THE INSPIRATION
SERVICEABILITY As the bridge will be maintained by the local community, it is important to keep this as simple as possible. The redundant system of arches allows major members to be easily replaced as necessary.
Structural members will be protected by the floor deck, which can easily be maintained. The proposed deck system will be created from splitting bamboo in half and joined to form roman-like shingles.
MATERIALS The bridge structure is formed from locally sourced bamboo.
The Bian-He Rainbow Bridge from the 900yr old famous Chinese painting by Zang Zeduan
The modular system means spar lengths are limited to 6m-7m - suiting transportation and availability. The form is rich in Chinese cultural and historical heritage in which arches traditionally express good emotion.
One of the unique features of the Rainbow Bridge is its interlocking arch made of wooden beams. This creates an arch that is as intricate as it is strong
The compression arch system avoids tension connections that can be difficult with bamboo.
THE SOLUTION The arched bridge is formed from “woven� straight wooden logs - appealing to the local tradition of woven baskets.
USERS LOCATION The design provides a free span with abutments above the max water level. Concept involves a series of arches that can accommodate variation in ground level
The wider bridge with a side rail will provide a safer crossing for the community, especially as it is used by children to go to school. The strong and robust design allows for the bridge used by variety of users - from barefoot farmers to buffalo.
JANE & RICHARD
The simple design results in a highly effective design that is capable of carrying people and cattle, is easy to build, does not require specialist tools or skill and uses component parts that are easy to transport.
6400
2500
CONSTRUCTION SEQUENCE Fix channel sections using chemical anchors to form buttresses Construct two outer arches on either side to support lateral members. Use temporary prop as required.
ELEVATION 1:100
3000
20000
Thread members in to install arches in sequence. Decking not shown for clarity Lateral Bracing
Hand Rail (non-structural)
PLAN 1:100
The catenary shape of the arch is the optimal for supporting a uniform load over the bridge. The paired 3 and 4 spar arches are arranged to approximate the catenary shape, allowing the load to be carried by compression of the members. Point loads require a bending stiffness to the arch to prevent local deformation of the arch. The pairing of the 3 and 4 member arches allows the bending stiffness of each spar to provide local restraint to the node at its midpoint against local deflection.
JANE & RICHARD
Add rail verticals and members. Install decking.