Analysis of long-span bridge fluctuations for finding its optimal safe operation

St. Petersburg State University of Architecture and Civil Engineering, Vtoraja Krasnoarmejskaja ul. 4, 190005 St. Petersburg, Russia

^* Corresponding author: esmirnovae@yandex.ru

Abstract

The paper studies the intense oscillations sustained by the Volgogradsky Bridge on May 20, 2010. The studies were carried out based on physical and mathematical experiments. The introduction indicates the causes of emergence of the intense aeroelastic oscillations. Description is given of the physical nature of one of the types of these oscillations, i.e. stall flutter. Catastrophes are considered that had been caused by the flutter. Methodological fundamentals of the experiment are named and modern software capabilities of computer-aided fluid and gas dynamics are listed. The results of the experiment are supplied, including visualization of the Karman vortex street and determination of the Strouhal number. The recalculation of the experimental data to natural conditions is substantiated. A description is given of calculation of the bridge’s aeroelastic oscillations. The main results of the aerodynamic calculation are supplied: the Strouhal numbers and critical velocities. The results of mathematical and physical experiments tallied well. A tally of the calculation and estimated full-scale results is pointed out. Results of this calculation (bridge oscillation amplitudes) are supplied. The conclusions point to the prospective viability of the mathematical experiment method. The proposed methods can minimize risks for the construction of long-span girder bridges, ensuring the precise estimation of their subsequent safe operation.