Читать книгу Rethinking Prototyping - Группа авторов - Страница 85

The basic structural concept discussed in this paper is based on the use of compression-only vaults in combination with continuous tension ties. This combination is of course known from masonry domes where continues tension rings are often inserted to resist the tensile hoop force towards the supports. Felix Candela used a similar system of combining tension and compression forces for his umbrella shells in the 1950s.

Fig. 4 illustrates the use of partial compression arches balanced by tension ties, showing (a) a barrel vault, and (b) a modern concrete arch bridge, both during the erection stage. Both structures are in static equilibrium thanks to temporarily attached cables which counteract the horizontal thrust until the barrel vault, respectively the arch, is closed. In these two examples the tension tie is used as a restraint during construction. However, this temporary state could also represent the structural system of a finalized structure. Hence, these examples serve as a sketch to illustrate the half-arch tension equilibrium system.

Fig. 4 (a) Medieval vault construction using tensioned ropes (Fitchen 1961); (b) construction of the Froschgrundseebrücke, near Coburg, Germany.