不同规范斜拉索风荷载计算方法对比研究

A Comparative Study on Calculation Methods of Stay Cable Wind Loads in Chinese and Japanese Specifications and ESDU

为深入了解斜拉桥斜拉索的风荷载计算方法以提高斜拉索风荷载计算精度,对中国规范、日本规范和ESDU中斜拉索风荷载计算方法进行对比。在此基础上,以苏通长江公路大桥为背景,计算单个索面A1~A34斜拉索的横、顺桥向风荷载,定量分析不同规范斜拉索风荷载计算结果差异。结果表明:对于阻力系数,ESDU考虑因素更全面;对于动力放大系数,日本规范比中国规范更精细;斜拉索的顺桥向阻力小于横桥向阻力,但不同规范两者之间的比例不同;不考虑动力放大作用时,对于单索面横桥向阻力,ESDU<日本规范<中国规范,考虑动力放大作用时,中国规范<日本规范;对于单索面顺桥向阻力,中国规范最大。整体而言,关于斜拉索风荷载的计算结果,中国规范和日本规范比ESDU更偏保守。

The methods to calculate wind loads of stay cables in different specifications are compared,specifically the Chinese specification(Wind-resistant Design Specification for Highway Bridges,JTG/T 3360-01-2018),Japanese specification(Wind Resistance Design Benchmark of Shikoku Contact Bridge in Hongshu)and the ESDU(Engineering Sciences Data Unit),aiming to improve the calculation accuracy.The study case is the Sutong Changjiang River Highway Bridge.The transverse and longitudinal wind loads of stay cables A1-A34 in one cable plane of the bridge were calculated by the methods suggested in these specifications,and the differences of the calculated wind loads were quantitatively analyzed.It is shown that ESDU considers fully the impact of drag coefficient,the Japanese specification specifies more detailed dynamic amplification factors than the Chinese specification,and the drags of the stay cables in the longitudinal direction are smaller than in the transverse direction,but the ratios of the two given by the three specifications are different.When the dynamic amplification effect is not considered,the transverse drags of stay cables in a single cable plane weaken from ESDU to Japanese specification and then to Chinese specification,however,when the dynamic amplification effect is taken into account,the transverse drags of stay cables in the Chinese specification are smaller than those in the Japanese specification.The Chinese specification gives the biggest transverse drags of stay cables in a single cable plane.In general,the wind loads of stay cables calculated by the methods given in the Chinese and Japanese specifications are relatively conservative.