FE model predicting the load carrying capacity of progressive FRP strengthening of masonry arches subjected to settlement damage

The retrofitting of masonry structures subject to differential foundation settlements is both an important and a highly challenging practice. Especially in the consideration of historical monuments, this challenge requires a strategic balance between providing the necessary modifications to ensure public safety while maintaining the integrity of the original structure. The use of strategically placed composite materials such as fiber reinforced polymers (FRPs) provides the potential to remove this dilemma and both preserve heritage while introducing a modern level of safety. This work studies, from an advanced FE point of view, a progressive reinforcement strategy to both strengthen and control the failure mechanism for masonry arches with an existing state of damage induced from a vertical differential abutment settlement. A heterogeneous FE approach of a semi-circular block and mortar arch on settled supports is examined. In this model a damage plasticity behavior is assigned to the mortar joints to allow for the hinge formations. Then utilizing the Italian CNR Recommendations for externally bonded FRP systems and the Abaqus birth and death approach, FRPs are introduced and strategically placed onto the settled support model after the initial hinge development. Finally, the structural behavior of the reinforced and unreinforced models are examined for an applied horizontal acceleration at a fixed support displacement.