An investigation of seismic response of connections in precast concrete double-tees /

Abstract

An experimental study of typical connections commonly used in precast concrete buildings subjected to reversed cyclic loads is presented, along with an analytical study of nonlinear behaviour of these specimens subjected to monotonically increasing loads until failure.Five different connection specimens were constructed and tested under reversed cyclic loading to determine their seismic responses. The specimens represent a series of horizontal connections between double-tee flanges or between a double-tee flange and lateral load resisting element in a typical roof of a precast concrete structure.The analytical study consisted of two parts: linear finite element analysis of the connection to determine the test specimen geometry and to define its boundary conditions, and non-linear finite element analysis, using the NONLACS program, to predict the complete responses of the connections subjected to monotonically increasing loads.The experimental results were compared with the predictions made using theoretical calculations, the CPCI design method and non-linear finite element analysis.It is noted that the CPCI design method gives conservative predictions for the ultimate strength of the connection reinforced with a bent deformed bar anchor and a 90$sp circ$ hook, and the one with two deformed bars oriented at 45$sp circ$ and headed studs, both welded to a steel plate. The predicted ultimate strength of the connection with a bent deformed bar anchor welded to a steel plate and one with two straight deformed bar, oriented at 90$sp circ$ and welded to an embedded steel angle, are close to the experimental results. The ultimate strength of the connection wit the headed studs welded to a steel plate predicted by CPCI method is overestimated. Design guidelines to increase the strength of the connections and to improve the displacement ductility are presented