NUMERICAL INVESTIGATION OF DISSIPATIVE BEHAVIOR OF CONNECTION USING POST-INSTALLED ANCHORS

Steel to concrete connections using post-installed anchors are nowadays used in seismic-prone countries worldwide. In the case of structures where steel to concrete connections link primarily members (e.g. resistant to seismic loads) or they are used for seismic retrofit, some questions may arise:(a) what is the stiffness of the structure; (b) what is q factor in case of new building (essential in commonly adopted design with response spectra). A lack of knowledge is recognized in the contribution of the connection to the seismic performance at whole structural level. Ductile behavior and hysteretic energy dissipation of the connection become fundamental aspects to be investigated complying with capacity design approach, namely to ensure local dissipation (plastic hinges) preserving the structure as a whole. The present paper addresses the problem of column-to-foundation connection using bonded anchors with stretch length, subjected to seismic loads. Numerical models, using simple beam elements with lumped plasticity, are calibrated starting from experimental results on the sub-structure namely (i) steel column, (ii) steel base plate; (iii) anchors. Changes in anchors’ non-linear behavior are investigated. An application to one-story frame subjected to seismic artificial accelerograms is then presented.