Study the Influence of Cable Breakage on Wind-Induced Vibration Characteristics of the Curved Beam Unilateral Stayed Bridge

Abstract

Existing studies have found that curved beam unilateral stayed bridges (CBUSB) have a risk of cable breakage under the design wind velocity. To ensure structural wind-induced vibration security, it is necessary to study the wind-induced vibration characteristics of CBUSBs considering the influence of the impact load due to the cable breakage. Based on the aerodynamic coefficients determined by a wind tunnel test and the established impact load model, parametric analyses of important CBUSBs’ characteristics (beam curvature and cable arrangement scheme) and the location of the cable breakage are carried out to assess the influence of cable breakage on the time-domain statistical values and frequency-domain distribution characteristics of wind-induced vibration response. The DAF, considering the influence of cable breakages on the wind-induced vibration peak value of CBUSBs, is proposed through dynamic analysis. Study results show that, with increasing curvature, under the two-modes action of wind loads and impact loads, the fluctuation component of the CBUSB is changed, resulting in a smaller proportion of resonant response. For CBUSBs with unilateral or bilateral cable arrangements, their wind-induced vibration behavior is significantly different. The former have dynamic characteristics and the latter have quasi-static characteristics. The breakage of the shortest cable at 7/33 to 7/22 of the curved beam length and its symmetry part significantly increases the wind-induced peak response of CBUSBs. The DAF recommended values can consider the amplification effect of wind-induced vibration due to the cable breakage.