Field testing of unreinforced masonry wall-to-diaphragm connection via through-bolt plate anchors and timber blocking

The ability of timber diaphragms to transfer seismic loads to masonry loadbearing walls significantly influences the global earthquake behaviour of unreinforced masonry (URM) buildings. Wall-to-diaphragm connection via through-bolt external plate anchors is one common technique adopted to facilitate the load transfer between horizontal and vertical members. Further to the presence of effective wall-to-diaphragm connections, it is necessary to ensure the load-path continuity by guaranteeing the ability of internal timber blockings and timber-to-timber connections to transfer the loads. Limited experimental research has been undertaken into this system despite it often being adopted. The experimental study reported herein was undertaken on two existing buildings and consisted of two phases: (i) testing 8 original vintage plate anchor connections by loading the timber joist in tension, and (ii) testing 6 timber blockings each with different arrangements of blocking and of timber-to-timber connection. Attained failure modes and results are presented herein.