Hidak Nográd megyében (Salgótarján, 2007)

Mellékletek

Mellékletek bridges were used in the place of the bridges blown up. The reconstruction started in 1948, almost exclusively reinforced concrete bridges with steel girders were built, 8 of them in 1948 and 24 in 1949, the longest ones with 20.8 m span are the Zagyvabridge by Tar and the Szentlélek-stream bridge by Szécsény. The bridge reconstruction was actually finished by 1952, excluded the Ipoly-bridges, and the bridge construction together with the road modernisation started, e.g. alongthe new route of the main road no. 21. The precast bridge girders FT that were made for bridges of 2-10 m spans can be considered as an important step forward in the construction of reinforced concrete bridges; by now, 75 bridges of such superstructure were built in the county. The use of precast bridge girders and of pile foundation made it possible that the too weak or narrow bridges or the ones which had not fitted intő the horizontal alignment of the road were reconstructed. Reinforced concrete frame bridges, as the frame with "turned-in legs" and 22 m span were built in 1963. A Freyssinet-type post-tensioned bridge with "saving cavity" and 20 m span was constructed in Mátraverebély in 1963, however, this bridge type has not come intő generál use. The bridges with spans above 10 m have been built in the county with precast (EHG) bridge girder since 1976; the longest one of such bridges has a span of 20 m. The longest spanned reinforced concrete bridge in the county is presently the continuous, hollowtubulargirdered Ipoly-bridge with 28 + 34 + 28 m spans built by Balassagyarmat in 1967. Two major flyovers are being built in Salgótarján; one of them is 139 m long with 5 spans, the other one 221 m with 9 spans. Steel bridges have been built in the county only, e.g. a "basket-eared" pedestrian bridge of 36 m span in 2004 and a railway truss bridge of 38.6 m span in Salgótarján as a part of a road modernisation. Ofthe bridges of county Nógrád, the Ipoly-bridges deserve a special attention. 47 bridges could have been found between Ipolytarnóc and the mouth of the river till 1920; presently, there are 12 of them, 4 bridges (road and railway ones together) exist in the area of state bordér. Hungary and Slovakia have agreed in the construction of new bridges at the major bordér crossing points. Two bridge designs in Rárós and Pöstény are already completed, other designs will be made for Kóvár, Ipolydamásd, Drégelypalánk, Hugyag, Nógrádszakái, Őrhalom, Ipolytölgyes, Vámosmikola, Ipolyvece. Summary There are 347 bridges on the national public road network of the county with a totál surface area of 26 103 m

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. The majority of the bridges (94%) has a span under 10 m, only 1 bridge has a span above 30 m. 81% ofthe bridges are of reinforced concrete superstructure, the structure of 12% is reinforced concrete with steel girder, while 7% of them have stone arch. Just 24% ofthe bridges were built before 1945, so the bridge stock is relatively young, the load bearing capacity and the width of the bridges are usually appropriate, there is no limitation on the main roads. The railway lines have 111 bridges of usually short spans with a totál length of 928 m. There are 25 with a span above 10 m, the highest (37.8 m) span was built in 2006. They are older than the highway bridges since 38% of the stock was built before 1945. There are 530 bridges on the local (municipality) public roads, 222 of them are pedestrian bridges. Most of the bridges have short span, only 2 bridges have spans above 15.0 m.The numberof temporary bridges amounts to 150. It can be seen that the county of relatively small area has more than 1000 bridges includingthe priváté, forestry and other structures. The book presenting the bridges in county Nógrád, the 15th volume of the series is destinated mainly to Professionalists, however, their illustrations can inform anybody interested. The book has the following chapters: geographical conditions, the forming of the highway system, early bridge history (timber bridges), arches, irón and steel bridges, reinforced concrete bridges, bridge reconstruction, bridges and art, the bridge stock of the county: national public road bridges, local public road bridges, railway bridges, Ipoly and Zagyvabridges, description of somé particular bridges, bridge names, appendices, chronology, designers, contractors, literature. In the completion of this book, designers, contractors, museums, archives, and, especially, road managers provided a significant help by making sources and illustrations available, a special thanks for that. The authors ofthe publication are engineers: Gyula Frics, Bence Hajós, Ms Erzsébet Kardos-Pintér, Tamás Makai, László Szabó, Ákos Ürmössy and Dr. Ernő Tóth, the editor of the book. The English summary was made by Dr. László Gáspár, and the Germán one by Dr. Herbert Tráger, the reader of the book. The book was published for the 48th Bridge EngineeringConference. 168