大跨懸索橋施工過程顫振穩(wěn)定分析6P.pdf

大跨懸索橋施工過程顫振穩(wěn)定分析 (1. 同濟(jì)工程力學(xué)與技術(shù)系,上�！�200092 ; 2. 同濟(jì)橋梁工程系,上�！�200092)

隨著懸索橋跨徑的不斷增大,抗風(fēng)穩(wěn)定性成為控制橋梁設(shè)計(jì)與施工的最主要因素. 尤其是在施工初期,結(jié)
構(gòu)的剛度比成橋要低得多,使得顫振臨界風(fēng)速最低,更容易發(fā)散. 通過對(duì)主梁非對(duì)稱拼裝順序以及采用臨時(shí)的水
平交叉加勁措施等方法的研究,討論如何提高橋梁施工過程的顫振臨界風(fēng)速. 分析結(jié)果表明,當(dāng)主梁采用非對(duì)稱
施工時(shí),會(huì)有效提高結(jié)構(gòu)的等效質(zhì)量,從而提高臨界風(fēng)速. 當(dāng)采用水平交叉索時(shí),結(jié)構(gòu)的抗扭剛度顯著增加,同樣
增強(qiáng)了橋梁施工過程中的抗風(fēng)穩(wěn)定性.

With the increase of span ,aerodynamic stability becomes the most important factor in designing and
const ructing suspension bridges. Especially , during the const ruction period , the stiffness of st ructure is often
less than that of the final state. Thus the flutter critical wind speeds are much lower and the bridge is more un2
stable during this period. The solutions to improve the critical wind speed are int roduced by analysing the ef2
fect of non - symmet ric erecting deck sequence and the method of temporary horizontal cross - cables. Accord2
ing to the analysis ,the equivalent mass is increased by choosing the asymmet ric erecting sequence ,and the tor2
sion stiffness is increased by using the temporary horizontal cross cables ,both of them can improve the flutter
critical wind speeds.