武汉青山长江公路大桥钢套箱围堰下沉施工技术  

Construction Techniques for Sinking of Steel Boxed Cofferdam of Qingshan Changjiang River Highway Bridge in Wuhan

作　　者：金红岩[1] JIN Hong-yan(The 5th Engineering Co.,Ltd.,China Railway Major Bridge Engineering Group,Jiujiang 332001,China)

机构地区：[1]中铁大桥局集团第五工程有限公司,江西九江332001

出　　处：《桥梁建设》2018年第2期7-12,共6页Bridge Construction

摘　　要：武汉青山长江公路大桥主桥为主跨938m的双塔双索面全飘浮体系斜拉桥,20号桥塔墩钻孔桩基础采用哑铃形双壁钢套箱围堰(平面尺寸103.8m×43.4m、高37.0m)平台一体法施工。围堰下沉过程中,上、下游两端的河床面高差大,下沉施工分为下沉准备、着床前与着床后下沉、清基与封堵4个阶段。下沉前安装控制及导向系统,布置吸泥设备,完成平台系统向下沉体系的转换;随着围堰下沉,向双壁舱内注水,使下沉力始终保持在吊挂力的允许范围内,完成着床前下沉;通过测量及数据分析掌握围堰姿态、入土深度、吊挂力,并根据检算分析指导围堰吸泥、配重,采用下游端优先下沉、上游端配合下沉的方式完成着床后下沉;下沉至设计高程后,进行清基及封堵,完成围堰下沉施工。围堰下沉过程姿态可控、安全平稳,围堰就位后的精度满足规范要求。The main bridge of the Qingshan Changjiang River Highway Bridge in Wuhan is a full floating system cable-stayed bridge with double pylons,double cable planes and with the main span of 938 m.The bored pile foundation for the pylon pier No.20 of the bridge was constructed,using the combination method of the dumbbell-shape double-wall steel boxed cofferdam(the plan dimensions being 103.8 m X 43.4 m and the height being 37.0 m)and the boring platform.In the sinking of the cofferdam,in consideration of the great height difference of the riverbed on the upstream and downstream sides,the sinking construction of the cofferdam was carried out in 4 stages of the sinking preparation,sinking before and after the cofferdam was landed onto the riverbed,clearing and sealing of the base of the cofferdam.Before the sinking of the cofferdam proceeded,the control and guide systems were installed,the air-lifting equipment was arranged and the platform system was converted into the sinking system.As the cofferdam was being sunk down,the water was pumped into the double-wall compartment of the cofferdam so as to keep the sinking load of the cofferdam to the allowable range of the suspending forces all the time and to complete the sinking of the cofferdam before it was landed onto the riverbed.By the measurements and the collected data,the posture,embedment depth in the riverbed and suspending forces of the cofferdam were analyzed and controlled.According to the checking calculation and analysis,the air-lifting and the counterweight arrangement of the cofferdam was guided and the further sinking of the cofferdam after it was landed onto the riverbed was completed by way of sinking the downstream side of the cofferdam mainly and sinking the upstream side as an aid.After the cofferdam was sunk down to the designed elevation,the base of the cofferdam was cleared and sealed and at this stage,the sinking construction of the cofferdam was entirely completed.In the sinking of the cofferdam,the posture of the cofferdam was controllable,the sin

关 键 词：斜拉桥 桩基础 双壁钢套箱围堰 下沉 桥梁施工 

分 类 号：U448.27[建筑科学—桥梁与隧道工程] U443.162[交通运输工程—道路与铁道工程]