The Mingshan Changjiang River Bridge is located in the Three Gorges Reservoir, the main bridge of which is a steel box girder cable-stayed bridge with a main span of 680 m.Due to the restrictions of topographical conditions and water level variation, the steel box girders in the hillside steep slope region between No.0 and No.1 piers as well as the water rising and falling region between No.1 and No.2 piers could not be hoisted and erected by the conventional way of using deck crane and barges, in the low-water-level period.In such cases, two construction schemes were proposed, one suggesting the combined use of the girder-delivery sliding system, luffing deck crane and girder storage frames, and the other the combined use of the girder-delivery scaffolding system, luffing deck crane and girder storage frames.The two schemes were compared from aspects of safety risk and economic performance, and the former was determined as the final option.The steel box girder sections in the barges were first lifted and placed onto the trolleys on the sliding tracks by the floating cranes, the trolleys were pulled by a traction system to the erection locations just under the girder, and then, the steel box girder sections were lifted to the storage frames between No.0 and No.1 piers by the luffing deck crane one by one.%名山长江大桥位于三峡库区内,其主桥为主跨680 m的钢箱梁斜拉桥.受地形条件及水位变化的影响,低水位时,南边跨0号、1号墩之间的山侧陡坡区及1号、2号墩之间的水位涨落区钢箱梁无法按照常规的"桥面吊机+运梁船"方式进行梁段吊装施工,因此提出方案一(运梁滑道系统+变幅式桥面吊机+存梁支架)和方案二(运梁支架系统+变幅式桥面吊机+存梁支架)2种施工方案.通过安全风险、经济效益等方面的比选后,最终决定采用方案一,即首先利用浮吊将运梁船上的钢箱梁逐个吊放在滑道上的运梁小车上,其次通过牵引系统将运梁小车移到吊装位置正下方,最后通过变幅式桥面吊机将钢箱梁逐个起吊、变幅,存放至0号、1号墩之间的存梁支架上.
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