阳台在建筑火灾中阻碍烟气垂直传播规律初探

建筑发生火灾,阳台能有效阻止火焰沿外墙面竖直向上传播蔓延速度,然而,阳台在现行国家建筑设计防火规范上未作任何要求.采用适当比例的物理模型进行实验研究,初步探讨了建筑在火灾条件下不同形式的阳台对烟气沿外墙面流动的影响因素,针对四种不同的阳台形式(封闭式凹阳台、开敞式凹阳台、封闭式凸阳台和开敞式凸阳台)进行了探讨,旨在推动我国在建筑阳台消防功能领域中进行更深一步的研究与分析.     

灌注桩泥浆浸湿范围及周边土体竖向位移试验

根据西安地铁试验段钻孔灌注桩周边土体深层竖向位移监测试验资料及泥浆浸湿对比资料,对黄土地区灌注桩施工过程中土体不同深度位移及泥浆浸湿范围进行了研究,为钻孔灌注桩的工程应用提供了有益的理论依据和参考。     

室外风对高层建筑竖井内烟气运动影响的数值模拟

采用火灾模拟专业软件FDS对不同火源位置、不同风向条件下火灾烟气的运动进行模拟,测定典型位置处温度、速度、CO及CO2体积分数变化情况。实验结果表明:在近地风场中,风向对竖井内烟气蔓延的影响大小顺序为迎风>背风>侧风,竖井开口位于迎风面时,外界风对竖井内烟气运动影响最大:火源位于中性面以上时,烟气通过竖井与前室的开口向竖井内蔓延,并向下运动;而火源位于中性面以下时,前室内烟气向外部运动,竖井内无烟气流入。     

A development of next generation intelligent construction liftcar toolkit for vertical material movement management

High-rise construction sites, especially those situated in spatially-constrained urban areas, have difficulties in timely delivery of materials. IT-driven management techniques can be further benefited from state-of-the-art devices such as Radio Frequency Identification (RFID) tags and Ubiquitous Sensor Networks (USN), which have resulted in notable achievements in automated logistics management at the construction sites. Based on those achievements, this research develops USN hardware toolkits for hoists, which aims to automate the vertical material delivery by sensing the material information and routing it automatically to the right place. The gathered information from the sensors can also be used for monitoring the overall status. To support the system, a hoist-mountable intelligent toolkit was developed. Its feasibility test was conducted by applying the implemented system to a test bed and then analyzing efficiency of the system and the toolkit.     

Responses of piles subjected to excavation-induced vertical soil movement considering unloading effect and interfacial slip characteristics

Soil excavation inevitably affects the work performance of adjacent on-service piles. It is of practical importance to estimate the excavation-induced pile responses accurately. Existing methods tend to ignore the impacts of the interfacial slip characteristics and the loading history. In this study, modified load-transfer models are first developed for the surrounding soil and the pile–soil interface. Then, a nonlinear two-stage analysis method is proposed by introducing a Double-Spring model. In comparison with existing methods, the proposed method models the interfacial slip characteristics more realistically, and, more importantly, it is able to consider the impact of the working load in the active stage. The results of parametric studies show that the impacts of the working load in the active stage and the interfacial slip characteristics on the excavation-induced pile responses are significant; unacceptable deviation could be induced if an elastic-perfectly plastic model or a rigid-plastic model is adopted instead of the damage model to describe a rough pile-sand (or soft rock) interface. Moreover, with the increase in the working load, the excavation-induced pile settlement increases, whereas the additional axial force decreases.     

综合管廊电缆舱中线性火源横向和竖向移动对火灾行为的影响研究

在长50 m的全尺寸综合管廊电缆舱模型中进行电缆火灾试验,研究线性火源的横向移动和竖向移动对火焰外形、火源质量损失速率、横向温度分布及烟气分层的影响.得到以下结论,火源横向移动会使火焰发生弯曲,火源竖向移动会在顶棚形成较大的火焰面积;侧墙和火焰对火源的辐射热反馈是影响火源质量损失速率的重要因素,且火焰对火源的热反馈要重要于侧墙的热反馈;在侧墙和火焰两种因素的共同作用下,使火源质量损失速率在火源发生横向移动时先增加后减少,发生竖向移动时一直减少;通过对横向温度的分析发现,火源的横向移动对烟气层的厚度影响不大,但竖向移动会使烟气层的厚度明显减小.     

竖向基础隔震框架结构的竖向地震反应分析

对竖向隔震框架结构的竖向地震响应进行了时程动力分析，对比了隔震结构及其相应非隔震结构的动力特性，给出了罕遇地震作用下结构的最大层间轴力、位移等，得到了竖向隔震结构的竖向地震反应明显降低的结论。     

浅谈住宅立面设计

介绍了住宅建筑立面的发展历程及其主要形式，从外挂空调机、外飘窗、雨篷、墙面雕塑、浮雕及色彩、用材等方面分析了住宅立面设计中应注意的问题，并着重从住宅立面用色程序、建筑立面用料、外立面的颜色与夜景照明几方面对建筑立面的色彩与用材进行了阐述，以供设计人员参考。     

探究城市竖向设计

结合区域现状地形地貌地物,通过阐述竖向设计的原则、作用、方法、深度、注意事项等内容,统一分析了区域内道路、排水、不同场地等的适用坡度,以利于建(构)筑物的布置与空间环境的设计,从总体上控制区域的竖向高程,使区域的建设整体效果更加优美。     

场地竖向设计

结合工程实践过程中积累的场地竖向设计经验,对总图设计中的竖向设计方法和原理进行了系统的论述,介绍了场地竖向设计工作的意义、内容及设计流程,重点阐述了场地竖向设计的方法及难点,对场地竖向优化设计具有重要意义。     

谈整栋楼房的搬迁

结合某砖混结构住宅楼搬迁实例，就其施工方案的确定作了简要描述，从准备阶段、施工过程及技术操作要求等方面，提出了建筑物搬迁的一般步骤，具有参考借鉴价值。     

浅谈竖向设计与城市竖向规划的协调

本文通过南阳市体育中心的竖向设计探讨了区域竖向标高与城市竖向规划的相互影响、补充和协调。     

碟形弹簧竖向减震装置的竖向地震反应分析

对河北理工大学研制的由碟形弹簧和粘弹性阻尼器组合而成的碟形弹簧竖向减震装置进行了力学性能试验研究,建立了恢复力模型。并以一个8层框架为例,对其竖向地震响应进行了时程反应分析,对比了隔震结构及其相应非隔震结构的动力特性,计算出罕遇地震作用下结构各层的最大加速度和位移。结果表明,该竖向减震装置能够起到有效减轻竖向地震动的作用。     

Investigation of large-scale circulations in room air flows using three-dimensional particle tracking velocimetry

Large-scale circulations in room air flows have been investigated with three-dimensional particle tracking velocimetry (3D PTV). This technique has been refined for large scales, enabling us to determine flow patterns, trajectories, and velocity vectors within a large cylindrical enclosure used as a model room for thermal convection. This test enclosure is called Rayleigh-Bénard (RB) cell and addresses the limiting case of room air with very high internal loads. The flow patterns are only created by buoyancy forces. The 3D PTV system consists of four CMOS cameras, two flash lamps, and an image recording and data processing system. Helium-filled latex balloons were used as tracer particles. The spatial resolution and accuracy were investigated in a test cell with the dimensions of 4 × 3 × 4 m³ by means of a given trajectory of a small glass sphere. First applications of the developed 3D PTV system in the large RB cell with a diameter of 7.15 m and a height of 3.58 m showed different characteristic flow patterns of large-scale circulation outside the boundary layers. From the recorded and analyzed long-term particle trajectories further important data of room air flows like velocity time series, probability density functions (PDF) of the velocity, and acceleration fluctuations were calculated. The proposed technique has a wide range of potential applications for the three-dimensional and time-dependent analysis of indoor air flows.     

场地竖向设计分析

介绍了场地竖向设计的意义与任务,分析了计算机辅助设计在竖向设计中的应用,并以太原市某地块竖向设计为例,阐述了竖向设计中的几个重要因素,提出了进行场地竖向设计的几点建议。     

房屋建筑竖向减震分析

对在输入不同场地、不同频谱的地震波作用下房屋建筑的竖向减震体系进行时程分析，得到在合理控制减震装置的竖向刚度下可以有效减小竖向地震作用的结论，以达到理想的减震效果。     

CAD on geocomposite vertical strip drains

In recent years, an increasing need has arisen for various types of construction on sites underlain by soft cohesive soils. In such cases, some methods of soil improvement are usually required to provide adequate bearing capacity and tolerable postconstruction total and differential settlements. These goals often may be achieved by precompression or preloading the site prior to construction. Precompression and preloading are frequently used in combination with vertical drains, especially in very thick soft deposits, otherwise the time required for consolidation may be unacceptably long or the instability of the foundation may be a serious concern. Therefore, the vertical geocomposite (jute and coir) drain may be used to accelerate the settlement of soil thereby making the site available for use in the shortest time. The computer program and the design chart for determining the spacing between geocomposite drains are presented. This technique is generally useful for embankment construction, tank foundation, underwater construction and landfill areas. Two projects (Haldia in West Bengal and Vashi Station Complex in Bombay) have utilized the application of geocomposite drains reported in this paper.     

北京东海防水系统及应用技术介绍(六)再论变形缝渗漏的治理

分析了地下工程变形缝渗漏治理效果不佳的原因，指出了治理工作中存在的一些误区，如注浆压力、密封胶的使用等。     

浅谈室内垂直绿化

简要介绍了垂直绿化的概念,针对室内垂直绿化设计进行了探讨,分别阐述了室内垂直绿化设计的主要形式、相关技术及植物品种的选择与养护等方面的内容,以指导设计人员合理设计,为人们提供立体化的景观绿化效果。     

a类竖向不规则结构的设计探讨

结合某工程实例，介绍了模拟计算方法并做了理论分析，获取了能够较大幅度降低地震效应的主要因素及设计方法，并得出了有关竖向不规则结构的设计结论。