隧洞内钢箱梁架设施工技术

Construction Technology for Steel Box Girder Erection in Tunnels

绿汁江特大桥是国内外首座单塔单跨钢箱梁悬索桥,主跨780m,楚雄岸未设置主塔,且山体为绝壁陡崖,设计将主跨钢箱梁直接伸入到相接的隧道内18m。因受楚雄岸悬崖绝壁地形条件限制,隧洞内架设空间狭小,盲区大,缆索吊机难以将钢箱梁直接吊装至隧洞内。本文结合现场实际施工情况,剖析本工程的施工难点,首创一种隧洞内钢梁架设方法(绝壁托架+缆索吊60m辅助牵引+洞内18m滑移)。此种方法成功的运用节省了洞内钢梁的吊装时间,缩短了钢梁架设总体工期,提前了绿汁江特大桥的合龙时间。

The Lvzhijiang Extra Large Bridge is the first single tower and single span steel box girder suspension bridge at home and abroad,with a main span of 780m.There is no main tower on the Chuxiong bank,and the mountain is a steep cliff.The design extends the main span steel box girder directly into the adjacent tunnel for 18m.Due to the limited terrain conditions of the cliffs and cliffs on the Chuxiong shore,the installation space inside the tunnel is narrow and the blind spot is large,making it difficult for the cable crane to directly lift the steel box girder into the tunnel.This article combines the actual construction situation on site,analyzes the construction difficulties of this project,and proposes a method for erecting steel beams in tunnels(cliff bracket+cable suspension 60m auxiliary traction+18m sliding inside the tunnel).The successful application of this method has saved the lifting time of the steel beams inside the tunnel,shortened the overall construction period of the steel beam installation,and advanced the closure time of the Lvzhijiang Extra Large Bridge.