Mechanical state inversion method for structural performance evaluation of existing suspension bridges using 3D laser scanning.

The abnormal mechanicalstate will cause the structural performance degradation of a suspension bridge. This paper presents a mechanical state inversion method for suspension bridges based on the measured intersection points of main cables using 3D laser scanning. First, based on the catenary, the mathematical model between the suspender force and the measured intersection points coordinates is established, and an accurate calculation method of suspender force is proposed. Then, an accurate calculation method for the internal force of suspension bridge components with abnormal suspender force is proposed to evaluate the structural performance. Numerical experiments show that the proposed method is accurate in theory. Finally, 3D laser scanning is used to capture the shape of the main cable, and an automated algorithm is developed to calculate the intersection point of the main cables precisely. The accuracy and reliability of the proposed method have been verified on a completed suspension bridge with a span of 808 m. [ABSTRACT FROM AUTHOR]