Wind environmental conditions in passages between buildings

Experimental measurements have been carried out in a boundary layer wind tunnel to determine wind velocity and turbulence conditions in a passage between two rectangular buildings. The experiments were done under simulated open country terrain conditions for a wide range of wind azimuths. Geometrical parameters included the height of two buildings and the passage width.Results show that the most critical wind velocity conditions occur for buildings of different heights and at a point near the passage entrance for a wind direction skewed by 30° from the passage centre line. Turbulence conditions, however, are found more critical for wind perpendicular to the passage centre line. Also, the larger the passage width, the lower the velocity amplifications and the higher the turbulence intensities in the passage. The paper demonstrates that different K parameters for the inclusion of wind gustiness in an equivalent effective wind speed make little difference in the comfort criteria evaluation.     

Wind excitation of neighbouring tall buildings

There is a growing concern about the importance of interaction effects between neighbouring tall buildings subjected to wind loading. Available results indicate that both the peak dynamic response as well as the mean wind loads may increase substantially due to building interaction.An extensive wind-tunnel study of the interaction between two square prisms with a height-to-base length equal to six was undertaken at the LAC, UFRGS. Fifteen relative prism positions were studied, for wind orientations at every 15°, under smooth-uniform as well as turbulent-shear wind. Mean force and torsional moment coefficients for uniform flow were reported in previous publications. Herein, complete results for turbulent wind are given. In addition, the most important interaction effects observed under both flow conditions are discussed in detail.     

靠近深基坑高耸构筑物的加固与纠偏技术

结合杭州某地铁车站高耸构筑物的保护,通过分析具体的施工过程,分析了城标发生较大偏移的原因,并针对性的提出了城标的加固措施,形成了系统的靠近深基坑构筑物的加固保护方案,论证了在设计阶段设计合理加固措施的重要性。     

地貌对高层建筑(群)风效应影响数值分析

高层建筑(群)风效应与地貌条件相关,分析掌握其内在关系是建筑布局规划和抗风设计的重要前提。基于雷诺时均模拟方法(RANS),引入具有分离流预测优势的SST k-ω湍流模型,以某高层建筑单体及群体风场为对象,模拟4类地貌条件下的风效应场,侧重分析人行高度(2m)风速场以及建筑立面的风压分布特性。分析结果表明,地貌除对人行高度的风速场影响明显外,对高层建筑表面风压系数影响也较为可观,实际工程应适当考虑地貌效应。     

Wind conditions around The Rock of Gibraltar

Full-scale data from two sources, structural damage to the East Side Water Catchment and a survey of turbulence on the approach flightpath to the airfield at Gibraltar, are compared with the results of wind-tunnel tests on a scale model of the Rock. The comparisons show that wind-tunnel simulation of the flow around large sharp-edged topographical features is practical at scale factors as high as $\text{1}\text{5000}$ for conditions of strong wind and neutral stability. The Rock is shown to behave as one half of a narrow-delta lifting body on an infinite ground plane.     

超高层建筑结构优化过程中的环境成本计算

近年来中国大陆掀起了超高层建筑的兴建热潮。超高层建筑体量巨大,其碳排放和能源消耗对环境有显著影响。在评估和优化超高层建筑的全生命周期环境成本时,提出了一个全新的全生命周期模型。新模型有两大特征：首先,同时考虑了建筑材料的空间分布与时间特征;其次,把单尺度生命周期概念拓展到多尺度生命周期概念,以从更多角度来研究碳排放情况。建立了一个基准超高层建筑模型来阐释对新模型的应用。根据初步研究结果,应用新方法可以选择出更优化的结构设计方法,以最大程度减少碳排放量。     

低矮房屋迎风屋面局部风压特性研究

基于尺寸比为1.5:1:1(长:宽:高)的低矮房屋的风洞试验数据,分析了9类不同坡角的低矮房屋在5个不同风向的风场环境下,迎风屋面屋檐、屋脊等局部区域测点的平均、脉动及峰值风压系数.通过对比低矮房屋在不同坡角、不同风向作用下屋面的风压变化规律,总结了坡角及风向对低矮房屋屋面局部风压的影响规律.结果表明,低矮房屋在45....     

Cross-wind response of tall buildings

A design procedure was developed using random vibration theory and uses mode-generalized cross-wind force spectra and aerodynamic data to calculate the cross-wind displacement and acceleration responses of tall buildings. The force spectra of a number of building shapes and sizes in both suburban and city centre type wind flow are presented. The proposed design procedure gives reasonable estimates of the cross-wind response, compared with wind tunnel measurements, at reduced wind velocities and at structural damping values consistent with modern habitable tall building design. This allows assessment of the structural requirements of tall buildings to be made at an early design stage, and also allows the designers to assess the need for more detailed and expansive wind tunnel model tests.     

Vibration control of tall buildings

Objectionable vibrations have been experienced in modern tall buildings. To alleviate the vibrations one may increase the structural stiffness and damping or use a passive control device such as a ‘tuned mass damper’. The drawback of the above mentioned methods is the greatly increased cost. An alternative approach is to use active control devices providing control forces based on the feed back control theory. This paper presents a systematic approach of first reducing a multistorey structure to a simpler equivalent system. Then a pole placement method is developed to obtain the conrol forces. A successive approximation method is used to reduce the responses to permissible magnitudes. An example is presented to demonstrate the feasibility of the method.     

Designing tall buildings in Moscow

The trend towards industrialisation is described in this article by engineer Dihovichney, who comments on the relative effectiveness of different structural and design solutions adopted.     

高层民用建筑的应急照明

论述了高层建筑的应急照明灯具、光源及供电电源，通过分析目前应急照明设计状况及存在的问题，总结了高层建筑应急照明的几点认识，供同行参考借鉴。     

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.     

Wind-induced motion of tall buildings

Modern buildings designed such that their lateral drifts under statically applied wind loads are less than some fraction of building height, may vibrate excessively during winds and cause occupant discomfort. Methods are presented for evaluating the vibration characteristics of buildings using random vibration theory to relate the fluctuating wind forces to structural response. These methods can be used to evaluate serviceability or to plan wind tunnel tests of buildings.     

Designing tall buildings in Moscow

The trend towards industrialisation is described in this article by engineer Dihovichney, who comments on the relative effectiveness of different structural and design solutions adopted.     

Decentralized control of tall buildings

The response of large‐scale building structures can be actively reduced using an appropriate control algorithm and a number of actuators and sensors located within the building. This paper presents a decentralized control approach for controlling the response of tall buildings. The proposed method aims to divide the structural model into several substructures, each one performing on its own controller algorithm. This approach has already been used in controlling large‐scale systems such as power transmission systems and space structures. An instantaneous optimal control scheme is used as the control algorithm with different control feedbacks such as velocity feedback alone and displacement and velocity feedback. The stability issue of this method is addressed. A numerical example is used to investigate the performance of the proposed method compared to the case with centralized control. Copyright © 2005 John Wiley & Sons, Ltd.     

Across-wind loads of typical tall buildings

Previous studies have indicated that the across-wind dynamic responses of super-tall buildings are usually larger than the along-wind ones. With the increase of heights, the across-wind dynamic response of super-tall buildings has been a problem of great concern. In this paper, 15 typical tall building models are tested with high-frequency force balance technique in a wind tunnel to obtain the first-mode generalized across-wind dynamic forces. New formulas for the power spectra of the across-wind dynamic forces, the coefficients of base moment and shear force are then derived. Parametric analyses of the effects of factors on the across-wind loads of the buildings are performed. Besides, a SDOF aeroelastic model of a square tall building with an aspect ratio of 6 is selected from the above buildings and is tested to investigate its across-wind dynamic response and aerodynamic damping characteristics. The power spectrum of the across-wind force of the square building is employed to compute its across-wind dynamic responses with and without considering the effect of the aerodynamic damping. The computed responses are then compared with the corresponding responses from the aeroelastic model test to verify the present formulas of the across-wind loads of buildings.     

Calculating evacuation times for tall buildings

This paper includes a summary of the history of investigations into calculating evacuation times. Included are the basic concepts along with selected calculation methods. Limitations of such efforts are reviewed to illustrate the limited applicability of some of the methods for actual conditions.     

Optimum structural modelling for tall buildings

It is a common practice to model multi‐storey tall buildings as frame structures where the loads for structural design are supported by beams and columns. Intrinsically, the structural strength provided by the walls and slabs are neglected. As the building height increases, the effect of lateral loads on multi‐storey structures increases considerably. The consideration of walls and slabs in addition to the frame structure modelling shall theoretically lead to improved lateral stiffness. Thus, a more economic structural design of multi‐storey buildings can be achieved. In this research, modelling and structural analysis of a 61‐storey building have been performed to investigate the effect of considering the walls, slabs and wall openings in addition to frame structure modelling. Sophisticated finite element approach has been adopted to configure the models, and various analyses have been performed. Parameters, such as maximum roof displacement and natural frequencies, are chosen to evaluate the structural performance. It has been observed that the consideration of slabs alone with the frame modelling may have negligible improvement on structural performance. However, when the slabs are combined with walls in addition to frame modelling, significant improvement in structural performance can be achieved. Copyright © 2012 John Wiley & Sons, Ltd.     

高层民用建筑中水泵结合器的设置

就高层民用建筑消防设计中水泵结合器的设置问题，从水泵结合器与消防车的配套设置、水泵结合器在自喷消防系统中的设置、安全阀的设置等方面介绍了具体方法，以合理设置并消除故障。