the Secrets of architecture the masters of the Renaissance has long been a subject of study by engineers and historians. Why is the great stone dome of the Florentine Cathedral of Santa Maria del Fiore in Italy have stood for six centuries unharmed as it can withstand its own weight without visible supports and how its built from the bottom up without any external support of the type of formwork? The same questions arise in the study of the Cathedral of St. Peter in the Vatican and many other churches of the early Renaissance – it is the era of the Quattrocento, Dating back to XV century.

Scientists at Princeton University in the United States and their Italian colleagues conducted a study using mathematical analysis and modern tools, the results of this work publishes the scientific journal Engineering Structures.

the technology was invented by the Italian architect of the XV century by Brunelleschi during the construction of the Florence Cathedral. The dome consists of two types of clutches. One layer was vertical, at an angle of 45 degrees, laid bricks, and the second horizontal layer of the bricks that filled the empty spaces inside cells, formed inside the first nest. It turned out produced by cross-helical spruce figure laying, allowing the design to keep stable equilibrium and samomoderirovanie.

Such technology, according to scientists, was used in Italy for a century or more for the construction of stone domes without formwork. However, until now it was unclear how this cross helical pattern of Christmas trees provides the equilibrium state of a self-balancing stone domes and does not allow him to break even in the process of construction.

In their study, the scientists analyzed a discrete element model, proved the existence of an available resistance and figured out how to change the stress distribution inside the dome when adding each new layer of bricks. Even at the stage of erection of a structure due to such stacking was prevented from slipping or tipping over of a dome. They also established a role in the structural properties of the so-called Cathedral of curbs – special projections of the bricks.

the Architect put these curbs in dome under a certain angle greater than 10 degrees. This ensured the stability of the structure, and she never moved. Therefore, the dome construction was not necessary to support formwork, and a lot of manpower is also not required.

These findings are important not only for the history, architecture and modern construction. Vintage technology can have practical applications in the creation of fully automated methods of construction of buildings with drones or robots.