The FengHua Brigde that located in Tiajin, China, was designed and completed by Marc Mimram Architects in 2007. The Fenghua Bridge project provides the opportunity to develop two themes: one on the geographical anchorage of the structure on the river, the other on the sign of modernism attached to the technological and artisanal capacities of contemporary China. The Fenghua Bridge project combines a complex structure fashioned by multiple arches developed in space according to the unchanging necessities but also developed on the essential links between these arches which were labeled in the project as “the petals”. These petals have two objectives: to connect the arcs to form a rigid structure resistant to the buckling of the very fine members of its arches, and to capture the light day and night along with the movements of the sun , and in function with the orientation of the cars on the roadway.
The 9 arches of the central span consist of box-girders welded together, where their dimensions are reduced to 40 cm wide by 55 cm high for a span of 127 m. They are shaped along the curves developing in the space permitting a global variation of the inertia of the structure according to the needs of the course of the forces. 128 petals link these arches to align and account for the internal stiffeners of this spatial structure. They are of 64 different types, varying between 2 m x 3 m and reaching up to 9 m in their maximum dimension. They form double curvature surfaces aligned by the geometric links between the arcs and their position in space.
The tailoring of these petals is a very particular expression of the connection between very advanced technology (reinforced polymerized fiberglass resin and metallic structure) and learned crafting in the fabrication of 64 molds of complex and elaborate geometries. By day, the petals capture, in their east-west orientation, the movements of the sun in the Tianjin sky. By night, they serve as large diffusers of light and transform the structure into a succession of orientated and separated reflectors floating above the river.