Seismic Retrofit with a New Type of Buckling Restrained Brace

This paper presents an effective practical application of a new type of Buckling-Restrained Brace, which has been developed using steel mortar planks. Through its application as retrofit to school gymnasia, a discussion is given based on elasto-plastic earthquake response analysis how the seismic capacities are upgraded against severe earthquakes. First, the outline of the BRB and an example of school gymnasium retrofitted with BRB are introduced, then followed by discussions on seismic capacities of school gymnasia retrofitted with BRB in the longitudinal direction, not gable direction, based on elasto-plastic earthquake response analysis. Finally, the effectiveness is proved by showing that responses can be reduced on account of retrofitting by the BRB, and its bearing earthquake intensity after retrofit is upgraded to 1.7 times ore more of original structure by adding the BRB of only quarter strength of existing braces.