Design, Refurbishment, Strengthening
Crouch Waterfall was requested by Network Rail to consider options to strengthen the structure beneath platform 1 at Ryde Pier. The original pier was constructed of timber members, which have degraded over time in the harsh coastal environment. This is particularly a problem on the pier legs between the low and high water levels also subject to erosion by water borne sand. Previous solutions to this problem, surrounding the pier legs in concrete, had unfortunately exacerbated the problem causing necking of the timber above the concrete jacket. Familiar with carbon fibre reinforced plates to strengthen bridge structures Crouch Waterfall looked at the possibilities of using similar composite materials. The solution was to use Fibre Reinforced Polymer (FRP) columns and beams for the superstructure, with galvanised steel plan cross bracing below deck level. The FRP columns, which are ‘H’ sections were then encased with High Density Polyethylene (HDPE) tubes to protect them from abrasion. The void was then filled with concrete.
The foundations comprised screw piles with a galvanised steel adjustable ‘table top’ pile cap to receive the columns. The foundation structure is all constructed below sea bed level. All works were undertaken in harmony with the tides without the need for significant cofferdams and dewatering.