Brandverhalten von Brettsperrholz

Fire behaviour of cross‐laminated timber Cross Laminated Timber (CLT) is currently used in modern timber structures for load‐bearing wall, floor or roof elements as a high quality, innovative and cost‐effective structural element. Careful planning and implementation ensures the safe use of CLT in buildings with increased fire protection requirements and in accordance with the requirements of building‐design standards (e. g. EN 1995‐1‐1 and EN 1995‐1‐2) [1, 2]. Worldwide, many fire tests with CLT have been per‐formed to investigate the influence of different cross‐sectional build‐ups and various adhesives on the fire resistance of CLT floor and wall elements. This paper gives an overview of the extensive investigations, main outcomes are summarized and recommendations on the fire design of CLT elements are given. The investigations show that an adequate data base exists to reliably describe the fire behavior of CLT.     

水平地震作用下框支剪力墙结构的变形研究

对工程结构中常用的底部为多层大空间的框支剪力墙结构采用分区混合法，进行水平地震作用下结构的变形研究。将框支剪力墙结构分成转换层上部剪力墙结构和转换层下部框架剪力墙结构两部分，采用子结构法进行分析。在水平地震作用下，转换层上、下部先分别按剪力墙结构和框架一剪力墙结构的变形曲线公式计算其变形，再充分考虑上下两种不同结构的变形协调性，推导了框支剪力墙结构在水平地震作用下的侧移曲线公式，并给出了方便结构侧移曲线计算的图表。方法简单实用，可用于地震区高层建筑结构的初步设计。     

双面叠合剪力墙关键问题研究：水平连接节点抗震性能试验

双面叠合剪力墙水平连接节点是传递竖向荷载和水平剪力的关键部位,其水平节点连接钢筋是“间接搭接”的形式。通过6个双面叠合剪力墙水平连接节点和2个现浇节点在竖向荷载和循环剪切荷载作用下的试验,研究双面叠合剪力墙水平连接节点和现浇节点的滞回特性、位移延性系数、刚度退化、承载力退化以及耗能特性。试验结果表明,双面叠合剪力墙水平连接节点的水平裂缝出现在灌浆层和上下墙体的交界面,双面叠合剪力墙水平连接节点的抗剪承载力和现浇节点较为接近,各项抗震性能指标较为接近。     

Continuous transfer beams supporting in-plane loaded shear walls in tall buildings

The failure mechanism and structural behavior of transfer beams supporting in-plane loaded shear walls have received added emphasis owing to their importance in connection with tall building construction. This paper presents an analysis of and investigation of the structural behavior of two-span transfer beam-shear wall systems in tall buildings. The interaction between the transfer girders and the shear wall has been investigated considering interior and exterior column interaction effects. The upper structural form has a significant effect on the failure mechanism of the transfer girders, which can act as full tension members or behave as ordinary flexural beams. Stress distributions in the shear wall interactive zone are presented. The relevant parameters that significantly influence the force transfer mechanism and structural behavior, such as the span/depth ratio of the transfer beam, the span of the shear wall and the stiffness of the support columns, are highlighted. The present paper provides a very useful reference for the design of continuous transfer girders supporting in-plane loaded shear walls in tall buildings.     

往复荷载下预应力正交胶合木剪力墙抗侧力性能研究

侧向荷载作用下,正交胶合木(cross-laminated timber,CLT)剪力墙的侧向承载力往往因墙体连接区域发生破坏而骤降。为了避免该破坏特征,提出在CLT墙板中贯穿无黏结预应力钢绞线,进而构成预压于基础上表面的预应力CLT剪力墙。通过拟静力往复加载试验,共测试了3面具有不同初始张拉力的无耗能件预应力CLT剪力墙和1面装有耗能件的预应力CLT剪力墙,所有试件均为2层楼层的缩尺墙体试件,且上、下层墙板间布置有经特殊构造设计的CLT-钢组合楼板系统。基于试验数据,分析侧向荷载作用下,墙体试件的力学性能参数,水平侧移、钢绞线张拉力变化特征和墙体破坏模式,计算墙板与钢基础间的最大静摩擦系数,研究耗能件对预应力墙体耗能能力的提高效果。结果表明：预应力CLT剪力墙具有良好的抗侧力性能,且加载结束后墙体试件几乎完好;位于上、下层墙板间的CLT 钢组合楼板系统能够在有效传递层间竖向力的同时,缓解其中的CLT楼板可能发生较大横纹受压变形的问题;耗能件能够一定程度上提高预应力CLT剪力墙的耗能能力,然而,耗能件与CLT墙板的连接方式还有进一步改进的空间。     

Theoretical and experimental study on composite steel-concrete shear walls with vertical steel encased profiles

The present work describes the theoretical study and the experimental tests on composite steel-concrete shear walls with steel encased profiles (CSRCW), performed at Politehnica University of Timi?oara, Romania. The composite steel-concrete structural shear walls with steel encased profiles can be used as horizontal resisting systems for buildings that require considerable large horizontal load capacity. The study consists in numerical analysis and tests on 1:3 scale experimental steel-concrete composite elements. The experimental elements differ by the arrangement of the steel shapes embedded in the cross section of the wall and by the cross section type of the steel encased element. Headed steel studs are provided to ensure the connection between the steel profiles and the concrete. The aim of this study is to analyze the nonlinear behavior of elements, focused on the connection between the steel profiles and the concrete respectively, to compare the behavior of shear walls with different steel shape encased profiles with typical reinforced concrete shear walls. Using the tests performed until failure, the maximum load, the deformation capacity and the dissipated energy were evaluated.     

Diagrid structures for tall buildings: case studies and design considerations

The originality of form is one of the new trends that can be identified in the current design of tall buildings. In this design trend, the so‐called diagrid structures, which represent the latest mutation of tubular structures, play a major role due to their inherent esthetic quality, structural efficiency and geometrical versatility. In this paper, an overview on application of such typology to high‐rise buildings is carried out; in particular, in the first part of the paper, the peculiarities of diagrid systems are described: starting from the analysis of the internal forces arising in the single diagrid module due to vertical and horizontal loads, the resisting mechanism of diagrid buildings under gravity and wind loads is described, and recent researches and studies dealing with the effect of geometry on the structural behavior are discussed. In the second part of the paper, a comparative analysis of the structural performance of some recent diagrid tall buildings, characterized by different number of stories and different geometries, namely the Swiss Re building in London, the Hearst Headquarters in New York and the West Tower in Guangzhou, is carried out, and some general design remarks are derived. Copyright © 2012 John Wiley & Sons, Ltd.     

正交胶合木墙与楼面钢梁预应力螺栓连接的抗滑移性能

正交胶合木(cross-laminated timber,CLT)-钢混合结构中,CLT剪力墙的抗侧能力主要取决于墙体与下部构件的抗剪连接.目前,角钢式抗剪连接件是工程中的主要连接形式,该类CLT墙体抗侧时,破坏往往集中在抗剪节点域,而CLT墙体受力并不大.为充分发挥CLT强度和刚度较大的优势,本文探索CLT墙与其下楼...     

An inter‐story drift‐based parameter analysis of the optimal location of outriggers in tall buildings

Outriggers are usually added in structural systems of tall buildings to collaborate central shear walls with peripheral columns. With outriggers, the structural overturning moment can be balanced, and the inter‐story drift can be controlled under horizontal loads. Therefore, the optimal location of outriggers plays a very important role in controlling the behavior of the whole building. Existing research has focused on the optimal position of outriggers on the base of the structural roof deflection. In the engineering practice, however, inter‐story drift is the most important target to control the design of tall building structures. This paper investigates the theoretical method of inter‐story drift‐based optimal location of outriggers. A Matlab program is written to perform the parameter analysis of optimal location of outriggers. Take a 240‐m tall building for a target building, the optimal location of one to three sets of outriggers under wind and earthquakes is obtained and can be utilized for the structural preliminary design of tall buildings. Copyright © 2015 John Wiley & Sons, Ltd.     

Interaction‐based design tables for transfer beams supporting in‐plane loaded shear walls

The analysis and behaviour of transfer beams that support in‐plane loaded shear walls have been receiving added emphasis owing to their importance in connection with the design of tall buildings. In this paper, analysis and structural behaviour of transfer beams supporting in‐plane loaded shear walls are presented, where emphasis is placed on the interaction between the transfer beam and the supported shear wall. The interaction effect is shown to cause significant stress re‐distributions both in the transfer beam and in the shear wall within an interactive zone. Parameters that significantly influence the structural behaviour and force transfer mechanism are also highlighted. Based on finite element analysis, interaction‐based design tables are constructed and presented for the design of the transfer beam–shear wall system, which is represented by an equivalent portal frame. The design tables have been shown to provide practising engineers a very simple and efficient, yet accurate, means of analysis of the internal forces of the transfer beams and the support columns. Copyright © 2001 John Wiley & Sons, Ltd.     

Diagrid: An innovative,sustainable, and efficient structural system

In recent years, diagrid structures have received increasing attention among both designers and researchers of tall buildings for creating one‐of‐a‐kind signature structures. This paper presents a state‐of‐the‐art review of diagrid structures. First, various diagrid configurations, main factors affecting their behaviors, and related design parameters and approaches are discussed. Then, diagrid applications for free‐form steel and concrete structures are introduced showing the diagrid applicability for complex structures followed by recent advances in structural design of diagrid connections, diagrid nonlinear behavior, and structural control of diagrids. Recent studies about a new variation of tubular and diagrid systems, hexagrids, are discussed briefly. Finally, the diagrid potential in design of sustainable buildings is delineated.     

A review of the diagrid structural system for tall buildings

Unlike vertical columns of traditional structure, diagrid structural systems for tall buildings have special inclined columns. Due to the inclined columns, a diagrid structural system for tall buildings produces axial force along the column direction under horizontal load, which has the advantage of resisting horizontal wind load and seismic load and gives more freedom to architectural design, so a diagrid structural system for tall buildings becomes an effective new structure style for tall and super‐tall buildings. Theories and tests regarding the diagrid structural system for tall buildings have been intensely researched since the exterior tube of diagrid structural system for tall buildings was first proposed by Torroja in his seminal book. At present, studies for mechanical characteristics, joint form, theories, and tests have been systematized. This paper systematically summarizes existing research achievements of the diagrid structural system for tall buildings and confirms that the structure has larger lateral stiffness and good seismic performance. Based on the favourable performance of concrete‐filled steel tubes, this paper advises the use of concrete‐filled steel tube columns as the columns in diagrid structural systems for tall buildings.     

Application of earthquake‐induced collapse analysis in design optimization of a supertall building

In recent years, a combination of rapid construction of supertall buildings and frequent occurrence of strong earthquakes worldwide demands a rational seismic design method for structures of this kind. Although earthquake‐induced collapse analysis is one of the most efficient methods to quantify the collapse resistance of buildings, little research has been reported on using the collapse analysis to evaluate the seismic safety of supertall buildings during the design stage. To optimize the design taking into account earthquake‐induced collapses, a real‐world supertall building with a height greater than 500 m is investigated in this work. Throughout its design procedure, earthquake‐induced collapse analyses are performed to optimize the design at three different levels (i.e. the structural system level, design parameter level and component level). At the structural system level, the influence of different lateral force‐resisting systems on the collapse resistance is discussed; at the design parameter level, the influence of minimum base shear force is discussed; and at the component level, the influence of high‐performance shear wall on the collapse resistance is studied. Based on these discussions, the optimal design scheme of the building is established to improve the seismic safety while maintaining the cost of construction. Given more and more supertall buildings will be constructed with new structural system and components, this work will provide important references for the seismic design of supertall buildings and the corresponding collapse resistance research in the future. Copyright © 2016 John Wiley & Sons, Ltd.     

搭接墙转换结构的试验研究

天津嘉里中心公寓楼,采用搭接墙转换层结构,其下部上下层剪力墙平行错位是在搭接柱转换结构研究的基础上,将搭接转换的概念推广而得到。本文对该工程搭接墙转换层结构1∶5的模型试件进行了拟静力加载试验研究和有限元分析,研究了模型的受力特点、在实际结构大震情况下的工作性能,以及搭接墙体的最终破坏形态。为搭接墙转换结构研究和实际工程配筋设计提供了依据。     

Behaviour of Loaded Cross-Laminated Timber Wall Elements in Fire Conditions

Cross-laminated timber (CLT) is increasingly being used in medium-rise timber buildings for a number of reasons, such as rapidity of construction, cost effectiveness and robustness. Like for other building materials, verification of the load-bearing performance in fire conditions is an important issue. Experimental fire tests have been performed on loaded CLT wall elements at research institutes in Sweden and Italy. In total, three large-scale and four medium-scale tests have been carried out. The aim was to gain information about initially protected and unprotected elements, to be used for classification and also for validation of calculation models. In the test series, reference tests at normal temperature were included to obtain information (e.g. stiffness, strength) about the material tested in fire conditions. In addition, model-scale fire tests were performed to investigate the loss in stiffness resulting from fire exposure and the effect of different protection types. Loaded fire tests varied in the range of 41.8 min to 120 min, depending on the CLT structure, the level of load, and the type of protection. Data on temperature within specimens and residual cross-sections were collected. Charring rates evaluated from experimental results were comparable with values proposed by Eurocode for the design of timber structures. Conservative solutions were obtained by using simplified design methods and comparing their results to test results and results of advanced modelling. It was shown that the load-bearing performance of CLT may show abrupt changes due to its layered structure. It is strongly recommended that a minimum residual depth depending on the CLT structure should be required in order to ensure robust building products.     

水平地震作用下底部多层大空间框支剪力墙结构中落地剪力墙合理数量研究

地震作用下,底郭多层大空间框支剪力墙结构中落地剪力墙合理数量的确定是关系到结构的安全和经济合理的关键问题。本文首先采用分区混合法将框支剪力墙结构分成转换层上二部剪力墙结构和转换层下部框架一剪力墙结构两部分。并将前者等效为等截面弯杆,后者等效为等截面弯一剪杆,在此基础上运用振型分解反应谱法计算出结构的地震作用效应,最后结合文献[4]中的框支剪力墙结构在水平地震作用下的侧移曲线公式,通过控制楼层层间最大位移与层高之比满足文献[5]的规定,推导了水平地震作用下底部多层大空间框支剪力墙结构中落地剪力墙的合理数量计算公式,并给出了方便计算的相关图表。本文方法可用于地震区高层建筑结构的初步设计。     

浅析斜玻璃幕墙的构造与质量控制

针对斜玻璃幕墙在大型建筑物外立面中的应用，对斜隐幕墙的构造进行了探讨，对幕墙金属框架、玻璃组件成型、玻璃组件挂装的质量控制进行了研究。以提高斜玻璃幕墙质量。     

Schutzzielorientierte brandschutztechnische Bemessung für mehrgeschossige Gebäude

Performance – based fire safety design of multi‐storey buildings. In most countries fire design of multi‐storey buildings is still based on the standard temperature‐time curve (ISO 834) which is supposed to cover real fire scenarios on the safe side. A fire safety design considering more realistic natural fires and the redundancies of entire structural systems is risk‐oriented as well as economical. Using international experience and test results and ongoing research of iBMB, a design fire is developed and so‐called real fire curves are derived. They serve as a basis for general calculation methods (according to the Eurocodes) which are able to grasp the real behaviour of structural systems in a fire. A probabilistic safety concept guarantees the necessary reliability of the design taking the probability of fire development, the boundary conditions of life safety and the uncertainties of the design parameters into account.     

正交胶合竹木（CLBT）研究进展

正交胶合木(CLT)结构因其具有施工便捷、结构性能优良和易于维护保养等优点在欧洲和北美等地获得了广泛关注,并越来越普遍地应用于多层甚至高层建筑之中。我国有丰富的竹资源,同时竹材具有良好的力学性能、可加工性和耐久性。在可工业化生产的结构用胶合竹(Glubam)基础上,作者借鉴CLT的概念进一步提出了正交或交错胶合竹木(简称CLBT或CLTB)。在综述国内外学者在正交胶合木结构的力学性能、连接方式和抗震性能等方面的研究成果基础上,介绍正交胶合竹木的力学与物理性能试验结果,包括正交胶合竹木板梁的弯曲试验、柱的轴心受压试验以及墙体的热学和声学性能试验等,提出基于高阶剪切变形理论的解析模型用以估算CLBT梁、柱在相应荷载作用下的变形量,并通过试验验证该模型的准确性。相关初步研究结果表明：正交胶合竹木CLBT有良好的力学性能和与正交胶合木相当的保温隔热及隔声性能;采用国产速生杨木与Glubam胶合竹组坯制备的正交胶合竹木梁板的力学性能不逊于采用进口木材的同类竹木梁板。因此,正交胶合竹木的研发与应用将有助于进一步合理利用我国的速生林资源和丰富的竹资源;竹木等生物质材料在建筑中的应用对于实现碳中和具有重要的促进意义。