Mechanical performance analysis of long-span continuous rigid-frame bridge

Owing to the coupling effects of various factors such as environmental conditions, vehicle loads and climate conditions, long-span continuous rigid bridges in service will experience significant continuous downward deflection. To effectively and accurately understand the structural deformation characteristics under specific service conditions, more exacting requirements have been put forward for the vertical deformation testing technology of long-span continuous rigid bridges. Non-contact video imaging has the characteristics of high efficiency, high precision, portability, adjustable frequency, low investment in personnel and short time, and has been gradually applied in bridge deformation detection. Taking a long-span continuous rigid bridge as the test sample, the non-contact and level displacement testing technology is used to obtain the vertical displacement of the main span by static load testing. The deflection curves of the main span of the bridge under controlled load conditions are extracted and compared. The deflection curves demonstrate a strong correlation between the non-contact testing technique for structural displacement and level measurement. The overall and local stiffness characteristics of the bridge structure are also analysed. The results indicate that the structural integrity is optimal, and the macroscopic stiffness on the symmetrical sides of the main span is consistent.