宁波新典桥拱肋合龙施工控制关键技术  

Key Arch Rib Closing Control Techniques for Xindian Bridge in Ningbo

作　　者：陈涛 顾惠明[3] 王吉 CHEN Tao;GU Hui-ming;WANG Ji(State Key Laboratory for Health and Safety of Bridge Structures,Wuhan 430034,China;China Railway Bridge Science Research Institute,Ltd.,Wuhan 430034,China;China Railway Major Bridge Engineering Group Co.,Ltd.,Wuhan 430050,China)

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

出　　处：《世界桥梁》2023年第S01期78-84,共7页World Bridges

摘　　要：宁波新典桥主桥为主跨213 m下承式简支系杆拱桥,2片拱肋内倾16.928°形成提篮状。拱肋为六边形封闭钢箱结构,采用支架法施工,受限于龙门吊净空,拱肋合龙段从侧面吊装合龙,合龙精度要求高。施工控制过程中,运用BIM技术模拟吊装拱肋合龙段时的碰撞情况,确定合龙口两侧拱肋节段切割值,配切成“外八字口”形状,便于合龙段进入合龙口;采用有限元法分析温度对合龙口长度的影响,并结合实测数据,选择阴天气温较平稳的时间段进行合龙,合龙温度28℃;对合龙口连续观测,运用图解法计算得到合龙段6条边的配切值,并进行现场配切;在合龙段内、外侧各设计1个主索吊点(承重兼调节拱肋内倾角),在内侧设置2个辅索吊点(调节拱肋纵倾角),实现合龙段空中姿态调整。采用上述拱肋合龙控制技术,合龙后焊缝宽度满足规范要求。The main bridge of Xindian Bridge in Ningbo is a through-type simply-supported tied-arch bridge with a main span of 213 m.The two arch ribs are composed of hexagonal steel tubes of box cross-section and incline inwardly at 16.928°,resembling a basket handle.The arch ribs were constructed by the scaffolding method,limited by the headroom of the gantry crane,the closure segments of the arch ribs were hoisted from the side of the deck to facilitate the closing operation and achieve the required closure precision.During the construction control process,the hoisting procedure of the arch rib closure segments was simulated in a BIM software to predict the possible collision events,and confirm the cutting amounts of the segments at the closure gap.According to the simulation,the ends of the segments at the closure gap should be shaped as inverted trapezoids to ease the feeding of the closure segments.The thermal effect on the closure gap length was numerically simulated,together with the measured data,to determine the closing schedule.And it was decided that the arch ribs be closed in a cloudy day when the temperature is relatively stable,exactly at the temperature of 28℃.Based on the consecutive monitoring of the closure gap,the exact cutting amounts of the six sides of the arch rib closure segment were calculated by the graphic method,and the cutting was performed on site.On both the inner and outer sides of the arch rib closure segment,one main cable lifting point to carry loads and adjust the inner inclination angle of the arch ribs was arranged and two auxiliary cable lifting points(to adjust the longitudinal inclination angle)were arranged on the inner side,to tune the position of the arch rib closure segments overhead.The adoption of the aforementioned techniques ensured that the widths of the welding joints after arch ribs closure met the code requirements.

关 键 词：系杆拱桥 拱肋 BIM技术 合龙监测 合龙段配切 吊点设计 合龙 施工控制 

分 类 号：U448.225[建筑科学—桥梁与隧道工程] U445.1[交通运输工程—道路与铁道工程]