【摘要】：為明確大跨度懸索橋扁平鋼箱梁溫度和溫度梯度特征,以南溪長(zhǎng)江大橋正交異性鋼箱梁為研究對(duì)象,基于健康監(jiān)測(cè)系統(tǒng)中溫度傳感器的長(zhǎng)期實(shí)測(cè)數(shù)據(jù),采用分段函數(shù)描述環(huán)境溫度和日照輻射共同作用下鋼箱梁日溫度變化曲線(xiàn)。在此基礎(chǔ)上,采用高斯混合模型描述鋼箱梁年溫度多峰概率分布,并引入赤池信息判別準(zhǔn)則(AIC)和貝葉斯信息判別準(zhǔn)則(BIC)確定最優(yōu)高斯分量數(shù)。統(tǒng)計(jì)鋼箱梁一年日溫差極值并進(jìn)行參數(shù)評(píng)估,得到鋼箱梁年溫差極值分布模型。對(duì)年溫差極值分布函數(shù)進(jìn)行外推,得到設(shè)計(jì)基準(zhǔn)期溫差的極值分布函數(shù)并計(jì)算溫差標(biāo)準(zhǔn)值。引入相關(guān)系數(shù)分析法對(duì)各溫差組進(jìn)行相關(guān)性分析,剔除實(shí)際不存在的溫差模型。研究結(jié)果表明:相比正弦函數(shù),分段函數(shù)能更準(zhǔn)確地描述太陽(yáng)輻射作用下箱梁截面日溫度變化特征;當(dāng)高斯分量數(shù)為3時(shí),混合高斯模型擬合鋼箱梁年溫度概率分布最優(yōu);外推設(shè)計(jì)基準(zhǔn)期模型能夠較好地計(jì)算設(shè)計(jì)基準(zhǔn)期溫差標(biāo)準(zhǔn)值;通過(guò)相關(guān)性分析剔除了4組不存在的溫差模式;得到頂板和腹板各8組溫差模式;最后與《公路橋涵設(shè)計(jì)通用規(guī)范》(JTG D60—2015)中鋼混結(jié)構(gòu)豎向正溫差設(shè)計(jì)值進(jìn)行對(duì)比,一、二級(jí)溫度梯度與設(shè)計(jì)規(guī)范分別相差4.2℃和2.3℃。
[Abstract]:In order to clarify the temperature and temperature gradient characteristics of flat steel box girder of long-span suspension bridge, the orthotropic steel box girder of Nanxi Yangtze River Bridge is taken as the research object, based on the long-term measured data of temperature sensor in health monitoring system. A piecewise function is used to describe the diurnal temperature variation curve of steel box girder under the action of ambient temperature and sunshine radiation. On this basis, the annual temperature multi-peak probability distribution of steel box girder is described by Gao Si mixed model, and the optimal Gao Si component number is determined by introducing the red pool information discriminant criterion (AIC) and Bayesian information discriminant criterion (BIC). The annual temperature difference extreme value distribution model of steel box girder is obtained by calculating the extreme value of annual temperature difference of steel box girder and evaluating the parameters. By extrapolating the extreme value distribution function of annual temperature difference, the extreme value distribution function of temperature difference in the design base period is obtained and the standard value of temperature difference is calculated. Correlation coefficient analysis method is introduced to analyze the correlation of temperature difference groups, and the non-existent temperature difference model is eliminated. The results show that compared with the sinusoidal function, the piecewise function can more accurately describe the diurnal temperature variation of the box girder section under solar radiation, and when the Gao Si component number is 3, the hybrid Gao Si model can best fit the annual temperature probability distribution of the steel box girder. Extrapolation of the design reference period model can better calculate the standard value of temperature difference in the design reference period, eliminate the non-existent temperature difference mode in 4 groups through correlation analysis, and obtain the temperature difference mode of each group of roof and web. Finally, the design values of vertical positive temperature difference of steel-concrete structures in JTG D60-2015 are compared. First, the difference between the second-order temperature gradient and the design code is 4.2 鈩，

本文編號(hào)：2173478