Non-linear analysis of Eduardo Torroja’s Frontón de Recoletos’ roof using a discrete reinforcement approach

• The paper contains a geometrical and material non-linear analysis of a concrete shell.
• The paper proposes an analysis tool for the assessment of RC historical structures.
• Real flow of stresses differs from the one found on the undeformed and uncracked case.
• The unpredictability of the non-linear performance of complex concrete shells is stated.
• The importance of geometrical and material non-linear analysis is verified.

Eduardo Torroja was a Spanish engineer and a famous figure in structural design. His vast production of technically demanding work includes thin reinforced concrete shells, daring structures that meet efficiency requirements through their thinness. One of his most remarkable works is the Frontón Recoletos, which is described in an extensive bibliography, enabling us to approach this milestone of structural engineering again with modern computational tools. Although thin shells have mainly been designed under the elasticity hypothesis, nonlinear analysis also deserves to be considered, since current computer processing speeds make this possible. The present work carries out a complete non-linear analysis of the roof of Torroja’s Fronton de Recoletos and can be considered as the continuation of the linear-elastic analysis previously carried out by Lozano-Galant and Paya-Zaforteza (2011). The key aspects of the investigation presented in this paper are the use of discrete reinforcement instead of the more common smeared approximation to modeling the roof reinforcement and the accurate definition of concrete through a robust constitutive equation, the Multi-crack model proposed by Jefferson (1999) for which FE software was used. The results have been checked against both the historical documentation in the Torroja Archive and the recent studies using linear models by Lozano-Galant and Paya-Zaforteza (2011). As it turns out, the relevance of geometric nonlinearities, material nonlinearities and stability behavior should not be neglected.