Two-stage gravity load analysis of framed-tube buildings

A two-stage solution procedure has been presented for the gravity loading (live load) analysis of framed-tube buildings. In the first stage, the solution is estimated by solving a simplified model and a number of substructures with much reduced numbers of degrees of freedom. In the second stage, the Gauss-Seidel iterative procedure is used to obtain the accurate solution. The proposed two-stage solution procedure requires a CPU time that is only a fraction of that needed in the standard solution procedure. The number of computer storage locations required is also small. Additionally, by using the proposed procedure, framed-tubed buildings of practically any size can be analysed on microcomputers.     

Core-frame interaction in tall buildings

A method is presented for solving by hand structural systems comprising frames and shear walls coupled together through floor slabs. The coupled system is viewed as a shear-flexure cantilever which resists the lateral loads by its combined actions and the coupled governing equations are solved by the Galerkin technique. The contribution of each term from the assumed displacement field is uncoupled by choosing appropriate admissible functions. This uncoupling condition is valid when the structure is uniform throughout the height.     

The interaction between buildings and the climate

Research in Japan shows that 'heat islands' in town centres can be materially reduced by expanses of grass and water. But can we do much about it, or do we always want to anyway? Yet the effect of climate on buildings is crucial, and the purpose of a recent symposium was to study the relationship of the variable factors with particular reference to the education and training of architects, engineers and meteorologists.     

浅谈高层住宅给水的二次污染

本文根据高层住宅给水的一些特征,对其遭受二次污染的主要原因进行了初步分析,并分别从每个环节的实际情况出发,提出了行之有效的应对措施.     

3栋相邻高层建筑上部结构-基础-地基相互作用研究

在同一场地地基上建设多栋高层建筑，应考虑建筑与地基之间的相互影响。利用数值计算方法模拟从基坑开挖到3栋建筑依次建立的整个过程，分析桩筏基础的变形和受力特性以及新建建筑与已建建筑的相互影响等。研究结果表明：已建建筑桩的轴力分布随新建建筑荷载的增加趋于均匀，而其最大值则逐渐减小；基坑开挖的卸荷作用使得基坑开挖面一定范围内应力有所减小；由于附加应力的扩散作用，使新建建筑的基础沉降最大值位置、桩的轴力最大值位置、筏板高应力区域均有向已有建筑物方向偏移的趋势。此外，基坑开挖后，已有建筑物的筏板沉降分布向基坑开挖方向有移动，并产生较明显的附加沉降，并且各种建筑荷载的相互叠加，最终会使基础周边的地面产生一定沉降。     

Office layout affecting privacy,interaction, and acoustic quality in LEED-certified buildings

The study investigated differences in worker satisfaction and perceived job performance regarding privacy, interaction, and acoustic quality issues in personal workspaces between five office types in LEED-certified buildings. It finds that people in high cubicles showed significantly lower satisfaction and job performance in relation to visual privacy and interaction with co-workers than both enclosed private and enclosed shared office types. They also showed significantly lower satisfaction with noise level and sound privacy and lower job performance perceived by acoustic quality than enclosed private, enclosed shared, and bullpen types. The bullpen type, open-plan office without partitions, presented significantly higher satisfaction with noise level and higher performance perceived by acoustic quality than both high and low cubicles. Considering the bullpen type also showed higher satisfaction with sound privacy than the high cubicle type, high partitions don't seem to contribute to creating workspaces where people can have a secure conversation. The bullpen type didn't show any difference from the enclosed shared type in all privacy, interaction, and acoustic quality questions, indicating it may be a good option for a small office space instead of the enclosed shared type.     

高层建筑中箱基和上部结构共同作用下的计算和调整沉降方案

笔者2次指出国内外技术规程中建议的箱基与上部结构共同作用下的计算是错误的,并建议新的计算。为了从理论上解决箱基渗漏问题,曾提出“反盆式沉降方案”,现改为“调整沉降方案”,并介绍了工程实例。     

Sources of elastic deformation in steel frame and framed-tube structures: Part 1: Simplified subassemblage models

Three simple models for including the effect of beam-column joint deformation in the analysis of steel moment resisting frame and framed tube structures are presented. The first model, called the Fictitious Joint model, is based on two-dimensional frame analysis and is useful for preliminary analysis only. The second model, called the Krawinkler Joint model, and the third model, known as the Scissors Joint model, use an assembly of rigid links and rotational springs to represent the joint, and may be used in preliminary and final analysis of full structural systems. All derivations are provided in the form of “displacement participation factors”, which allow a detailed breakdown of the various components of subassemblage displacement.When applied to isolated beam-column subassemblages, it is shown that all three modeling approaches produce the same general expression for computing deflections arising from shear deformations in the panel zone region. However, the Krawinkler and Scissors models do not include the effects of flexural deformation within the beam-column joint, whereas the Fictitious Joint model does. While not the dominant source of deformation, it is shown in the paper that the effects of flexural deformations in the beam-column joint should not be ignored.It is also shown in this paper that the overall displacements predicted by the simplified models correlate very well with displacements computed from detailed three dimensional finite element analysis of the same subassemblage. However, the finite element analysis approach, taken alone, is not capable of providing a breakdown of the subassemblage displacements into components, such as panel zone shear, or column joint flexure. Part 2 of the paper presents a method for providing this information from the results of detailed finite element analysis.     

Influence of soilestructure interaction on seismic collapse resistanceof super-tall buildings

Numerous field tests indicate that the soilestructure interaction （SSI） has a significant impact on thedynamic characteristics of super-tall buildings, which may lead to unexpected structural seismic responsesand/or failure. Taking the Shanghai Tower with a total height of 632 m as the research object, thesubstructure approach is used to simulate the SSI effect on the seismic responses of Shanghai Tower. Therefined finite element （FE） model of the superstructure of Shanghai Tower and the simplified analyticalmodel of the foundation and adjacent soil are established. Subsequently, the collapse process of ShanghaiTower taking into account the SSI is predicted, as well as its final collapse mechanism. The influences ofthe SSI on the collapse resistance capacity and failure sequences are discussed. The results indicate that,when considering the SSI, the fundamental period of Shanghai Tower has been extended significantly,and the collapse margin ratio has been improved, with a corresponding decrease of the seismic demand.In addition, the SSI has some impact on the failure sequences of Shanghai Tower subjected to extremeearthquakes, but a negligible impact on the final failure modes.
2014 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.     

Seismic analysis of asymmetric multistorey buildings including foundation interaction and P-Δ effects

This paper presents a method of seismic analysis of three-dimensional asymmetric multistorey buildings founded on flexible foundations. The building-foundation system considered in this study is a linear elastic N-storey asymmetric building with a rigid footing resting on the surface of a linear elastic soil half-space. The method of analysis also includes the P-Δ effects, in which the additional overturning moment and torsional moment at each storey due to P-Δ effects have been replaced by fictitious lateral forces and torques. The whole system has 3N + 5 displacement degrees-of-freedom. The necessary governing equations have been developed considering the three motions of each floor and the five motions of the whole building. Recognizing that the superstructure alone admits classical normal modes, the governing equations of the floors are first uncoupled in terms of footing displacements using the mode superposition method. Substitution of structural deformations, in combination with the dynamic soil-structure interaction force-displacement relationships into the governing equations of the whole system results in five integro-differential equations for footing displacements, which are then solved by numerical step-by-step time history analysis. The floor displacement responses, storey shears, storey torque, etc., are obtained by back substitution of footing accelerations into the relevant governing equations. As a demonstration of the method of analysis and in order to obtain the soil-structure interaction effects, P-Δ effects, and the eccentricity effects, a 10-storey asymmetric building on soft soil was subjected to El Centro 1940 earthquake excitations. The results show that the soft soil conditions increase the lateral deflections, but reduce the twists, storey shears and torques. Increasing eccentricity increases the floor twists and storey torques, however, it does not modify the lateral deflections at the centre of mass, and the total storey shears. The significance of P-Δ effects along with soil-structure interactions on the response of this building has also been discussed.     

论历史建筑中背景建筑的再生

在当代历史建筑保护的框架下,分析历史建筑和背景建筑的定义,提出历史建筑中背景建筑的概念,对比传统建筑保护思路,采用当代城市背景建筑的设计方法,从城市角度讨论历史建筑中背景建筑再生。     

建筑中的桥

通过与室外工程桥进行比较，阐释了建筑中桥的概念、本质、功能和内涵，对现代建筑中的桥进行了分类，并浅析桥的构建，为建筑师创造好建筑中的桥做出更人性化和趣味化的建筑空间提供参考。     

Seismic response of multi-storey buildings including foundation interaction and P-Δ effects

This paper presents a method of seismic analysis of multi-storey buildings when both soil-structure interaction and P-Δ effects have been taken into account. The additional overturning moment at each storey due to P-Δ effects is replaced by two fictitious horizontal forces acting in opposite directions at the upper and lower ends of each storey. Then, the governing equation for each floor is developed in which these fictitious horizontal forces are incorporated along with seismic inertia forces. Considering the footing as a rigid disc resting on the surface of an elastic half-space, two equations expressing the equilibrium of the building as a whole in translation and rotation complete the set of equations in terms of floor displacements and two rigid body base displacements. Recognizing that the superstructure alone admits classical normal modes, floor governing equations are uncoupled and substituted into the remaining equations, which results in two coupled integro-differential equations in terms of two rigid body displacements. These two equations can be solved using numerical procedures. The method is applied to two unbraced steel buildings and numerical results are presented for different foundation soil conditions. The influence due to P-Δ effects and soil-structure interactions on the responses of these buildings is discussed.     

Sources of elastic deformations in steel frame and framed-tube structures: Part 2: Detailed subassemblage models

This paper examines the accuracy of a set of equations for computing Displacement Participation Factors (DPFs) for beam-column subassemblages of steel moment resisting frame buildings. These factors allow the analyst to determine how the entire subassemblage or individual components of a subassemblage contribute to a given structural displacement. Additionally, the component’s contribution to displacement may be evaluated in terms of sources of axial, flexural, or shear deformation.When applied to a set of 12 isolated subassemblages, it was shown in Part 1 of the paper that deformations in the beam-column joint are very significant, and that flexural deformation in the joint, which is often ignored, should be considered in all analyses. The total displacement predicted through the use of the DPFs correlates extremely well with the results of detailed three dimensional finite element analyses of the same subassemblages. However, it was also shown that there is considerable uncertainty in the bending moments and moments of inertia that are used to compute joint flexural deformations.The objective of this paper, which is the second part of a two-part paper, is to further investigate the accuracy of the DPF expressions developed in Part 1. This is done by computing DPFs from the results of detailed three dimensional finite element analysis, and comparing these to those computed through the use of the simple expressions.The results of the analysis show that the joint flexural deformations are accurately predicted by the simple DPF expressions, but that this accuracy arises from compensating “errors” in the simplified analysis. It is also shown that the use of beam flange continuity plates has a marginal effect on computed displacements. The paper ends with recommendations for using the simplified expressions for computing subassemblage deformations, and for including such deformations in structural analysis of steel frame and tube structures.     

地下空间建筑在建筑物区分所有权中的归属问题

针对地下空间及其建筑的权利归属问题,对现有的相关规定进行了梳理,并对地下空间建筑的人民防空工程权利归属展开分析,在此基础上对住宅小区地下空间建筑的权属争议进行了探讨,以供参考借鉴。     

地基基础与框架结构协同抗震的数值模拟分析

对爆破地震波作用下框架结构进行了动力分析,建立了爆破地震波作用下框架体结构的时程分析方法,并将爆破地震波输入框架与地基、基础协同工作体系,对爆破地震波作用下框架与地基、基础协同工作的反应进行了实例分析,通过与底部刚结构模型在爆破地震波作用下的动力反应进行比较,分析了两种结构模型的动力反应特点。