Foreword to the Special Issue for the 2019-2021 RINTC (The Implicit Seismic Risk of Existing Structures) Project

This special issue of Journal of Earthquake Engineering (JEE) follows a previous one from 2018, which dealt with the results of a research project performed between 2015 and 2017, whose acronym was RINTC, and aimed at evaluating the seismic reliability of code-conforming structures in Italy (Iervolino and Dolce 2018). The need for research on this topic, and its international value, come from the well-known fact that in most building codes, applying multi- limit-state-based design (sometimes also referred to as a simplified version of the performance- based design), the structural reliability is not explicitly controlled, and ultimately it is unknown. This happens even if the ground motion intensity is determined based on the limit state considered in the design and the corresponding exceedance return period from the probabilistic seismic hazard analysis (PSHA) for the construction site.