| 摘要 |
1,188,958. Prestressed concrete bridges BATAAFSCHE AANNEMING MIJ N.V., V/H FA. J. VAN DER WAL & ZOON. 1 Aug., 1967 [13 Jan., 1967], No. 35302/67. Heading E1G. In a method of building a prestressed concrete bridge by abutting and connecting prefabricated sections 1, m, n, o &c., end to end, an auxiliary girder 4 is extended from an existing span 3 to the next pier 2, and the sections are successively brought along the girder (e.g. by trolley 5) and suspended in the required positions by individual rods 6 and jacks 8, all the jacks being hydraulically interconnected. The abutting sections are successively glued together and connected by temporary pre-stressing elements 7. The jacks 8 serve effectively to support the sections under all the changing loads as building proceeds. When all the sections have been assembled on the girder 4 the latter may be displaced to bring the new span into engagement with the span 3. The two spans are then interconnected by permanent pre-stressing ropes, Fig. 3 (not shown), before the jacks are released, and the elements 7 may then be removed. In a modification the sections are progressively attached to the existing span 3. |
