Seismic response distribution expressions for rocking building contents under ordinary ground motions

Citation

Kazantzi, A.K., Lachanas, C.G., Vamvatsikos, D. (2022). Seismic response distribution expressions for rocking building contents under ordinary ground motions. Bulletin of Earthquake Engineering, 20, 6659 to 6682.

Read the full article via DOI ›
https://doi.org/10.1007/s10518-022-01424-w

Summary

Much of what disruption actually looks like inside a building during an earthquake is not structural collapse but the overturning of the free standing contents a business depends on: server racks, laboratory and medical equipment, storage and process units. This paper proposes analytical expressions for predicting the rocking response of rigid, free standing building contents subjected to seismic induced floor excitations. The study spans a wide range of rigid block geometries and uses floor acceleration histories recorded during actual earthquakes in instrumented Californian buildings, so the results cover, in a fully probabilistic way, the whole spectrum of rocking behaviour from the onset of rocking to overturning. A notable finding is that, unlike anchored contents, the response of free standing blocks is not governed by the predominant period of the supporting structure. The resulting equations let engineers estimate response statistics and carry out an analytical seismic fragility assessment of building contents without bespoke simulation for every case. For resilience planning, this is directly useful: it puts numbers on the failure of the equipment whose loss most often drives downtime, informing both protection measures and realistic recovery objectives.

About this research

This work forms part of Resilience Guard's contribution to European research, where the firm's consultants develop and test methods in Horizon 2020 and Horizon Europe consortia and apply them in client engagements. See the research portfolio for the projects behind the publications, and the case studies for the practice they inform.