西南交通大学学报
西南交通大學學報
서남교통대학학보
JOURNAL OF SOUTHWEST JIAOTONG UNIVERSITY
2014年
2期
247-253
,共7页
低矮房屋%极值分布%现场实测%坡角可调%短时距
低矮房屋%極值分佈%現場實測%坡角可調%短時距
저왜방옥%겁치분포%현장실측%파각가조%단시거
low-rise building%extreme value distribution%field measurement%adjustable roof pitch%short time interval
探讨了低矮房屋实测风压的极值计算方法,以便为建筑抗风设计提供重要依据。基于同济大学土木工程防灾国家重点实验室在上海浦东国际机场附近海岸边建造的风工程实测基地(包括一栋坡角连续可调的低矮试验房和高分别为10和40 m的测风塔)的现场实测数据,分析了良态气候条件下低矮房屋表面风压的分布特性,并探讨了由短时距样本估计长时距下极值的计算方法对实测风压极值估计的可靠性。研究表明:屋面来流分离区实测风压表现出明显的非高斯性,其概率分布与Gamma分布和对数正态分布符合较好;将屋盖风压时程划分成若干子段时,利用极值Ⅰ型分布参数转换关系计算风压极值,估计极值比观察极值法的结果更准确,且最佳观察时距可由自相关分析确定;以该最佳观察时距划分单个子段风压样本,实测观察极值基本服从极值Ⅰ型分布,估计极值能较准确地给出实测时程极值,表明基于极值I型的短时距极值估计方法合理、有效。
探討瞭低矮房屋實測風壓的極值計算方法,以便為建築抗風設計提供重要依據。基于同濟大學土木工程防災國傢重點實驗室在上海浦東國際機場附近海岸邊建造的風工程實測基地(包括一棟坡角連續可調的低矮試驗房和高分彆為10和40 m的測風塔)的現場實測數據,分析瞭良態氣候條件下低矮房屋錶麵風壓的分佈特性,併探討瞭由短時距樣本估計長時距下極值的計算方法對實測風壓極值估計的可靠性。研究錶明:屋麵來流分離區實測風壓錶現齣明顯的非高斯性,其概率分佈與Gamma分佈和對數正態分佈符閤較好;將屋蓋風壓時程劃分成若榦子段時,利用極值Ⅰ型分佈參數轉換關繫計算風壓極值,估計極值比觀察極值法的結果更準確,且最佳觀察時距可由自相關分析確定;以該最佳觀察時距劃分單箇子段風壓樣本,實測觀察極值基本服從極值Ⅰ型分佈,估計極值能較準確地給齣實測時程極值,錶明基于極值I型的短時距極值估計方法閤理、有效。
탐토료저왜방옥실측풍압적겁치계산방법,이편위건축항풍설계제공중요의거。기우동제대학토목공정방재국가중점실험실재상해포동국제궤장부근해안변건조적풍공정실측기지(포괄일동파각련속가조적저왜시험방화고분별위10화40 m적측풍탑)적현장실측수거,분석료량태기후조건하저왜방옥표면풍압적분포특성,병탐토료유단시거양본고계장시거하겁치적계산방법대실측풍압겁치고계적가고성。연구표명:옥면래류분리구실측풍압표현출명현적비고사성,기개솔분포여Gamma분포화대수정태분포부합교호;장옥개풍압시정화분성약간자단시,이용겁치Ⅰ형분포삼수전환관계계산풍압겁치,고계겁치비관찰겁치법적결과경준학,차최가관찰시거가유자상관분석학정;이해최가관찰시거화분단개자단풍압양본,실측관찰겁치기본복종겁치Ⅰ형분포,고계겁치능교준학지급출실측시정겁치,표명기우겁치I형적단시거겁치고계방법합리、유효。
The peak pressure estimation methods of field measurement-based wind loads on low-rise buildings were investigated for the design of wind resistance on low-rise buildings. Based on pressure data measured on the roof of the test building during monsoon climate at the wind engineering field measurement base constructed on seashore beside Pudong International Airport of Shanghai by the State Key Laboratory of Disaster Reduction in Civil Engineering of Tongji University,including a full-scale low-rise building with adjustable roof pitches and two anemometer towers respectively with a height of 10 and 40 m,the distribution characteristics of wind pressures were analyzed,and the validity of the peak value estimation method to use the extreme pressure of short time interval samples to estimate that of long time interval samples from field measurement data was discussed. The research result shows that as for the flow separation region,the probability distributions of wind pressure coefficient have non-Gaussian features and a good agreement with the Gamma and lognormal distributions. When the time-history curve of wind pressures on the roof are divided into several sub-sections and the relationships of typeⅠEVD (extreme value distribution )parameters between parent section and sub-sections are used to estimate peak pressures,the estimated peak pressures are more accurate than observed extreme values,and the optimal length of a sub-section can be determined by the auto-correlation analysis of the parent section. For the full-scale data the extreme value distribution has a good conformity with typeⅠEVD when sub-section data are divided by the optimal length,and the peak pressure estimation method based on typeⅠEVD for short time interval samples has reliable results.