ABSTRACT
Due to the dynamic fluctuations caused by vehicle-bridge interaction and road roughness, the influence line (IL) cannot be obtained directly from bridge responses. This paper proposes a rapid method for identifying bridge IL using bridge dynamic responses. Initially, analytical solutions for the IL of a simply supported bridge are presented. To address dynamic fluctuations, empirical mode decomposition is utilized to decompose bridge responses into intrinsic mode functions to approximate quasi-static response. Subsequently, the equations based on residual bridge responses induced by forward and reverse passages, which can automatically remove the scale error of IMFs, are introduced to calculate the bridge’s IL at discrete points. Furthermore, cubic spline interpolation, with boundary conditions, is used to obtain the complete IL. Numerical simulations, incorporating a two-axle vehicle and a simply supported bridge, are conducted to verify the effectiveness of the proposed method. Results show a close match between identified IL and analytical results.
