海洋复杂气候多塔公铁同层斜拉桥主梁施工控制关键技术  

Superstructure Construction Control Techniques for a Multi-Pylon,Cable-Stayed Bridge Accommodating Road and Rail Traffic on Same Deck in Complex Marine Environments

作　　者：张华兵 余毅 ZHANG Huabing;YU Yi(State Key Laboratory of Bridge Intelligent and Green Construction,Wuhan 430034,China;China Railway Bridge Science Research Institute,Ltd.,Wuhan 430034,China;China Railway Britech Co.,Ltd.,Wuhan 430034,China)

机构地区：[1]桥梁智能与绿色建造全国重点实验室,湖北武汉430034 [2]中铁大桥科学研究院有限公司,湖北武汉430034 [3]中铁桥研科技有限公司,湖北武汉430034

出　　处：《世界桥梁》2024年第3期48-54,共7页World Bridges

摘　　要：珠海西江公铁大桥为(58.5+116+3×340+116+58.5)m公铁同层斜拉桥,两中塔塔梁墩固结,两边塔塔梁固结、塔墩分离。主梁采用单箱三室截面钢箱梁,总宽49.6 m,梁高4.676 m;全桥钢梁共划分为47个节段,标准节段长24 m;钢梁节段接头除顶板为焊接外,底板、腹板均为高强度螺栓连接。考虑既有施工机具和桥址环境特点,钢梁节段均为超大、超重、超高结构。边跨、次边跨钢梁节段最长80.25 m、最大吊重2600 t,利用大型浮吊吊装,通过“分段顶升(下降)、逐端合龙”的施工控制方法,3个大节段钢梁无折角拼接;中塔两侧主梁采用一侧钢梁节段吊装时另一侧配水袋压重的“小步快走,多轮次平衡”异步悬拼施工,将结构抗倾覆稳定系数控制在1.5以上;利用在中中跨合龙口施加主动顶推力结合改变合龙口结构构造的保障措施,实现大桥在高温条件下的高精度合龙。成桥结构内力、线形状态均达到设计理想状态。The Xijiang Rail-cum-Road Bridge in Zhuhai is a cable-stayed bridge accommodating road and rail traffic on the same deck.The bridge features its four pylons that create three main spans of 340 m,flanged on each side by two spans of 116 m and 58.5 m.The two intermediate pylons are fixed with the superstructure and the piers,while the two side pylons are fixed with the superstructure,but connected with the piers via bearings.Measured 49.6 m in full width,the superstructure consists of three-cell steel box girders that are 4.676 m in depth.To facilitate erection,the superstructure was divided into 47 segments,with typical segment length of 24 m.During assembly,the top plates of the two adjacent segments were welded together,and the bottom plates and webs were connected via high-strength bolts.Considering the equipment available and the environments at the bridge site,the steel box girder segments were relatively larger in dimension,weight and depth.The maximum steel box girder segments in the side and end spans,which were 80.25 m long and 2600 t in weight,were erected by floating cranes.The superstructure was jacked up and lowered in segments,and closed end by end,and the three larger final segments were assembled without bending angles.During the erection of the paired two steel box girder segments on the two sides of each intermediate pylon,the segment on one side was hoisted and installed,and its counterpart on the other side was counterweighted with water bags,creating an asymmetric cantilever assembly of"proceeding in small steps and adjusting balance in multiple cycles",to control the anti-overturning stability coefficient of the structure above 1.5.Active pushing forces were applied at the midspan closure gap of central main span and the structural details at the closure gap were modified to ensure the high-precision closure of the bridge at high temperatures.The internal forces and alignment of the completed bridge reach the design levels.

关 键 词：斜拉桥 多塔刚构体系 钢梁 分段顶升 水袋压重 异步悬拼 主动顶推 施工控制 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U445.4[交通运输工程—道路与铁道工程]