Acoustic emission monitoring of strengthened steel bridges: Inferring the mechanical behavior of post-installed shear connectors

摘要

This study proposes an acoustic emission (AE) monitoring approach for old steel bridges strengthened with postinstalledshear connectors. In this strengthening method, cyclic traffic loads gradually fatigue the connectors andincrease the bridge deflection at which the connectors engage in shear transfer. The key parameter that this study aims toestimate is how much the connectors need to slide before they engage in shear transfer. To estimate this parameter, thispaper leverages the difference in AEs from shear connectors before and after they engage in shear transfer. Specifically,the b-value of AEs a k-mean clustering approach are used. To validate this novel approach, a full-scale, two-span steelgirder with a concrete deck was used. The girder was strengthened with post-installed shear connectors and subjected to20 cycles of sequential loads representing moving trucks. The results confirmed the effectiveness of the approach basedon AE during the unloading of the girder.