基于蠕变理论的自锚式悬索桥索夹预紧力研究  

Study on Pre-tightening Force of Cable Clamp of Self-anchored Suspension Bridge Based on Creep Theory

作　　者：唐冕[1] 车天鑫 宋旭明[1] 胡省阳 TANG Mian;CHE Tianxin;SONG Xuming;HU Shengyang(School of Civil Engineering,Central South University,Changsha 410075,Hunan,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《华南理工大学学报（自然科学版）》2022年第1期59-68,共10页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51178471,51508574)。

摘　　要：自锚式悬索桥主缆直径小、垂跨比大,为了研究悬索桥在使用过程中主缆索夹的蠕变松弛造成预紧力的损失对全桥安全的影响。以长沙市三汊矶湘江大桥主缆索夹为研究对象,并基于金属时间硬化蠕变理论,得到主缆蠕变随初始应力及时间变化的经验公式。考虑主缆蠕变导致的径向收缩及高强螺栓的预紧力时效松弛等因素的影响,得出自锚式悬索桥运营阶段索夹高强螺栓预紧力损失计算公式,并通过ANSYS建立主缆和索夹一体化的精细有限元模型进行验证。经验证,计算公式解稍大于数值解,差值为10~20 kN,拟合精度良好,可为悬索桥预紧力检测与加固提供参考。The main cable diameter of self-anchored suspension bridge is small and the vertical span ratio is large.In order to study the influence of the pre-tightening force loss caused by creep relaxation of the main cable clamp on the safety of the whole bridge,this study took the main cable clamp of Sanchaji Xiangjiang Bridge in Changsha as the research object,and obtained the empirical formula of the main cable creep changing with initial stress and time based on the metal time hardening creep theory.Considering the influence of radial shrinkage caused by the creep of the main cable and the aging relaxation of the pre-tightening force of the high-strength bolts,the calculation formula of pre-tightening force loss of the high-strength bolts in the cable clamp of the self-anchored suspension bridge during operation was obtained,and the fine finite element model of integration of the main cable and the cable clamp was established by ANSYS for verification.The verification results show that the solution of the calculation formula is slightly larger than the numerical solution by 10~20 kN,and the fitting accuracy is good.Therefore,the empirical formula can provide reference for the detection and reinforcement of the pre-tightening force of suspension bridges.

关 键 词：主缆 索夹 蠕变理论 预紧力损失 经验公式 

分 类 号：U447[建筑科学—桥梁与隧道工程]