Seismic fragility assessment of RC frame structure designed according to modern Chinese code for seismic design of buildings

Following several damaging earthquakes in China, research has been devoted to find the causes of the collapse of reinforced concrete （RC） building sand studying the vulnerability of existing buildings. The Chinese Code for Seismic Design of Buildings （CCSDB） has evolved over time, however, there is still reported earthquake induced damage of newly designed RC buildings. Thus, to investigate modern Chinese seismic design code, three low-, mid- and high-rise RC frames were designed according to the 2010 CCSDB and the corresponding vulnerability curves were derived by computing a probabilistic seismic demand model （PSDM）.The PSDM was computed by carrying out nonlinear time history analysis using thirty ground motions obtained from the Pacific Earthquake Engineering Research Center. Finally, the PSDM was used to generate fragility curves for immediate occupancy, significant damage, and collapse prevention damage levels. Results of the vulnerability assessment indicate that the seismic demands on the three different frames designed according to the 2010 CCSDB meet the seismic requirements and are almost in the same safety level.

Seismic performance evaluation of typical dampers designed by Chinese building code

Adding dampers is a commonly adopted seismic risk mitigation strategy for modern buildings, and the corresponding design procedure of dampers has been well established by the Chinese Building Code. Even though all types of dampers are designed by the same procedure, actual seismic performance of the building may differ from one to the others. In this study, a nine-story benchmark steel building is established, and three different and typical types of dampers are designed according to the Chinese Building Code to realize structural vibration control under strong earthquake excitation. The seismic response of the prototype building equipped with a viscoelastic damper, viscous damper and buckling-restrained brace(BRB) subjected to 10 earthquake records are calculated, and Incremental Dynamic Analysis(IDA) is performed to describe progressive damage of the structure under increasing earthquake intensity. In the perspective of fragility, it shows that the viscoelastic damper has the highest collapse margin ratio(CMR), and the viscous damper provides the best drift control. Both the BRB and viscoelastic dampers can effectively reduce the floor acceleration responses in the mid-rise building.

Revision of seismic design codes corresponding to building damagesin the “5.12” Wenchuan earthquake

A large number of buildings were seriously damaged or collapsed in the "5.12" Wenchuan earthquake. Based on field surveys and studies of damage to different types of buildings, seismic design codes have been updated. This paper briefly summarizes some of the major revisions that have been incorporated into the "Standard for classification of seismic protection of building constructions GB50223-2008" and "Code for Seismic Design of Buildings GB50011-2001." The definition of seismic fortification class for buildings has been revisited, and as a result, the seismic classifications for schools, hospitals and other buildings that hold large populations such as evacuation shelters and information centers have been upgraded in the GB50223-2008 Code. The main aspects of the revised GB50011-2001 code include: (a) modification of the seismic intensity specified for the Provinces of Sichuan, Shanxi and Gansu; (b) basic conceptual design for retaining walls and building foundations in mountainous areas; (c) regularity of building configuration; (d) integration of masonry structures and precast RC floors; (e) requirements for calculating and detailing stair shafts; and (f) limiting the use of single-bay RC frame structures. Some significant examples of damage in the epicenter areas are provided as a reference in the discussion on the consequences of collapse, the importance of duplicate structural systems, and the integration of RC and masonry structures.

A Comparison of Saudi Building Code with 1997 UBC for Provisions of Modal Response Spectrum Analysis Using a Real Building

The study uses an actual building to compare the modal response spectrum analysis results of Saudi Building Code (SBC) and the 1997 Uniform Building Code (UBC) used in Saudi Arabia before the introduction of SBC. A sample of four buildings with reported analysis of comparison between IBC and UBC is taken for confirming the comparison. Eight sample places from SBC map for Saudi Arabia together with two sample places of high seismic activity in USA were taken for the comparisons. The study used software package ETABS in this study for modeling and analysis. The results are dissimilar from the comparisons reported for test places of USA. It is concluded that at most places SBC base shear is higher for both ELFP and MRSA. However, the results cannot be generalized and considered always right. The same is factual for overturning moments. Consequently, we cannot report that SBC is more conservative than UBC for all scenarios.

Discussion on the application of the concept of environmental protection and energy saving in the design of building water supply and drainage

With the current,our country social economy rapid development,people's living standard and quality of life and therefore have got improved,at the same time,it is the concept of environmental protection and energy saving is also enhanced value,many fields in our country environmental protection and energysaving concept can be seen in the application,especially the application in building water supply and drainage design more widely,to protect the environment,to maximize the use of limited resources,how to reasonable use of water resources in building water supply and drainage construction,above is current the paper mainly discusses the problems in the construction field,this paper based on environmental protection and energy-saving concept,discusses its application in the building water supply and drainage design,for your reference.

Effect of URM infills on seismic vulnerability of Indian code designed RC frame buildings

Unreinforced Masonry (URM) is the most common partitioning material in framed buildings in India and many other countries. Although it is well-known that under lateral loading the behavior and modes of failure of the frame buildings change significantly due to infill-frame interaction, the general design practice is to treat infills as nonstructural elements and their stiffness, strength and interaction with the frame is often ignored, primarily because of difficulties in simulation and lack of modeling guidelines in design codes. The Indian Standard, like many other national codes, does not provide explicit insight into the anticipated performance and associated vulnerability of infilled frames. This paper presents an analytical study on the seismic performance and fragility analysis of Indian code-designed RC frame buildings with and without URM infills. Infills are modeled as diagonal struts as per ASCE 41 guidelines and various modes of failure are considered. HAZUS methodology along with nonlinear static analysis is used to compare the seismic vulnerability of bare and infilled frames. The comparative study suggests that URM infills result in a significant increase in the seismic vulnerability of RC frames and their effect needs to be properly incorporated in design codes.

An evaluation of force-based design vs.direct displacement-based design of jointed precast post-tensioned wall systems

The unique features of jointed post-tensioned wall systems, which include minimum structural damage and re-centering capability when subjected to earthquake lateral loads, are the result of using unbonded post-tensioning to attach the walls to the foundation, along with employing energy dissipating shear connectors between the walls. Using acceptance criteria defined in terms of inter-story drift, residual drift, and floor acceleration, this study presents a multiplelevel performance-based seismic evaluation of two five-story unbonded post-tensioned jointed precast wall systems. The design and analysis of these two wall systems, established as the direct displacement-based and force-based solutions for a prototype building used in the PREcast Seismic Structural Systems （PRESSS） program, were performed at 60% scale so that the analysis model could be validated using the PRESSS test data. Both buildings satisfied the performance criteria at four levels of earthquake motions although the design base shear of the direct displacement-based jointed wall system was 50% of that demanded by the force-based design method. The study also investigated the feasibility of controlling the maximum transient inter-story drift in a jointed wall system by increasing the number of energy dissipating shear connectors between the walls but without significantly affecting its re-centering capability.

A comparison of IBC with 1997 UBC for modal response spectrum analysis in standard-occupancy buildings

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.

Development of seismic force requirements for buildings in Taiwan

This paper describes static and dynamic procedures to calculate seismic demand specified by the current seismic design code for buildings in Taiwan, which was issued in 2005. For design levels with a return period of 475 years, the design spectral response acceleration can be developed for general sites, near-fault sites and Taipei Basin. In addition, in order to prevent building collapse during extremely large earthquakes and yielding of structural components and elements during frequent small earthquakes, the required seismic demands at the maximum considered earthquake level （MCE, 2%/50 years） and operational level are also included in the new seismic design code.For dynamic analysis procedures, both the response spectrum method and time history method are specified in the new seismic design code. Finally, procedures to generate spectrum compatible ground motions for time history analysis are illustrated in this paper.

Design between Architecture and Structure: Case Studies of Pilot Interventions on Italian Monumental Buildings

Two case studies,referring to historic Italian buildings housing city halls,provide an opportunity to investigate the design of non-standard elements aimed at protecting masonry vaults,with particular reference to the preliminary works prior to the actual structural restoration work.There is in fact a phase in which it is a priority to secure the vault to avert possible risks to the users of that portion of the building.This phase is temporarily intermediate between the detection and aggravation of injuries and the renovation and consolidation project.Although these are provisional works,they are intended for buildings that are often public and therefore intended for a wide range of users,such as schools,offices or monumental buildings.In analyzing traditional techniques and systems used in similar cases,the possibility of developing evolutionary aspects with respect to,above all,simple shoring techniques emerged.In these areas,hybrids between a structural and architectural project,it is possible to reconcile static requirements with architectural techniques of space management,attentive to the quality of the interior and the integration of the provisional work with the reference context.

古建筑保护中色彩采集方法及流程设计的应用研究——以岳麓书院为例

建筑色彩数据库的建立,是古建筑保护工作深化的重要技术节点,其技术流程可包括色彩体系的选择、取色仪器的匹配及色彩样本的误差处理。当前古建筑保护存在着色彩原真意识淡薄、数据资料缺乏以及采集规范不全等问题,古建筑色彩保护严谨性与科学性亟待提高。通过梳理色彩数据采集流程以及方法,初步建立了一个系统、明确、可执行的工作模式,为古建筑色彩采集工作提供参考;并规范色彩数据采集工作的流程设计以及数据定量纠偏方法,为古建筑色彩定量研究提供支持。实践结合岳麓书院古建筑群色谱研究,致力于解决建筑古迹色彩采集所涉及的样本选择、高度障碍、材质不均、光强条件、湿度差异、色温影响等重难点问题,为岳麓书院古建筑群后续色彩研究奠定数据基础,是古建筑色彩保护中色彩采集技术路线的有效支撑。

基于建筑设计防火规范的高校课程设计实践研究

将建筑设计防火规范纳入课程设计教学过程中,是培养学生综合设计能力的重要教学任务,是工程认证体系(CDIO)的基本要求。文章结合燕山大学建筑学专业商业综合体课程设计,通过将建筑设计防火规范在不同设计阶段有针对性地引入课程设计过程中,让规范成为课程设计的重要内容,不仅对课程设计具有重要的指导作用,对学生树立消防安全和社会责任意识、保持对防火规范的敬畏感也具有重要现实意义,而且对于今后从事建筑设计工作都有深远的影响。

基于空间归属关系下的木构古建筑构件信息分类编码研究

古建筑构件的信息编码是实现信息共享和实施信息系统的基础,可为古建筑数字化保护工作提供支撑。目前古建筑构件分类方式多参考现代建筑构件的分类方法,不能契合古建筑构件构造特点。通过对我国木构古建筑相关文献的分析与现状的调研,进行了木构古建筑构件信息分类编码体系的研究。研究表明,我国传统木构建筑具有“三段式”的整体特点,以“间”为单位、强调轴线对称的平面布局特点以及造型、空间布局、构件构造相统一的体系特点,进一步从木构古建筑特点中发掘出构件与空间归属关系。基于此提出了“三分”构件分类原则并设计了构件位置码制订规则。结合实例对提出的传统木构建筑构件分类方法进行了说明和运用。该构件信息分类编码体系具有较高的适应性、可扩延性以及兼容性,可为实现各地区传统木构建筑构件信息标准化以及古建筑数字化保护工作奠定基础。

苏州太仓阿尔卑斯雪世界超限高层结构设计

苏州太仓阿尔卑斯雪世界结构形式为钢筋混凝土框架结构,屋盖采用平面桁架体系。存在扭转不规则、楼板不连续、偏心率大于0.15、错层等不规则项,为超限高层建筑。对基础形式、结构体系、荷载取值、性能目标等进行了介绍,并采用YJK、PMSAP、MIDAS Gen三种软件进行了弹性计算,应用Paco-Sap软件进行动力弹塑性分析;阐述了雪场结构设计中的关键问题,如层间位移角、长短柱、桁架关键节点、温度荷载等。计算结果表明,结构的周期比、层间位移角等指标均满足规范要求。采用性能化设计和动力弹塑性分析方法实现结构和构件在中震和大震作用下的既定性能目标,并对结构关键部位和构件采取了针对性的加强措施。

历史建筑保护与低碳再生设计研究热点及趋势分析

历史建筑作为城市文脉记忆的传承,对其进行保护与更新利用具有十分重要的意义。自2020年提出“双碳”战略以来,低碳建筑理念和技术逐渐成熟并广泛应用于城市建设中,但在历史建筑保护与再生设计相关研究中尚未得到充分的考量,通过文献综述研究,可以为历史建筑低碳再生设计提供有效的理论支撑和科学依据。运用CiteSpace软件对该领域2013-2022年的研究动态进行可视化定量分析,并结合定性分析予以辅助。结果表明:我国历史建筑与低碳再生设计领域研究文献数量整体呈上升趋势,主要研究内容为历史建筑原真性保护与更新策略,在历史建筑碳排放、节能优化方面研究较少。因此,运用数字化技术与建筑节能新技术等开展历史建筑低碳再生设计将会成为未来该领域的研究重点。

基于2021年版广东省高规的某含错层超限高层结构抗震性能化设计

2021年实施的广东省标准《高层建筑混凝土结构技术规程》(DBJ/T 15-92—2021)(简称广东省高规)在抗震计算和性能化设计方面做了一些调整。根据广东省高规相关要求,通过YJK软件对某含错层的超限高层结构作设防地震验算和抗震性能化设计,采用Perform-3D进行动力弹塑性分析以验证按广东省高规设计的错层结构在大震中的性能。结果表明,对于该项目错层处框架柱,按照广东省高规进行的性能化设计,相较于《高层建筑混凝土结构技术规程》(JGJ 3—2010),纵向钢筋用量平均节省约7%。

建筑防火技术在高层建筑设计中的应用研究

随着城市化进程的加速,高层建筑成为现代城市发展的重要标志,但其火灾风险也相应增加。系统性地探讨了高层建筑火灾的特点,包括快速蔓延、疏散困难、人员密集和扑救难度大等。针对这些特点,提出了建筑防火技术在高层建筑设计中的应用流程与方法,包括火灾风险评估、设计阶段的火灾模拟、防火分区设计和配备消防设施等。最后,系统地总结了建筑防火技术在高层建筑设计中的应用要点,包括材料选择、设计合理的疏散通道、定期维护检查。这些方法的综合应用能够有效降低高层建筑火灾风险,保障人员生命财产安全,对高层建筑设计具有重要的指导意义。

区域性超高层地标建筑设计分析

以西安民荣中心为例,从建筑设计的角度分析超高层建筑设计要点,对核心筒设计、避难层设计等超高层设计核心内容进行分析,并提出未设置裙房的超高层建筑为保证建筑的纯粹美学,为避免在首层立面出现通风百叶,采用了多种特殊的设计手法。从总平面图设计、核心筒设计、消防设计、场地设计等多个方面,逐步剖析了项目从方案设计到施工图设计完成的过程,还原方案设计的理念,期望相关设计思路与手法能为类似建筑提供参考。

既有建筑改造防火性能评价体系和方法研究

当前,我国城市建设模式已从大规模拆旧建新转向存量增效,党的二十大报告中明确提出“实施城市更新行动”。既有建筑改造作为城市更新的重要载体,事关人民群众的幸福感、获得感、安全感。在消防标准规范适用中,如何在兼顾既有建筑改造的经济性的同时又确保建筑消防安全,是亟待解决的关键问题。在总结国内既有建筑改造防火设计经验和研究国外既有建筑改造消防安全评估方法的基础上,以现行规范为基准,按改造后的实际使用功能,将既有建筑防火设计与现行规范不一致的条目(即偏离项)分为4种类型。同时根据偏离项可能导致的火灾风险高低或与规范的偏离程度,提出了豁免法和等效替代法对既有建筑的防火设计进行定性/定量的评估,以达到规范等同的安全标准。提出的既有建筑消防评估体系和方法可破解我国既有建筑改造的消防难题。

建筑电气智能化设计对智能建筑发展的影响研究

文章深入探讨了建筑电气智能化设计对智能建筑发展的多维影响。在当前节能减排、绿色环保的大趋势下,建筑电气智能化设计通过集成先进的信息技术和自动化技术,为绿色建筑、海绵城市和综合管廊等新型城市建设模式提供了有力支持。本研究梳理了建筑电气智能化设计的基本框架,进而详细分析了其在绿色建筑中的应用,包括节能减排、提高环保性和促进可持续发展等方面。同时,电气智能化设计在海绵城市建设中通过优化水资源管理,提升了城市的生态韧性。在综合管廊领域,电气智能化设计则通过智能化监控和管理,显著提高了管廊的运行效率和安全性。