摘要
夜郎湖特大桥为净跨径210m的钢筋混凝土拱桥,主拱圈采用宽7.0m、高3.5m的单箱单室结构,共分29个节段,节段最大长度为7.14m、最大重量为1886kN。2~14号节段采用三角桁架式挂篮悬臂浇筑施工。挂篮包括主桁承重系统、C型挂钩、行走装置、斜拉吊带和锚吊杆等,底模采用大模板,通过垫块使模板形成微小转角,实现以直代曲和线形调控。施工时,挂篮按挂钩、后篮、前篮的顺序拼装完后,在原地面设置竖向锚索,采用钢绞线反拉的方式预压;挂篮前移施工中采用内滑梁支撑系统,辅助混凝土浇筑,保证了混凝土浇筑质量;借助液压助推千斤顶实现挂篮倒退行走,直到挂篮依靠自重自行行走时拆除助推千斤顶;挂篮倒退至拱脚后,利用已浇节段的吊杆孔安装吊杆,临时固定挂篮,按前篮、后篮、挂钩的顺序拆除挂篮。
The Yelang Lake Bridge is a reinforced concrete arch bridge with a net span length of 210 m.The arch rib,a single box structure that is 7.0 m wide and 3.5 m high,is divided into 29 sections,with a maximum length of 7.14 m and a maximum weight of 188 t.The sections No.2 to No.14 are cast by the form travelers of triangular truss type.The form traveler consists of the main truss that is used as the load bearing system,C shaped hookers,walking devices,stays and suspenders.The bottom formwork adopts the large-area formwork,which can be rotated with a small angle by the pad blocks to realize the aim of using straight line to replace the curve line and the alignment tuning.During the construction,the form traveler was assembled following the sequence of hookers,rear frame and front frame.Then,vertical anchor stays were installed in the original place,to pre-load the form traveler by reversely tensioning the steel strands.During the forward-walking of the form travelers,the inner sliding beam supporting system was used to assist the concrete casting,aiming to assure the casting quality of concrete.And the hydraulic jacks were used to push the form traveler to walk backward,which were demolished until the form traveler could walk by the force of self weight.When the backward-walking of the form traveler reached the arch springs,suspenders were installed into the holes of the already-cast sections to fix the form traveler.And the form travelers were dismantled following the sequence of front frame,rear frame and hookers.
作者
刘增武
周建庭
马虎
吴月星
周逸
LIU Zeng-wu;ZHOU Jian-ting;MA Hu;WU Yue-xing;ZHOU Yi(School of Civil Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Chongqing Rail Transit(Group) Co.,Ltd.,Chongqing 400042;Chongqing Yapai Bridge Engineering Quality Inspection Co.,Ltd.,Chongqing 401121,China)
出处
《世界桥梁》
北大核心
2019年第5期22-26,共5页
World Bridges
基金
国家重点研发计划(2017YFC0806007)
国家杰出青年科学基金(51425801)
重庆交通大学研究生教育创新基金项目(2019B0105)
关键词
拱桥
三角桁架式挂篮
钢绞线反拉
内滑梁支撑系统
千斤顶
悬臂浇筑
施工技术
arch bridge
form traveler of triangular truss type
reverse tensioning of steel strands
inner sliding beam supporting system
jack
cantilever casting
construction technique
