A Structural Optimization of Félix Candela’s Chapel of St. Vincent de Paul in Coyoacán, Mexico City

Abstract

Félix Candela gained fame as a builder of thin shell concrete structures, and many of his creations are examples of structural art. Using the most sophisticated optimization procedures, we sought to perform a structural optimization of his chapel of St. Vincent de Paul in Coyoacán, Mexico City. In this investigation, we define the optimal design as the one that minimizes tension and deflection in the structure and reduces the overall materials needed for construction. The variables that we examined were the thickness of the shell (different uniform thicknesses, as well as a systematically determined distributed thickness) and the shell geometry. We also studied the structure both with and without a concrete edge beam. The results of this study show that Candela’s design could have been improved slightly with some small changes in geometry, but overall, the structure performs very well as built. In our trials without the edge beam, the optimal thickness distribution thickens the edges first, suggesting that the edge beam is a crucial component of the shell. In our trials with the edge beam, the distributed thickness results are not optimal because they require significantly more concrete than what was used in the built structure. Lastly, the methods that we employed in this investigation provide for easy manipulation of structural models and relatively simple optimization. Therefore, they may prove useful for designers in creating new thin shell concrete structures in the future.