Cost/performance evaluation of traditional and low-damage structural & non-structural building configurations

The current seismic design inherently accepts high post-earthquake damages to both structural and non-structural components and very high post-earthquake economic losses are expected. Therefore, in the last decades research moved towards a damage-control concept to develop innovative systems for building elements with high seismic performance and low post-earthquake damage, thus resulting into reduced repair costs and business interruption. These low-damage solutions have been numerically and experimentally studied in terms of seismic behavior, but a cost/performance-based evaluation is needed to provide the decision makers with more substantial evidences on the benefits of these technologies. This paper investigates the convenience of implementing innovative structural and non-structural solutions through cost/performance evaluations of multi-storeys reinforced concrete buildings designed for low and high seismicity. Alternative damage-resistant solutions are considered: 1) a low-damage structural skeleton with traditional non-structural elements; 2) a monolithic (cast-in-situ) building with low-damage non-structural components; 3) an integrated structural/non-structural low-damage system. Different exterior enclosures (claddings, infill walls, curtain walls) and internal elements (partitions, ceilings, building contents) are also introduced. The seismic performance at different levels of seismic intensity is numerically investigated using Ruaumoko 2D and performing non-linear static analyses and an ADRS (Acceleration-Response Spectrum) approach, while loss assessment analyses are carried out, following the FEMA P-58 methodology. The loss assessment results provide evidences on the benefits of the low-damage solutions, expecially for the integrated low-damage system that reduces the expected annual losses by 50-80% for both high and low seismicity conditions. Notwithstanding the benefits in the use of damage-resistant structural members, low-damage non-structural elements produce a considerable reduction of repair costs and downtime, especially for heavy infill walls for the condition of low-seismicity design (i.e. direct savings of about 220 €/m2 in a 50-years building life, in addition to a dowtime reduction of about 8 months under the design level earthquake - ULS seismic intensity).