悬索桥的锚碇-锚跨单元研究及应用  

Study and Application of Anchorage-Anchor Span Element for Suspension Bridges

作　　者：齐东春[1] 沈锐利[1] 唐茂林[1] 

机构地区：[1]西南交通大学土木工程学院,四川成都610031

出　　处：《公路交通科技》2011年第2期82-87,92,共7页Journal of Highway and Transportation Research and Development

基　　金：国家科技支撑计划资助项目(2008BAG07B05)

摘　　要：为在悬索桥结构分析中精确计算锚跨索股的张力,建立了包括锚碇、散索鞍及锚跨索股在内的3节点组合单元,该单元精确考虑了锚跨内各索股的空间走向,满足索股与鞍座相切及节点间索股无应力长度不变两个重要条件,并能考虑锚碇的沉降对锚跨索股索力的影响。假定成桥状态锚跨索股张力的合理分布模式后,根据散索鞍的自立平衡条件及锚跨索股与散索鞍的几何关系,迭代出索股与鞍座的切点坐标及切点索力,根据悬链线索的刚度矩阵定义并利用静力平衡条件推导出单元切线刚度矩阵。结果表明:将该单元用于悬索桥结构有限元计算中,能准确计算出锚跨索股的索力分布,提高锚跨索股施工控制的精度。In order to accurately calculate the tension of anchor span strands in structural analysis of suspension bridges,a three-node combination element,including anchorage,splay saddle and anchor span strands,was established.The element can precisely deal with the spatial location of each cable strand in the anchor span,contains two important conditions： the cable strands are always tangential to the saddle,and the unstressed length of the strands between node pairs remains constant,and also can take into account the effect of anchorage subsidence on the tension of anchor span strands.On the assumption that the distribution of tension of anchor span strands in completed stage is feasible,according to the equilibrium condition of splay saddle and the geometric relation between anchor span strands and splay saddle,the tangent point coordinate and tension were calculated by iteration,and the tangent stiffness matrix of the new element was derived by using the stiffness matrix of elastic catenary cable and the static balance condition.The result shows that the application of the new element can accurately calculate the tension distribution of the anchor span strands and improve the construction control accuracy of anchor span strands in computation of suspension bridges by FEM.

关 键 词：桥梁工程 锚碇-锚跨单元 有限元法 锚跨索股 散索鞍 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]