Periodic Reporting for period 2 - STAND4HERITAGE (New STANDards for seismic assessment of built cultural HERITAGE)
Berichtszeitraum: 2021-03-01 bis 2022-08-31
S4H team has investigated the dry-joint interface stiffness and damping parameters of block-based structures. A new experimental procedure based on vibration tests has been proposed to identify such properties. In addition, S4H team has developed a novel methodology to correlate the numerical viscous damping with the analytical coefficient of restitution for the dynamic analysis of rocking structures, based on extensive numerical simulations. It also revealed the conditions under which rocking motion terminates even when the structure is still subjected to ground motion. Finally, the S4H team demonstrated the great impact of low dry-joint stiffness on the seismic capacity of masonry structures underlining that current design recommendations are not appropriate for these structures.
The S4H team is producing datasets of simulated earthquake ground motions. First, a methodology was proposed to generate randomised seismic signals based on real records of the same area (herein, Europe). As an example, direct simulations of underground effects and their propagation through the soil layers give a thorough understanding of the possible future earthquake events in the region of Azores (Portugal). The outcomes of these simulations are being used to understand the effect of signal characteristics on the response of masonry and rocking structures.
Engineering tools are being developed, with a comprehensive limit analysis model for the failure of masonry corners. In particular, a rapid tool for the seismic assessment of masonry structures has been proposed. It combines limit analysis and rocking dynamics and serves as a fast methodology for engineering practice in the built cultural heritage field. Further works on these aspects are under development. The team is also preparing graphic tools to quickly generate masonry structures to facilitate the structural analysis of various masonry patterns, including rubble masonry.
The dynamic signals used in the experimental campaign will come from a massive dataset of artificial seismic signals generated by the project, based on stochastic analysis of the most important seismic features of real accelerograms recorded during earthquakes. Both seismic input signals datasets and experimental shaking table results will be shared with the broadest community.
S4H will develop fast numerical and analytical tools for the seismic analysis of masonry structures. At the end of the project, numerous analytical rocking simulations would have been conducted to prove their efficiency to predict the response of masonry specimens under stochastic loading and therefore to be used in practice as a simplified analysis tool. Similarly, an all-integrated macro-block approach will be validated to facilitate rapid assessments of masonry structures. This model will also include an automated generation of the geometry for faster and easier practical use.