Buildings can be submitted to extreme events such as natural disasters (hurricanes, tsunamis, flooding and earthquakes), accidents (explosions, vehicle collisions…) and actions such as terrorist attacks and sabotages. These events cause damage to their structure, which can lead to a total collapse. This is where the term “progressive collapse” comes into play, the process whereby localised damage can cause a series of chain errors that lead to the complete collapsing of the building, or a significant part of it. This collapse can in turn cause severe personal and material losses.
A team from Valencia’s Polytechnic University (UPV) has developed a research project headed by professor José Miguel Adam, with the support of a Leonadro grant, whose results will contribute to prevent this collapse, thus guaranteeing greater robustness and security for the buildings. In the project, researchers established a series of design recommendations in order to achieve these more robust and resilient buildings.
The UPV researcher’s work has focused on the corner columns. According to professor Adam, one of the situations that will most probably lead to the progressive collapsing of a building is when the localised damage affects these columns. Thus, the researchers propose a new design so that, in the event of an extreme event, the load of the corner column is distributed through the rest of the building.
“It is about defining design techniques that make it possible to create alternate load paths so that, when a column falters, its load is redistributed among other elements of the building. In essence, buildings have resistant mechanisms that do not activate under normal situations, but which can be of great importance when withstanding an extreme event. It is the possible activation of these mechanisms where improvement of the building’s resistance to collapsing is focused on,” explains José Miguel Adam.
Together with professor Adam, the research team is composed by Elisa Bertolesi, Manuel Buitrago and Pedro Calderón, all from the Concrete Science and Technology Institute (ICITECH) of the UPV. Furthermore, the project also included the collaboration of researcher Juan Sagaseta, from the University of Surrey.
First test building against extreme events
To date, corner column faults have hardly been studied, mainly because the works conducted have only considered scaled parts of buildings, which were tested in the laboratory. In this study, researchers built the first Spanish full-sized test building with these design recommendations. Construction of the building, and the tests conducted, have been co-funded by company Levantina, Ingeniería y Construcción – LIC.
The test building has been monitored with a series of state-of-the-art sensors, specifically strain gauges, sensors which make it possible to monitor the deforming inside concrete, movement sensors and accelerometers, both electrical and optic fibre-based. Furthermore, several cameras were also used to assess and visualise the building’s response.
“To have a test building fully at the disposal of the project has led to very trustworthy results which, in turn, will contribute to understand resistant mechanisms in buildings which had hardly been analysed to date,” stresses José Miguel Adam.
The research is framed in the “Secure Societies” challenge of Horizon2020. More specifically, it intends on contributing to achieve the goal of “protecting and improving the resiliency of critical infrastructures, supply chains and modes of transportation.”
“With the development of this project, it will be possible to decrease the vulnerability of critical buildings (hospitals, schools, passenger terminals and public and military buildings), of high occupancy or with a large number of storeys,” concludes Adam.