Wind loads analysis at the anchorages of the Talavera de la Reina cable stayed bridge

Introduction Cable stayed bridges are a feasible choice for middle length spans and can be also an alternative to suspension bridges in the range of 1000 m spans. In the last three years, cable stayed bridges having more than 1 km span have been built in China (Sutong Bridge, 1088 m and Stonecutters Bridge, 1018 km). The increasing in length implies higher aeroelastic interaction with wind action to be considered in the design stage. The present paper deals with the wind response of a cable stayed bridge, the Talavera de la Reina Bridge (Spain), by means of both sectional model and full bridge aeroelastic wind tunnel tests. Talavera de la Reina is a middle-size city in Central Spain. A new highway has been recently built by-passing the city at its Southern limit and a landmark cable-stayed bridge has been designed spanning the river Tagus. The bridge has a single span of 318 m which is supported by a single inclined pylon 164 m high. The pylon angle of inclination with respect to the vertical direction is 22 deg. Two planes of cables connect the deck and the pylon which is back-stayed by another two planes of cables. In Fig. 1 the general geometric definition of the bridge along with the deck cross-section can be perused. The deck is a multi-cell prestressed concrete box with overhangs at the sides for pedestrians. The total width of the deck is 36 mwhile the depth is 2.77 mwhich results in a width to depth ratio close to 13. The bridge enjoys a careful aesthetic design, adequate for structures located in urban areas. The particular design of the bridge makes it noteworthy and its wind response worth to be investigated in wind tunnel at design stage. Aims of the tests were the evaluation of the deck force coefficients and, by means of full bridge aeroelastic wind tunnel tests, the evaluation of the wind-structure interaction in terms of aeroelastic stability and analysis of the response to turbulent wind, as a function of the wind angle of exposure. Several authors already pointed out the importance of confirming sectional model tests results with full aeroelastic model tests. This is particularly true in the case of cable-stayed bridges,