Frictional load-transfer path reconstruction and instability mechanism of historic brick masonry walls under cyclic loading

Historical brick masonry pagoda walls are governed by interface cracking, opening–closure, sliding and residual friction under cyclic loading, but the role of damaged interfaces in sustaining load transfer after cohesive degradation remains unclear. This study develops an interface-resolved framework to reconstruct residual frictional load-transfer paths in such walls, using a specimen representative of the Small Wild Goose Pagoda as a benchmark. A meso-scale cohesive-frictional finite element model was validated against joint-dominated cracking, sliding deformation and lateral resistance degradation. Interface-level cohesive damage, contact pressure and tangential shear stress were then used to identify damaged but closed frictionally active interfaces and connect them as weighted contact networks. Four descriptors quantify frictional participation, transfer intensity, path connectivity and shear-transfer localization. The results indicate that damaged interfaces may continue transferring load through residual friction until progressive path fragmentation and localization contribute to post-peak instability.