Experimental Investigation of Effect of Windshield Barriers on the Aerodynamic Properties of the Multi-box Bridge Decks

Abstract

With the development of aerodynamic investigation methods, long-span bridge projects gradually became more open to adopt challenging geometric optimizations and countermeasure implementations. Thus the bridge girder decks improved as well, changing from the compact box-deck girders shapes, to twin-box and multi-box deck sections. The objectives of the current research are first to experimentally investigate the aerodynamic properties of a new type of bridge deck with multiple-decks consisting of two side decks for traffic lanes and two middle decks for railway traffic. Secondly, the aerodynamic effect of the windshield barriers with two different heights (30 mm and 50 mm) was experimentally analyzed for the multiple-deck bridge deck model. Finally, the Iterative Least Squares (ILS) method was used for extracting the eight flutter derivatives of this new type of deck section model. Furthermore, a detailed comparison of the aerodynamic characteristics between the current research model and other types of box girder bridges was carried out for identifying the similarities and discrepancies in the overall aerodynamic performance of the bridge deck. A wind tunnel facility was used for testing the force coefficients and the flutter derivatives for the multi-box deck model for wind speeds in the range of 0.8 m/s to 11.0 m/s. In total, 301 test cases for 7 different attack angles (±6°, ±4°, ±2°, 0°) and two different windshield heights (30 mm and 50 mm) were carried out, as part of this research.