基于零位移与无应力状态控制的斜拉扣挂施工扣索力确定方法  

Combined Algorithm for the Fastening Stay Force Determinations in Cantilever Construction by Synthesizing the Zero-displacement and Zero-stress State Control Methods

作　　者：余玉洁 罗永琪 周文 蒋丽忠[1] YU Yujie;LUO Yongqi;ZHOU Wen;JIANG Lizhong(School of Civil Eng.,Central South Univ.,Changsha 410075,China;Bridge Eng.Co.,Ltd.of China Railway Guangzhou Eng.Group Co.,Ltd.,Guangzhou 510800,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中铁广州工程局集团桥梁工程有限公司,广东广州510800

出　　处：《工程科学与技术》2024年第3期83-89,共7页Advanced Engineering Sciences

基　　金：国家重点研发计划项目(2022YFC3004304)。

摘　　要：大跨度拱桥常采用斜拉扣挂法开展拱肋施工,但在节段拼装过程中扣索索力和拱肋空间位形之间互相影响,索力优化计算以及扣索状态控制问题复杂。提出改进零位移法结合无应力状态控制法的复合扣索力计算方法:基于改进型零位移法快速得到满足成拱线形要求的扣索力大小,基于成拱索力采用无应力状态法反推各施工阶段扣索索力。该复合方法可避免传统零位移法扣索力不准和反复迭代计算的缺陷,施工中扣索可实现一次张拉,后续节段拼装中无需对扣索进行索力调整。以某跨径430 m大跨度钢管混凝土拱桥缆扣合一施工为工程应用背景,采用的零位移法结合无应力状态法对大跨度非对称式钢结构拱肋进行斜拉扣挂拼装的扣索力求解和施工模拟。分析拼装过程中扣索力变化规律,并对比验证实际线形与目标线形偏差,以及拱肋应力与设计应力之间偏差程度。结果表明,所提出的复合算法理论简单且索力求解计算便捷。所求的扣索力可有效保证拱肋拼装完成及松索后拱肋线形和受力均满足要求。Long-span arch bridges often utilize the cantilever construction method to erect the arch rib.The cable forces of fastening stays and the spatial configurations of the rib mutually influence each other during segmental assembly.Calculating cable forces and controlling the state of fastening stays are complex processes.This study proposes a combined algorithm that integrates the improved zero-displacement method with the zero-stress state control method for determining cable forces.The optimized cable forces at the arch formation stage can be quickly calculated us-ing the improved zero-displacement method.Based on the calculated fastening stay forces,the zero-stress cable lengths and the cable forces at each assembly stage can be deduced using the zero-stress state method.This composite method avoids the inaccuracies and repeated iterative cal-culations of the traditional zero-displacement method.The fastening stays require only one-time tensioning during construction,eliminating the need for repeated cable force adjustments during the segment assembly process.The combined algorithm is applied to the cantilever construction analysis of a long-span concrete-filled steel tube arch bridge with a span of 430 m.The zero-displacement method,combined with the stress-free state method,determines the tension forces of fastening stays during the asymmetric cantilever construction of the long-span arch ribs.Variations in cable forces during the assembly process were analyzed,comparing the deviations between the actual rib and the target rib lines and between the rib stresses and the designed member stresses.The results indicated that the proposed combined algorithm is simple and facilitates easy calcu-lations.The fastening stay forces obtained can effectively ensure satisfactory control of the arch rib assembly at the arch formation and cable loosening stages.

关 键 词：钢管混凝土拱桥 斜拉扣挂法 扣索力计算 零位移法 无应力状态法 

分 类 号：U448[建筑科学—桥梁与隧道工程] TU311[交通运输工程—道路与铁道工程]