【摘要】：分析了混凝土結構溫度場邊界條件計算方法,以青海省海黃大橋H形混凝土橋塔為工程背景,計算了高原高寒地區(qū)四季典型氣象條件下的橋塔溫度場分布,對比了四季的橋塔表面溫差和塔壁局部溫差,確定了橋塔的最不利溫度荷載,建立了橋塔整體有限元模型,分析了四季橋塔的偏位、豎向應力、橫向應力和縱向應力等溫度效應。分析結果表明:橋塔表面溫差與橋塔局部溫差均在冬季最大,最大值分別可達11.88℃、20.79℃,在夏季最小,最大值分別可達5.15℃、15.25℃;橫橋向和縱橋向橋塔表面溫差最大值分別達到9.15℃、11.88℃,遠大于《公路斜拉橋設計細則》(JTG/T D65-01—2007)推薦值±5℃;接近正南方向的塔壁局部溫差最大,沿壁厚方向的溫差分布接近指數(shù)形式,冬季和夏季溫度衰減系數(shù)最大值分別為4.50、5.01,故冬季橋塔壁板局部溫度分布較夏季更不均勻;橋塔溫度效應同樣在冬季最大,1天中最大橋塔偏位超過40mm,白天橋塔偏位變化值超過15mm,不利于施工過程中的橋塔偏位監(jiān)測;橋塔根部豎向最大拉應力達到2.2MPa,橋塔根部同樣產(chǎn)生較大水平向拉應力,縱橋向和橫橋向最大拉應力分別為1.82、0.82 MPa,均發(fā)生在橋塔內(nèi)側,在與其他作用組合時可能會造成橋塔開裂,建議在橋塔塔壁內(nèi)側布置一定量的鋼筋網(wǎng)片來控制裂縫;在進行高原高寒地區(qū)橋塔設計和施工控制時,應充分考慮溫度效應帶來的不利影響。
[Abstract]:The boundary condition calculation method of temperature field of concrete structure is analyzed. Taking the H-shaped concrete bridge tower of Haihuang Bridge in Qinghai Province as the engineering background, the temperature field distribution of the bridge tower under the typical meteorological conditions of four seasons in the alpine plateau region is calculated. By comparing the surface temperature difference of the bridge tower with the local temperature difference of the tower wall of the four seasons, the most unfavorable temperature load of the bridge tower is determined, the integral finite element model of the bridge tower is established, and the deflection and vertical stress of the four seasons tower are analyzed. Temperature effects such as transverse stress and longitudinal stress. The results show that the difference between the surface temperature of the bridge tower and the local temperature of the bridge tower is the largest in winter, the maximum value is 11.88 鈩，

本文編號：2273216