主索鞍固结的双塔三跨自锚式悬索桥施工控制关键技术研究

Study on the key technology of the construction control for a three-span self-anchored suspension bridge with anti-sliding cable saddles

以某主索鞍与索塔采用固结连接的双塔三跨自锚式混凝土悬索桥为工程背景,对施工过程仿真模拟计算及体系转换施工控制等关键技术进行研究。结果表明:通过正装模型和倒装模型反复迭代计算确立的基准正装模型,可为自锚式悬索桥施工控制提供准确指导,并获得主梁的浇筑线形和主缆、吊杆无应力长度;基于有限元计算确定的从远离塔柱侧吊杆往近塔柱侧吊杆张拉的施工顺序可以避免吊杆的二次张拉,为该桥较优的体系转换方案。通过在主塔两侧吊杆对称张拉的方法有效地控制了塔柱内力,安全顺利地实现主梁从支架受力向缆索体系受力的体系转换。本文相关方法可为类似工程的施工控制提供借鉴。

In this paper,a self-anchored suspension bridge with cable saddle without sliding is selected as the sample of the required engineering background. The key technology of the construction monitoring,such as the simulation calculation and the construction process control of the background bridge is discussed. It can be concluded from the analysis that the benchmark positive model for self-anchored suspension will provide accurate guide to construction,which is confirmation from iteration calculation. The line shape of the main girder and the unstressed length of the cable can be confirmed with the benchmark positive model. The internal force can be effectively controlled with symmetry tension method,safely realizing system transformation from scaffold to cable-suspender under stress of main girder. The tension method which tensions from mid-span suspender to side span suspender can avoid secondary tension. The related methods in this paper can provide reference for similar engineering construction control.