Effect of Cohesive Contact of Backfill with Arch and Spandrel Walls of a Historical Masonry Arch Bridge on Seismic Response

Historical masonry bridges generally consist of arches, spandrels walls, backfills, piers and foundations. Under the effects such as earthquake, flood and wind, the most vulnerable structural elements of bridges against out-of-plane seismic motions are spandrel walls. Increasing length and height of spandrel walls increases the vulnerability of the bridge under loads in vertical and transverse directions. The aim of this research is to examine the in-plane and out-of-plane non-linear structural responses of the spandrel walls of a historical masonry bridge. For this purpose, a historical masonry arch bridge with built in 1787 in Bartin-Turkey was chosen as the subject structure. The 3D finite element model and nonlinear seismic analyses of the bridge were performed with ABAQUS. Initially, the backfill-spandrels and backfill-arch interfaces of the bridge were modeled with and without cohesive contact. The non-linear material responses of the spandrel walls and the arch units were defined using Concrete Damage Plasticity material model and those of the backfill unit were defined with Mohr-Coulomb material model. The east-west component of 17 August 1999 Kocaeli Earthquake's acceleration records was used in the analyses. The east-west acceleration component was applied on the bridge in-plane and out-of-plane directions during the time-history non-linear seismic analysis of the bridge. The results obtained from the analyses with and without the consideration of cohesive contact were compared to evaluate the seismic responses of the spandrel walls. As a result, cohesive interface behavior was found to significantly affect the spandrel wall response under in-plane and out-of-plane seismic forces.