Explicit modelling of collapse for Dutch unreinforced masonry building typology fragility functions

Autor: Michele Palmieri, Giovanni Milan, Damian N. Grant, Pedro Negrette, Richard Sturt, Jamie Dennis, Rene da Costa, David McLennan
Rok vydání: 2020
Předmět:
Zdroj: Bulletin of Earthquake Engineering. 19:6497-6519
ISSN: 1573-1456
1570-761X
Popis: The development of seismic fragility functions for buildings generally relies on simplified modelling methods and the use of indirect engineering demand parameters (EDPs) for the determination of collapse or other damage states. The collapse response of real buildings, particularly those that have not been specifically designed for seismic resistance, can often be driven by local failures that may not be captured in simplified models. Furthermore, the use of EDP thresholds to indicate damage states may not be consistent with multiple possible failure modes, which may be triggered by different characteristics of the ground shaking or variations in model parameters. This paper demonstrates the use of non-linear finite element models including explicit progressive collapse simulation for the development of fragility functions. It presents an overview of the method developed and its application to an unreinforced masonry (URM) building typology in the Groningen region of the Netherlands, where induced seismicity risk is currently being evaluated. Multiple index buildings were selected to represent the variations in geometry, material properties, and connection types found within the typology. For each index building, Latin Hypercube sampling was used to generate batches of several hundred realisations of an LS-DYNA time-history analysis, each selecting from a set of 100 hazard-consistent ground motions, and varying material properties and other uncertain variables according to pre-assigned probability distributions. Automation was used in model generation, running analyses and in post-processing to allow the required computation with minimal analyst intervention. The main output from each analysis was a normalised debris cover estimate, which describes the extent of damage observed in the model and is correlated with life safety risk. Regression analyses were carried out directly on threshold levels of debris cover identified building collapse. Fragility functions were developed for the URM terraced house typology by combining results from the individual index buildings together.
Databáze: OpenAIRE