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:

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:

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: