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美国路易斯安那州卢凌市赫尔鲍格斯大桥于1983年10月5日建成通车,时为跨越密西西比河的第一座斜拉桥。该桥很多拉索的聚乙烯保护层在施工和运营期间出现破损。已往的维修工作都试图弥补拉索保护层的缺陷,但大多数未能奏效,没有起到对主承拉构件的保护作用。在72根拉索中,有39根急需维修。为了解决这些问题,并且保证桥梁结构的整体性,通过费用分析,对维修和换索方案进行了评估,最后决定更换全部拉索。更换全部72根索的方案在北美属于首例,最终的换索方案在很大程度上受到了原锚位几何形状的制约。新索的设计寿命是75年,并且在防腐及减振方面融入了最先进的技术。该桥是重要的区域性连接通道,也是发生飓风时的疏散路线。为了尽量避免对公众和商业带来不便,作为这一项目不可缺少的内容,进行了换索期间保持交通畅通的设计。
Columbus Bridge, Lu Ling, Louisiana, USA was opened to traffic on October 5, 1983, the first cable-stayed bridge to cross the Mississippi River. Many of the cable’s polyethylene coverings were damaged during construction and operation. Previous repair efforts have tried to make up for the deficiencies of the cable sheath, but most failed to work and failed to protect the main tensile members. Of the 72 cables, 39 are in urgent need of repair. In order to solve these problems and to ensure the integrity of the bridge structure, the cost of repair and replacement programs were assessed and the final decision was made to replace all the cables. The first of its kind in North America was the first of its kind to replace all 72 cables, and the final cable change was largely constrained by the original anchor geometry. The new cable has a design life of 75 years and incorporates state-of-the-art technology in corrosion protection and vibration reduction. The bridge is an important regional link and is also an evacuation route in the event of a hurricane. In order to avoid any inconvenience caused to the public and businesses as much as possible, as an indispensable part of this project, a design was put in place to maintain smooth traffic during the search.