Torsional response of U-shaped walls

Details

Supervisors

Saraiva Esteves Pacheco De Almeida, João ; Hoult, Ryan

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil des constructions, à finalité spécialisée

Abstract

Whether it is for structural or architectural reasons, many modern buildings are based on the presence of reinforced concrete central cores. These cores take up the lateral loads and are known to have a much bigger stiffness than any other typical elements in the building due to their geometry and larger section size in comparison to gravity load resisting elements (i.e. columns). Such sections are often so-called U-shaped sections, as they are used for lift shafts or staircases and therefore require openings over their height. Moreover, these cores are frequently moved to the periphery of the building for architectural purposes. The consequence of the previous considerations is that in configurations where the U-shaped RC core is placed on the perimeter, center of rigidity (also called the stiffness centroid) will be located close to the core. Knowing that the external resulting lateral forces (e.g., wind and earthquake) will be applied at the center of mass, the result will be a plan asymmetry that gives the configuration the potential to create a torsional response (twist). The RC U-shaped walls are extensively used in millions of RC buildings around the world, they act as a backbone for the entire building, their location on the perimeter has the capacity to create a torsional response that may lead to important damages and in spite of that there is a really poor amount of researches and experiments that have been focusing on the torsional response of those walls. It is in this context that this thesis humbly aims to contribute to a better understanding of these crucial elements of modern construction. This contribution is expressed through a comprehensive review of the state of the art, followed by the development of a new mechanical model capable of predicting two central values of the response of walls: the torque at the onset of the first cracks and the ultimate torque before the failure of the element.