As it is well known in literature, infills modify the behaviour of framed structures under lateral loads. Nevertheless, infills are generally neglected in structural analysis, and this, in many cases, may lead to unreliable evaluations of structural response. Although several theoretical and experimental researches express the necessity to take into account the infills, today reliable models of infilled structures do not exist, due to the difficult interpretation of experimental results. The aim of the proposed approach is to evaluate the effect of infills in the global and local response of a building under earthquake loads, identifying the most significant parameters that influence its behaviour. In this paper a convenient tool for the evaluation of the effects of the infills is suggested, in order to reach acceptable results in global and local analyses. The attention is focused on the most used typology in Italy: reinforced concrete structures infilled with masonry panels, realized in contact with the frame after its hardening and without connectors nor joints.
telai tamponati
Influenza delle Tamponature sulla statica dei telai in c.a. in zona sismica
This paper describes a model able to evaluate the effect of masonry panels on reinforced concrete frames subjected to a seismic action. The panel is modelled as an equivalent diagonal element with a bilinear constitutive relation. The efficacy of the model is verified with an hysteretic model which considers some fundamental characteristics of masonry subjected to a seismic action (transitory phase between elastic and elasto-plastic behaviour, stiffness and strength decay, reduction of the hysteresis cycles due to the opening and closing of the cracks). This study shows that the presence of masonry panels causes a different distribution of the seismic action that usually concentrates in the lower floors (with accumulation of the damage in these levels) and the whole structure keeps in the elastic field.
This paper is available in Italian only.