A ROCKING SPINE FOR ENHANCED SEISMIC PERFORMANCE OF REINFORCED CONCRETE FRAME BUILDINGS WITH INFILLS

This research aims to develop a novel approach to improving collapse safety in reinforced concrete frames with infills through the use of strong, stiff structural spines that resist earthquakes through rocking action. The rocking spines can be constructed as slender, stout infill frames or reinforced concrete walls with shallow foundations. The use of rocking action as the primary yielding mechanism significantly reduces the required level of detailing that is needed to achieve ductility in concrete frames, resulting in significant material cost savings. The system relies on gravity and the restraint provided by structural members connected to the spine as the primary sources of overturning resistance. These include the beam elements framing into the spine as well as infill panels constructed in the adjacent bays on either side of the spine. The goal of this study is to characterize the behavior of the rocking spine system and demonstrate its effectiveness in improving collapse performance. The behavior of the rocking spine system is idealized using a system backbone curve that illustrates the effect of the various sources of overturning resistance and yielding mechanisms. Non-linear analysis models are developed and analyzed in OpenSees to evaluate its ability to improve seismic performance.