Second-order effects in URM walls subjected to compression and out-of-plane bending: From numerical evaluation to proposal of design procedures

•Evaluation of second-order effects for URM walls mainly subjected to compression.•Assessment of URM walls subjected to combined vertical and relevant lateral loading.•Refinement of strength verification based on axial load capacity reduction factor, ϕm.•Refinement of strength verification based on moment capacity reduction factor, ϕM.•Demonstration of one-to-one correspondence between the two reduction factors, ϕ.