ANTONI GAUDI (1852-1926)
Gaudi was a man of simple ideas and common sense. In his architecture it fuses structure and decoration. He clearly accepted nature as his guide. All aspects of his work evince this. It does not copy the nature but that includes/understands its geometry and its principles: it has infinity of forms that can be studied by means of regulated geometry; he studies the laws of statics and dynamics like example the natural structures of fibrous composition, such as rushes, canes and bones. His interest in nature was in three dimensional forms, rather than in two dimensional and he was interested primarily in nature’s inner forces, which expressed themselves on the surface. This can be seen in the tilted columns and the warped walls supporting the roof of the chapel in the Colony Guell, or the doorway and columns of the Mila house.
If the nature always works looking for functional solutions, since it is put under the inexorable law of the gravity, he is very wise to study the natural structures that during million years have had a perfect operation. Knowing the essence these structures, it was intention of Gaudi to take them to the land of the construction.
Helicoid is the form that takes the trunk from the eucalyptus, and Gaudi used in the columns of the Teresiano School. The hyperboloid is the form of femur, and Gaudi used in the columns of the Sagrada Family. The conoid is frequent form in the leaves of the trees, and Gaudi used in the covers of the Provisional Schools of the Sagrada Familia. Parabolic the hyperbolic one is the form that adopts the sinews between the fingers, and Gaudi applied it in the vaults of crypt of the church of the Güell Colony.
Tree vs columns of Sagrada Familia Cathedral, structures subjected to compressive and bending stress have branching systems with increasing slenderness as a result of the higher stability due to bundling. These are of equal proportions on all branching levels. Branching structures are used to transmit forces which attack in space in a distributed manner. The three-dimensional growth of trees follows the same forming principles due to the biological necessity to occupy free unshaded spaces. The branched structure results in a favourable structural system, in addition to making optimum use of the available surface. The elements verticalizing the resulting forces are interior in the Sagrada Familia cathedral, these columns resemble trees and are divided into several branches at certain heights. This comparison of columns to trees has often been made in reference to Gothic cathedrals, but the parallel is not exact as trees support independent loads, while the columns of the gothic cathedrals do not. On the other hand, it holds good for the Sagrada Familia where each branch of a column and the column itself only support one particular section of the superstructure, roof and ceiling, independently from the rest. Each branch of the tree-column is directed towards the centre of gravity of the section of the vault that it is supposed to carry. Their shapes are hyperboloids and hyperbolic paraboloids.
Trunk of a sweet chestnut tree vs parc Guell columns. In the parc Guell columns and the Sagrada Familia cathedral either, Gaudi made use of a warped surface, the helicoids. This helicoid form was specially applicable to columns, since columns are probably in their origin derived from tree forms and the tree grows in a similar way, Gaudi planed all the columns for the Sagrada Familia using this form and made many models and studies for these helicoid generated columns. Their sections vary, some are polygonal, regular and irregular, others star shaped. He chose warped surfaces because model makers and masons can construct them easily, as both the hyperboloids.
Human bones, tibia and fibula vs Batllo house columns.
Towers of the Sagrada Familia Cathedral. In the course of time, as Gaudi’s work developed, the influence of natural forms became more noticeable in his larger shapes. He no longer applied them decoratively as he did in his early buildings. Natural shapes created to resist wind and weather require sound structures. Shell shapes that have these qualities may have inspired the towers of the Sagrada Familia. Their curves follow similar mathematical formulas.
Spiral Staircase into the towers of the Sagrada Familia Cathedral vs Perisphinctes spiral shell. The helical form is universal, existing in every form of matter. From the microcosmic, atomic structure of crystal growth to the molecular structure of DNA to the macrocosmic spiral form of galaxies.
Inverted Catenary arches in Casa Mila building vs rips. After the careful study of the structure of skeletons of animals, plants or shells, he found fresh forms which he adopted as guides, after mathematical computations had proved them to be right for his purpose.
The Hanging Model
Between 1889 and 1908 Gaudi designed the Colonia Guell Church with a highly innovative method: the hanging model. With the model inverted, a very lightweight masonry brick structure was developed.
The hanging model is based on the theory of the "reversion of the catenary." A chain suspended from two points will hang spontaneously in the shape of a so-called "catenary". Only tension forces can exist in the chain. The form of the catenary upside down gives a perfect shape for an arch of stone masonry, and in such an arch only reversed forces of tension, being compression, will occur.
In Gaudi's hanging model a system of threads represents columns, arches, walls and vaults. Sachets with lead shot resemble the weight of small building parts.
Gaudi spent ten years working on studies for the design, and developing a new method of structural calculation based on a stereostatic model built with cords and small sacks of pellets. The outline of the church was traced on a wooden board (1:10 scale), which was then placed on the ceiling of a small house next to the work site. Cords were hung from the points where columns were to be placed. Small sacks filled with pellets, weighing one ten-thousandth part of the weight the arches would have to support, were hung from each catenaric arch formed by the cords. Photographs were taken of the resulting model from various angles, and the exact shape of the church's structure was obtained by turning them upside-down obtaining therefore the form, absolutely precise and exact, of the structure of the building, without to have conducted no operation of calculation and without possibility of error. The forms of cords corresponded to the lines of tension of the prim structure and when investing the photo, the lines of pressure of the compressed structure were obtained. An absolutely exact and simple method, giving an example of the intuitive and elementary methods that Gaudi applied in its architecture and that allowed him to obtain balanced forms very similar to which it offers the nature.