房山五渡桥钢塔架施工关键技术

The key technique of steel tower of Wudu Bridge in Fangshan

房山五渡桥采用三角钢架悬吊连续梁组合桥结构体系,主塔采用十字形钢箱截面,钢塔架截面变高变宽均采用线性变化,总高为35m,与V墩共同组成W型,钢塔架共分11段进行吊装。由于倾斜型钢塔架施工难度大,质量和精度要求较高,因此针对钢塔架预制、防腐、搭设临时支架、吊装等方面进行了深入的研究,提出钢塔架的施工全过程的重点和难点方面的施工关键技术。

A structural system of triangle steel frame and suspension continuous girder bridge has been adopted in the design of Wudu Bridge in Fangshan district.The cross steel box has been designed to be main tower interface.The transitional form on height and width of variable cross-section is followed by linear variation theory,in which the total height is 35m and composing a ＂W＂ shape together with ＂V＂ shape piers.The steel towel is hoisted by 11separated segments.We have made a deep study on the prefabricate,preservation,hoisting temporary kickstand fixing and hoisting of steel tower because of the challenging construction technology and the high requirement on quality and precision.Moreover,the key technology on important and difficult points used in the whole steel tower construction is also proposed.