摘要
异形桥塔使城市桥梁的景观效应得到显著提升,但独特的外形设计会导致其局部产生开裂风险。为改善异形桥塔开裂区域的受力状况,以某自锚式悬索桥为工程背景,采用拓扑优化法构建了其“合手”形桥塔的拉压杆模型,校核压杆和节点承载力,计算拉杆区域所需的预应力筋数量,并对预应力补偿设计进行了验证。结果表明,采用拓扑优化法构建的桥塔拉压杆模型能很好地满足异形桥塔的受力要求,压杆和节点的承载力均大于桥塔的设计内力;对桥塔开裂区域的预应力补偿可以大幅度降低混凝土桥塔的拉应力,在成桥状态下的最大主拉应力为1.79 MPa,小于材料的抗拉强度限值(2.65 MPa);桥塔在整个施工过程中未现开裂迹象,基于拉压杆模型的桥塔预应力设计可以有效预防异形桥塔复杂应力区域的开裂。可为同类型桥塔的开裂控制提供参考。
The special-shaped bridge tower has significantly improved the landscape effect of urban bridges,but the unique shape design will lead to local cracking risk.In order to improve the stress condition of the cracking area of the special-shaped bridge tower,taking a self-anchored suspension bridge as the engineering background,the topological optimization method is used to construct the strut-and-tie model of its"hands-shaped"(put one's palms together)bridge tower,check the bearing capacity of the strut and node,and calculate the number of prestressed reinforcement required in the tie area.Combined with the calculation data of the construction process,the prestressed design of the cracked area of the bridge tower is verified.The results show that the strut-and-tie model of bridge tower constructed by topological optimization method can well meet the mechanical requirements of special-shaped bridge tower.The bearing capacity of struts and nodes is greater than the designed internal force of the bridge tower.The prestress compensation for the cracked area of the bridge tower can greatly reduce the tensile stress of the concrete bridge tower.The maximum principal tensile stress in the completed bridge state is 1.79 MPa,which is less than the tensile strength limit of the material of 2.65 MPa.The bridge tower shows no signs of cracking in the whole construction process,indicating that the prestressed design of the bridge tower based on the strut-and-tie model can effectively prevent the cracking of the complex stress area of the specialshaped bridge tower.The research results of this paper can provide reference for the crack control of the same type bridge tower.
作者
缪伟
MIU Wei(Fujian Provincial Traffic Engineering Cost Station,Fuzhou 350001,China)
出处
《公路》
北大核心
2025年第12期161-168,共8页
Highway
关键词
桥梁工程
桥塔
拉压杆模型
拓扑优化
有限元
预应力
bridge engineering
bridge towers
strut-and-tie model
topology optimization
finite element method
prestressing
