Improving Seismic Vulnearability Assessment using Field Testing Data

Seismic vulnerability of existing structures is difficult to assess, due to the low knowledge of degradation phenomena and consequently the difficulty in predicting the real conditions of the structure. On the other hand, this assessment is an urgent necessity for structures designed before the introduction of technical standards for seismic design. In order to deal with the low knowledge of the real-time condition of existing structures, field testing data could be used. This paper shows that the use of this data to update the structure model is a good strategy to improve its seismic vulnerability assessment. A simple and complete procedure to assess the seismic vulnerability of existing structures is proposed in this paper. This procedure includes also the improvement of the structure model through field testing data. The procedure is applied to a case study. The seismic vulnerability of a unreinforced masonry building sited in Vienna is assessed. The numerical model of the building is improved by means of modal characteristics identified from forced field testing data. So the improved model is assumed to be deterministically known and the load-damage behaviour of the building perfectly described. Then a stochastic seismic scenario is defined. Finally, it is used to estimate the fragility curves for different damage levels of the building.