Interpretation of the Results of PsD Testing on a Full-Size RC Plan-Wise Irregular Building

In the framework of the research activity of the ELSA Laboratory of the Joint Research Centre, pseudo-dynamic testing of a real-size plan-wise irregular 3-storey frame structure, both in the ‘as-buit’ and in two retrofitted configurations, was carried out as the core of the research project SPEAR (Seismic PErformance Assessment and Rehabilitation of existing buildings). The experimental activity carried out on the SPEAR structure allowed a one-of-a-kind wealth of data to be collected, in a field where, until now, experimental validation of a long-lasting and lively debate in the earthquake engineering community has been vastly insufficient: that of the seismic behaviour of plan-wise irregular structures. Once in the post-test phase, it became clear that a good understanding of the complex features of the response of the specimen was difficult to be obtained, due to the effects of double eccentricities, adding up to poor structural detailing and lack of ductility. For this reason, it was decided to apply to the most significant collected data series the Karhunen-Loéve (K-L) (or principal component analysis) method. The method, applied to the analysis of the data collected in the test in the original and in the two different retrofitted configurations, allowed conclusions to be drawn on the relative effectiveness of the retrofitting strategies in affecting the seismic response and eventually in reducing the averse torsional effects in the response. Moreover, the energy dissipation patterns in the different configurations were analysed in modal perspective. The final aim of the paper is to put the obtained results in a performance-oriented perspective, in the framework of the currently open discussion on the parameters of election to be taken into account in the design or assessment phase in order for the engineer to correctly predict or originate the desired behaviour in the presence of plan irregularity inducing twisting effects.

MOLA Elena;  NEGRO Paolo; 

2010-01-22

EAEE & ESC

JRC33353

https://publications.jrc.ec.europa.eu/repository/handle/JRC33353,