多跨连续梁拱组合体系桥梁施工关键问题研究  

Study of Critical Issues on Construction of a Hybrid System Bridge of Multi-Span Continuous Girder and Arches

作　　者：梅葵花[1] 王贤良[1] 赵育[1] 

机构地区：[1]长安大学公路学院,陕西西安710064

出　　处：《桥梁建设》2017年第4期48-53,共6页Bridge Construction

基　　金：国家自然科学基金项目(50908016)~~

摘　　要：安康市城东汉江大桥主桥为(75+2×125+160+2×125+75)m多跨连续梁拱组合体系桥梁,全桥采用先梁后拱法施工,系梁采用平衡悬臂浇筑法施工,中跨跨中33m梁段采用支架现浇法施工。为选择合理的现浇段支架拆除时机、边跨配重卸载时机、临时固结拆除顺序以及吊杆张拉顺序和次数等,采用MIDAS Civil建立全桥有限元模型,针对各种方案下的结构进行模拟分析。结果表明:跨中现浇段的支架应在张拉完全部吊杆后再拆除;边跨配重应在中跨或次边跨合龙后再卸载;应待相邻孔合龙后再拆除前一合龙孔的临时固结;应对称交替地张拉吊杆,设计张拉力较小时可一次张拉到位,设计张拉力较大时应分批张拉到位。该桥采取以上方案施工后,结构受力状态良好。T h e main b r id g e of th e Ch en g d o n g H an j ian g River Bridge in An k an g City is a h y b r id system br idge of mul t i-span cont inuous girder and arches wi th span ar rangement （75 ＋ 2 X 125 ＋160 ＋ 2 X 125 ＋ 75） m. T h e w h o le b r id g e of th e b ridg e is c o n s t ru c te d , usin g th e m e th o d of con-struct ing the girder before construct ing the arches, of which the t ie girder is cast in situ, using the free cant i lever method and the 33 m long girder segments at the midspan of the central span are cast in si tu, using the scaffolding method. In the construct ion of the bridge, to choose the reasona-ble t ime for removal of the scaffolding for the cast-in-si tu segments, the t ime for unloading of the counterweight on the side spans, the sequences for removal of the temporary rigid fixity and the sequences and t imes for tensioning of the hangers, the MIDAS Civil was used to establ ish the finite element model for the whole br idge and the st ructure under the different schemes was simulated and analyzed. The resul ts suggest that the scaffolding for the cast - in-si tu segments at the midspan of the central span should be removed after the whole hangers are well tensioned. The counter-weight on the side spans should be unloaded after the central span or the secondary side spans are closed. The temporary rigid fixi ty for the previous closed span should be removed after the adja-cent spans are closed. The hangers should be tensioned symmetrically and al ternat ively. For the hangers wi th l i t t le designed tension, the hangers should be tensioned in place in one time while forthe hangers with great designed tension, the hangers should be tensioned in place in batch. With the above mentioned different schemes, the force conditions of the structure after the construction have been so far so good.

关 键 词：梁拱组合体系桥 悬臂浇筑法 有限元法 现浇支架 配重 临时固结 吊杆张拉顺序 桥梁施工 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]