Structural safety and sustainability

Earthquake-resistant structures using repairable connections with increased lifetime and sustainability

We have been developing and testing seismic resistant composite steel frames with dissipative fuses, where the earthquake damage can concentrate during the seismic event, after which the repair work will be limited only to replacing the fuses. Currently, our team in Politecnico di Milano is coordinating the research project DISSIPABLE “Fully Dissipative and Easily Repairable Devices for Resilient Buildings with Composite Steel-Concrete Structures”, funded by EU-RFCS with contract n. RFCS-PDP 800699, 2018-2021. DISSIPABLE team is performing large scale demonstration of the steel-concrete composite structures with anti-seismic reparable systems. In the project, systematic post-earthquake repair and reassembly procedures are being developed and will be provided as “instructions for use” in the end. We are quantifying the economic and environmental benefits of the tested systems.

Construction of a shaking table specimen (using dissipative and repairalbe components) within EU-RFCS DISSIPABLE project

More details can be read in the following articles:

Alper Kanyilmaz, Milot Muhaxheri, Carlo Andrea Castiglioni, Influence of repairable bolted dissipative beam splices (structural fuses) on reducing the seismic vulnerability of steel-concrete composite frames, Soil Dynamics and Earthquake Engineering, Volume 119, 2019, Pages 281-298, ISSN 0267-7261, https://doi.org/10.1016/j.soildyn.2019.01.007

Carlo A. Castiglioni, Alper Kanyilmaz, Luis Calado, Experimental analysis of seismic resistant composite steel frames with dissipative devices, Journal of Constructional Steel Research, Volume 76, 2012, Pages 1-12, ISSN 0143-974X

M. Valente, C.A. Castiglioni, A. Kanyilmaz, Dissipative devices for earthquake resistant composite steel structures: bolted versus welded solution, Bull Earthq Eng, 14 (12) (2016), pp. 3613-3639, doi: https://doi.org/10.1007/s10518-016-0002-9

M. Valente, C.A. Castiglioni, A. Kanyilmaz, Numerical investigations of repairable dissipative bolted fuses for earthquake resistant composite steel frames, Eng Struct, 131 (2017), pp. 275-292, DOI: https://doi.org/10.1016/j.engstruct.2016.11.004

Marco Valente, Carlo A. Castiglioni, Alper Kanyilmaz, Welded fuses for dissipative beam-to-column connections of composite steel frames: Numerical analyses, Journal of Constructional Steel Research, Volume 128, 2017, Pages 498-511, ISSN 0143-974X, https://doi.org/10.1016/j.jcsr.2016.09.003

Racking systems (pallet racks and automated warehouses) in earthquake regions

Automated Rack Supported Warehouses (ARSW) represent the future of storage technology, providing substantial savings in terms of cost, space and energy with respect to traditional warehouses. Currently, designers refer to building codes, without controlling their applicability to the specific typologies of such structures. This creates safety and efficiency problems being ARSWs’ structural characteristics considerably different from those of steel structures for normal buildings. Objective of the research is to analyse actual design practices, to investigate logistics’ imposed loading strategies, unconventional loading conditions, constructional phases and seismic design and to propose new approaches aiming at increasing ARSW safety, reliability and economy.

More details can be read in the following articles:

Alper Kanyilmaz, Giovanni Brambilla, Gian Paolo Chiarelli, Carlo Andrea Castiglioni, Assessment of the seismic behaviour of braced steel storage racking systems by means of full scale push over tests, Thin-Walled Structures, Volume 107, 2016, Pages 138-155, ISSN 0263-8231, https://doi.org/10.1016/j.tws.2016.06.004

Alper Kanyilmaz, Carlo Andrea Castiglioni, Giovanni Brambilla, Gian Paolo Chiarelli, Experimental assessment of the seismic behavior of unbraced steel storage pallet racks, Thin-Walled Structures, Volume 108, 2016, Pages 391-405, ISSN 0263-8231, https://doi.org/10.1016/j.tws.2016.09.001

Kondratenko, A., Kanyilmaz, A., Castiglioni, C.A. et al. Structural performance of automated multi-depth shuttle warehouses (AMSWs) under low-to-moderate seismic actions. Bull Earthquake Eng (2021). https://doi.org/10.1007/s10518-021-01193-y

Carlo A. Castiglioni, Alberto Drei & Alper Kanyilmaz (2020) Continuous Monitoring of Service Conditions of a Steel Storage Racking System, Journal of Earthquake Engineering, 24:3, 485-505, DOI: 10.1080/13632469.2018.1453402

Carlo A. Castiglioni, Alberto Drei, Alper Kanyilmaz, Harris P. Mouzakis, Earthquake-Induced pallet sliding in industrial racking systems, Journal of Building Engineering, Volume 19, 2018, Pages 122-133, ISSN 2352-7102, https://doi.org/10.1016/j.jobe.2018.05.004

Seismic design of concentrically braced frames under low-to-moderate seismicity

Within MEAKADO research project, we proposed an adjusted design approach for the low-to-moderate seismicity design of Concentrically Braced Frame (CBF) structures. With the new approach, we aim to satisfy both economy and safety criteria, based on the exploitation of the three features of CBFs, which had not been deeply examined before: “frame action provided by gusset plates”, “contribution of compression diagonal and its post-buckling strength and stiffness”, and “energy dissipation capacity of non-ductile bracing joint connections”.

Full scale tests performed within MEAKADO project

We investigated these aspects by means of incremental dynamic analysis of case studies, based on the numerical models calibrated on full-scale experimental tests published elsewhere by us.

Fig. 1 — Some highlights from the experimental results

Based on the results of full-scale experiments, we quantified the ductility provided by the bolt hole ovalization and the slippage of preloaded bolts of standard bracing joints of concentrically braced frames that are not fulfilling the current over-strength design criteria.

Fig. 13 — Stresses around bolts indicated by thermal immage classification

More details can be read in these articles: