In view of the limitation of the code in taking the value of the double-deck girder drag force coefficient for large-span truss bridges, a method of calculating the drag force coefficient of the girder is proposed. Based on the wind tunnel test results of the bridge’s construction phase segmental model, its aerostatic coefficients were calculated using CFD after simplifying the model of the double-deck truss girder. The effect of characteristic size on the drag force coefficient of the girder was analyzed using different windward face characteristic sizes, the number of truss bays, and the truss spacing. The influence trend of different truss spacing and number of bays on the drag force coefficient of the girder is discussed. The results show that the characteristic height and characteristic width of the windward face have different effects on the drag force coefficient of the girder. Therefore, the fitting formula of the drag force coefficient of the girder of a double-deck truss is proposed, which takes the longitudinal height ratio of the truss as the variable. When the truss spacing is small, the number of trusses has no effect on the drag force coefficient of the girder. However, when the ratio of truss spacing to truss height reaches 3, the change in the number of trusses has a considerable impact on the drag force coefficient of the girder.
LIJ W, GUANQ H, ZHAOG H,et al .Wind tunnel test of aerostatic drag shielding factor of a typical truss bridge girder section[J].Journal of Highway and Transportation Research and Development,2014,31(7):80-83.(in Chinese)
LIJ W, HUOW X, ZHANGY, et al .Study of vortex-induced vibration performance and three-component coefficients change of cable-stayed bridge with double deck type Π girder[J].Highway, 2020, 65(9): 78-83.(in Chinese)
CHENY R, CAOZ, LIUZ W, et al .A study on pedestrian level wind environment and wind-resistance performances of a steel truss footbridge[J]. Journal of Vibration and Shock, 2019, 38(16): 274-280.(in Chinese)
ZHAIX L, ZHUQ, QIANC, et al. Study on wind-resistance performance of steel truss girder suspension bridges in mountainous canyon[J]. Journal of Highway and Transportation Research and Development, 2020, 37(11): 56-62.(in Chinese)
[12]
FANGC, HUR J, TANGH J, et al. Experimental and numerical study on vortex-induced vibration of a truss girder with two decks[J]. Advances in Structural Engineering,2021,24(5):841-855.
[13]
CHENZ S, LIUS M, YUX F,et al. Experimental investigations on VIV of bridge deck sections:a case study[J]. KSCE Journal of Civil Engineering, 2017, 21(7): 2821-2827.
[14]
LIY L, TANGH J, WUB,et al. Flutter performance optimization of steel truss girder with double-decks by wind tunnel tests[J].Advances in Structural Engineering, 2018, 21(6): 906-917.
[15]
BAIH, JIN, XUG, et al. An alternative aerodynamic mitigation measure for improving bridge flutter and vortex induced vibration (VIV) stability:sealed traffic barrier[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2020, 206: 104302.
[16]
ZHUL D, TANX A, GUOZ S,et al .Effects of central stabilizing barriers on flutter performances of a suspension bridge with a truss-stiffened deck under skew winds[J]. Advances in Structural Engineering, 2018, 22(1): 17-29.
ZHANGR L, YANGH B, LIUZ W, et al .Segmental model tests for post flutter characteristics of truss-stiffening girder suspension bridge[J]. Journal of Vibration and Shock, 2022, 41(5):1-8.(in Chinese)
GUOW W, CAIB S, LOUY F,et al .Wind tunnel test on tri-component force coefficients of the train-bridge system for a long-span rail-cum-road cable-stayed truss bridge[J].Engineering Mechanics, 2021, 38(3): 192-201.(in Chinese)
[21]
TANGH J, LIY L, SHUMK M,et al .Non-uniform wind characteristics in mountainous areas and effects on flutter performance of a long-span suspension bridge[J].Journal of Wind Engineering and Industrial Aerodynamics,2020,201:104177.
[22]
TANGH J, LIY L, WANGY F,et al .Aerodynamic optimization for flutter performance of steel truss stiffening girder at large angles of attack[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2017, 168: 260-270.
[23]
TANGH J, SHUMK M, TAOQ Y,et al. Vortex-induced vibration of a truss girder with high vertical stabilizers[J]. Advances in Structural Engineering, 2018, 22(4): 948-959.
[24]
GUOJ J, TANGH J, LIY L, et al .Optimization for vertical stabilizers on flutter stability of streamlined box girders with mountainous environment[J]. Advances in Structural Engineering,2020, 23(2): 205-218.
ZOUM W, ZHENGS X, TANGY,et al. Study on aerodynamic parameters of inverted trapezoid section of truss bridge[J].Railway Standard Design, 2018, 62(3): 53-57.(in Chinese)
LIUH S, LEIJ Q. Identification of three-component coefficients of double deck truss girder for long-span bridge[J]. Journal of Zhejiang University (Engineering Science), 2019, 53(6): 1092-1100.(in Chinese)
[29]
HEX H, WANGQ A, ZHANGC L,et al .Research on a flutter stability control measure of a fabricated steel truss bridge[J].Transactions of the Canadian Society for Mechanical Engineering,2017, 41(2): 181-195.
HANY, CHENH, HUP, et al. Research on correction of streamlined bridge section drag coefficient measured by pressure measurement based on CFD[J]. Journal of Railway Science and Engineering, 2016, 13(1): 96-102.(in Chinese)
[32]
葛耀君. 桥梁风洞试验指南[M]. 北京:人民交通出版社, 2018.
[33]
GEY J. Guidelines for wind tunnel testing of bridges[M]. Beijing: China Communications Press, 2018. (in Chinese)