8B. ANALYSIS PART 2

CHAPTER 8B 'ANALYSIS' 57 2. I identify the existing basic seismic class which is, for example, B2. I need to move up at least one class, i.e. go to B2+ and I need to is higher than minimum of table PA2.2, which for our example is B2+ but improved by one class, i.e. B1. So the target is B1. Comparing the two cases and assuming approximately that B and C classes diagonally are approximately the same, C1 corresponds approximately to B2+. So the second method will give me less favourable results than the first. In general, the second, new method favours older and weaker buildings while the existing method favours newer ones. For the second method in which the determination of the basic seismic class is initially required, the designer can initially by testing and selecting one by one the basic seismic classes (those corresponding to the B level of performance) to determine the class of the building, i.e. the seismic action for which the existing reinforcement is sufficient and all the checks according to CEE.EPE.