Effects of bridge deck gratings on the aerostatic responses of a long-span pedestrian suspension bridge with a SDBG

Abstract

As long-span pedestrian suspension bridges (LPSBs) have narrower decks and lower stiffness, there are significant aerostatic responses. However, there is no literature on how to design bridge deck gratings (BDGs) to mitigate the aerostatic responses of LPSBs. Therefore, in this study, taking a LPSB with a streamlined double-side box girder (SDBG) and BDGs as an example, the section models of the LPSB with different arrangements and percentages of opening (β) of BDGs were made. Then, the force-measured tests were carried out to measure the aerostatic force coefficients (AFCs) of all the section models, which were used to calculate the static wind loads of the LPSB with a SDBG. Furthermore, by applying the static wind loads to the SDBG, the effects of the arrangements and β of BDGs on the aerostatic responses of the LPSB with a SDBG were also studied. The results indicated that: (1) by using the BDGs with β ≥ 11%, the aerostatic responses and their fluctuations along the bridge axis can be significantly reduced, and β ≥ 33% is proposed for the design of BDGs, which has more significant effects on reducing the aerostatic response of the LPSB with a SDBG; (2) by using the BDGs arrangements of Cases O (the original cross-section of the SDBG, β = 66%) and S (two strips of BDGs, β = 11%–55%), the aerostatic responses can be significantly reduced, which are conducive to the LPSB with a SDBG.