大跨度连续钢桁梁桥无支墩顶推施工可行性分析

摘要

With the advantage of no-effect to shipping ,shorter construction time and lower cost ,the incremental launch-ing construction method without supporting piers is widely used in the construction of steel and prestressed concrete bridges .At home and aboard , the cases of incremental launching construction of long-span bridges whose cantilever length exceeds 160 m are rare ,and the feasibility research on incremental launching construction method in long-span bridges is insufficient .With the example of Dongying Yellow River Bridge ,the feasibility of the incremental launching construction method without supporting piers was analysed by using finite element method .The results indicate that ,the strength of bridge can’t meet the constructional requirements when the length of launching nose is 80m ,and the strength and stability of bridge will both meet the requirements when the length of launching nose is 100 m or 120 m .So the method of incremental launching construction is feasible .%无支墩顶推施工技术具有不影响通航、工期短和施工成本低等优点，广泛应用于钢桥与预应力混凝土桥梁施工。国内外桥梁顶推施工，最大悬臂长超过160 m的顶推施工案例较少，对大跨度桥梁无支墩顶推施工的研究有所不足。以东营黄河铁路特大桥为工程背景，采用有限元方法，计算分析大跨度连续钢桁梁桥无支墩顶推施工方法的可行性。研究结果表明，设置80 m长导梁，不能满足结构强度要求；设置100 m或120 m长导梁，可满足施工过程中强度和稳定性要求，故该桥采用顶推施工方案具有较大可行性。