Steel-based applications in earthquake-prone areas

Steel-Earth project aims at distributing among technicians, engineers, design companies and standardization bodies the results of three past RFCS projects (Steel-Retro [3], Opus [2] and PrecaSteel [1]), providing useful tools for the design and for the retrofit of existing buildings. Technical documents and practical applications to case studies, regarding design of steel and composite steel/concrete buildings and innovative steel-based techniques for the retrofit of existing r.c. and masonry constructions, have been elaborated and collected into a volume distributed during the final workshop of the dissemination project. Pre-normative and background documents concerning the design of steel and composite structures and the rehabilitation of existing constructions have been prepared. A lot of attention has been paid to the analysis of the influence of overstrength factors on the seismic design of steel and composite structures. The prepared documents have been distributed to the attending people and to the members of WG 2 (CEN/TC 250/SC 8/WG 2 “Steel and Composite Structures”) during the final workshop of the project. Technical sheets, working examples and background documents have been translated into several languages (German, French, Italian, Romanian and Greek) and are free available on the website of the project (https://www.steelconstruct.com/site/), where information regarding Steel-Earth are also presented.11 Workshops in Italy, Greece, Germany, Belgium, Portugal, Spain and Romania and 5 conferences in Emilia-Romagna have been organized, as well as 2 practical courses for engineers and academic people in Pavia (Italy). Flash-drives with the technical documents and applications elaborated in Steel-Earth have been distributed to the attending people

Influence of variability of material mechanical properties on seismic performance of steel and steel-concrete composite structures

Modern standards for constructions in seismic zones allow the construction of buildings able to dissipate the energy of the seismic input through an appropriate location of cyclic plastic deformations involving the largest possible number of structural elements, forming thus a global collapse mechanisms without failure and instability phenomena both at local and global level. The key instrument for this purpose is the capacity design approach, which requires an appropriate selection of the design forces and an accurate definition of structural details within the plastic hinges zones, prescribing at the same time the oversizing of non-dissipative elements that shall remain in the elastic field during the earthquake. However, the localization of plastic hinges and the development of the global collapse mechanism is strongly influenced by the mechanical properties of materials, which are characterized by an inherent randomness. This variability can alter the final structural behaviour not matching the expected performance. In the present paper, the influence of the variability of material mechanical properties on the structural behaviour of steel and steel/concrete composite buildings is analyzed, evaluating the efficiency of the capacity design approach as proposed by Eurocode 8 and the possibility of introducing an upper limitation to the nominal yielding strength adopted in the design

Industrial and techno-economic feasibility of concrete structures reinforced with DP rebars

Dual-Phase (DP) steel reinforcing bars represent a valid alternative to traditional TempCore®, characterized by good mechanical properties and by improved performance under aggressive environmental conditions. As known, TempCore® rebars highlight relevant decrease of the deformation capacity in presence of corrosion, with possible negative consequences for the overall building behaviour. Being the mechanical assessment of DP rebars widely presented in other already published works, the present paper shows the analysis of the industrial feasibility of the production process of DP rebars, analysing how actual plants can be adapted to achieve the desired DP microstructure and finally providing an overall estimation of the cost increase. The techno-economic and environmental analysis of the feasibility of reinforced concrete (RC) constructions using DP rebars is therefore performed using the conventional method for the Expected Annual Loss index evaluation; comparison to RC buildings with TempCore® B450C rebars is provided

PANCREAS

PANCREA

Influence of soil-foundation-structure interaction on overall behaviour and diseases of a medioeval building in Pisa

The University of Pisa was established in 1343, but only in XVI century a specific venue, Palazzo La Sapienza, was built. The building was subjected to various modifications in relation to the users’ requirements, with the following irregular structural growth due the absence of a specific and organized global and general scheme. The present paper describes the investigations carried out on the construction and on the foundation soil to clarify their mutual interactions and explain some of the damage today affecting the building. A deep in situ experimental test campaign was executed to define masonry typology, dimensions of structural elements, mechanical properties of materials, geotechnical parameters of the soil and foundations’ geometry and masonry characteristics. Dynamic properties of the subsoil were investigated in order to properly define the local seismic action and the local influence of subsoil profile, necessary for the execution of safety assessments on the global model of the building