Experimental and numerical evaluation of school desks with earthquake life-saving function

This study presents a methodology for investigating the capacity of school desks to provide protection during earthquakes when failures of structural and non-structural components generate falling debris. The focus is on the performance of a recently presented school desk designed to protect pupils in case of seismic damage, a solution developed within interdisciplinary research projects addressing two main issues: the weakness of conventional school desks, and the impracticality and high cost of largely oversized seismic-proof desks. The featured school desk is composed of a dual steel frame, a perforated steel sheet combined with a plywood tabletop, and dissipative feet to absorb impact energy through plastic deformation. The design aims at providing resistance to vertical overloading without compromising practicality in everyday use, while limiting weight and cost increases. Following a previous testing campaign on an earlier prototype using falling brick assemblies as impact loads, a new comprehensive experimental programme featuring quasi‑static and impact tests was conducted on commercial reference desks, the earlier life‑saving prototypes, and newly developed life‑saving desk prototypes. Quasi‑static tests confirmed that, while all desks met current normative requirements, the standard testing procedures for school desks are inadequate for assessing their performance under falling debris. The developed impact testing protocol ensured consistent loading conditions and involved a 100‑kg steel sphere dropped on the desks’ tabletop. These impact tests demonstrated that reference desks are prone to brittle tabletop failure, whereas life‑saving prototypes can withstand severe impacts through ductile deformation and thus energy dissipation, protecting the space underneath and providing a safe shelter during earthquakes. Additional tests involving corner impacts, different dropping heights, and repeated impacts further confirmed the effectiveness of the proposed design. A detailed nonlinear finite element model of the refined prototype was developed and validated against both quasi-static and impact test results, accurately reproducing the observed behaviour. The model was afterwards used to verify that the considered loading configuration represented the most demanding case. The combination of experimental and numerical evidence supports the formulation of guidelines for standardised testing of the seismic performance of school furniture and highlights the potential of non-structural elements to reduce seismic risk in earthquake‑prone regions.