Experimental Study of Buffeting Control of Pingtang Bridge during Construction

Abstract

This paper presents a control strategy that simultaneously reduces vertical and lateral buffeting responses during the construction of China's Pingtang Bridge, a multiple-span, composite, cable-stayed bridge with supertall concrete towers. The buffeting performance of the bridge and its suppression under the most extended double-cantilever state were investigated via a wind-tunnel test of a 1:225 scale aeroelastic model. The model's modal properties were checked before testing. The vertical and lateral displacements at the cantilever end of the longest double-cantilever state were measured; buffeting responses of the bridge deck reached the maximal values in the yaw-wind case at some mean wind speeds. The inclined wind-resistant cables (WRCs) on both sides of the cantilevered spans were designed considering the pretension and inclination degree. The combination of vertical WRCs and lateral tuned mass dampers was also considered as an alternative measure. Results show that both measures can effectively control both vertical and lateral deck buffeting, especially for the inclined WRCs, and the reduction ratio is larger at a low wind speed than that at a high wind speed due to the aerodynamic damping effect.