基于事例推理的高层建筑结构初步设计专家系统(基础篇)

通过研究工程设计的本质和基本原理,作者结合高层建筑初步设计的内容和目标,利用人工智能技术来存贮和运用专家的设计经验,实现了基于事例推理的高层建筑结构初步设计的专家系统,以帮助设计人员提高设计质量和效率。全文分为基础篇和应用篇两部分。基础篇主要讲解与系统有关的概念、研究背景和基础理论;应用篇详细介绍了作者完成的原型系统HIPRED-2的各项实现手段和技术。     

Design of steel portal frame buildings for fire safety

This paper describes a study into the fire behaviour of steel portal frame buildings at elevated temperatures using the finite element programme SAFIR. The finite element analysis carried out in this report is three dimensional and covers different support conditions at the column bases, the presence of axial restraints provided by the end walls, different fire severities within the building, different levels of out-of-plane restraint to the columns and the effect of concrete encasement to the columns. From a large number of analyses, it is shown that the bases of the steel portal frames at the foundations must be designed and constructed with some level of fixity to ensure that the structure will deform in an acceptable way during fire, with no outwards collapse of the walls. The analyses also show that to avoid sidesway (i.e. collapse outwards) it is not necessary for steel portal frame columns to be fire-protected unless the designer wishes to ensure that the columns and the wall panels remain standing, during and after the fire.     

Determination of the steel fire protection material thickness by an analytical process—a simple derivation

Structural fire safety is assured if the design value of the effect of the actions (thermal and mechanical) is lower than the design value of each structural element fire resistance or, in other words, structural safety is assured when the steel temperature in a fire situation only reaches values less than the structure critical temperature. The critical temperature is the temperature that causes structural collapse in a fire situation. The temperature in the structural element can be determined either experimentally or analytically. In the case of a structure covered with thermally protective material, such methods serve, in practice, to determine the thickness of the protective material. In this work, a previously unpublished expression for the calculation of the temperature in thermally protected steel structural elements in fire is derived. Comparisons with international recommendations and with experimental and numerical analysis results are made. In view of its simple form and derivation, the use of such expression is recommended for the revision of the Brazilian Standard “Steel structures fire design”.     

高规部分疑难问题解读

对高层民用建筑消防设计中经常遇到的一些疑难问题进行了探讨,并对个别问题给出了设计建议,希望能为设计人员理解及执行规范提供帮助。     

Multiperformance optimization design of a hybrid vibration mitigation system for super high‐rise buildings to improve earthquake resistance

A structure must meet many performance requirements to survive an earthquake. For a super high‐rise structure, the dominant control performance metric is stiffness when considering earthquake resistance because the lateral displacement of the structure often does not meet the requirements of the code even if the structure meets strength requirements. For moderate and major earthquakes, stiffness and strength play a leading role jointly. Viscous damper (VD) and buckling restraint brace (BRB) are damping devices that are commonly used in modern engineering. The efficiencies of these devices are different for different situations, and combining them can yield improved structural vibration mitigation. In this study, the performances of VD and BRB are summarized. A kind of virtual VD model with an additional damping ratio is proposed on the basis of which a VD priority placement analysis method is developed, and an optimal design is proposed. A detailed analysis of various stress states of a BRB is also performed, and a BRB arrangement method based on brace stress level analysis is proposed. The two kinds of vibration damping equipment are combined in the structure, and a practical design method for a hybrid vibration damping system is proposed. The accuracy of the proposed method is verified by considering a 10‐story plane frame. Finally, a hybrid vibration mitigation design for different objective damping ratios is performed for a super tall building project, and the design results are compared. The analysis results show that a VD can effectively increase structural damping and reduce the seismic response of the structure. A BRB is used to replace supports that experience high stress and reduce their section size, thereby reducing costs. Therefore, the proposed hybrid vibration damping structure is cost effective while providing good energy dissipation and is thus promising for engineering applications.     

对《高规》和《建规》中部分条款的理解

结合工程设计中发现的问题,谈及对《高规》和《建规》中部分条款的理解,对排烟设施的设置限定范围、限定条件以及自然排烟的限定条件、补风的设置依次进行了分析,并提出了修改建议。     

建筑设计防火规范在实际应用中的几个问题

通过对现行建筑防火技术规范在实际应用中存在的一些困惑，阐述了规范中的某些概念不是很清楚，规定不是很具体的情况，呼吁在加强性能化防火规范研究的同时，加快格式防火规范的研究步伐，以期更好地指导工程实践。     

基于事例推理的高层建筑结构初步设计专家系统(应用篇)

通过研究工程设计的本质和基本原理,作者结合高层建筑初步设计的内容和目标,利用人工智能技术来存贮和运用专家的设计经验,实现了基于事例推理的高层建筑结构初步设计的专家系统,以帮助设计人员提供设计质量和效率。全文分为基础篇和应用篇两部分。基础篇主要讲解与系统有关的概念、研究背景和基础理论;应用篇详细介绍了作者完成的原型系统HIPRED-2的各项实现手段和技术。     

日本建筑抗震标准的变迁和现行的抗震标准

介绍了日本现行抗震标准及其修订背景。1924年世界上最早的建筑抗震标准在日本诞生,规定了至少取建筑物总重量的0.1倍的力作为设计水平地震荷载。日本现行抗震标准中的抗震设计由两次设计构成,即对在建筑使用年限中发生的中等地震进行第一次设计及对在建筑使用年限中可能发生的罕见大地震进行第二次设计。其现行抗震标准有四个基本的抗震设计方法。     

无卤高阻燃型铝塑复合板在高层建筑外墙装饰应用上的防火安全性试验与材料应用研究

本文采用中等尺寸多层建筑燃烧试验方法（NFPA285）和高层楼房大型实体火灾的实景试验等新方法，取代传统的难燃级小型试验（GB/T8625）和单体燃烧SBI中型试验（GB/T20284）等试验方法，研究了无卤高阻燃填充芯料选作防火铝塑复合板芯材取代普通不阻燃聚乙烯芯村的防火特性差异，并从试验结果参数对其燃烧性能的影响进行了评价分析，因而对防火铝塑板在高层建筑幕墙装备上的材料选用有一定的指导意义。