Читать книгу Rethinking Prototyping - Группа авторов - Страница 97

The roof is positioned on an existing bridge which constrains its column positions. The area that needs to be sheltered, however, defines the roof’s oval perimeter. The two conflicting requirements lead to asymmetric loading conditions with different spans and cantilevers. Therefore, a regular grillage connecting the columns with the roof proved inappropriate and would lead to oversized elements. Furthermore, a hierarchical grid with primary beams between the columns and secondary beams in-between did not suit the architectural design approach. The construction was meant to be minimalistic in its detailing, an approach which is also reflected in the choice of the beam cross-sections.

Fig. 3 The grid, prominently exposed when approaching the gate, is both an undulating ornament and an expression of the relationship between matter and force.

Fig. 4 Existing infrastructure and street layout defines the location of the new columns and the area that needs shelter.

The design team selected upstanding flat steel lamellas to form the structural grid of the roof. Being strong in y-axis but very weak in z-axis the elements needed to be positioned in a system where they mutually brace each other: A network of intricate interrelations replaces hierarches of primary and secondary structure. The roof is currently under construction and will be erected in August 2013.

It was prefabricated in seven parts in the workshop (Fig. 5) and assembled on the ground next to its final position on the bridge. After applying the final coatings of the anticorrosion paint the wooden covering plate and the waterproofing were mounted, so that the number of outstanding work steps after lifting the whole structure on the top of the bridge is minimised.

Fig. 5 Prefabrication of the canopy in the workshop

Fig. 6 The completed project in August 2013 © Messe Frankfurt/ Bach