Spanning the Guishui River in an unspoiled natural setting, this new highway bridge serves to provide an optimal link between two future international events to be held on opposite banks: the 2017 Horticultural Expo and the 2020 Winter Olympic Games.
Our design for this bridge was informed by both classic arch bridges found in the region, as well as innovative use of large spanning shell structures, optimized by new parametric design tools. The result of our design research is a unique three-tiered structure – shell arch, metal truss and roadway deck - that is both efficient and visually light, and avoids any support structure above the roadway.
The proposed design is comprised of three brick clad shells spanning 139 meters each combined with a light-weight metal truss supporting the flat car deck above. The three elements working together form an efficient use of materials – a hybrid structural composition - visually dynamic at both a distance and up-close: the double-curvature shape of each of the shells create extra rigidity over the same thickness, will possibly be the largest masonry arches to be built to date.
The bricks are the visible finish to the arches and serve to strengthen the shell in compression, as well as used as a lost form-work for the concrete pouring during construction, for a tight project timetable.
Working in conjunction with the arch is a grid of slender metal trusses that dissociates visually the bridge roadway from the arches. The concrete roadway deck above, with its large 56 meter width, split by a linear open slot along the entire length of the bridge, completes the three-tiered composition, and visually floats above the masonry shell arches.
These three architectural and structural choices allows each element of the bridge to be easily “read”, reinforcing the duality of the bridge as both light-weight and monolithic, movement and stability, past and future, rapid (car) and paced (pedestrian) flow.