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Đure Jakšića 3
11000 Belgrade, Serbia
To build the crossing from the mainland to the Island of Krk two sea canals had to be overbridged. Tihi Canal between the mainland and the Island off St. Marko with the water table of 462 m width, and Burni Canal between the islands of St. Marko and Krk of 250 m width.
The basic designing and construction execution problems had to be solved by way of overbridging with greater bridge span. Introducing the arch foundations and supports into the sea, the span of the concrete arch structure was brought to 390 m. In ,spite of that. the greatest ,span of the concrete arch in the world existing up to that time i. e. the bridge arch of the Gladesville Bridge on the Parramatti near Sidney. was surpassed by 85 m.
§ The arches were made from prefabricated elements with cantilever application. and they were held from the coast by the system of temporary steel tie-rods. In order to decrease forces in these temporary structures which provided the arches with cantilever support during the construction, they were built in two or more stages: first, the central part of the box cross section, and then their lateral ports which after being joined in the apex became monolithic creating a unity. The execution of the central part of the box cross section of this big reinforced concrete arch is original, very brave solution by cantilever method of building, with concrete assembly elements. Special problems occurred clue to very strong winds (hurricane storm with the speed of 142 km/h) which required additional safety measures.
§ Besides the method of construction of the arches, the building of this bridge vas full of other very interesting and original technological construction procedures:
- foundation for big arch by means of concrete assembly elements of individual weight of over 600 t;
- manufacture of very slim and specially light piers in sliding forms;
- manufacture and erection of concrete prestressed girders for carriageway structure above high and slim piers using a launching truss;
- manufacture of assembly elements for carriageway concrete slabs
- anchoring in the rock material with the force of about 10,000 tons which was present in the main tie-rod for arch bracket support;
- manufacture of two cable cranes with the span of 635 m each. and a pylon up to 80 m high.
§ In the bridge there were incorporated about 3,60 m3 of plain concrete, 20,500 m3 of reinforced concrete, 4,500 tons of reinforcement and about 130 t of prestress high yield wire.
§ On average there used to work about 350 Iabourers on the bridge