摘要
重庆两江新区龙兴新城寨子路大桥主桥为(131+205)m的提篮式连拱钢结构体系桥,其中大拱理论矢高为116 m,矢跨比为1/1.77,拱肋与铅垂面夹角为11.31°。针对该桥主拱拱高且较陡等特点,结合桥址处地质条件以及设备储备情况,采用支架法和垂直提升法进行大拱拱肋施工。大拱拱肋分为29个节段,主拱肋分单元节段在工厂制造并预拼装,将拱肋单元节段运至岸边拼装场内,搭设大拱满堂施工栈桥形成工作平台,其中大拱两岸拱脚底部的6个拱肋节段采用支架法安装;对于中间拱轴线纵向水平投影段113 m内的15个拱肋节段,利用设计拱肋轴线投影下方栈桥上的弧形支架组拼成整体提升段,再利用两侧提升塔架将整体提升段垂直提升至设计位置;最后在整体提升段的两端吊装嵌补段焊接合龙成拱。垂直提升施工中,通过计算确定了使整体提升段在提升过程中变形最小的提升塔架纵向净间距,以及预留嵌补段合龙的方式,最大合龙误差22.7 mm,合龙精度满足设计要求。
The main bridge of Zhaizilu Bridge is a basket-handle steel arch bridge with two continuous arched spans of 131 and 205 m.The 205 m-long arch rises 116 m,creating a rise-to-span ratio of 1/1.77,and the arch rib and the vertical plane forms an angle of 11.31°.Considering the characteristics of the arches,geological conditions at the bridge site and available facilities,the 131 m-long arch was assembled on scaffolds,while the 205 m-long arch was erected by the combined utilization of scaffolds and tower cranes.The 205 m-long arch was divided into 29 segments for prefabrication and pre-assembly first,and then transported to the assembly yard on the bank and lifted onto the full-span construction trestle.The six segments forming the arch springing were erected on scaffolds,while the 15 segments within the 113-long horizontal project area along the arch alignment were first assembled into an integral big segment on the arch-shaped scaffolds on the trestle under the projection of the design arch alignment,and then vertically lifted and placed into position by two tower cranes.Afterwards,the key segments were placed to fill the gaps and welded for the closure of the arch.The space between the two tower cranes was calculated to minimize the deformation of the big segment during lifting.The placement of the key segments was numerically simulated as a result,the maximum closure error was at 22.7 mm,and the closure accuracy reached the required level.
作者
彭德力
PENG Deli(Chongqing Liangjiang New District Longxing Industrial Park Construction Investment Co.,Ltd.,Chongqing 401135,China)
出处
《世界桥梁》
北大核心
2023年第6期48-52,共5页
World Bridges
关键词
拱桥
钢箱拱肋
提升塔架
弧形支架
节段拼装
垂直提升
施工栈桥
桥梁施工
arch bridge
steel box arch
tower crane
arch scaffold
segmental assembly
vertical lifting
construction trestle
bridge construction
