首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
《Building and Environment》2005,40(11):1450-1458
Determination of driving rain exposure typically requires hourly values of rainfall and mean directional wind speed. Weather data at most observing stations in Norway are not recorded as hourly values and are therefore not amenable to this type of analysis. We present an alternative method for assessing driving rain exposures based on multi-year records of synoptic observations of present weather, wind speed and direction. Distributions of numbers of rain observations and wind speeds versus wind direction combined with average annual rainfall totals yield quantitative information about driving rain exposures at stations. Results from four weather stations in Norway are presented and discussed, using weather data from the period 1974–2003.  相似文献   

2.
《Building and Environment》2005,40(11):1479-1491
This paper presents derivation of a water entry function of a hardboard siding-clad wood stud wall assembly. Water entry function provides input data to heat, air and moisture simulation models to facilitate the prediction of the long-term water entry performance of the specific assembly. Initially, an experimental work was conducted in which the hardboard siding-clad wood stud wall specimen was subjected to simulated driving rain loads, i.e. spray rates and static pressure differential. The specimen included a drainage cavity and specific deficiencies such as a missing length of sealant at the interface between the cladding and penetrating components, i.e. window, ventilation duct and electrical outlet. Water entering the deficiencies was collected at the drainage and stud cavities just below the penetrating components. Water entry results provided information on water entry rates as functions of simulated driving rain loads, which in turn permitted the development of a water entry function of the assembly. Entry function is a basic relationship that relates the quantity of water entry in a certain location within the assembly to the simulated driving rain loads. Measured climatic data of a specific climate, i.e. rainfall intensity and wind speed, was related to the simulated driving rain loads, and the entry function provided a means of estimating the water entry loads of the hardboard siding-clad wood stud wall assembly located in the specific climate.  相似文献   

3.
In this article, driving rain spell amounts are calculated from hourly wind and rainfall data for three cities in Great Britain, and comparisons are made with average annual driving rain values, also from hourly wind and rainfall data. The results show that the maximum observed driving rain spell intensities versus wall angles are qualitatively similar to angular distributions of annual driving rain both at and between the stations. For driving rain spell intensity expressed as the average number of exceedances of a threshold spell intensity value versus wall angle, results are both qualitatively and quantitatively very similar to angular distributions of annual driving rain. This suggests that average annual driving rain might be useful as a proxy measure of spell driving rain intensity in situations where relative risk of repeated penetration of masonry walls in building facades is of interest but quantitative spell data are not available.  相似文献   

4.
In this article, maximum hourly driving rain intensities calculated from hourly wind and rainfall data for five cities, three in Great Britain and two in Norway, are examined and comparisons are made with average annual driving rain values, also from hourly wind and rainfall data. The results show that the maximum observed driving rain intensities versus wall angle are quite different from angular distributions of annual driving rain both at and between the stations. For driving rain intensity expressed as the average number of exceedances of a threshold intensity value versus wall angle, on the other hand, results are qualitatively and quantitatively very similar to angular distributions of annual driving rain. This suggests that average annual driving rain might be useful as a surrogate measure of driving rain intensity in situations where relative risk of repeated rain penetration of doors, windows and other openings in building facades is of interest but long series of hourly wind and rain data are not available.  相似文献   

5.
Field surveys in Turkey indicate that a significant number of exterior wall assemblies in various regions of the country suffer from moisture degradation. These cases reveal that designers are in need for a climate scheme of Turkey, which indicates regions that require special provisions to prevent moisture degradation. Hence, this paper presents an approach for defining climate regions for Turkey. Initially, annual driving rain index (aDRI) based on monthly data is calculated and a driving rain map of Turkey is produced. Then, population-weighted heating degree-days (PW HDD) zones of Turkey are presented. Based on the aDRI and PW HDD zones, three climate regions of Turkey are established. Region 1 represents sheltered locations, i.e. locations which have aDRI less than 3. Region 2 represents locations (aDRI between 3 and 6 and PW HDD<1600), which are exposed to moderate driving rain between September and the end of May when the mean temperatures are above zero. Region 3 includes locations (aDRI between 3 and 6 and PW HDD between 1601 and 2500) which are moderately exposed to driving rain all throughout the year when the mean temperature is well above zero. As a conclusion, the proposed climate regions suggest that the design of wall assemblies located at Regions 2 and 3 must incorporate special provisions to prevent moisture degradation.  相似文献   

6.
The quantitative driving rain exposure for 15 important Canadian cities is derived by making use of the climatological data recorded at local meteorological stations. The driving rain parameters, namely, precipitation, intensity, impact frequency and impact duration, provide both long term and short term characteristics of local driving rain exposure on a vertical surface. These driving rain parameters are useful to designers in designing tight building envelopes against rain penetration. A realistic driving rain exposure test environment can be simulated by making use of these quantitative results for evaluating the performance of the building envelope.  相似文献   

7.
The use of computer-based systems to monitor and display vehicle location is currently an area of strong interest, and a number of organizations have developed such systems. Real-time vehicle systems monitoring, which can fit hand-inglove with location monitoring, is less well developed. Our requirement for vehicle data acquisition systems (DAS) was to monitor and store data on driving cycle, temperatures, pressures, engine stoichiometry, etc. In the course of working with fleets, it became clear that if vehicle systems data could be transmitted to a base station in real time, could be interpreted by base station software to provide a diagnostic capability, and could be combined with a map location display capability, then it would be of interest to a large number of fleets. The system, which has recently been developed, consists of enboard vehicle microprocessor monitoring, data reduction and transmission components, a VHF or satellite communications link, a base station signal modem, and an AT-type microcomputer for data analysis and display. This paper traces the evolution of the microcomputer-based systems monitoring of vehicles and provides some insight into the capabilities of such systems.  相似文献   

8.
吴和俊 《消防科学与技术》2022,41(10):1468-1471
摘 要:收集统计了2016-2021年广东省消防救援数据,并从数量变化趋势、区域分布特征、类型分布特征以及出警时间分布情况等方面开展分析。随后,基于空间分析法构建分析模型,综合考虑现状城镇建设用地、接警频次数据和城镇开发边界3个方面的因素,针对消防救援站开展布局优化分析,为制定消防救援站建设计划提供数据支撑。最后,结合分析结果对消防救援工作发展提出了改进措施和建议。  相似文献   

9.
Resistance to driving rain of pitched roof structures ‐ German and European assessment methods for rain penetration into tiled roofs and the resistance to driving rain of covering underlays and self supporting underlays. Resistance to driving rain describes the ability of an external component to offer protection against ingress of water into the component or the building under specified wind force, rainfall and rain duration. Standardised tests already exist for assessing and classifying the resistance to driving rain of components such as windows, external doors and gates, while for covered pitched roof structures no such tests have been established as yet. This applies to the actual roof covering consisting of small‐sized roofing elements such as tiles as well as covering underlays and self supporting underlays, which are exposed to the weather during the construction phase and during alterations or refurbishment. Over recent years great efforts have been made to try and compare the resistance to driving rain of covered pitched roof structures and exposed covering underlays and self supporting underlays used as temporary roof covering.  相似文献   

10.
The penetration of atmospheric water (rain) into facades creates problems for building habitability and the durability of construction materials. This study analyses the exposure of Brazilian facades to the two main climate factors responsible for this penetration: wind-driven rain and driving rain wind pressure. Daily weather records (spanning 2005–14, from 171 weather stations) were analysed. Both exposure factors were combined to assess the risk of water penetration at each site. The relationships between the different exposure indices calculated from daily, monthly and annual records were determined and compared with results from other countries. From this analysis, detailed isopleth maps are provided that allow a graphical characterization of the moisture exposure conditions of facades anywhere in Brazil. A comprehensive characterization of the water penetration exposure in Brazilian enclosures is created and can be used to establish normative design requirements for actual climatic conditions in each area of the country. In general, an increased risk of penetration was identified in the flat areas of the South and Northeast regions of the country. The sites located in the Amazon basin present comparatively lower risks, despite a greater amount of rainfall, because the wind intensity is less in these inland areas.  相似文献   

11.
The capacity of drying out moisture accumulated within stud cavities, especially moisture due to rain penetration, is an important characteristic affecting the performance and durability of building envelope systems. This paper introduces a new approach for evaluating such drying performance based on the concepts and procedures of Limit State Design (LSD) used in structural engineering. For a well performing envelope, the moisture load must be less than the drying capacity of the system. The drying capacities are obtained through full-scale experiments that utilize moisture loading derived from a moisture source (water tray) placed at the bottom of the stud cavity. In moving out of the cavity, part of the moisture will be absorbed by the materials surrounding the stud cavity. When any part of the wall specimen reaches 20% MC, the cumulative evaporation from the water tray is termed as the ICEA (in-cavity evaporation allowance) of that wall system. The ICEA value is dependent on the envelope configuration and is a good indicator of the drying performance of that wall system. By comparing ICEA values of wall systems with their respective moisture loads, those envelopes having ICEA values higher than the amount of rain penetration calculated from prevailing driving rain and faults in the envelope are deemed to have adequate drying capacity.  相似文献   

12.
Water penetration of a building envelope assembly is typically assessed on the basis of the degree of watertightness (i.e. lack of water ingress) of the components of the assembly when subjected to simulated driving rain conditions. Test standards provide the magnitude and extent of these test conditions as suggested by the test parameters, i.e. the water spray rates and pressure differences and the dwell time over which these are to be applied. Such conditions would presume to simulate driving rain and wind conditions of locations spread over a broad geographical area. For example, the water spray rate suggested for use in watertightness performance tests in EN 12155—Curtain walling–watertightness–laboratory test under static pressure—is considered appropriate for simulating driving rain and wind conditions for locations across Europe. However, test parameters should be based on the expected driving rain intensities and wind pressures that are likely to occur for a specific climate and a given return period. It might also be based on the building type (e.g. high or low-rise building), or even on the location on the building facade. Hence, a method is required for calculating water penetration test parameters for specific buildings located in a specific climate. The purpose of this paper is to propose a method for calculating water penetration test parameters. A survey of existing methods is first provided that focuses on the quantification of driving rain on buildings and thereafter, calculation of water penetration test parameters. The merits and drawbacks of these methods are then discussed. Based on this review, a method for calculating test parameters is proposed and is applied to developing water penetration test parameters for Istanbul, Turkey. A comparison of test parameters calculated from the proposed method with those given in existing Turkish standards TS EN 12155–Curtain walling–watertightness–laboratory test under static pressure—and TS ENV 13050—Curtain walling–watertightness–laboratory test under dynamic condition of air pressure and water spray—related to Istanbul, indicated that the water spray rate given in the TS standards is higher than spray rates calculated from the proposed method for return periods of 5, 10 and 30 years.  相似文献   

13.
An estimation of moisture loading severity for building components in Greece was attempted. Annual driving rain indices were calculated for 31 stations spread all over the country, based on the average annual rainfall and wind speed values derived from data, published by Hellenic National Meteorological Service. The analysis revealed that the majority of the locations are sheltered from driving rain. A driving rain map for Greece was produced. A second set of annual driving rain indices were calculated for these sites, based on average monthly data. The relationship between these two sets of indices for the 31 locations was best approximated by a hyperbolic function. Thessaloniki, a city in northern Greece, was further studied using average annual and daily data provided by the Institute of Meteorology and Climatology, A.U.Th. For Thessaloniki, the exposure estimated from daily data was bigger than the one resulting from annual data. Finally, a moisture index for the comparison of building components' exposure to moisture, with the drying potential also being considered, was calculated for the 31 sites studied and a ranking of these sites' climates in terms of moisture loading on buildings was obtained. The drying potential's contribution to this ranking is very important.  相似文献   

14.
《Water research》1999,33(10):2255-2264
The variable nature of wet weather flow events has made it difficult to assess the toxicity of these events with conventional toxicity testing methods. This paper proposes a test protocol that includes an event-focused toxicity test method, a corresponding test metric that more accurately represents the toxicity of brief exposures, and an event-based index that describes the acute toxicity of wet weather events. This testing protocol is designed to quantify toxic response produced by brief contaminant exposures (<24 h), as well as time-varying contaminant exposures, which are typical of wet weather events. The protocol describes the use of an event-focused toxicity test to determine a PE-LET50 (post-exposure lethal exposure time for 50% of the population) metric for individual event samples. The PE-LET50 is a new metric that represents the exposure duration to a sample necessary to produce a 50% response during a post-exposure observation period. The protocol then describes the development of an index that integrates the toxicity of event samples (PE-LET50s) into a measure of total event toxicity. This index is the event toxicity unit (ETU). The development and use of the test protocol is described and results are provided from single and multiple sequential exposures to reference toxicants and from two wet weather discharge events.  相似文献   

15.
为解决概率积分法参数反演时计算不稳定、初值依赖、优化指标难以选取、非矩形工作面,多工作面影响下难以反演的问题,提出采用地表空间移动矢量反演概率积分法参数的遗传算法模型。该模型采用地表移动矢量的误差平方和最小作为计算指标,以遗传算法作为参数优化的核心算法进行概率积分法参数反演。用空间移动矢量指标可以解决分别采用下沉、水平移动监测值反演结果不相同、精度难以估算的难题。矢量反演模型对观测站设置没有特别严格的要求,降低了设站不当引起的计算误差。为解决遗传算法多次计算结果不同的问题,建立了组合预测计算方法,依据中误差加权均值得到唯一的计算结果。基于矢量移动值的反演模型,避免了传统计算方法的多个缺陷,计算效率高、易于与已有开采沉陷预计程序结合,为解决非矩形、多工作面地表移动观测站参数反演的工程应用问题提供了新的解决思路和计算方法。  相似文献   

16.
Although moisture significantly affects the performance and durability of building envelope systems, effective methods to quantify the relative drying capacity of these systems are yet to be developed. A new testing method and an evaluation approach for comparing the drying capacity of wood-frame wall systems in evacuating water due to rain penetration in the stud cavities are presented in this paper. A controllable and consistent moisture loading is created by placing a water tray on a load cell at the bottom of the stud cavity of the wall assembly which is then subjected to lab generated indoor/outdoor conditions. The data on water evaporation from water trays and the monitored moisture accumulations in the materials surrounding the stud cavities are used to establish load–response relations. Using these relations the relative performance of various building envelope systems in preventing biodeterioration caused by rainwater penetration into the stud cavities can be compared. The concept of in-cavity evaporation allowance (ICEA) has been proposed and it is based on the limit of 20% moisture content (MC) being reached at any location of the building envelope.  相似文献   

17.
Experiments performed on "Marais" catchment, in central Paris, aimed to follow up the quality of wet weather flows from the entry to the exit of a combined sewer network. SS, VSS, COD, BOD5, Cd, Cu, Pb, Zn concentrations were measured for an important number of rain events in roof, yard, street runoff, as well as in dry and wet weather flows at the catchment outlet. Mass entry-exit totals, at the scale of the catchment, were calculated over 31 rain events in order to evaluate the contribution of different types of runoff, of sanitary sewage and of sewer sediments to the total wet weather pollutant loads at the catchment outlet. The erosion of in-sewer pollutant stocks was found to be the main source of particles and of organic matter in wet weather flows, whereas heavy metal loads mainly originated from roof runoff, due to the corrosion of metallic roofs. Particles eroded inside the sewer during rain events were found to be quite different from the particles constituting the main part of sewer sediments: they are organic and biodegradable, with rather important settling velocities and seem to accumulate during dry weather periods. A change of the chemical form of heavy metals was noticed during the transport in the sewer and it is suspected that a fraction of the dissolved metals from the runoff is adsorbed on sewer sediments.  相似文献   

18.
青藏高原机场道面混凝土抗冻指标研究   总被引:4,自引:1,他引:3  
在我国青藏高原地区建造的机场,因其独特的高海拔特征而与内地机场有着迥异差别,因此在建设上带来特殊的要求.依托正在建设的青海省玉树机场,在详细分析其独特的气候特点基础上,有针对性地进行了高原机场道面混凝土抗冻指标研究.  相似文献   

19.
Hygrothermal loads and service life of external wall insulation systems. Service life and aging behaviour of external wall systems depend on their hygrothermal loads. Apart from the fluctuating climatic conditions temperature, solar radiation and humidity there are often additional exterior or interior sources of moisture, e.g. driving rain, construction moisture or surface condensation acting on facades. External wall insulation systems (ETICS = E xternal T hermal I nsulation C omposite S ystems) are especially affected due to their low mass. However, the long‐term observation by repeated inspections of the same objects over a period of 30 years proves that ETICS show not more damage than traditional facades. Apart from minor esthetical problems due to soiling or microbial growth their long‐term behaviour is very encouraging. Maintained at normal intervals ETICS are as durable as traditionally rendered masonry walls.  相似文献   

20.
 受地形地质条件所限,宜兴抽水蓄能电站上库主坝为一修建在斜坡上的土石坝与高重力挡墙联合作用构成的混合坝型,这种坝型为国内外较少见,高45.9 m的重力挡墙在国内外也十分少有。高挡墙在土石坝堆石的强大推力作用下,如何在斜坡上保持稳定,一直为各方所关注。根据监测资料和三维有限元数值分析结果,得到作用在高重力挡墙后的土压力大小及其分布规律,确定典型剖面上土压力的作用位置和作用方向,验证太沙基关于挡墙后土压力不是作用在传统认为的下三分点,而是作用在0.4倍左右墙高位置的论断。在此基础上,根据设计和有关规范要求分析了高重力挡墙在水库运行条件下的抗滑、抗倾稳定安全度,同时,结合挡墙及其地基的内、外部变形和受力监测资料,对高重力挡墙的稳定性做出综合评价。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号