Research on monitoring index of transverse cooperative working performance of assembled multi-girder bridges based on displacement spectrum similarity measure

The assembled multi-girder bridges (AMGBs) are widely constructed. Hinge joints are the most significant but vulnerable part of AMGBs. Therefore, condition assessment of hinge joints is the key point for health monitoring of AMGBs. To this end, displacement spectrum similarity measure (DSSM) is proposed as an index to characterize the health condition of hinge joints. Theoretical derivation shows that the index is subject to the stiffness of hinge joints and traffic loads. Because the index is a statistic over a period of time, short-term vehicle loads hardly affect the value of DSSM. Numerical simulation is further applied to demonstrate that the proposed index is sensitive to structural condition but insensitive to external loads. Therefore, DSSM is a good index that can exclusively characterize the hinge condition.