An overview of the current code provisions on the seismic response of acceleration-sensitive non-structural components in buildings

The seismic response of non-structural components in civil and industrial buildings, often neglected or disregarded in the common design/assessment practice, revealed its dramatic relevance in recent seismic events that resulted in significant damage observed in the wide class of “objects” referred to as “non-structural components” (e.g., partitions, masonry infill, suspended ceilings, finishing, specific equipment and so on. The observed damage, sometimes leading to collapse of these components and even loss of human lives, highlighted the lack of knowledge that still affects both analysis procedures and design/assessment methods currently adopted for analysing their seismic response. This paper is mainly intended at providing readers with an overview of both the historical development and the current state of the formulations adopted by codes and standards for evaluating the maximum accelerations induced by seismic shakings on non-structural components. The difference among these formulations is firstly outlined and the predictions based on the most up-to-date codes are compared with the results of a wide parametric analysis based on a 2DOF system, intended at simulating the coupled response of both main structure and non-structural component. This parametric comparison shows that the current formulations are not fully capable of reproducing the effect of the interaction between main structure and non-structural components.