Hidak Csongrád megyében (Szeged, 2003)

Összefoglaló, Zusammenfassung, Summary

carbon steel Gerber's hinge truss bridge designed by Professor Dr. János Kossalka and Gerő Szikszay in 1925 and 1926. In September-October 1944, during the World War II, all river bridges of the county were destroyed by air-raid or explosion. Also seven minor bridges were ruined. It was a huge task to reconstruct the Tisza-bridges. In Algyő, the 100 m long river span and every flood area span were blown up. For the restarting of traffic, the sound part of river span had to be lifted from a depth of 30 m and to be supplemented, furthermore the flood area spans had to be reconstructed using several pieces and added parts. For the Tisza-bridge between Csongrád and Szeged, the river span had to be divided into two shorter spans by adding a new pillar to it in order to solve the reconstruction by a military bridge and an unused railway truss structure. Both bridges were reconstructed by the end of 1946. The size of the work can be characterised by the 3.7 million man-hours spent for bridge reconstruction. Two spans of the highway Tisza-bridge in Szeged were destroyed. It could not be replaced since the stability of the river span became critical due to several reasons in 1942. Thus a new bridge with a changed span distribution: a 147 m span Langer-girder arch was built, the flood area spans became continuous girders. The iron structure of two sound spans were used in the construction of four other bridges in the country. After the World War II, almost exclusively only minor reinforced concrete bridges were built, from 1960 on with precast superstructures. In 1970, an intensive bridge rehabilitation started with the construction of Maros and Tisza-bridges. In 1974, the Maros-bridge in Makó was modernised using a three-span combined steel-reinforced concrete structure stiffened by skew bars, then in the same year, a new highway Tisza-bridge was completed in Algyő. The three-spanned river-bridge is a steel construction with changing height and prestressed reinforced concrete slab; the FÜGGELÉK flood area bridges are six and four-spanned with site prestressed girder superstructure. The girders of 24,8 m length are of segmented construction with post-tensioned joints. In 1976, the flood area spans of then only railway Tisza-bridge by Algyő were reconstructed to continuous truss bridge. The river span was substituted by a new truss structure already in 1960. In 1979, the second highway Tisza-bridge was completed in Szeged which is the largest bridge on the national highway network. The longest span of the 19-span bridge amounts to 144 m, its total area exceeds 15000 m

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. This bridge has welded joints similarly to other structures built after 1970. It is of steel plate superstructure. The steel girder bridge of changing height has four spans. The next large steel bridge was the total reconstruction of the Tisza-bridge between Csongrád and Szentes which carries already just railway traffic. Beside the pillars constructed in 1903, new pillars with Soil-Mec bored pile foundation were built; the river pillar constructed temporarily in 1946 was removed. A 3-spanned truss-bridge with new span distribution and a deck plain web girder above the flood area were made. For the pushing in of welded bridge structure, PTFEplates were utilised for the first time. In a seven-year period, four new Tiszaand one Maros bridges were built using upto-date techniques. The period after 1974 was active from the point of view of reinforced concrete bridge construction. Beside the steel structures mentioned, a 112 m and a 72 m long reinforced concrete flood area bridge was built for the Maros-bridge by Makó. The 9 and 6-spanned parts of the new highway Tisza-bridge in Szeged are of 236 and 152 m length, they have curved form and EHGT-girders. 212 SUMMARY