Hybrid surrogate-based models for the evaluation of the fundamental period of regular URM buildings

The fundamental period can be interpreted as the structures’ DNA since it carries essential information about their behavior and response to dynamic loads, such as seismic events. Most practitioners are familiar with using the fundamental period to calculate the seismic response coefficient for base shear estimation of regular buildings using the equivalent lateral procedure, the so-called Lateral Force Method in the current version of Eurocode 8 – part 1. The most straightforward method for determining the fundamental period usually relies on empirical formulas derived from the data observation of several instrumented buildings. Despite the usefulness and adequacy of these formulas in the regions where these buildings are located, their generalization for other regions with different seismicity levels and different building typologies may not be suitable. The present work aims to develop surrogate models for estimating the fundamental period of regular URM buildings in Portugal. This is achieved by combining representative numerical models with experimental data within a Bayesian framework. The results support the technical community in the validation of structural numerical models and provide a reliable estimation of the fundamental period, consistent with the region and structural typologies.