汶川地震建筑震害启示——三水准设防和抗震设计基本要求

汶川大地震造成大量房屋建筑破坏倒塌,通过对砌体结构和工业厂房、设备及设施的震害调查与分析,对我国《建筑抗震设计规范》(GB 50011-2001)的三水准设防和抗震设计基本要求进行探讨,分别对比了在遭遇"小震"、"中震"和"大震"情况下,按一定设防烈度设计的房屋建筑的破坏状态,判别是否达到了设防目标。结果表明,在1990年以后设计建造的房屋建筑,基本都能达到三水准抗震设防目标,严重破坏或倒塌的大多是建造年代较早、设计不满足规范要求或施工质量存在问题的建筑。针对抗震设计规范中有关结构整体性、传力路径、地基基础、抗震缝、疏散通道、设备和设施的抗震设计基本要求,对照实际震害情况,包括过去地震震害情况,总结经验教训,提出改进意见。对震前经过加固的建筑物在地震中的表现作了介绍,证明了结构抗震加固的效果和必要性。     

汶川地震中单层钢筋混凝土柱厂房典型震害分析

通过对四川江油市、成都市、彭州市、绵阳市汉旺镇、甘肃天水市、陕西汉中市单层钢筋混凝土柱厂房的震害调查,以及对典型震害的分析,得出以下结论:按抗震规范设计的建筑,钢筋混凝土主体结构破坏轻微;非结构构件震害相对比较严重,特别是纵墙端开间、高大山墙、高低跨悬墙,以及高大设备和基础的连接;未进行抗震设计且未进行加固的老厂房震害一般较严重。为此,要特别加强非结构构件和高大设备的抗震设计,对未进行抗震设计的老厂房要尽快安排抗震加固。     

Evaluation of geotechnical characteristics of Lasbela barite deposits of Balochistan,Pakistan, as heavyweight aggregate

A number of medium to small sized barite deposits are located within the Mor Mountain Range, Pakistan. The present study evaluated eight barite deposits from the Lasbela area, Balochistan, Pakistan, representing the different parts of the Mor Range. Evaluation of the barite content and those properties important in the production of heavyweight concrete aggregate indicated that the material would be suitable for the construction of earthquake resistant buildings and for radiation shielding.     

青海村镇砌体结构房屋抗震缺陷分析

青海玉树地震中砌体结构的严重震害表明,村镇砌体结构房屋存在着较大的抗震缺陷。依据《建筑抗震设计规范》(GB 50011-2010)的抗震设防标准,通过玉树地震中砌体结构房屋表现出的震害特征,从墙体、结构基础、结构体系及结构布置四方面对青海村镇砌体结构房屋存在的主要抗震缺陷进行了分析,并结合青海省现有村镇砌体结构房屋在抗震性能方面存在的主要问题,提出了相应的加固改造措施。     

汶川地震峨眉山市房屋排查及震害研究

2008年5月12日四川汶川8.0级特大地震后,对峨眉山市区及周边村镇房屋进行应急排查.该地区大部分房屋基本为砖混、砖木结构及底框结构,震后出现不同程度的开裂受损.其中,按现行<建筑抗震设计规范>新修的房屋,此次地震中抗震性能很好.文章就所排查房屋的震害特点及震害原因进行分析研究,并对震后加固及后期工作提出建议.     

桥梁抗震设计

分析了桥梁震害及产生原因,着重介绍了拱桥的震害形式,并从设计的角度提出了一些桥梁抗震设计中遵循的基本原则,最后分析比较了我国《建筑抗震设计规范》和《公路工程抗震规范》,从而为桥梁的抗震设计提供了理论依据。     

5·12汶川地震绵阳市区房屋震害统计与分析

历次大地震的经验总结是推动建筑抗震技术发展的重要途径。通过绵阳市区房屋在汶川大地震后的震害应急评估和调查,对市区各类房屋结构的震害进行了统计,总结分析各类房屋的震害特征和经验教训。得到一些启示和建议：绵阳市区按现行抗震规范设计的房屋基本经受住了地震考验;不同的结构体系表现出的抗震性能差别较大;老旧房屋始终是抗震薄弱环节,应有选择地进行抗震鉴定加固,开展砖混结构墙体抗震防裂措施研究,采取措施有效减轻框架结构中填充墙等非结构构件的震害,开展楼梯抗震设计计算与构造措施的研究。     

Performance‐based seismic design of an irregular tall building in Istanbul

Structural design of a 50‐story tall reinforced concrete residential building, which was planned to be constructed in Istanbul and given up afterwards by the investor, has been completed in accordance with the draft version of Seismic Design Code for Tall Buildings in Istanbul that adopts performance‐based seismic design as the basic approach as Tall Buildings Initiative Guidelines do. Seismic design of the building has formed the main part of the structural design process due to high seismicity of the proposed location and extremely irregular floor plan not conforming to usual tall building structures. The building consists of two individual buildings linked through sky floors at the top 12 stories whose design was one of the most challenging works. The building has been designed for design basis earthquake by elastic response spectrum analysis, and its seismic performance has been checked for maximum considered earthquake by nonlinear time‐history analyses carried out using PERFORM‐3D. Copyright © 2015 John Wiley & Sons, Ltd.     

城市老旧房屋抗震性能的调查研究

对城市中的老旧房屋和“城中村”中近二十多年来未经正规设计建造的房屋进行了调查研究 ,依据《建筑抗震设计规范》(GB 5 0 0 11 2 0 0 1) ,对一栋典型二层砖砌体结构房屋进行了抗震验算。根据调研和单体房屋抗震验算的结果 ,评价这类房屋的抗震性能 ,指出这类单体房屋在抗震性能方面、在老居民区、城中村整体环境方面存在的一些共性问题 ,希望引起有关部门的重视。本文还从抗震防灾的角度 ,提出一些解决问题的思路和措施。     

Das Waldkirch‐Erdbeben (Baden‐Württemberg) vom 5. Dezember 2004

The Waldkirch earthquake (Baden‐Württemberg) on Dezember 5, 2004. The Waldkirch earthquake on December 5, 2004, was the strongest event on the area of the Federal Republic of Germany since the Roermond earthquake in 1992. The shaking effects of this earthquake were perceived in neighboring areas at a distance of 200 km. During a field investigation of several days the damaged buildings in the affected area were surveyed and the regional distribution of damages documented. The paper gives an impression of the damages and attempts to derive conclusions regarding the strength of the quake (and corresponding parameters) by applying mean damage grades. Based on the damages of the buildings, the maximum observed shake effects on the scale of the EMS‐98 [8] reached the intensity of I(EMS) = VI, but didn't exceed it. This can be explained by the location of the epicenter in a sparsely populated forest area, and by the circumstance that any significant communities can only be found at a distance of 15 to 20 km. The version of the German Seismic Code DIN 4149: 1981, still valid until 2005, does not consider the affected area as a particular seismic one. Nevertheless, the low degree of damage is regarded as the consequence of respecting basic design principles. In this context the lasting and sustained contribution of a planning guide for earthquake‐resistant design, published by the Ministry of Interior Baden‐Württemberg, is recognized.     

汶川地震建筑震害启示——抗震概念设计

汶川大地震造成大量房屋建筑破坏倒塌,通过在地震区对遭受中震、大震作用的砌体结构和钢筋混凝土结构以及非结构构件的震害调查与分析,以典型的结构破坏为例,针对多道抗震防线、强柱弱梁、剪力墙连梁、砌体结构整体性、楼梯间、非结构构件等抗震设计问题,对照《建筑抗震设计规范》(GB 50011-2001)所规定的抗震概念设计原则进行讨论,总结经验教训,提出改进建议。震害分析结果表明,只要严格按照规范设计,保证施工质量,房屋建筑就能达到"小震不坏,中震可修,大震不倒"的三水准设防目标。     

农村建筑抗震调查的综合分析

结合我国各地区地震灾后的建筑物破坏情况，依照抗震鉴定标准和抗震设计规范的基本思想，对农村建筑从综合抗震能力作了综合抗震鉴定，并以此为基础提出了结合村镇建设改善农村建筑综合抗震能力的设想。     

某公寓楼结构部分初步设计

高层建筑的抗震计算及抗震构造措施,须满足《高层建筑混凝土结构技术规程》（JGJ3-2002）,《建筑抗震设计规范》（CB50011-2001）。     

Blast and residual capacity analysis of reinforced concrete framed buildings

Iconic and public buildings have become a universal target of bomb attacks from terrorists. Most of these buildings have been or are built without consideration for their vulnerability to such events. Planning and building control authorities have begun to recognise the risks of these events and have introduced provisions in planning guidelines for mitigation of such impact. This paper is a study of the impact of near field explosions on the structural framing system and key elements such as columns and describes the component material response. This information can be used in planning strategies to mitigate potential catastrophic and progressive collapse of the structure. Reinforced concrete framed buildings have been selected for this study. A two stage finite element modelling (FEM) and analytical technique has been used to interrogate the structural framing system and components for global stability and local residual strength capacity in the linear elastic and non-linear plastic response regimes. The first stage involved linear time history analysis carried out using SAP 2000 to verify the response of the complete framing system and its ability to restore global frame stability and to enable iterative interrogations. An explicit rigorous analysis accounting for strain rate effects of the reinforced concrete elements was carried out in stage two using LS DYNA code to investigate the non-linear response of vulnerable elements identified in the first stage. The damage mechanisms and the extent of damage have been studied using principal stress plots along with plastic strain diagrams and used to assess the residual strength capacity of key elements that can cause catastrophic failure of large sections of the building and propagate progressive collapse. Numerical analysis is based on techniques that have been established in previous research work and the models have been calibrated with similar work by others. The method used in this research work can be used for assessing vulnerability, damage and residual strength capacity of building frames and component elements subjected to near field blast events.     

规范中C级普通螺栓抗拉强度设计值是否考虑撬力影响的探讨与建议

在编制07SG359-5《悬挂运输设备轨道》（适用于门式刚架轻型房屋钢结构）国家建筑标准设计图集时,提出连接轨道的C级普通受拉螺栓抗拉强度设计值是否考虑撬力影响的问题,对此GB50017-2003《钢结构设计规范》国家标准管理组作了肯定性答复。通过一些探讨和计算,提出对规范修改的参考建议。     

Seismic response of multistory reinforced concrete frame with vertical mass and stiffness irregularities

Irregular buildings behave differently as compared with regular buildings. Seismic design codes have quantified the irregularities in terms of magnitude only ignoring the effect of irregularity location. In the present study, a single parameter to quantify mass, stiffness and strength irregularity in terms of both magnitude and location is proposed on the basis of the dynamic characteristics of the building. Furthermore, building models with different types of irregularity with variation in magnitude and location of irregularity are analyzed by subjecting them to an ensemble of 27 ground motions to create a seismic response databank. In the analysis, the torsional effects generated due to irregularities in the building systems (as per EC 8:2004 provisions) are included. On the basis of regression analysis conducted on this seismic response databank, equations to estimate seismic response parameters such as fundamental period, maximum roof displacement and maximum inter‐story drift ratio etc. are proposed for the irregular buildings in terms of the proposed irregularity index. Finally, applicability of the proposed equations is discussed in brief, and these equations are validated for 2D and 3D building models. Copyright © 2012 John Wiley & Sons, Ltd.     

Structural damage accumulation and control for life cycle optimum seismic performance of buildings

Seismic reliability and expected performance functions of structural systems are sensitive to the process of damage accumulation associated with the random sequences of ground motion excitations that those systems may experience. Optimum life cycle-based engineering decisions must examine the influence of concepts related to both the target safety level of the initial system and the eventual repair and maintenance actions that may be undertaken during the life of the system. This study includes an overview of the general framework supporting these decisions as well as some available results about (a) the influence of damage accumulation of the seismic vulnerability functions of building structures, (b) approximate estimates of accumulated damage and (c) optimum damage threshold values for repair of structural frames or replacement of energy dissipating devices. Some comments are presented concerning desirable studies about life cycle optimisation of systems exposed to different types of excitations.     

浅谈底部框架-抗震墙结构设计

结合底部框架-抗震墙房屋的设计难点,在深刻理解《抗震规范》有关条文的基础上重点对底部框架-抗震墙房屋中剪力墙的布置进行了探讨,从而更好的设计出抗震性能良好的底部框架-抗震墙房屋。     

非抗震区多层房屋的整体防灾思考

21世纪,全球灾害形势严峻。房屋的抗灾性能直接影响着社会的抗灾能力。GB 50011—2001《建筑抗震设计规范》和JGJ 3—2002《高层建筑混凝土结构技术规程》中计算设计与概念设计的结合保证了抗震区结构的基本抗灾能力,而GB 50010—2002《混凝土结构设计规范》和GB 50003—2001《砌体结构设计规范》由于未作计算加强考虑,概念设计应用亦不全面,导致非抗震区的多层房屋整体性能明显不足,抗灾能力低。从经济性考虑,建议把概念设计更多的应用到这两本规范中,以改善非抗震区多层房屋的抗灾能力。     

混凝土多孔砖砌体模型房屋抗震性能试验研究

混凝土多孔砖是近年来兴起的新型承重墙体材料。为了掌握混凝土多孔砖砌体房屋的抗震性能,拓宽其应用范围,本文采用基于位移控制的多点地震波输入的拟动力试验方法,开展了一个8层24m高混凝土多孔砖砌体1/2比例模型房屋子结构拟动力试验。研究表明,模型房屋主要呈剪切破坏形态,墙体的裂缝形式及模型房屋地震破坏形态与普通粘土砖砌体房屋基本相似;模型房屋的滞回曲线呈反S型,具有明显的捏拢和滑移效应;模型房屋的延性系数为2.43,模型房屋具有良好的水平承载能力。因此,模型房屋能够满足7度抗震设防的“小震不坏”和“大震不倒”的要求,而采用《混凝土多孔砖砌体结构暂行技术规程》(DB 43/172—2003)及《建筑抗震设计规范》(GB 50011—2001)规定的相应构造措施的混凝土多孔砖砌体房屋在6度抗震设防区可建到8层24m高。