小浪底库区黄河特大桥永久钢护筒沉放施工技术

南村黄河特大桥是黄河小浪底库区蓄水后首次在库区建造的桥梁,为了解决该桥永久钢护筒沉放难题,针对库区水位变化大、与外界不通航的特点,比选了目前常用的钢护筒沉放方案后,首次提出了在钻孔平台上采用履带吊配合龙门吊将永久钢护筒分节吊挂接长、分次振动沉设的施工方法,并介绍了关键施工工艺。工程应用结果表明,采用该施工方法和施工工艺在库区进行永久钢护筒的振动沉设施工是可行的。

Construction Technique of Sinking Permanent Steel Casing for Yellow River Grand Bridge in Xiaolangdi Reservoir

The Nancun Yellow River Grand Bridge is the first bridge built in Xiaolangdi Reservoir area of the Yellow River after its impoundment.In order to solve the problem of sinking permanent steel casing,the construction method of using the crawler crane and the gantry crane to lift the permanent steel casing on the drilling platform,weld,joint,vibrate and sink the casing section by section was put forward for the first time on the basis of the characteristics of the reservoir,including dramatic variation of water level and unnavigable status,after comparing and selecting the current commonly used steel casing sinking schemes.The engineering application results demonstrate that it is feasible to apply this construction method and technique to perform vibration sinking of permanent steel casings in the reservoir area.