黄河桃花峪自锚式悬索桥体系转换方案的比较研究

Comparative study on the optimal system transformation schemes for Taohuayu self-anchored suspension bridge

结合世界最大跨度自锚式悬索桥黄河桃花峪大桥的工程实例,针对平面主缆双塔三跨自锚式悬索桥缆索体系各阶段的几何和力学特点,明确该桥型吊索张拉有"先边后中"、"边中共进"2类和每类6种的吊杆张拉思路,分析空缆状态及各种方案转换过程缆索系统的几何与力学特点、"多轮循环法"与"逐步推进法"的施工特点,指明体系转换方案择优的方向。在此基础上,确定并比较"先边后中"的方案2、"边中共进"的方案1和"边中共进"的方案2,明确"先边后中"的方案2和"边中共进"的方案1是黄河桃花峪大桥较优的体系转换方案,且各有特点和优势。继而给出其中之一的体系转换优选典型方案——"先边后中"的方案2的关键计算结果,证明该方案的可行性、安全性、经济性和可控性。体系转换的结构效应实测值与理论值吻合良好,表明了体系转换方案确定与论证的正确性,以及体系转换方案实施的高质量。

According to the geometry and mechanical characteristics of cable system in different construction stages for Taohuayu 2-tower 3-span self-anchored suspension bridge,two tensioning sequence with 6 patterns for suspenders are determined. One scheme is that the side suspenders are tensioned before the middle suspenders( TS1),and another scheme is that side and middle suspenders are tensioned simutaneously( TS2). The geometry and mechanical characteristics of cable system at initial stage and system transformation stages are analyzed,the construction methods of'multi-round cycles'and'step by step'are compared,and then the optimal goals and system transformation parameters are proposed. Based on the comparison results of different system transformation plans for self-anchored suspension bridge,the tensioning sequence for suspenders( TS1) is chosen as the optimal scheme,and some key calculated results at optimal scheme are provided and compared with measured ones. The calculated results of structural responses agree well with the measured ones,which indicate the feasibility,safety and controllability of the optimal system transformation scheme.