Seismic Response of a Half-Scale Masonry Building with Flexible Diaphragms

摘要

Unreinforced masonry (URM) buildings constructed on Army installations before the development of modern seismic codes may be susceptible to earthquake damage and therefore could benefit from seismic mitigation measures. Improved understanding of URM structural response under multidirectional loads is required to develop the most effective seismic structural retrofit strategies. This research used a half-scale structural model to investigate the seismic response of URM buildings with flexible diaphragms. The objectives were to determine failure mechanisms and deformation behaviors; examine amplification of ground motion acceleration by walls and diaphragms; approximate any strength effects that flange portions of out-of- plane walls may have on in-plane walls; investigate vertical distribution of lateral forces; and identify any combinational effects of multidirectional base motions. An unexpected level of out-of-plane wall flange contribution to in- plane wall strength indicates the need for experimental quantification using different pier layouts, URM wall combinations, and wall connection methods. Results also indicate the need to investigate the effect of overturning forces on the in-plane strength of piers and to determine critical ground motion characteristics that lead to the direct combination of response quantities due to orthogonal earthquake components.