Tests and analysis of RC building, with or without masonry infills, for instant column loss

Stathas, Nikolaos; Karakasis, I.; Στρεπέλιας, Ηλίας; Palios, X.; Bousias, Stathis; Fardis, Michael N.

doi:10.1016/j.engstruct.2019.05.015

Cited by 9 publications

(3 citation statements)

References 14 publications

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“…This strategy is particularly focused on the effect of the wall on the whole global seismic behavior of the building. The presence of the infill walls in reinforced concrete buildings causes an increase in their lateral stiffness, reduces their natural period, and causes an increase in the expected seismic loading [27,28]. It was evident in recent earthquakes that the walls were responsible for global failure mechanisms such as soft-story and short-column mechanisms that caused the building collapse [29].…”

Section: Structural Retrofitting Techniquesmentioning

confidence: 99%

Interactions between Seismic Safety and Energy Efficiency for Masonry Infill Walls: A Shift of the Paradigm

et al. 2022

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Currently, the upgrade of existing reinforced concrete (RC) buildings focuses only on energy retrofitting measures due to the current policies promoted in the scope of the European Green Deal. However, the structural deficiencies are not eliminated, leaving the building seriously unsafe despite the investment, particularly in seismic-prone regions. Moreover, the envelopes of existing RC buildings are responsible for their energy efficiency and seismic performance, but these two performance indicators are not usually correlated. They are frequently analyzed independently from each other. Based on this motivation, this research aimed to perform a holistic performance assessment of five different types of masonry infill walls (i.e., two non-strengthened walls, two walls with seismic strengthening, and one wall with energy strengthening). This performance assessment was performed in a three-step procedure: (i) energy performance assessment by analyzing the heat transfer coefficient of each wall type; (ii) seismic performance assessment by analyzing the out-of-plane seismic vulnerability; (iii) cost–benefit performance assessment. Therefore, a global analysis was performed, in which the different performance indicators (structural and energy) were evaluated. In addition, a state-of-the-art review regarding strengthening techniques (independent structural strengthening, independent energy strengthening, and combined structural plus energy strengthening) is provided. From this study, it was observed that the use of the external thermal insulation composite system reduced the heat transfer coefficient by about 77%. However, it reduced the wall strength capacity by about 9%. On the other hand, the use of textile-reinforced mortar improved the strength and deformation capacity by about 50% and 236%, but it did not sufficiently reduce the heat transfer coefficient. There is a need to combine both techniques to simultaneously improve the energy and structural energy performance parameters.

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Section: Structural Retrofitting Techniquesmentioning

confidence: 99%

Interactions between Seismic Safety and Energy Efficiency for Masonry Infill Walls: A Shift of the Paradigm

et al. 2022

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“…Among others, cases with high relevance are the collapse of the Ronan Point Building (London, 1968) [7], of the Murrah Federal Building (Oklahoma City, 1995) [8] and the World Trade Center (New York, 2001) [9]. Since the 1940s, many research studies focused on this issue, investigating widely diverse aspects of the problem by performing components [e.g., 10,11,12,13] and large scale experimental tests [e.g., 14,15,16,17,18,19,20,21,22], numerical modelling and simulations [e.g., 23,24,25,26,27,28,29,30,31] and investigating several aspects of the design against progressive collapse [e.g., 32,33]. These studies allowed building up an increasingly understanding of the structural response in these scenarios and the definition of possible design strategies nowadays incorporated in design guidelines and codes [e.g., 34,35,36].…”

Section: Introductionmentioning

confidence: 99%

Retrofit of existing steel structures against progressive collapse through roof-truss

Freddi

Ciman

Tondini

2022

Journal of Constructional Steel Research

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The paper presents the results of a comprehensive study on the evaluation of the effectiveness of a retrofit strategy of existing steel buildings against progressive collapse. In this respect, it investigates the performance and the design of a retrofit solution to increase the robustness of steel Moment Resisting Frame buildings. A truss steel system added at the building's rooftop level (i.e., 'roof-truss'), and intended to define an alternative load path, was investigated as a retrofit solution. The numerical model key components, including the plastic hinges and the beam-column connections, were validated against available experimental results. The validated models were then used to study the robustness of the structure under column loss scenarios by means of non-linear static and dynamic analyses performed in OpenSees. The simulations allowed for the identification of possible failure modes and alternative load paths together with the definition of the Dynamic Increase Factor (DIF). In this regard, it is shown that column buckling is critical for the selected case study. Moreover, the outcomes showed how the proposed retrofit solution allows the definition of effective alternative load paths when subjected to column loss scenarios and informs on the critical details that should be checked by employing this retrofit system.

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“…Some iconic cases, such as the collapse of the Ronan Point Building (London, 1968) [1], the Murrah Federal Building (Oklahoma City, 1995) [2], and the World Trade Centre (New York, 2001) [3] highlighted the high consequences of progressive collapse, in terms of loss of lives and properties, significantly increasing the interest of the research community in this topic [4]. Since the 1940s, many studies focused on this research area, widely investigating various aspects of the problem by performing components [e.g., [5], [6], [7]] and large-scale experimental tests [e.g., [8], [9], [10], [11]], numerical modelling and simulations [e.g., [12], [13], [14], [15], [16], [17]] and investigating several aspects of the design against progressive collapse [e.g., [18], [19]]. These studies allowed to build up an increasing understanding of the structural response in progressive collapse scenarios, along with the definition of possible design strategies.…”

Section: Introductionmentioning

confidence: 99%

Assessment and Retrofitting of a Rc Building Through a Multi-Hazard Approach: Seismic Resistance and Robustness

Scalvenzi¹,

Freddi²,

Parisi³

2021

Proceedings of the 8th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering (COM

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Most of the existing buildings in seismic prone regions have been built before the publication of modern design provisions against seismic events and progressive collapse. Nonetheless, some studies have highlighted the possible interaction between earthquake resistance and structural robustness, the latter being of interest to either individual extreme hazards (e.g., blast, impact, fire) or interacting hazards (e.g., landslides produced by seismic events). While retrofit strategies to improve the seismic performance of reinforced concrete (RC) structures have been widely investigated since many years, the topic of mitigation strategies against progressive collapse received very little attention. Progressive collapse can be described as a special type of structural collapse that involves several components of the structure as consequence of an initial localised damage. The present study aims at investigating whether and how much seismic retrofitting may improve not only the earthquake resistance but also robustness. A four-storey, five-bay, RC frame building designed according to Eurocode 2 is considered as a case study. The frame was assessed by evaluating: 1) the capacity of the structure to redistribute loads after a local damaging event; 2) the seismic capacity of the structure. Non-linear static analyses, i.e., PushDown and PushOver analyses, were carried out in OpenSees to evaluate the robustness and seismic resistance of the structure, respectively. The progressive collapse capacity was evaluated under two relevant column-removal scenarios, i.e., the sudden loss of an internal and an external column, while the seismic resistance was assessed under two load distributions, i.e., proportional to the first vibration mode and to the inertia masses. Subsequently, the impact of retrofitting with carbon fibrereinforced polymers on both structural robustness and seismic resistance was evaluated. The use of the retrofit measure allowed, on the one hand, the removal of all the shear failures due to horizontal seismic actions and, on the other hand, to increase the robustness of the structure.

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Tests and analysis of RC building, with or without masonry infills, for instant column loss

Cited by 9 publications

References 14 publications

Interactions between Seismic Safety and Energy Efficiency for Masonry Infill Walls: A Shift of the Paradigm

Interactions between Seismic Safety and Energy Efficiency for Masonry Infill Walls: A Shift of the Paradigm

Retrofit of existing steel structures against progressive collapse through roof-truss

Assessment and Retrofitting of a Rc Building Through a Multi-Hazard Approach: Seismic Resistance and Robustness

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