高速铁路槽形连续梁拱桥拱脚局部应力分析与验证

为了解高速铁路槽形连续梁拱桥拱梁固结段的真实应力状态及验证局部分析中边界条件表达的准确性,以济青高速铁路(66.5+142+66.5) m双线有砟轨道预应力混凝土连续槽形梁拱桥为工程背景,利用FEA有限元软件建立细化的空间实体有限元模型,分析中支点横截面空间效应,并对局部模型的边界条件模拟的正确性进行验证。分析表明:中支点截面应力呈现明显的空间不规律现象,恒载比活载剪力滞效应更为明显,局部位置如拱肋与主梁连接部位、主梁下缘支座处、横隔板进人孔倒角处应力集中,应适当加强配筋,其余部位应力均满足要求,通过验证局部模型的内力分布,确保实体模型应力结果的准确性,保证结构安全。

Local Stress Analysis and Verification of Arch Foot of High-Speed Railway Continuous Channel-Beam Arch Bridge

In order to investigate the real stress state of the arch foot of the prestressed concrete continuous channel beam arch bridge and verify the accuracy of the expressed local boundary conditions, a refined space solid finite element model is established. With the model, the spatial effect at the section of the support is analyzed and the accuracy of the expressed local boundary conditions are verified with reference to the engineering of a(66.5+142+66.5) m ballasted double line prestressed concrete continuous channel beam arch bridge on Jinan-Qingdao high-speed railway line. The analysis shows that the section of the support presents obvious spatial irregularities and the dead load is more irregular than live load in shearing force lag effect. The analysis also indicates that the pier-tower-girder fixed region experiences stress focus at several local positions such as the connection part of arch and girder, bearing edge, chamfer of manhole, where reinforcement should be strengthened appropriately, and the remaining parts' stress can meet the requirement. The accuracy of the solid model stress results is guaranteed by the validation of the local model's internal force distribution. As a result, the structural safety is ensured.