Nonstructural elements (NEs) are generally defined as elements typically housed within buildings/facilities that are not part of the structural system. Nonstructural elements are often classified as architectural elements, mechanical/electrical/hydraulic systems, and building contents. Nonstructural elements are often associated with critical seismic risk, due to their high vulnerability and exposure to seismic actions, especially for critical facilities such as hospitals and nuclear plant facilities. Accordingly, the combination of major exposure and vulnerability makes NEs extremely critical in terms of seismic risk even for low to moderate seismicity. The paper reviews and evaluates the main international testing approaches and protocols for the seismic assessment of NEs by means of experimental methods, which are referred to for seismic qualification. Existing test protocols are technically analyzed considering quasi-static, single-floor dynamic, and multi-floor dynamic procedures, supplying technical and operative guidance for their implementation, according to the latest advances in the field. The study proposes novel perspectives and a unified approach for the seismic assessment and qualification of NEs. The technical recommendations lay the groundwork for a more robust and standardized testing and qualification framework. In particular, the provided data might represent the first step for developing code and regulation criteria for the experimental seismic assessment and qualification of NEs.

The seismic response of freestanding elements is typically extremely critical, and this is associated with a high seismic risk in the case of museum objects and artefacts. This paper reports the preliminary results of an experimental testing campaign aimed at assessing the dynamic properties and the seismic performance of museum objects and artefacts. Shake table tests of a typical museum display case containing a representative art object (vase) are performed. Both dynamic properties and seismic behavior of the specimens were assessed. Tentative damage assessment correlations are developed. The study sheds light on the critical behavior of the tested specimens, stressing the need for further studies towards a more comprehensive assessment of freestanding museum objects and artefacts.

Past earthquakes highlighted the vulnerability of cleanrooms, especially in earthquake-prone countries like Italy; the post-earthquake reconnaissance showed that damage to cleanrooms led to immeasurable economic losses. This study investigates the seismic performance of an innovative cleanroom, seismically designed and provided with innovative components. Full-scale shake table tests were performed on the cleanroom according to ICC-ES AC156 protocol; the cleanroom was tested under operating conditions. Both dynamic properties and seismic behavior of the specimen were assessed. The tests showed the excellent seismic behavior of the cleanroom, confirming that simple devices can significantly improve the seismic performance of nonstructural elements.

Starting from considerations on the high seismic vulnerability of nonstructural elements, and at the same time the scarce consideration of their performance at the different stages of the design and assessment process, this paper proposes a very simple and ready-to-use seismic classification scheme for nonstructural elements. The proposed approach is based on a limited set of information, which may take advantage of the availability of a numerical model of the building and its results, although it may also rely on code formulations and evaluations of seismic performance from the literature. The different seismic classes are assigned to nonstructural elements by quantifying their expected seismic performance by means of fragility curves. This classification may be applied to newly designed nonstructural elements to help identify the best typology for the site and building of interest, and also for existing nonstructural elements that are already installed in existing buildings. In the latter case, the classification may help in defining a prioritization scheme for interventions required to make nonstructural elements safer for the building of concern. The feasibility of the proposed procedure is demonstrated by its application to two case studies, referring to existing buildings located at different seismicity sites.