Kilifi Bridge is the longest bridge in Kenya with a total length of 420 metres. The superstructure is a prestressed continuous box girder carrying two lanes. The bridge has three spans. The construction of Kilifi Bridge was completed in 1991.
At Sabaki, the mouth of River Athi (Sabaki at the coast) the current concrete bridge replaced a steel suspension bridge in 1996. The steel suspension bridge was eventually transferred and used at Masalani Bridge. The bridge length is approximately 184 metres with three spans. The superstructure is prestressed box girder carrying double lane. The substructure is reinforced concrete founded on piles.
Beam bridges
They are the simplest in structural forms. They are supported by an abutment at each end of the deck. Since no moments are transferred through the support their structural type is known as simply supported. Bridges designed for modern infrastructure will usually be constructed of steel or reinforced concrete, or a combination of both. The concrete used can either be reinforced, prestressed or post-tensioned.
Constructions could have various beams side by side (with a deck across the top of them), to a main beam either side supporting a deck between them. The main beams could be I-beams, trusses, or box girders. They could be half-through, or braced across the top to create a through bridge. Beam bridges are not limited to a single span. Some viaducts such as the interchanges under construction in Nairobi – Thika highway and Eastern by pass at North Airport road and City Cabanas have multiple simply supported spans supported by piers.
Beam bridges are often only used for really short distances because, unlike truss bridges, they have no built in supports. The only supports are provided by piers.
Some of the major bridges in the country under this category include: Nyali and Mtwapa bridges both in Mombasa city. The construction of the two bridges started in 1978 and completed in 1980 and was done by Sumitomo Construction Company under the supervision of H.P. Gauff.
