Experimental study on flutter stability of a long-span bridge subject to wind-rain actions

• 作 者: XIN DaBo LI Hui OU JinPing WANG Liang CHEN DongYing
• 机 构: School of Civil Engineering,Harbin Institute of Technology,School of Civil & Hydraulic Engineering,D
• 出 处: Science China(Technological Sciences)
• 发表日期: 2013年08期
• 关键词: rainfall simultaneous tunnel inhomogeneous bridges extracting specimen separated

Based on the free vibration test method for extracting flutter derivatives,an experiment on flutter stability of a long-span bridge under simultaneous actions of wind and rain was carried out in a wind tunnel.A separated twin-box girder section model was employed as the specimen.The flutter derivatives and critical flutter wind speed of this girder subject to both wind and rain(with various rainfall intensities,wind speeds and attack angles)were obtained,then the flutter stability of the bridge influenced by rainfall was analyzed.Experimental results showed that the flutter derivatives of this bridge depend on the angles of attack of wind flow in the wind and rain fields.Also,rainfall has great effect on three flutter derivatives(H2*,H4* and A4*)and has less effect on other three flutter derivatives(H1*,H3* and A3*).With the increasing rainfall density,the critical flutter velocity first increases and then decreases.Low density of rainfall has the effect of increasing mass,stiffness and damping on bridge decks,and higher density of rainfall has the effect of random inhomogeneous impact on bridge decks.

Based on the free vibration test method for extracting flutter derivatives, an experiment on flutter stability of a long-span bridge under simultaneous actions of wind and rain was carried out in a wind tunnel. A separated twin-box girder section model was employed as the specimen. The flutter derivatives and critical flutter wind speed of this girder subject to both wind and rain (with various rainfall intensities, wind speeds and attack angles) were obtained, then the flutter stability of the bridge influenced by rainfall. that the flutter derivatives of this bridge depend on the angles of attack of wind flow in the wind and rain fields. Als, rainfall has great effect on three flutter derivatives (H2 *, H4 * and A4 *) and has less effect on other three flutter derivatives (H1 *, H3 * and A3 *). With the increasing rainfall density, the critical flutter velocity first increases and then decreases. Low density of rainfall has the effect of increasing mass, stiffness an d damping on bridge decks, and higher density of rainfall has the effect of random inhomogeneous impact on bridge decks.