Seismic retrofit of reinforced concrete buildings designed for gravity loads: Performance of structural model

A partially prestressed concrete alternative and two masonry retrofit alternatives are analyzed for improving the local and global response performance of reinforced concrete frame structures designed only for gravity loads and constructed in low-to-moderate seismic zones. The objective of these retrofits is to reconfigure the structural failure mode by averting a catastrophic soft-stop collapse and enforcing a more ductile beam side-sway mechanism. A prestressed concrete jacketing alternative to limited columns was selected to retrofit the one-third scale model RC frame building that had been previously tested by Bracci, Reinhorn, and Mander. The seismic response of the retrofit model structure was investigated experimentally using the `shaking table' at SUNY at Buffalo. A comparison is made of the experimental frame response before and after retrofitting. It is concluded that the seismic performance of vulnerable (soft-story prone) GLD frames may be effectively enhanced by strengthening limited columns and thus, changing the failure mode to a beam sidesway mechanism with acceptable story deformation levels.

Seismic retrofit of reinforced concrete buildings designed for gravity loads: Performance of structural model Academic Article