Highway Bridges Bespoke Steel Stayed Bridges
REIDSTEEL HIGHWAY BRIDGES STEEL STAYED BRIDGES
Effective spans 35-100m with one tower; 70-200m with 2 towers.
The Carriageways can be as you specify the distance between crash barriers.
They will have local Reinforced Concrete decks 0.25m thick, placed on our lost formwork decking with no propping needed. They can have 0.05m of surfacing; or they can have anti-skid steel decks if the bridges are temporary or relocatable.
They have three levels of steel crash barrier on both sides of the carriageways so that neither trucks nor their payloads can hit or damage the steel stays.
The Bridge Decks are carried by a series of sloping stays from a tower at the 'home' end of the bridge; or from towers at both ends. Several stays at different angles go from the top of the tower down to the deck. These towers are stabilised with a bracing system between them above 6m clear of the carriageways. The bridge stay loads are resisted by stays on the land side of each tower going down to substantial anchor blocks.
The bridge decks can be cambered from side to side using pre-cambered steel transoms; and slightly cambered from end to end using the adjustment of the stays.
There can be two walkways, both outside the main trusses, as wide as you like, with handrails outside. The pedestrian, handcart and cycle traffic using them is protected from the vehicle traffic by the crash rails and main trusses.
The decks of the walkways are local reinforced concrete 0.125m thick placed on our lost formwork decking; or they can be in anti-skid steel if the bridges are temporary or relocatable.
The bridge steel is entirely bolted together using regular high strength tension and shear bolts. There are no friction grip bolts. Most of the main connections are end-plated. Adjustment is by means of steel packs which can be inserted between end plates.
The bridge steel is all in pieces which can easily be transported in 20ft or 40ft containers, or on regular road vehicles.
The bridges are designed to British Standard BS 5400 for 2 lanes of full highway loading, and for 30 units of HB loading, equivalent to an occasional 120 tonne truck; or you can specify your own loading system. All the structural design is in house by Reidsteel.
All the steel work is hot dip galvanised 85microns, 610gm/m2, for long low maintenance life; or you can specify your own coating.
There are two arrangements possible: either the towers and the anchor block are on one side only, with a stayed bridge stayed only form one side of the gap and with a short simply supported link at one end: or there can be towers and anchor blocks at both ends, with a simply supported link at the centre of the span. The first step is the erection of the abutments, anchor blocks, towers and back-stays. Then the first segment of deck is erected, and the first transoms bolted between them. A railway is built on these transoms, and on the railway an erection gantry. The erection gantry permits the addition of the steel stays and then further extensions of the bridge deck, and further stays. For a bridge with towers at both sides, 2 erection gantries may be used at the same time.
The bridges will sit on our steel bearings on your abutments. Expansion joints for the roadway are provided at both ends of the simply supported link section.
The erection gantries are re-usable on other bridges of the same span.
Our work carries a ten year warranty.
When access to the gap is not possible. When a cantilever launch is not possible because of curved approaches (as long as a distance of about 35% of the length of a single tower is available, or 18% of a double tower bridge). When widthways extension is not wanted. A single tower stayed bridge is practicable for lengths of 35m to 100m. A double tower bridge is practicable for lengths of 70m to 200m.
To find out more about your Steel Stayed Bridge specific requirements, please complete our Highway Bridge Enquiry Form.