Developments Relating to Seismic Action in the Eurocode 8 of Next Generation

The purpose of this paper is to present the main changes introduced by CEN-TC250-SC8 concerning seismic action in the next revision of Eurocode 8, consisting principally of:- Introducing the concept of seismic action class in place of seismicity level.- Anchoring the standard spectrum by its plateau value, S-alpha, and its value at 1 s spectral period, S-beta, instead of the PGA.- Introducing, in an informative annex, two European hazard maps, one for S-alpha, and one for S-beta, both defined for 475 years return period, based on the ESHM20 hazard model.- Revising the site categorization by introducing the bed rock depth in addition to the shear wave velocity.- Introducing new site amplification factors based on this site categorisation and dependent on input motion level.- Introducing a new spatial model of input motion for bridges and pipelines.- Providing miscellaneous specifications on conventional values of magnitude and strong motion duration, dependence of spectra to damping, ..