外文翻譯--斜拉橋的未來-其他專業(yè)-展示頁
2025-01-31 10:11本頁面
【正文】 fety against buckling in the deflected stage. d) The spacing of the cables should be such, that no heavy erection equipment is needed to cantilever out for placing the next following stay cable. e) Feasible spacings may be between 6 and 12 m for concrete girders and between 8 and 16 m for steel girders. In order to satisfy these rules, my office developed a new type of cable anchorage in cooperation with BBR Switzerland, which allows ultimate cable forces up to almost 2,000 tons, using parallel wires or strands of very high strength, inside a polyethylene tube for perfect corrosion protection. The anchorage was developed to get high fatique strength, therefore called High Amplitude(HiAm) cable. These cables can be prefabricated and shipped on reels and allow a simple and inexpensive erection. Several bridges have been designed lately using these principles:The Pasco bridge, bridges in Parana, Argentina, and others. As we designed these bridges, I knew already the favorable effect of system damping in multistay cable bridges by experience which I had gained from the behavior of a pedestrian stay cable bridge in Stuttgart, but we had to prove the dynamic safety for these larges. A dynamic model test was made at the Ismes Institute of Profssor Oberti in Italy, 18 m long designed for full dynamic similitude. Short and long trains or just lootives could run on the rails with different speedsno adverse oscillations could be detected. Then the test engineers excited artificially oscillations going through all possible modes and frequencies and at many points of the b
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