Seismic assessment of existing precast industrial buildings using static and dynamic non linear analyses

Protection of existing constructions against natural hazards and in particular earthquakes is a relevant problem nowadays, since enlargement of seismic zones occurred in many European countries. As a consequence, a large number of constructions built without specific seismic provisions is characterized by relevant levels of structural risk. Quantitative evaluations of such risk is certainly of interest also for industrial buildings, that in many very urbanized areas are frequently subjected to extended and expensive interventions and changes of functional destinations. In this framework, a research study on industrial existing precast structures built in Italy between the 1950s and the 1970s appeared to be significant. Therefore, a large effort has been devoted to identify structural types, details and materials commonly adopted during the reference period. Then, attention has been paid to seismic vulnerability issues derived from nonlinear and dynamic analyses. Specific reference is made to elastic analyses under design forces with an evaluation of the relevance of the second order effects, to nonlinear static analyses by N2 method, also taking into account the vertical seismic component effects and to nonlinear dynamic analyses forcing the structure by all the three components of the earthquake. The presented research study shows that existing industrial precast buildings can be affected by severe damages under medium intensity seismic forces because of beam–column connection failure.