STRESSED RIBBON FOOTBRIDGE IN THE PEAK DISTRICT

The bridge, which is the first of its kind in this country, is essentially a very simple structure consisting of a prestressed concrete ribbon 160 mm thick hanging in a shallow catenary. The ends of the catenary are supported by reinforced concrete abutments interconnected below the surface of the railway cutting by struts and anchored to the ground by near-vertical ground anchors. The ribbon is prestressed so that under the worst loading conditions there is a small compressive stress throughout the span. Conventional galvanised steel handrails are used which play a significant role in helping to damp vibration set up by foot traffic. An alternative design for the bridge utilising pre-cast concrete panels is also discussed.(a) /TRRL/