Technical publications: The design professionals' response

Summarized here are the results of a detailed study for the UK Building Research Establishment to discover how those involved in building design react to and use the technical publications of BRE and others. The results merit wider study; they reveal the types of publication preferred — and why — and also when and how technical publications are consulted. Also of wider interest are the comments elicited about BRE's output and how it could be improved.     

Problems with the Moscow office

When the new Office Building for the United States Embassy in Moscow was in the final construction stage, visible defects caused work on the building to be suspended; a detailed structural analysis was then carried out by the NBS Center for Building Technology. Its report highlights the problems that can arise both with a structural design — such as guarding against buckling and progressive collapse — and with the detailed execution of that design.     

Upward or outward? Politics, planning and council flats, 1919-1939

High-rise housing — although now generally seen as a post-1945 disaster — was built up to 14 storeys high in late Victorian London, before being severely restrained by the London Building Acts of the 1890s. Between the wars the issue of flats versus cottages for social housing became highly politicised, with Labour taking a consistently strong stand against multi-storey solutions until the party won control of the London County Council (LCC) in 1934 and, with it, responsibility for delivering the capital's slum clearance and re-housing programme. This paper tracks the course of the high-building debates during the inter-war years. It argues that the adoption of a flat-building policy after 1934 by the Labour-controlled LCC should be seen as a critical turning point, stimulating changes in the design and image of the working-class flat, encouraging a number of pro-flat initiatives, and smoothing the path for the adoption of very much higher social housing proposals after 1945.     

Structural steel and plane frame assemblies under fire action

By means of series of tests carried out on simply supported beams of standard rolled sections subjected to bending, fully analytically formulated calculation values were derived for the temperature-dependent stress-strain relationships of structural steel under fire action from normal temperature to 1000 °C.

Systematic series of investigations carried out on frame assemblies made up from rolled sections with high scale accuracy revealed the characteristic parameters influencing the critical temperatures. The analyses showed good-to-excellent agreement both for the temperature-displacement curves and for the critical temperatures, so that the integrity of the stress-strain relationships could also be verified for combined bending and compressive stress states and for stability-endangered assemblies.

The knowledge gained by the of experiment and computation furnished — in generalized terms — a basic concept for the simple and uniform assessment of the resistance to fire action of single elements and whole assemblies of structural steel subject mainly to bending stresses or endangered in stability. This allows the collapse temperatures of uniformly heated systems to be determined as a function of load utilization factor and system slenderness. These major parameters — load utilization factor and system slenderness ratio — are normal temperature design characteristics and can be determined using conventional methods.     

Bolted joints in glulam and structural timber composites

The widespread adoption of the European design code for timber structures (EC5) will facilitate a number of design options previously unsupported by British Standards. This code uses design equations that need characteristic material data, which exists for solid timber and some sheet materials, but not for the structural timber composites that were evaluated in this research. In this programme high-tensile steel black bolts have been used with solid timber, glulam and two commercially available structural timber composites — Microlam™ and Parallam™. The results suggest that the timber composites offer similar performance to high-density timbers in line with EC5 design guidance.     

An evaluation of construction time performance in the building industry

Building industries in many countries have been increasingly recognising the need for more efficient and timely completion of projects. Often, a number of unexpected problems and changes from original design arise during the construction phase, leading to cost and time overruns. Therefore, exploring the reasons for delay is one of the prerequisites of keeping the cost within budget and of good construction time performance. The primary objective of this paper is to identify the principal factors responsible for delays in the Hong Kong building industry, and determine their relative importance as perceived by different participant groups. A questionnaire survey, based on 83 previously identified delay factors, grouped into eight major factor categories, was conducted in early 1995. Responses from 78 construction personnel — from client, consultant and contractor organisations — suggest a strong consistency in perception between clients and consultants, for example as to the importance of the “poor site management and supervision” delay factor and the “contractor-related” delay factor category. However, there was a substantial disagreement between consultants and contractors, as well as between clients and contractors, in respect of the rankings of both the individual factors and the factor categories. Suggestions are given for more effective project management based on the observations. The results of this survey also provide a foundation for further research towards the development of an envisaged “construction time” prediction model for local building projects.     

《高层建筑混凝土结构技术规程》若干问题讨论——兼谈京、沪、粤三地对“高规”的理解

《高层建筑混凝土结构技术规程》(JGJ 3-2002)自2002年6月颁布以来,各地在对“高规”的应用实施中,大部分都能遵循“高规”的要求,但是对于“高规”中涉及的某些条文,由于缺少具体量化或各地对规范条文理解不同,在应用中也出现各种差异,北京、上海、广东等地也结合当地设计经验和工程实践相继发布本地的技术措施或规程。通过对国家规范及其宣贯材料、《北京市建筑设计技术细则-结构专业》、上海市《建筑抗震设计规程》、“广东省实施《高层建筑混凝土结构技术规程》(JGJ 3-2002)补充规定”等,谈谈各地对“高规”部分条文的理解,以供修订规范时参考。     

Research information: Open Building Systems: a case study

Karel Dekker from TNO Building & Construction Research in The Netherlands explains the Open Building approach for design and construction as the principles of ordering and combining subsystems to create variety and efficiency. The disentanglement of subsystems allows for alteration over time and higher possibility of user choice. The case study of a post-war housing estate in the Netherlands demonstrates how Open Building strategies combined with a flexible rent policy have been used to improve quality on three scales (neighbourhood, building and dwelling interior) and to provide residents with choices about their living conditions.     

某保障性住房绿色建筑结构设计与评价

结合<绿色建筑评价标准>(GB/T 50378-2006),对某保障性住房,分别从结构体系、结构形式、结构刚度、结构布置及基础等方面做了精细化设计,展示了绿色建筑中结构设计的重要性,有助于增进结构专业人员对绿色建筑的理解.     

Interrupted interface on the cybernetics of digital design process

From the viewpoint of Batesonian cybernetics, ‘conscious purpose’ and ‘artistic process’ are distinct ends of a spectrum of the functioning of ‘self’. The conceptual stage of the design process is essentially an artistic activity unencumbered with accuracy, dimensionality, scale, program or even tectonics, albeit all of these maybe tacitly present at the ‘back of a designer's mind’. Artistic activities involve broad mental processes that are beneath the stratum of consciousness. By definition, consciousness is selective awareness; it is linear in execution and limited in its capability to synthesize complex parameters. One of the central questions of this paper is “if artistic process requires one to abandon, or relinquish conscious purpose at the time of the generation of the work of art, and if the early stages of artistic process is a result of a vast number of ‘unconscious’ forces and impulses, then how can the computer, which demands (and thus propagates) geometric precision, focused operation and rational execution, be part of that process?” This paper will explore how, cybernetically, the computer can be ‘coupled’ with ‘self’ (via a visual interface) and the artistic process. Three specially devised conceptual design exercises—namely BlurrDesign, BlinDesign and BlitzDesign—and three corresponding “interruptive” computer interface modifications were deployed in an introduction to digital media course. The results of this study are now under consideration for their effectiveness in promoting conceptual design using the computer, and how the ‘self’ might form a cybernetic whole with the machine. The findings could have implications in design pedagogy, informatics and interface design.     

CCTV新台址主楼结构设计与思考

CCTV主楼为倾斜双塔连体结构,位于8度抗震设防区,设计使用年限为100年,属特别复杂超限超高层连体建筑。主体结构采用刚度较大的支撑外筒结构体系。新颖的结构体型给结构设计及施工带来了很多新课题和难点。通过采用性能化的抗震设计方法以及理论分析与试验研究相结合,对结构关键技术如施工模拟、高含钢率SRC柱、罕遇地震下的弹塑性时程分析、新型节点构造的应用以及防连续倒塌等加以综合研究与分析,很好地解决了工程中遇到的技术难题。施工过程中的应力和变形监测结果也初步验证了结构设计方法的正确性和可靠性。CCTV主楼结构经历了艰辛的设计历程,其设计成果是对现有设计理念、设计方法的丰富和推进,同时也在设计理论、抗震性能化目标、现行规范运用、复杂形体建筑设计等方面引发了新的课题和思考。     

A review of the emission of VOCs from polymeric materials used in buildings

Building and furnishing materials and consumers products are important sources of formaldehyde and other volatile organic compounds (VOCs) in the indoor environment. The emission from materials is usually continuous and may last for many years in a building. The available evidence indicates that VOCs can cause adverse health effects to the building occupants and may contribute to symptoms of ‘Sick Building Syndrome’.

Control of VOC emission should increasingly become an important consideration for the design and manufacture of polymeric materials used in buildings. The EC Construction Products Directive ‘Essential Requirements’ set a framework for limiting the use of materials that could pose a health risk to building occupants. Furthermore, the on-going development of voluntary labelling schemes and data bases of material emissions that could be used by building designers, should further strengthen the demand for ‘low VOC emitting’ products.

This paper reviews available information about the emission of VOCs from polymeric building materials, the level of emissions in the indoor environment and the requirements for testing of the materials.     

Structural analysis and design of sandwich panels with cold-formed steel facings

Superior structural efficiency, ease of erection, mass-production capabilities and thermal-insulation qualities are making sandwich panels with flat or thin-walled cold-formed steel facings and rigid foamed insulating core increasingly popular as enclosures for system buildings. In this paper the structural behavior — including flexural stresses, deflections, vibration and thermal stresses — is presented, summarizing more than two decades of research. Methods used are analytical (boundary-value approaches), numerical (finite-strip, finite-layer, finite-prism approaches) and experimental (full-scale testing). Key equations are formulated, and results by different methods are compared. Design guidelines are also suggested.     

System reliability considerations in probabilistic risk assesment of nuclear power plants

The frequencies and consequences of severe accidents at nuclear power plants are examined using a systematic procedure called probabilistic risk assessment (PRA). These accidents may be initiated by equipment malfunctions, operator errors or external initiators such as earthquakes, floods and tornadoes. It is in the case of the external events that the structural system reliability concepts are utilized. Taking the seismic risk analysis as an example, this paper discusses the different elements of the analysis — hazard analysis, fragility evaluation, systems analysis and risk quantification — and examines how the structural system reliability methods are applied. Areas requiring further investigation by the PRA analysts are indicated and the data and research needs are identified.     

The problem of durability in building design

Durability is an integral part of modern building design. The demands for innovative building techniques and the inclusion of materials and components with lower life-cycle costs test the knowledge and skills of building designers. The pressing need for reliable information about the role of durability in the building design process has led to the formation of a working commission on ‘Design for Durability’ (CIB W94) by the international Council for Building Research, Studies and Documentation (CIB). This paper is a state-of-the-art review of this area based largely on the proceedings of the International Conferences on the Durability of Building Materials and Components held in 1978, 1981, 1984, 1987 and 1990. The paper emphasizes the importance of the development and utilization of an internationally accepted systematic approach to the durability problem in building design, and of the development of computerized expert systems to support designers with decision making information.     

The application of BS5950: Part 8 of fire limit state design to the performance of ‘old’ structural mild steels

An investigation has been carried out to extend the guidance given in the new British Standard BS5950: Part 8, on fire limit state design, to the refurbishment and fire damage reinstatement of old steel framed, buildings.

Structural mild steel produced to BS15 approximately 50 years ago was found to be generally weaker at elevated temperatures than its modern counterpart—BS4360: Grade 43A (BS EN 10025: Grade 430A). However, providing in design calculations due recognition is given to the lower yield stress of old mild steel at ambient temperature, its performance in fire will be as good as that being currently produced. For the present time, it is therefore appropriate to adopt the same relationships between strength, loading and temperature for structural members given in the new Code, with no additional penalties on fire protection thickness should this be necessary.

Fire simulation treatments on steel manufactured to BS15 demonstrated that the degradation in strength properties is in agreement with work reported earlier on ‘weak’ mild steel—BS4360: Grade 43A. The results of a similar evaluation on mild steel produced since the 1986 revision of BS4360: Grade 43A are also in line with previous work.     

Limit state design in Canada

Based on material prepared for CIB working commission W23, this article from the Canadian Research Council's Division of Building Research discusses the implications of the new National Building Code. This now enables the concept of limit state to be applied to structural design.     

Improved thermal building management with the aid of integrated dynamic HVAC simulation

Building simulation is a tool that has only recently been recognised as a possible utility to accomplish enhanced building management (Build. Environ. 37 (8–9) (2002) 891). Thermal management however is often neglected. This is due to the complex nature of problems associated with determining the effect of changes to heating ventilating and air-conditioning (HVAC) system properties (Build. Environ. 32(2) (1997)). Effective thermal management is nevertheless a major concern since energy cost and operation cost of buildings are directly influenced by how well the HVAC systems perform (Occup. Med.—State Art Rev. 4(4) (1989)). The aim of this study was to introduce the process of integrated dynamic HVAC simulation as a viable tool to improve thermal management of buildings. This entails both improved maintenance and energy utilisation. The applicability of the integrated simulations was investigated by means of a case study for which a well-verified simulation model was constructed and discussed in a previous article. To illustrate the process of improved management three different scenarios are investigated. Finally the conclusion is drawn that improved management is indeed possible with the aid of integrated simulation.     

CCTV新台址主楼施工模拟分析及应用研究

根据施工模拟方法的原理,提出CCTV新台址主楼的施工模拟分析方法,在设计过程预先考虑施工进度上限、下限进行结构包络设计。计算分析表明,施工模拟分析方法模拟CCTV新台址主楼结构可以较为准确地反映恒载作用下结构的变形和内力分布,是很有必要的。在建造期间根据承包商实际采用的施工过程进行了施工模拟分析的调整和对比分析,结果表明结构锁定内力仍满足结构承载力要求;同时介绍了悬臂段合拢方案的细化施工模拟及关键工况分析。