23. Performance-Based Assessment of Existing Buildings in Europe: Problems and Perspectives

It is by now well recognized that existing structures built before a proper knowledge of seismic hazard was acquired and according in most cases to inadequate seismic design provisions represent by far the major contributor to the total seismic risk. It is equally well known that guidance documents for the assessment of the seismic safety of these structures have lagged behind the development of documents for the seismic design of new structures. In Europe the reference document, Eurocode 8 Part 3 (CEN 2005) is only a few years old. The document is aligned with the recent trends regarding performance requirements and check of compliance in terms of displacements, providing also a degree of flexibility to cover the large variety of situations arising in practice. Nonetheless, in spite of the efforts made to make it rational and to introduce into it results from purposely made original research, the fact remains that EC8-3 could not enjoy at the time of release the support coming from a sufficiently long experience of use. Hence, it comes to no surprise that the widespread use ongoing in a few Countries is already providing suggestions for improvements. The contribution of the paper is two-fold. To provide an overview of the most relevant aspects dealt with in EC8-3, together with remarks coming from use. To indicate how the current state of progress of probabilistic assessment methods can provide today a feasible alternative that overcomes the problems identified in the deterministic codified procedure.