高速铁路下承式大跨度系杆拱桥无碴轨道桥面结构形式的对比研究

针对高速铁路下承式大跨度无碴轨道系杆拱桥,通过有限元分析,对桥面结构采用混凝土板与纵横梁半结合方案和全结合方案的动力特性、稳定性和受力性能进行综合对比研究。研究结果表明:与半结合方案相比,全结合方案桥梁刚度较大,尤其是横向刚度;桥梁动力特性和稳定性也较好;系梁承受的纵向力较小,桥面系参与系梁的第一系统作用较大,混凝土板应力水平整体较高,尤其是在端部节间;纵梁面外弯矩及其对应的面外弯曲变形都较小,横梁面内、面外弯矩及其对应的弯曲变形也都较半结合方案的小。建议半结合方案加强纵横梁交接处的局部构造,尤其是横梁与外纵梁交接处;全结合方案混凝土桥面板宜采用高配筋,特别是端部节间。

Comparison of deck structure of large span through tied - arch bridge with non - ballasted track on high - speed railway

Using the finite element method,the half-composite deck scheme and full-composite deck scheme between concrete and longitudinal-cross beams for through steel box tied-arch bridge with non-ballasted track on high-speed railway were studied.A comprehensive comparison was made with respect to dynamic characteristics,stability and force-bearing characteristics.The results show that the full-composite deck scheme has better lateral rigidity,dynamic characteristics and stability than the half-composite deck scheme.And the tie beams of the full-composite deck scheme endured less of the axial force and the deck system bears more.The stress of the deck slab is higher on the whole especially in the first panel.The out-of-plane bending moment and deformation of the longitudinal beams become less,and the in-plane and out-ofplane bending moment and deformation of the cross beams are also less than those of the half-composite deck scheme.The joints between the longitudinal beams and the cross beams of the half-composite deck scheme must be strengthened and reinforcement in the deck slab of the full-composite deck scheme especially in the first panel must be added.