刚构连续梁桥墩梁固节点结构的光弹性试验及有限元分析

某铁路特大桥的主桥部分采用预应力混凝土刚构连续梁桥,本文采用光弹性模型冻结应力法对该刚构连续梁桥墩梁固节点结构进行了应力分析,给出了结构边界应力分布和主应力迹线。应用ANSYS软件对墩梁固节点实际结构进行了有限元计算。将实验与有限元分析结果进行了比较,结果表明,实验应力分析法与有限元数值法吻合较好。在有限元分析中,对墩梁固节点结构梁端加载边界的影响区进行了研究,通过合理选择梁的长度可以有效减小局部应力。模型实验和有限元计算的结果为结构的优化设计提供了重要的依据。

Numerical Analysis and Photoelastic Experiment for the Joint Structure in the Rigid Frame Bridge with Continuous Beam

The main portion of a railway super bridge is a prestressed concrete rigid frame bridge with continuous beam. The total length of three-span is 216m. In this paper, using the three-dimensional photoelastic frozen stress method, the stresses for the pier beam joint structure in the rigid frame bridge with continuous beam were analyzed. The results of boundary stress distribution and principal stress trajectories were given as well. The pier beam joint actual structure was also analyzed with the finite element program ANSYS. After comparing experimental solutions with finite element results, it is shown that the results from experimental stress analyses agree well with the calculated data by using finite element method. In finite element analysis, we studied the influence area of loaded restraint at the end of beam in the joint structure, and find that it is effective to reduce the local stress by choosing appropriate length of beam. The results obtained from the model experiments and the finite element computations are helpful for optimizing the structure design.