Wind Shielding on Long Span Bridges

Long span bridges are often located in exposed areas subject to strong winds. In recent years the advantages of installing wind shields to protect traffic on such bridges have been recognised, and now there are many examples. Generally there are two types of wind shields - continuous ones along the deck edges, and those which smooth out changes in air flow locally around towers. The incorporation of wind shields results in higher design loads and a cost premium - not just the components themselves, but the effect they have on the overall structure. For new bridges, these effects can be designed for and a suitable balance found between performance and cost. Retrofit of existing bridges with the addition of wind shields to improve traffic safety is often compromised by the changes in structural and aerodynamic behaviour that they would induce, and usually only limited measures are possible. This paper will present the studies carried out for a long span cable stayed bridge to determine the most suitable performance criteria for wind shielding and verify performance.