大跨钢混叠合梁斜拉桥索梁锚固区局部应力分析

Local Stress Analysis of Cable Girder Anchorage Zone of Long Span Steel and Concrete Composite Girder Cable-Stayed Bridge

以某大跨钢混叠合梁斜拉桥索梁锚固区为研究对象,借助大型有限元程序ANSYS建立索梁锚固区有限元计算模型,采用弹塑性理论对索梁锚固区进行分析,通过逐级加载得到索梁锚固区在不同索力阶段的应力状态,并提出索梁锚固区极限承载力的简化算法,可直接指导设计。计算表明:锚拉板与索导管相连的倒圆弧区域应力集中明显,索梁锚固区极限承载力满足受力要求。正常使用状态下,锚拉板区域的混凝土桥面板上缘易出现拉应力,若开裂易进水将影响锚拉板的耐久性,有必要加强该部位的构造设计。

Taking the cable girder anchorage zone of a long-span steel concrete composite girder cable stayed bridge as the research object,this paper establishes the finite element calculation model of cable girder anchorage zone by the large finite element program ANSYS,and adopts elastic-plastic theory to analyze the cable girder anchorage zone.The paper obtains the stress situations of cable beam anchorage zone in different cable tension stages by gradual loading,and proposes a simplified algorithm guiding the design process of the ultimate bearing capacity of cable tension anchorage zone.Calculation results show that the concentration of stresses at the end of fillet welds between the tensile anchor plate and the tensile anchor is obvious,and the ultimate bearing capacity of the anchorage zone meets requirements.In service ability limit state,the upper edge of the concrete bridge deck in the anchor plate area is prone to tensile stress.If the easy water intrusion will affect the durability of the anchor plate,it is necessary to strengthen the structural design of the part.