ES EN 1998:2015 states the following fundamental requirements: Structures in seismic regions shall be designed and constructed in such a way that the following requirements are met, each with an adequate degree of reliability( ES EN 1998:2015, Art. 2.1): - No-collapse requirement : The structure shall be designed and constructed to withstand the design seismic action defined in section 3( ES EN 1998:2015, SECTION 3) without local or global collapses, thus retaining integrity and a residual load capacity after the seismic events. *The design seismic action is expressed in terms of a) The reference seismic action associated with a reference probability of exceedance, PNCR in 50 years or a return period, TNCR and b) The importance factor yi( gamma i) to take into account reliability differentiation * PNCR(IN 50 years)=10% and TNCR=475 years -Damage limitation requirement The structure shall be designed and constructed to withstand a seismic action having a larger proba...