无锡钱皋路京杭运河大桥拱形钢桁梁浮托顶推法架设施工技术

Barge-aided Incremental Launching Technique Used to Construct Arch-Shaped Steel Truss Girder of a Beijing-Hangzhou Grand Canal Crossing on Qiangao Road, Wuxi

无锡钱皋路京杭运河大桥主桥为106m拱形钢桁梁桥,采用3片主桁结构,钢桁梁重约2200t。钢桁梁采用浮托顶推法架设,按照陆地滑移、水陆协同滑移、水上支架滑移、落梁4个阶段进行。在施工过程中,打设6排共108根钢管桩,以铺设滑移轨道,并分段立体拼装钢桁梁;钢桁梁上设置18个滑靴,在9个主动滑靴处左右各布置1台60t的顶推器;浮船选用3000t级驳船,在其上铺设路基箱和格构式浮托支架,采用4台卷扬机锚固和调节;顶推施工时,首先将钢桁梁顶推出一定的悬臂端,然后将浮船排水上浮支承钢桁梁前端,使中间支点脱空,保留后端支点作为顶推点,形成简支结构向前推进,最后待浮船移至指定位置并注水拖走后,钢桁梁滑移至指定位置落梁,完成架设。

Themain bridge of Beijing-Hangzhou Grand Canal Crossing on Qiangao Road, Wuxi, is an arch-shaped steel truss girder bridge with a length of 106m. The steel truss girder consists of three trusses, weighing about 2 200 t. Erected by the barge-aided incremental launching, the steel truss girder was first slid on the ground, then experienced a ground-water collaborative sliding to be shifted to the water scaffoldings, and slid to the designed location and lowered into position. During the construction process, a number of 108 steel tube piles that were arranged in six rows were driven for the installation of sliding rails, and the steel truss girder was divided into sections and vertically assembled. 18 sliding boots were installed on the steel truss girder, and at the locations of each of the 9 active sliding boots, a 60 t-capacity pushing device was installed. The barge was the 3 000 t grade barges, on which roadbed boxes and lattice supporting frames were installed, and subsequently anchored and adjusted by 4 winches. During the incremental launching, the steel truss girder was first pushed to have a cantilever, then the barge was drained to float upward to support the cantilever end, at the same time, the central support was disengaged, leaving the rear support as the incremental launching point, and a simply-supported structure for incremental launching took form. At last, the barge wasmoved to the designated place, filled with water and dragged way, the steel truss girder was slid to the design location and lowered into position, and the erection was completed.