Bio-inspired Bridge Design - Biotechnologies and Biomimetics for Civil Engineering - page 237

Fig. 10.5 Bio-inspired design proposals: a Douglas river bridge (photo Exploration Architec-
ture); b Spiral bridge
concrete in a stone arch (Billington 2003 ). Therefore, future structural form must
be material-adapted to achieve high efficiency.
Figure 10.5 shows three bio-inspired proposals of new structural systems. A
bridge crossing the River Douglas in Lancashire (Fig. 10.5 a) was turning biomi-
metic research into pioneering lightweight structures with small steel elements and
a pressurized air beam.
This design was inspired from the internal pressures seen in nature which create
self-supporting structures. Another interesting design (Fig. 10.5 b) has a series of
intersecting spirals as the structural system. The designers incorporated a seedpod
spiral shape from the tree Tipuanatipu and a rectilinear lattice seen in the
Euplectella as bridge cover (Dollens 2005 ). The spirals also reflect the colors of
the trees, light so that they will merge into the environment. It is noted that the
optimized structural form in future bridge designs should utilize appropriate
material-adapted form and certain manufacturing technology.
Energy costs on man-made structures are always a big concern. Future bridges
may also play an important role relating to sustainability and the use of green
energy. ''Green'' bridges are designed to reduce the overall impact of the built
environment on the natural environment. The idea of ''running on natural energy''