Engineering Judgment and the Design That Got Away

This paper examines an ethical dilemma related to the residential construction industry in Florida, where homes must be engineered to withstand extreme load conditions induced during high wind events. Overwhelming contractor pressure to minimize construction costs has resulted in the propagation of inadequate construction designs. The overwhelming adoption of these inadequate designs weakens the integrity of our industry, creating the impression that market pressure can influence our judgment despite conflicting results gained through engineering analysis. This paper illustrates the frailty of engineering judgment as a design fundamental. Further, it raises the question as to what extent professional engineers should substitute engineering judgment for concrete evidence such as numerical analysis or experimental verification.     

MALEO: Modular Assembly in Low Earth Orbit: Alternate Strategy for Lunar Base Development

Modular assembly in low Earth orbit (MALEO) is a new strategy for building an initial operational‐capability lunar habitation base, the main purpose of which is to safely initiate and sustain early lunar base buildup operations. In this strategy the lunar base components are brought up to low Earth orbit (LEO) by the Space Transportation System (STS), and assembled there to form the complete lunar base. Specially designed propulsion systems are then used to transport the MALEO lunar base, complete and intact, all the way to the moon. Upon touchdown on the lunar surface, the MALEO lunar habitation base is operational. The strategy is unlike conventional concepts, which have suggested that the components of the lunar base be launched separately from the Earth and landed one at a time on the moon, where they are assembled by robots and astronauts in extravehicular activity (EVA). The architectural drivers for the MALEO concept are, first, the need to provide an assured safe haven and comfortable working environment for the astronaut crew as safely and as quickly as possible, with the minimum initially risky EVA, and secondly, the maximum exploitation of the evolutionary benefits derived from the assembly and operation of space station Freedom (SSF‐1). Commonality and inheritability from the space station assembly experience is expected to have an advantageous impact on both the space station program as well as the MALEO lunar base.     

Feasibility of Rigidified Inflatable Structures for Housing

Rigidified inflatable structures (RIS) are thin, flexible membrane structures that are pneumatically deployed. After deployment, these structures harden because of chemical or physical change of the membrane. Because of this change, or rigidification, these structures no longer require pneumatic pressure to maintain their shape. With the aim of reducing the cost and examining the feasibility of RIS structures, a new material is proposed, developed, and evaluated. This material involves the formation of a semi-interpenetrating polymer network based on polyvinyl chloride and an acrylate-based reactive plasticizer. The economical and environmental performances of RIS using this new material are assessed by means of a case study. In this study, the performance of RIS technology is compared with that of a typical wood light-frame structure in the application of a small single-family house. The study indicates that the cost of ownership in present day value for the RIS is approximately 35% less than the cost of a comparable wood light-frame structure. The study also indicates that significant environmental benefits exist with the use of RIS. These structures use significantly less in terms of resources than do wood frame structures: approximately 2 times less in materials originating from nonrenewable fossil resources, approximately 2 times less in material originating from trees, and approximately 19 times less in materials originating from inorganic resources. The study concludes by delineating various means available to further increase the economical and environmental performance of RIS technology.     

Effects of Mine Blasting on Residential Structures

Blasting is common in the coal industry to remove rock overburden so that the exposed coal can be mechanically excavated. The ground vibrations and air blast produced by blasting are often felt by residents surrounding the mines. There has been a trend for regulatory authorities, especially those concerned with the environment, to impose low limits on blast vibration levels in response to community pressure, based on human perception and response to vibration. This paper reports the findings of an extensive study on a house which was located adjacent to a coal mine. The house was monitored for over 1?year and was subjected to ground peak particle velocity (PPV) ranging from 1.5?to?222?mm/s. The house was instrumented with accelerometers to measure its dynamic response due to blasting and it was also monitored for cracks before and after each blast. Based on this study, ground motion amplifications along the height of the structure have been established. A simplified methodology presented in this paper has been used to estimate the ground PPV at which cracking is likely.     

Economic Analysis of Thermal Energy Storage Systems

This paper describes an investigation of the economic performance of a central chiller plant with thermal energy storage (TES) operating in a hotel in California and an office building in Wisconsin for the following three conventional control strategies: chiller-priority, constant-proportion, and storage-priority control. Since all control strategies depend on properly selected design parameters, the storage and chiller capacities as the primary design parameters were varied over a wide range, and the life-cycle economic feasibility of each possible design was assessed over a 20-year economic life using the net present value method. Measured cooling and weather data for both buildings were used in annual calculations to determine annual utility cost savings on the basis of one of four artificial rate structures. Trends in the life-cycle economic performance of TES systems as a function of chiller and storage capacities were revealed, and design guidelines were developed.     

基于环境性能模拟的历史建筑更新设计优化研究

作为当代的国际学术热点,特别 是近年来我国建筑界由增量时代转向存量 时代,旧建筑的更新改造成为我国建筑内涵 式增长的关键。我国历史建筑改扩建中建筑 形式与环境脱节以及环境性能低效的矛盾亟 待解决。本文以哈工大土木楼改扩建设计为 例,针对其进行问卷调查,挖掘新时期建筑 学院人群空间行为规律和需求,进而基于 Rhinoceros与Grasshopper平台,结合拓扑思 想与图解静力学理论,探索空间与结构耦合 逻辑以及建筑体量生成方法,并针对其风热 环境进行Ecotect环境性能模拟及评估优化。 比较优化方案与原方案的模拟结果发现,天 窗开启面积占顶界面面积增至15.3%时,过 渡季节逐月不舒适度比例增长0.4%;遮阳面 积为顶界面面积71.8%时,过渡季节逐月不舒适度比例降低2.46%;而在此基础上,天窗开启面积占比增至28.2%,侧界面上舷窗占 比1.8%时,过渡季节逐月不舒适度比例则降低2.19%。基于此,本文提出改扩建设计设置 遮阳设施,辅以可开启天窗与侧立面上舷窗的优化设计策略,进而凝练出基于性能模拟的 历史建筑更新优化设计方法流程,旨在为历史建筑改扩建提供理论指导。     

京津冀地区公共建筑中庭物理环境优化设计研究

目前,公共建筑中庭物理环境舒适度不 足,且建筑集成化物理性能模拟较缺失。基于中 庭物理环境待优化的目的,通过Grasshopper建 立集成参数化模拟平台,以光环境、热环境、风 环境舒适性为评价维度,以全年热舒适小时数、 采光系数、全天然自然采光百分比、眩光指数、室 内平均风速为优化指标,对京津冀地区典型二、 三、四向中庭的层高、中庭天窗比、窗墙比、窗台 高度、走廊宽度等设计参数进行多目标优化模 拟,并基于上述模拟最优解集运用Odeon对语言 传输指数进行进一步筛选,分别获得优选设计参 数指标,并获得以光热舒适性为目的的中庭设计 参数建议。所提出的集成化模拟流程和可为建 筑设计初期的中庭设计提供参考。     

英国和中国历史建筑改造更新的比较分析：基于能源利用视角

在英国,更新改造成为节能减排的核心政策。尽管有很多实际应用的案例,但研究表明,更新改造和政策要全面实施仍然存在许多悬而未决的问题。与此同时,在中国等发展中国家,国际生态学者、开发者和决策者指明了更新理念和政策的发展方向。但是调查初步显示,在发展中国家,更新实践的全面实施也非常困难,这是因为与更新既有普通建筑和遗产地建筑相比,地方决策者和开发者对新建设项目更感兴趣。鉴于英国是较早实施更新改造的国家,而中国是近期开始更新实践的国家,本文选择它们作为核心案例进行研究。文章揭示了两个国家在更新历史建筑时面临的不同阻碍,探索了在各自的国情下,更新改造的潜在驱动力。     

上海市体育建筑场地布局策略研究

体育建筑的场地布局包括场地功能分区、建筑实体布局、交通安排及绿地配置等,作为对场地整体形态的统筹,在场地设计中起着关键作用。通过实地调研,该文分析了上海市体育建筑场地布局现状,归纳其主要影响因素,明确场地布局原则;进而借鉴国内外优秀案例的先进理念,探讨适宜上海市体育建筑的场地布局策略。上海市近年来大力兴建体育建筑,对场地布局策略进行深入研究,具有较强的现实性。该研究期望对体育建筑场地布局有一定的理论参考价值和实践指导意义。     

节能与舒适 表皮材料的建筑性能表现及其设计应用

文章指出建筑能耗和环境舒适是建筑性能表现的主要方面之一,同时是绿色建筑概念所强调的重要内容。然而能耗最小化的节能设计和舒适最大化的设计却存在着一定的矛盾,如果将二者放置在建筑表皮的关联中,会发现表皮材料在这个矛盾关系中扮演着非常重要的角色。为了平衡这种矛盾关系,对建筑表皮材料的特征分析,应该综合考虑建筑位置、整体形态和朝向、建筑内部的功能布局、使用者活动空间、空间使用特征,甚至使用者的背景和行为模式等因素。文章通过案例分析研究,提出基于整体设计和基于使用者群体特征的两个思路,并阐述了其中的建筑表皮的材料特征及其设计应用。