新型铁路钢箱梁斜拉桥索梁锚固结构传力机理及应力分析  

Load Transfer Mechanism and Stress Analysis of New Type of Cable-Girder Anchorage for Railway Cable-Stayed Bridge with Steel Box Girder

作　　者：蒲黔辉[1] 么超逸[1] 施洲[1] 刘振标[2] 

机构地区：[1]西南交通大学土木工程学院,四川成都610031 [2]中铁第四勘察设计院集团有限公司,湖北武汉430063

出　　处：《中国铁道科学》2015年第5期12-18,共7页China Railway Science

基　　金：中国铁路总公司科技开发计划重点课题项目(2009G004-C)

摘　　要：针对大跨度铁路斜拉桥活载重、索梁锚固区应力幅度变化较大等特点,宁波铁路枢纽北环线甬江特大桥采用了全新设计的双挑式索梁钢锚箱。作为双挑式索梁钢锚箱的主要受力构件,支承板和承压板分别通过其双侧焊缝与主梁边腹板和风嘴板焊接在一起,形成由主梁风嘴板与边腹板共同承受并传递索力的新型索梁锚固结构。采用仿真分析与模型试验相结合的方法,进行该新型索梁锚固结构传力机理及应力分布的研究。结果表明:采用新型索梁锚固结构后,通过支承板与主梁边腹板和风嘴板间的连接焊缝,以受剪的形式将大约94%的斜拉索索力传递给钢箱主梁;虽然新型索梁锚固结构的各关键受力构件均存在一定程度的应力集中,但与传统的钢锚箱相比,可有效解决偏心弯矩引起支承板焊缝顶端应力集中严重的问题。For the characteristics of heavy live load and the big change of the stress range on the cablegirder anchorage zone of long-span railway cable-stayed bridge, a new type of cable-girder steel anchor box with double-end fixed was designed and adopted by Yongjiang super large bridge on the north ring line of Ningbo railway hub. As the main load bearing members of the cableirder steel anchor box with doubleend fixed, the support plate and load bearing plate was respectively welded onto the web and wind fairing plate of the main girder. In this way, the new type of cable-girder anchorage structure was formed, in which the wind fairing plate together with the web plate of the girder bore and transferred cable force. With the method of simulation analysis and model test, the load transfer mechanism and stress distribution of the new type of cable-girder anchorage structure was studied. The results indicate that, after the new type of cable-girder anchorage structure being adopted, about 94% of the stayed cable force is transferred to the main girder in shear mode through the weld seam between the support plates of the anchor box and the web plate and wind fairing： plate of the main girder. Although each key load bearing member of new type of cable-girder anchorage structure has certain degree of stress concentration, however, compared with the traditional steel anchor box, the new design can effectively solve the serious problem of the stress concentration induced by eccentric bending moment at the top of the weld seam of support plates.

关 键 词：铁路斜拉桥 索梁锚固 模型试验 仿真分析 传力机理 索力 应力分布 

分 类 号：U441.4[建筑科学—桥梁与隧道工程]