Analyzing the effect of workmanship quality on performance of unreinforced masonry walls through numerical methods

•The effect of workmanship quality (in terms of mortar cohesion) on wall’s lateral strength is greater in in-plane direction than out-of-plane direction.•The performance of a masonry wall under in-plane load is very sensitive to mortar joint cohesion. Even walls with good workmanship quality exhibited different failure mechanisms under the same loads.•The influence of workmanship quality on wall strength decreases in in-plane direction under combined loads.•The effect of workmanship quality on wall strength in the out-of-plane direction is increased under combined load.

The considerable effect of workmanship quality on the performance of masonry structures is well-known. In this study, a 3D nonlinear FE model was used to investigate the effect of workmanship quality on masonry wall strength under in-plane and out-of-plane loads. Mortar joint cohesion was utilized as a random variable to represent variation in workmanship quality. In-plane and out-of-plane displacements were applied to the wall, separately and simultaneously. Results indicate that mortar cohesion has a considerable effect on wall strength under in-plane loads. However, under combined loads, the influence of workmanship quality on wall strength decreases/increases for the in-plane/out-of-plane direction.