Resumen
With the ever-increasing occurrence of extreme abnormal events, it is now well recognised that there is a need for robust
buildings that can withstand local initial damage without experiencing failure propagation. In fact, many design codes now
explicitly require buildings in high-risk consequence classes to be designed with a sufficient degree of redundancy to ensure
that the failure of a single component does not lead to disproportionate collapse.
Fortunately, thanks to the great research effort made in the field of progressive collapse over the last few decades,
engineers already have several methods and solutions at their disposal for the design of new constructions. Nevertheless,
the vast majority of that research is not applicable to existing building structures. In addition, the few retrofitting solutions
proposed to enhance structural robustness tend to be overly invasive or complex to implement. Many of them are also local
in nature and are thus generally ineffective. At the same time, most buildings around the world were designed and built with
little or no consideration for structural robustness. Many of these existing buildings are occupied by a large number of people
or form part of critical infrastructure facilities, meaning that their collapse would result in catastrophic consequences for
society. Simply replacing such buildings is not only unfeasible, but also unsustainable, since it is essential to maximise the
use of existing structures and even extend their lifespan as much as safely possible in the fight against climate change and
resource scarcity. As such, there is an urgent need for efficient and practical retrofit solutions to improve the robustness of
existing buildings.
A promising solution to address this challenge involves adding stiffening beams on the roof of buildings. Floor slabs would
then be suspended from these beams in the event of the failure of one or more columns in the lower floors. Unlike most
retrofitting techniques studied in the past, this solution would not interfere with the interior space of the building and would
mostly require construction work on the roof level. Despite this strategy having been mentioned previously, no research has
been carried out to date that could result in its effective implementation in buildings.
Enhance aims to develop a novel approach for retrofitting existing buildings based on hanging floors from the roof to ensure
they comply with the latest structural robustness requirements.
