Enhance portada
Enhance portada

Enhance: Hanging floors from the roof. Retrofitting existing buildings for improved robustness

Principal researcher:

JOSE M. ADAM

Team members:

  • LISBEL RUEDA-GARCÍA
  • BRAIS BARROS
  • MARCOS ARIAS-GRACEY
  • JUAN S. FONTALVO-GARCÍA

Funding Agency:

LOGO-CONSELLERIA-INNOVACION-UNIVERSIDADES

Duration: 01/01/2023 – 31/12/2026

Reference:  CIPROM/2022/47

Imagen-Enhance

Abstract

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.