高层建筑塑料门窗抗风压计算与提高抗风压性能、降低成本的措施(一)

本文论述了风荷载标准值、塑料门窗主要受力杆件荷载、玻璃荷载计算原理与方法,纠正了业内某些不正确观点,评价了国外门窗荷载计算方法,并提出提高塑料门窗抗风压性能、降低成本的措施.     

塑料门窗钢衬惯性矩(手工)计算

1 序言 塑料门窗行业标准JG/T 3017-1994与JG/T3018-1994分别在4.1.3中规定:"门窗用增强型钢及其紧固件的表面应经防锈处理,增强型钢的厚度应不小于1.2mm."随着塑料门窗在南方高层建筑的推广应用,仅要求型钢厚度达到1.2mm,显然满足不了塑料门窗杆件抗风压性能要求.必须依据建筑所在地区的基本风压与不同建筑高度处的标准风荷载值,选用适合风压要求的型钢,对受力杆件进行风压计算.     

严寒地区节能塑料窗设计与抗风压的计算

本文叙述严寒地区的气候特点,结合特殊地理气候条件,进行第三代塑料窗开发设计,实现建筑节能65%的要求,取得了节能保温的效果,并对塑料门窗抗风压进行了计算.     

热压及室外风压对高层建筑楼梯间加压送风系统影响的网络模拟分析

以两幢高度不同的高层建筑为例,利用网络模拟软件CONTAM3.0模拟分析了热压及室外风压单独作用和二者耦合作用对楼梯间加压送风效果的影响。结果显示:建筑高度、建筑内外温差、室外风的风向和风速都会影响楼梯间加压送风效果;由建筑内外温差产生的热压作用会导致楼梯间压力重新分布,冬季的热压作用极可能导致楼梯间的压力小于安全阈值,使加压送风系统失效;当热压和室外风压耦合作用时,最不利情况是夏季建筑上部迎风面房间着火和冬季建筑下部迎风面房间着火,这两种情况下着火层前室门处的压差均降至6Pa左右,远低于规范规定的25Pa,导致楼梯间加压送风系统失效。     

大连市某高层建筑风振和地震反应的主动质量阻尼(AMD)控制分析与设计

本文以大连市某大型高层钢筋混凝土结构为背景,进行了高层建筑结构抗风抗震的AMD主动控制分析和方案设计。首先,根据实际工程数据建立了结构动力分析的计算模型,编制了风荷载随机抽样程序,给出了用于分析的典型风荷载和地震波动荷载样本。其次,进行了脉动风荷载作用下AMD控制系统物理参数和控制算法软参数的优化分析,得到了AMD子系统的最优质量、刚度和阻尼等物理参数。然后,在AMD子系统取得最优参数的情况下,进行了结构脉动风荷载作用下和常遇地震作用下AMD主动控制的反应分析;计算结果表明,采用AMD主动控制系统可以使结构的风振加速度控制效果达40％以上,大幅度提高规范要求的风振舒适度,对常遇地震作用下位移反应的控制效果也可以达到40％左右。最后,仿真分析了AMD控制结构平动-扭转耦联振动的控制效果。此外,本文还给出了实际工程结构进行AMD主动控制设计的一般性步骤,可供类似高层建筑结构进行AMD主动控制分析和设计时参考。     

高层建筑防火排烟研究(1):压差法与流速法不宜用于高层建筑加压送风量计算

从流体力学角度对压差法与流速法用于高层建筑加压送风量计算所存在的问题进行了分析,认为压差法与流速法不适用于高层建筑加压送风量计算。     

排烟排热系统(RWA)用于现代建筑的消防与通风控制(二)

(接上期) 3 排烟排热系统(RWA)基本原理与构成 排烟排热系统(RWA)是由一个或多个排烟和排热单元(窗户、采光顶窗等)、控制及操作元件、开启组件、电源输入以及各种辅助部件构成的设备系统.     

Evaluating the use of electrical resistivity imaging technique for improving CH(4) and CO(2) emission rate estimations in landfills

In order to improve the estimation of surface gas emissions in landfill, we evaluated a combination of geophysical and greenhouse gas measurement methodologies. Based on fifteen 2D electrical resistivity tomographies (ERTs), longitudinal cross section images of the buried waste layers were developed, identifying place and cross section size of organic waste (OW), organic waste saturated in leachates (SOW), low organic and non-organic waste. CH(4) and CO(2) emission measurements were then conducted using the static chamber technique at 5 surface points along two tomographies: (a) across a high-emitting area, ERT#2, where different amounts of relatively fresh OW and SOW were detected, and (b) across the oldest (at least eight years) cell in the landfill, ERT#6, with significant amounts of OW. Where the highest emission rates were recorded, they were strongly affected by the thickness of the OW and SOW fraction underneath each gas sampling point. The main reason for lower than expected values was the age of the layered buried waste. Lower than predicted emissions were also attributed to soil condition, which was the case at sampling points with surface ponding, i.e. surface accumulation of leachate (or precipitated water).     

从日本COCOON工程浅谈工程抗震、防水、排水的结构处理及幕墙物流配套管理（二）

本文通过介绍日本COCOON工程的全面管理,阐述现代幕墙物流配套管理的重要性。     

Human placenta as a 'dual' biomarker for monitoring fetal and maternal environment with special reference to potentially toxic trace elements. Part 2: essential minor, trace and other (non-essential) elements in human placenta.

A survey of elemental composition of the human placenta was undertaken to evaluate reference values for minor and trace elements (essential and non-essential). The new data collection was narrowed down to results generated between the period of 1975-2000, since analytical methodology was becoming increasingly reliable with time for many elements. The search revealed the following results (microg/g, based on wet weight): Ca = 770; Cl = 1900; K = 1685; Mg = 100; Na = 360; P = 1700; and S = 350. However, Na, P and S need further confirmation. For a group of essential trace elements following average values were evaluated (microg/g, based on wet weight): Co = 0.007; Cr = 0.03; Cu = 0.9; Fe = 69; I = 0.005; Mn = 0.08; Mo = 0.02; Se = 0.2; and Zn = 10. However, the iodine value needs further confirmation. In addition, information values have been identified for a number of so-called non-essential elements such as Ag, Au, B, Ba, Br, Cs, F, La, Rb, Sb, Sc, Si, Sn, Sr, Ti, V and W. The survey results for toxic trace elements As, Cd, Hg, Ni and Pb are discussed in part 3 of this paper along with placenta as a biomonitor for toxic trace elements.