EXAMPLE 6. BUILDING VALUATION & REDESIGN STUDY

EXAMPLE 6: "STUDY FOR THE VALUATION AND REDESIGN OF A BUILDING ACCORDING TO THE CANC. 7 • αg,ref is the horizontal ground acceleration reference, defined with a 10% probability of exceeding the seismic action in the 50 years of the conventional life of the project. • αg is the horizontal ground acceleration. Indicatively, for new structures, a design objective B1 is provided according to Pin. 2.1. Adopting a valuation or redesign target with a probability of exceeding the seismic action greater than 10% generally results in more frequent, more extensive and more severe damage compared to a corresponding target with a probability of exceeding the seismic action of 10%, while when the probability of exceeding the seismic action is less than 10%, generally less frequent and less damage is expected. The probability of overrun: • 30% in 50 years corresponds to an average recovery period of about 135 years, • 10% in 50 years corresponds to an average recovery period of about 475 years. The choice of a specific valuation or redesign target implies the use of appropriately modified q or m indices, or tolerable deformations δd, the values of which are specified in Chap. 4 and 9. In the previous revision of the Regulations, Appendix 2.1 was added, which includes the minimum acceptable targets for the assessment or redesign of an existing building. The Minimum Wind Assessment Targets provided in §2.2 in relation to the Performance Level of the load-bearing structure and the probability of exceeding the Seismic Action within the contractual life of 50 years, are defined according to the importance category of the building as follows: