自锚式悬索桥桥塔钢—混结合段局部受力分析

摘要

To study the local stress distribution and the force condition characteristics of connectors for the steel and concrete joint section of the tower of self-anchored suspension bridge with double cable planes and to check if the local stress of the joint section could accord with the design requirements,the Sixth Jianghan Bridge in Wuhan was cited as an example.The finite element software ANSYS was used to set up the three-dimensional model for the joint section,the load cases of the construction process,completed bridge dead load and the greatest axial force were analyzed and the stress distribution and stress changing of the principal components of the steel structure,concrete structure and prestressing anchor rods of the joint section in the construction were acquired.The results of the analysis indicated that with the exception that the stress of a few stress concentration points was great,the stress levels of the joint section generally could accord with the design requirements.In the light of the calculation results in the analysis,the optimization proposal for dividing of the construction stages was made and it was also proposed that the first time pushing of the tower saddle should be carried out appropriately ahead of time in order to avoid that the local compressive stress in the lower columns of the tower would be too great and the reinforcing measure of adding indirect reinforcement to the areas with great principal tensile stress between the latticed columns of the steel tower part should be taken.%为研究双索面自锚式悬索桥桥塔钢-混结合段局部应力分布和连接件的受力特点、验证该部位受力是否满足设计要求,以武汉江汉六桥为背景,利用有限元软件ANSYS建立桥塔钢-混结合段三维模型,对施工过程、成桥恒载和最大轴力等工况进行分析,得到结合段钢结构、混凝土及预应力锚杆等主要受力构件在施工过程中的应力分布和变化情况.分析结果表明,除少数应力集中点应力较大外,整体上结合段的应力水平符合设计的要求,针对计算结果对施工阶段的划分提出了优化建议,建议适当提前第1次鞍座顶推的时机以避免下塔柱局部压应力过大,对钢桥塔格构柱间主拉应力较大区域采用增设间接钢筋的加强措施.