechanisms approach to observed in situ damage. The various aspects of the procedure are highlighted with application to a real case. It is shown how once the typologies within a sample have been identified, fragility curves for each of them can be derived and predictive cumulative damage curve obtained for samples for which direct survey of damage data is lacking. Finally the paper shows how the failure mechanism approach can be used to derive damage scenarios both in terms of spectral acceleration and spectral displacement     

Seismic Performance of RC Frames Designed to Eurocode 8 or to the Greek Codes 2000

For the first time after the finalisation of the European Norm for seismic design of buildings (Eurocode 8 – EC8),the performance of RC buildings designed with this code is evaluated through systematic nonlinear analyses. Regular 4-, 8- or 12-storey RC frames are designed for a PGA of 0.2 or 0.4 g and to one of the three alternative ductility classes in EC8. As the Eurocodes are meant to replace soon existing national codes, design and performance is also compared to that of similar frames designed with the 2000 Greek national codes. The performance of alternative designs under the life-safety (475 years) and the damage limitation (95 years) earthquakes is evaluated through nonlinear seismic response analyses. The large difference in material quantities and detailing of the alternative designs does not translate into large differences in performance. Design for either Ductility Class High (H) or Medium (M) of EC8 is much more cost-effective than design for Ductility Class Low (L), even in moderate seismicity. It is also much more cost-effective than design to the 2000 Greek national codes.     

基于SPOT-5图像的城市水体自动提取模型研究

以南京市主城区为对象,研究基于SPOT-5图像的城市地区水体信息的提取方法.分析表明,对SPOT-5的SWIR波段进行简单的阈值处理,可以清晰地将水体与阴影提取出来.在分析水体和阴影光谱特征和空间特征（形状指数等）的基础上,建立了基于SPOT-5图像的城市地区水体的自动提取决策树模型.精度验证表明,该模型的水体提取精度较监督分类的提取精度提高2.5%,尤其在具有许多建筑物阴影的局部区域,本模型的水体提取精度提高11.6%.此外,本模型还具有很好的移植性,只是在阈值大小的确定上会有部分差异.     

2003年民乐-山丹6．1、5．8级地震房屋震害分析

通过对2003年民乐-山丹6．1、5．8级地震的现场调查，划分了灾区房屋类型及结构特征，揭示了不同类型房屋的震害特点，分析了房屋震害的原因，总结了防御和减轻震害的经验与教训，强调了规范民房建设管理的重要性。     

基于建筑功能与性态要求的抗震设计--简评《建筑工程抗震性态设计通则(试用)》(CECS 160:2004)

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。     

In situ experiments and seismic analysis of existing buildings. Part I: experimental investigations

Recent results of in situ measurements and their interest for a seismic assessment of existing buildings are presented and analysed. The present paper (Part I) is devoted to the experimental programme. The response to ambient vibrations, harmonic excitation and shock loading is recorded on intact buildings but also after their structure or their vicinity was modified. These tests aim to identify the dynamic behaviour of ordinary intact buildings built in a conventional practise. Moreover, taking advantage of their demolition, it was possible (through these tests) to determine the actual influence of the light work elements, full precast facade panels, bearing masonry walls, and the presence of neighbouring joined buildings. These experiments realized on real buildings show that information gathered from ambient measurements provide reliable and efficient data of real interest for a clear understanding of the actual building behaviour. The advantage of integrating these data in the vulnerability assessment is presented and discussed in the next paper (Part II). Copyright © 2005 John Wiley & Sons, Ltd.     

建筑物3维模型在地籍管理中的应用

房屋作为地籍管理中最主要的研究对象之一,具有明显的几何特征。本文叙述了用于3DCM建模的几种方法及数据采集方式,着重讨论了基于规则几何体构建建筑物实体模型的方法,实现了建筑物3维模型的可视化。介绍了基于AUTOCAD建立房屋图像与外部数据库之间链接的过程与方法;为丰富地籍管理中的房屋信息,探讨建立房屋图像库的方法;通过建立图像库与图形的链接,实现了由图形对象浏览房屋3维模型的图像信息。     

解决街道与建筑物图形冲突的移位模型研究

介绍了在地图缩编中因道路符号所对应的实际尺寸加宽而破坏了建筑物与道路符号的正确关系时,针对第二、三、四类建筑物进行移位所涉及的数学方法,并给出了实验结果。最后,介绍了用栅格探测加矢量计算法对移位后可能产生的要素间的后继图形冲突所进行的探测,以及消除后继冲突的方法。     

Alternative method to locate centre of rigidity in asymmetric buildings

Response of asymmetric buildup under earthquake excitation often involves lateral vibration coupled with torsional vibration. Floor slab is, in general, assumed as rigid along the in‐plane direction. Building code provisions to account for the torsional effect in static force procedure are based on centre of rigidity or shear centre of the building. A convenient procedure is developed here to locate the centre of rigidity or shear centre, which can be implemented, using any standard building analysis software. The procedure is applicable for orthogonal as well as non‐orthogonal building systems and accounts for all possible definitions of static eccentricity to compute the design response. An irregular building is analysed to illustrate the proposed methodology. Significant variation in member force resultants is observed due to different definitions of static eccentricity. Finally, a mathematical proof is presented to substantiate the applicability of the proposed procedure to a non‐orthogonal building. Copyright © 2006 John Wiley & Sons, Ltd.     

Seismic loss estimation of non‐ductile reinforced concrete buildings

Non‐ductile reinforced concrete buildings represent a prevalent construction type found in many parts of the world. Due to the seismic vulnerability of such buildings, in areas of high seismic activity non‐ductile reinforced concrete buildings pose a significant threat to the safety of the occupants and damage to such structures can result in large financial losses. This paper introduces advanced analytical models that can be used to simulate the nonlinear dynamic response of these structural systems, including collapse. The state‐of‐the‐art loss simulation procedure developed for new buildings is extended to estimate the expected losses of existing non‐ductile concrete buildings considering their vulnerability to collapse. Three criteria for collapse, namely first component failure, side‐sway collapse, and gravity‐load collapse, are considered in determining the probability of collapse and the assessment of financial losses. A detailed example is presented using a seven‐story non‐ductile reinforced concrete frame building located in the Los Angeles, California. Copyright © 2012 John Wiley & Sons, Ltd.