摘要
汝郴高速公路赤石特大桥主桥为165 m＋3×380 m＋165 m的四塔预应力混凝土双索面斜拉桥，桥塔为双曲线形，桥塔高271．63～299．13 m ，上塔柱由4个内倾塔肢渐变为2个竖直塔肢。为避免施工中塔肢根部的混凝土开裂，对内倾塔肢施加预顶力，设置了对撑结构。对撑结构由2道纵向对撑和3道横向对撑组成，每道对撑均采用2根φ1000mm×16mm螺旋钢管。施工时先安装上横梁支架，待浇注完上塔柱第5，第7，第8，第10节混凝土时，分别安装第1道和第2道横向、纵向对撑，第3道横向对撑，并施加预顶力，安装相关联结系。施加预顶力时，焊接内衬管和外包管使对撑结构成为整体，利用250 t千斤顶施加预顶力。拆除横梁支架的同时，按自上而下的顺序拆除对撑结构。
The main bridge of the Chishi Bridge on Rucheng‐Chenzhou Expressway is a pres‐tressed concrete cable‐stayed bridge with four pylons ,double cable planes and with span arrange‐ment 165 m＋3 × 380 m＋165 m . T he pylons of the bridge are in the hyperbolic shapes and the height of the pylons is 271 .63-299 .13 m .The upper part of each pylon changes gradually from 4 inward tilting pylon legs to 2 vertical legs .To avoid the concrete cracking in the footings of the py‐lon legs in the construction ,the pre‐jacking forces were applied to the tilting legs and the bracing structure was arranged .The structure for a pylon was composed of 2 longitudinal and 3 transverse bracings .Each bracing had 2φ1 000 mm × 16 mm helix steel pipes .In the construction ,the scaffol‐ding for the upper cross beam of the pylon was installed first and after the concrete for the seg‐ments 5 ,7 ,8 and 10 of the upper part of the pylon was cast ,the 1st and 2nd transverse and longi‐tudinal bracings and the 3rd transverse bracing were respectively installed ,the pre‐jacking forces were applied and the related tie systems were installed .As the pre‐jacking forces were applied ,the lining and encasing steel pipes were welded to make the bracing structure an integrity .The 250 t jacks were used to apply the pre‐jacking forces .At the same time the scaffolding for the cross beam was removed ,the structure was removed in the sequence from the upper to the lower .
出处
《桥梁建设》
EI
CSCD
北大核心
2015年第3期110-114,共5页
Bridge Construction
关键词
斜拉桥
桥塔
内倾塔肢
对撑结构
桥梁施工
cable-stayed bridge
pylon
inw ard tilting pylon leg
bracing structure
bridge construction
