To reduce the risk of early wood split failure at a timber connection, the application of selftapping
screws was introduced as a reinforcement technique in this study. A lap-joined connection
which was assembled using Japanese cedar structural glulam beam and column members was used
to investigate the effect of reinforcement with self-tapping screws on the shear resistance capacity
of the connections. Results showed that the maximum shear resistance capacities of connections
reinforced with 1 or 2 pairs of self-tapping screws were 2.21- and 2.35-fold, respectively, that of
an unreinforced connection. Ductility ratios of 5.70~9.88 were obtained for retrofitted and prereinforced
connections to change the brittle behavior of an unreinforced connection. Adequate
ductility was found in lapped connections which were retrofitted or pre-reinforced using 2 pairs
of self-tapping screws. The shear resistance performance of the retrofitted connections using selftapping
screws showed similar effects to those of pre-reinforced connections. Energy dissipation
tremendously increased from 35.73 to 1923.2 kN·mm as the connections were pre-reinforced or
further retrofitted with self-tapping screws in the direction perpendicular to the wood grain. Higher
characteristic values and allowable shear capacities of lapped connections were obtained through
the use of self-tapping screws to effectively control wood splitting and hence reduce variations in
the shearing resistance of the connections.