摘要
重庆寸滩长江大桥为主跨880m的钢箱梁悬索桥,桥塔下、中、上横梁分别重3 062t、1 020t和1 050t,按照下、上、中的顺序采用无落地式支架法施工。支架主要受力构件为贝雷片支架、托架和钢靴,中、上横梁支架倒用下横梁支架构件。经优化设计,下横梁支架的4片托架顺桥向间距为1.2m+4.0m+1.2m,中(上)横梁支架的3片托架顺桥向间距为2.2m+2.2m;支架设4个钢靴(长1.1m、宽0.9m、高1.72m),钢靴嵌入塔柱并与塔柱接触面顶紧;计算表明支架和塔柱结构受力满足相关要求。支架施工时,首先利用塔吊在塔柱内侧安装提升支架,其次吊装钢靴、牛腿及其上端的分配梁,然后利用提升支架安装托架,其它构件由塔吊安装。横梁支架拆除时,通过在横梁施工时预留4个孔位,穿入钢丝绳(与托架分配梁锚固),采用千斤顶缓慢下放支架。
The Cuntan Changjiang River Bridge in Chongqing is a steel box girder suspension bridge with a main span of 880 m.Each tower of the bridge is equipped with three cross beams,the lower,intermediate and upper cross beams respectively weigh 3 062 t,1 020 tand 1 050 t,which are constructed using the suspended scaffolds following the sequence of from the lower cross beam to the upper cross beam,and then to the intermediate cross beam.The main load bearing components of the scaffolds are the Beiley truss frame,corbels and steel sockets.After the erection of the lower cross beam was completed,the scaffolds were dismantled and reassembled for the erection of the intermediate and upper cross beams.After optimization,the intervals among the four corbels in the scaffolds of the lower cross beam along the bridge length are 1.2m＋4.0m＋1.2m,and the three corbels in the scaffolds of the intermediate and upper cross beams along the bridge length are 2.2 m＋2.2 m.The scaffold system has four steel sockets,with dimension of1.1×0.9,and 1.72 min height.The steel sockets are embedded in the tower legs and tightened with the surfaces of the tower legs touched.The calculation indicates that the load bearing condition of the scaffolds and the tower legs meets the relevant requirements.During the construction of the scaffolds,the tower cranes were first used to install lifting frames next to the inner side of the tower legs,then the steel sockets,brackets and the distributive beams on the brackets were hoisted and installed,subsequently,the lifting frame was used to install the corbels,and the remaining components were installed by tower cranes.When the cross beam scaffolds were dismantled,four holes were reserved during the cross beam construction,steel ropes anchored to the distributive beams on the corbels were threaded through the holes,and the scaffolds were lowered slowly by jacks.
出处
《世界桥梁》
北大核心
2015年第2期40-44,共5页
World Bridges
关键词
悬索桥
横梁施工
无落地式支架
托架
钢靴
提升支架
下放系统
支架设计
suspension bridge
cross beam construction
suspended scaffolding
corbels
steel socket
lifting scaffold
lowering system
scaffold design
