张家界大峡谷玻璃桥加劲梁架设施工技术

摘要

张家界大峡谷玻璃桥为主跨430 m空间主缆人行悬索桥,加劲梁采用钢制纵、横梁结构,两端各50 m范围为变宽段,桥面宽度由6 m按线性规律变化至15 m,共划分37个节段.根据桥址处特殊的建设条件及空间主缆悬索桥的特点,通过比选,确定加劲梁采用缆索吊吊装方案.缆索吊机起重量设计为45 t;由于运输宽度限制,厂内横梁和纵梁分开制作,运至现场后再组装成节段;端横梁及端部节段(L7节段)在临时支架上拼装后安装并固定在支座垫石上,然后由两侧向中间对称架设其它节段,节段间使用临时连接件进行连接.该施工技术在保证加劲梁施工过程中峡谷抗风稳定性的同时,缩短了工期,37个节段吊装完成仅用了10 d.%The Zhangjiajie Grand Canyon Glass Bridge, which has a main span of 430 m,is a pedestrian suspension bridge with spatial main cables.The stiffening girder consists of steel stringers and cross beams, incorporating 37 sections.The deck width reveals changes in a 50 m-long distance starting from both ends of the bridge.According to the special construction conditions at the bridge site and the characteristics of the suspension bridge with spatial main cables, it was determined that the stiffening girder would be erected by cable cranes of a design capacity of 45 t each, depending on the scheme comparison and selection.Limited by the transportation scale, the cross beams and stringers were fabricated independently in the workshop, delivered to the bridge site and then assembled to girder sections.The end cross beams and an end section (section L7) were assembled on the temporary props first, and then installed and fixed to the bearing pad stones.Subsequently, the remaining sections were symmetrically installed from the two sides towards the center, and linked to one another by temporary connectors.This construction method helped saving the construction time while assuring the wind-resistant stability of the bridge during the construction of the stiffening girder.The installation of the 37 sections took only 10 days.