METHOD FOR LATTICE SPAN STRUCTURE DISASSEMBLING BY SPAN STRUCTURE DIVISION INTO THREE-DIMENSIONAL BLOCKS Russian patent published in 2007 - IPC E01D22/00 

FIELD: bridge construction, particularly to disassemble metal span structures (trusses) for overhaul of bridge included in existent motor roads or motor roads under construction.

SUBSTANCE: method for bridge span having upper belt height of up to 30-35 m over water surface and length of more than 40 m involves constructing temporary supplementary piers in areas of span structure separation into three-dimensional blocks; installing hydraulic jacks on temporary piers under lower truss joints; provisionally retaining thereof against vertical displacement for at least span structure separation time by shimming thereof with steel sheets arranged at permanent or supplementary supports; separating span structure into three-dimensional blocks having lengths of not less than 20 m by cutting-off separate truss members along with internal truss strain regulation to provide internal truss strain within the range of static load applied to truss members and not exceeding design load by shimming and/or by means of hydraulic jacks installed at supplementary piers; performing block strapping; releasing three-dimensional blocks and demounting thereof with the use of floating crane with at least 80 tons lifting capacity; moving three-dimensional blocks to preliminarily prepared receiving building berths for further division thereof onto smaller parts; demounting temporary piers. Bridge span structure may be separated beginning with upper belt and then lower belt is disintegrated starting with upper truss plane. The receiving building berths are arranged on banks. Separated three-dimensional blocks are moved to the berths by means of floating crane immediately after demounting thereof so that this becomes unnecessary to transmit the block on barge or pontoon. In another embodiment the receiving building berths may be formed on banks and three-dimensional blocks may be moved thereto by means of floating crane after block laying on barge or pontoon.

EFFECT: possibility of bridge disassembling without water body occupation with floating crafts and temporary supports, as well as decreased labor inputs and costs of bridge disassembling.

4 cl, 4 dwg