Isambard Kingdom Brunel, legendärer britischer Ingenieur, hätte im Jahr 2006 seinen zweihundertsten Geburtstag feiern können. Ihm zu Ehren fragt die University of Bristol: »How do you bridge the gap?« — Natürlich mittels einer Hängebrücke!
The task: save the view
The obstacle to bridge is the beautiful and highly dramatic location at the Avon Gorge linking Clifton with the Western side of Bristol. The structure to bridge that gap will be seen from far away becoming an iconic and magnificent landmark as well as an object of identification that stands for innovation and knowledge.
The concept: two decks
The basic geometry consists of two functional decks which are split up. The pedestrian deck which ties in at the center achieving lateral stiffness and the car deck that runs underneath it. Both cars and pedestrians have the same entrance level which separates towards the middle of the bridge, reuniting at the opposite end.
The wooden pedestrian deck gently slopes up from two entrance paths on each side to become a grand observation deck in the middle of the bridge, allowing the user and potential visitor of the bridge to enjoy the breathtaking scenery and outstanding natural beauty of the location. It is a universal space used as a cultural platform for different events like air balloon festivals, fireworks or a concert stage and will host temporary catering facilities. It also becomes a stunning open air cinema in warm summer nights and a well known gathering point for young people. Although being a designated event platform it is a public space at the same time allowing the user to gently drop by to enjoy the scenery and the happening. This place of outstanding public and spatial quality has a unique relationship with the sky above and the canyon beyond as it stages the geographical setting. As pedestrians stroll on the upper deck, cars pass the bridge underneath equally enjoying the stunning views as well as the exciting geometry of the bridge.
Located underneath the bridge directly in the magnificent structure of the abutments and the base, will be viewing platforms for visitors that could potentially host additional functions. People experience the bridge as an object and the amazing view into Avon Gorge and beyond.
The construction: prestress
The wing shaped abutments reintroduce tension forces exerted by three main Kevlar suspension cables back into the deck. These forces prestress the deck and increase its structural performance.
It is a system of Tensegrity as the structure stabilizes itself by balancing the counteracting forces of compression and tension. This reduces the use of material for the base that would be necessary for a self suspended bride, bringing the forces back into the rock which it is anchored to.
This concept of maximizing the efficiency also keeps member sizes slender and light contributing to the aesthetic appearance of the bridge.
Additional features: electricity
In integrating passive and active systems the suspension cables reintroduce forces into dampers that act as Piezo-Electricity generators and active damping mechanisms, tuning the bridge to optimize its performance in different load cases. Like a sail on a yacht is trimmed by the sailorman to act as efficiently as possible, so the bridge is actively tuned, manipulating tensions and deflections.
Through the electricity that is generated for lighting, the bridge becomes self sufficient and indicates usage by modularization of lighting. It interacts with the user and responds to load, so gaining another rather subtle spiritual quality.