高速铁路下承式结合梁系杆拱桥桥面结合方式

Composite Deck System of Through Tied-Arch Bridge on High-Speed Railway

针对高速铁路下承式结合梁系杆拱桥,通过有限元分析,对纵横梁桥面系和密布横梁桥面系2种结合方式、混凝土桥面板不同的分块方式等问题进行研究。结果表明:纵横梁桥面体系在纵横梁交点处存在应力突变,其横梁应力较密布横梁高。对于密布横梁方案,随着混凝土断缝数量的增多,系梁挠度增幅不大,系梁和拱肋内力变化不大,但横梁应力有所降低,混凝土桥面板的整体应力大致呈降低趋势;在施工上,密布横梁体系比纵横梁体系简单方便。对于128 m跨度双线下承式钢系杆拱桥的桥面结合方式,建议采用密布横梁体系,桁距16 m,混凝土桥面板设置断缝,按5节间(25 m+27 m+24 m+27 m+25 m)布置。

Using the finite element method, the longitudinal and transverse girder deck system and dense transverse girder deck system including different number of concrete deck slab gap of through tied-arch bridge on high-speed railway are studied. Results show that, there are stress concentration phenomena at the intersection of longitudinal and transverse girder deck system. the stress of transverse girder is higher than that of dense transverse girder deck system. With the increasing of concrete deck slab gap for dense transverse girder deck system, the vertical displacement of tied-girder increases unconspicuously, and the internal forces of tied-girder and arch rib vary slowly. However, the stress of transverse girder and concrete deck slab decrease obviously. Moreover, the construction of dense transverse girder deck system is easier and more convenient than that of longitudinal and transverse girder deck system. It＇s highly recommended that the dense transverse girder deck system with 4 gaps of concretes deck slab （25 m＋27 m＋24 m＋27 m＋25 m） and 16 m truss space is suitable for through steel tied arch bridges with 128 m main span on newly-built double line high-speed railway.