Conceptual design of structures as a meeting point between architecture and engineering. The formalization of structural intuition and its use as a design and teaching tool

Resumen

Structural creativity is the combination of three inseparable elements. The first element is the ability to conceive a structure that optimally solves all the structural issues related to equilibrium, stability, resistance, stiffness, ductility, and durability. The second element is the creation of the spaces and volumes required by each architectural project. The third element is the optimization of all the other architectural requirements such as illumination, aeration, and aesthetics. Therefore, the conception of a structure is a creative process, as it means the creation of a new object from a series of external conditions set by the architectural project. However, this creativity is not as free as artistic creativity, as it requires in-depth knowledge of the fundamental structural principles. Hence, this type of creativity, unlike that of art, does not exclusively rely on personal talent, but people can be trained and taught in it. The main goal of this work is the formalization of structural creativity, revealing the structural principles on which it is based, in order to transform it into a design tool available to architectural and structural designers. This project is based on four premises. The importance of a common language between architects and engineers and the existence of teaching methods that favor collaboration make up the first premise. After identifying the reasons why the separation between architecture and engineering occurred, some teaching approaches that have been experimented with since the 1980s in different European and North American universities are presented, with the aim of promoting a rapprochement between the two professions. The advantages of using graphic statics and graphic methods to favor the collaboration of architects and engineers is the second premise. Graphic statics has a fundamental role in the creation of structural creativity. In order to overcome the limitations that have led to graphic statics being abandoned in favor of analytical statics, i.e., the laboriousness of graphic constructions and the iterative nature of the process of researching the natural shape of the loads, an original formulation of the Cremona-Maxwell method in matrix form is presented. This formulation enables graphic statics to be used for form-finding purposes. The importance of the history of constructions and of structural engineering and the lack of research and courses on these subjects in engineering faculty curricula are the third premise. After defining the characteristic of this hybrid discipline, which integrates historiographic methods with technical engineering methods, two original examples of research on the history of structures are presented. The first of these examples is the importance of the Palace of Ctesiphon in the history of structural engineering, and the second is the work of the Swiss engineer Henry Lossier. The advantages of collaboration between architects and engineers based on the structural conception is the fourth premise. The analysis and presentation of two specific projects, the Volta school in Basel, by the architects Miller and Maranta and the engineer Jürg Conzett, and the retirement home in Giornico, by the architects Baserga and Mozzetti and the engineers Pedrazzini Guidotti, show how collaboration between architects and engineers from the early stages of design encourages structural creativity. In order to formalize structural creativity, the objective, measurable, and therefore, formalizable aspects of this creativity must be identified. These aspects come from the fact that all structures need to be safe and efficient. This need for safety and efficiency limits, and also drives, structural creativity. There are many aspects that an engineer must consider to guarantee structural safety and efficiency: balance, structural typology, shape, mechanical properties of materials, geometry of the elements, position of supports, etc. All these aspects and the variety of solutions available that meet safety and efficiency requirements are the essence of structural creativity. After highlighting the role of intuition and experience in the conception of a creative structure, the formalization of three technical aspects on which structural creativity depends have been developed: equilibrium, the position and type of the supports, and the form. These technical aspects are illustrated by presenting and analyzing buildings that exemplify each of these three aspects. The APG Golf Club in Luque, Paraguay, by the architect Javier Corvalán, has been analyzed to show the role of equilibrium in the formation of structural intuition. The roof of the Ascona lido by the architect Livio Vacchini has been chosen to show the role of the type and position of the supports. In order to show the role of form in the creation of structural intuition, the structural solution chosen by Livio Vacchini for the roof of the gymnasium in Losone, a grid of prestressed reinforced concrete beams, has been compared to other possible structural solutions involving the use of shape resistant structures and vector resistant structures. Finally, the role of context – geographical, economic, political, and of tradition – in the creation of structural intuition has been analyzed, by presenting an original piece of research on promoting the diffusion of timber buildings in the Swiss region of Ticino, as a result of the enhancement of local building traditions. If structural intuition can be formalized, it can also be taught. Therefore, some teaching experiments carried out at the Mendrisio Academy of Architecture, Switzerland, on the teaching of structural design, are presented. These experiments are based on research on the formalization of structural intuition, as well as on the results of some questionnaires specifically prepared and given to architecture students and professional architects to investigate the level of interest that architects have in structural issues and the state of the relationship between architects and engineers. The purpose of the experiments is also to show the advantages of fruitful collaboration between architects and engineers.