Seismic performance and fragility functions of a 3D steel-concrete composite structure made of high-strength steel

• Published in: Engineering structures 2018-11, Vol.174, p.373-383
• Main Authors: Tondini, N., Zanon, G., Pucinotti, R., Di Filippo, R., Bursi, O.S.
• Format: Article
• Language: English
• Subjects: 3-D technology; 3D analysis; Composite materials; Composite structure; Composite structures; Computer simulation; Demand analysis; Dynamic response; Earthquake accelerograms; Earthquake damage; Earthquake engineering; Earthquake incident angle; Earthquakes; Economic impact; Environmental risk; Fragility; Fragility functions; Ground motion; High strength steel; High strength steels; Hypercubes; Image reconstruction; Incidence angle; Latin hypercube sampling; Limit state design; Low carbon steels; Probability theory; Risk assessment; Seismic activity; Seismic design; Seismic engineering; Seismic performance; Steel; Steel structures; Three dimensional composites; Three dimensional models
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2018.07.026

•Development of fragility functions of a 3D composite structure.•Analysis of novel building endowed with moment resisting frames made of high-strength steel.•Multicomponent incremental dynamic analysis that includes the randomness of the earthquake incident angle.•The Peak Ground Displacement-interstorey drift ratio pair entails a more efficient probabilistic model. This paper provides insight into a probabilistic seismic demand analysis of a steel-concrete composite structure made of a novel type of high-strength steel moment resisting frame, to be used either in a seismic risk assessment or a fully probabilistic Performance-Based Earthquake Engineering (PBEE) framework. The application of the PBEE methodology with a full probabilistic character is able to rigorously evaluate the seismic risk to which a structure may be exposed, as well as to quantify economic losses, including both direct -repair, reconstruction costs, etc.- and indirect costs -downtimes, etc.-. In this respect, the knowledge of seismic fragility functions is paramount. Moreover, due to the dynamic complexity of the examined structure caused by irregularity in elevation and different lateral-force resisting systems in the two main directions -moment resisting frames (MRFs) and concrete shear walls- the seismic behaviour is not straightforward to foresee. Therefore, two separate 2D analyses along the building main directions may not suffice to identify the actual dynamic response and, consequently, a 3D comprehensive probabilistic seismic demand analysis was performed by taking into account the earthquake incident angle. In order to exploit the inherent overstrength of non-dissipative members, consistently with the capacity design philosophy, the structure, that is a representative example of a realistic office building, is characterised by a newly-conceived type of moment resisting frame made of high-strength steel circular columns filled of concrete and of mild steel beams. In this respect, a nonlinear 3D FE model was developed and calibrated on experimental tests performed on both beam-to-column and column-base joints that formed MRFs. A multiple incremental dynamic analysis (MIDA) was then performed with two groups of bespoke accelerograms characterised, on one hand, by large magnitude and large distance and, on the other hand, by near-source effects. The earthquake incidence angle was also considered and, to decrease the number of simulations, the accelerogram-incident angle pairs we