平潭海峡公铁大桥钢桁梁斜拉桥整节段悬臂拼装杆件对接顺序研究  

Study of Members Butt Joint Sequence in Integral Steel Truss Segment Cantilever Assembly of Pingtan Straits Rail-cum-Road Bridge

作　　者：沈大才 王东辉[1] SHEN Da-cai;WANG Dong-hui(China Railway Major Bridge Engineering Group Co. , Ltd. , Wuhan 430050, China;State Key Laboratory for Health and Safety of Bridge Structures, Wuhan 430034, China)

机构地区：[1]中铁大桥局集团有限公司,湖北武汉430050 [2]桥梁结构健康与安全国家重点实验室,湖北武汉430034

出　　处：《桥梁建设》2021年第3期131-137,共7页Bridge Construction

基　　金：中国工程院重点咨询研究项目(2016-XZ-13)。

摘　　要：平潭海峡公铁大桥3座通航孔桥均为钢桁梁斜拉桥,主跨钢桁梁采用架梁吊机整节段悬臂架设。为选取合适的钢桁梁整节段悬臂拼装杆件对接顺序,以该工程大小练岛水道桥为背景,采用MIDAS Civil软件建立该桥整节段钢桁梁悬臂拼装模型,分析结构受力状态,并对不同的杆件对接顺序进行研究比选。结果表明:架梁吊机起吊待架钢梁节段后,已架设主桁上、下弦纵向位移相差25.4 mm,宜首先对接主桁下弦。综合考虑合龙状态及措施力大小,无预拱度的钢桁梁节段可采用主桁下弦→斜杆→主桁上弦→副桁(方案1),或主桁下弦→主桁上弦→副桁→斜杆(方案2)的顺序对接,最大调整措施力约1000 kN,调整措施力相对较小。对于有预拱度的节段,若最后对接斜杆,还需沿斜杆方向纵向对拉399 kN,因此宜采用方案1的顺序对接。The three navigational channel bridges of Pingtan Straits Rail-cum-Road Bridge are all steel truss girder cable-stayed bridges.The steel truss segments in main spans were erected in cantilevers by derrick crane.To find the proper members butt joint sequence in the cantilever assembly of integral steel truss segments,the Dalian Islet-Xiaolian Islet Waterway Bridge of the project was taken as a study case,based on which the cantilever assembly model of integral steel truss segments was established by MIDAS Civil,to analyze the load bearing behavior of the structure and compare different butt joint sequences of members.According to the result of the study,the longitudinal displacement difference between the upper and lower chords of the already-erected main truss reached 25.4 mm,when the derrick crane lifted the adjacent steel truss segment.Hence,it is proper to join the members in the lower chords first.When the closure condition and effect of the measures employed are taken into account,the members butt joint sequence of from main truss lower chord through diagonals and main truss upper chord to secondary truss(scheme 1)is recommended for the steel truss girder segments with no precamber,and the sequence of from main truss lower chord through main truss upper chord and secondary truss to diagonal(scheme 2)is also applicable,the maximum adjustment force is about 1000 kN,which is a relatively smaller force.For the steel truss segments with pracamber,if the diagonals are the last members for butt joint,a longitudinal pull-back force of 399 kN should be applied along the direction of the diagonals.Therefore,scheme 1 is more preferred than scheme 2.

关 键 词：公路铁路两用桥 斜拉桥 钢桁梁 架梁吊机 整节段悬臂拼装 杆件对接 对接顺序 有限元法 

分 类 号：U448.121[建筑科学—桥梁与隧道工程] U448.27[交通运输工程—道路与铁道工程]