准朔铁路黄河特大桥拱上简支T梁支座布置研究

Research on Abutment Arrangement of Simply Supported T-beam of Yellow River Bridge of Zhungeer-Shuozhou Railway

研究目的:准朔铁路黄河特大桥是朔州至准格尔新建铁路重要工程,大跨度上承式拱桥拱上桥墩纵向位移由桥墩和拱肋变形两部分组成,拱上简支T梁支座布置对拱肋结构的受力影响较大,因此需要通过合理的支座布置方案降低拱上高墩的纵向水平位移,降低纵向水平力对拱肋产生的不利影响。研究结论:(1)相邻桥墩纵向最大相对位移发生在交界墩与拱脚G1和G12号墩之间;(2)拱脚第一孔简支梁梁端需要采取大位移量纵向活动支座和伸缩装置,并设置纵、横向防落梁措施;(3)大跨度拱上桥墩墩顶位移对桥上无缝线路的影响较大,桥上无缝线路应采取小阻力扣件来适应桥墩变形要求。

Research purposes： The Yellow River Bridge is a very important engineering of Shuozhou - Zhungeer Railway. The pier longitudinal displacement of large - span deck - type arch bridge is caused by the pier and arch - rib deformation. The abutment arrangement of simply supported T -beam has big effect on the loading bearing of the arch rib, therefore, it is necessary to arrange the abutment rationally to reduce the longitudinal displacement of the high pier and cut its adverse effects on the arch rib. Research conclusions： （ 1 ） As the maximum relative longitudinal displacement of adjacent pier on the arch bridge occurs between the junction pier and G1 or G12 pier. （2） The movable abutment with large longitudinally displacement and expansion device should be used for the first beam at arch foot and the measures for prevention of span collapse should be taken. （3） As the pier top displacement of large - span arch bridge has big effect on the CWR track, the fastening with small resistance should be used for the CWR track on bridge to adapt the pier deformation.