对我国高速铁路上的第一座大跨钢箱叠合拱桥哈大高速铁路138 m新开河桥进行了拱脚结构局部应力分析.根据圣维南原理,运用ANSYS有限元计算软件,利用壳单元和梁单元建立了精细的系梁-拱肋-吊杆-横梁的空间计算模型,根据结构的实际情况模拟边界及荷载,对桥梁结构在恒载及客运专线活载作用下拱脚位置的应力分布情况进行了分析.计算结果表明:新开河桥拱脚的支座顶板部位和钢箱系梁变截面位置的应力较大,虽然未出现超过材料屈服应力的现象,但是为了保证桥梁使用的安全,在设计和施工中应加以重视.
The local stress is studied on the arch-spring structure of the Xinkai River Bridge on the Harbin-Dalian high-speed railway, which is the first long span steel box stacked tied arch bridge for high-speed railway in China. According to the Saint-Venant Principle, a detailed analysis model of "tied girder-arch rib-suspender-cross beam" system is established with shell and beam elements by using the ANSYS software. The loads applied on structure and the actual boundary conditions are simu- lated, and the stress distribution at the arch-spring under the dead-load and the live-load of passenger dedicated line is obtained. The calculation results show that the stresses at top support plate and the variable cross-section place of tied girder are rather high. Although they are within the yield stress allowance of the steel material, it is also worth paying more attention to the local stress at arch-spring in design and construction to ensure the working safety of the bridge structure.