基于频率法的悬索桥锚跨索股索力精细化计算分析  

Refined calculation and analysis of cable force of anchor span of suspension bridge based on frequency method

作　　者：齐东春[1,2] 宋敬 刘章军 胡海龙 QI Dong-chun;SONG Jing;LIU Zhang-jun;HU Hai-long(College of Civil Engineering and Architecture,China Three Gorges University,Yichang 443002,China;Hubei Key Laboratory of Disaster Prevention and Mitigation,Yichang 443002,China;School of Civil Engineering and Architecture,Wuhan Institute of Technology,Wuhan 430074,China)

机构地区：[1]三峡大学土木与建筑学院,湖北宜昌443002 [2]湖北省防灾减灾重点实验室,湖北宜昌443002 [3]武汉工程大学土木工程与建筑学院,湖北武汉430074

出　　处：《广西大学学报（自然科学版）》2022年第2期320-329,共10页Journal of Guangxi University（Natural Science Edition）

基　　金：国家自然科学基金项目(51778343);国家山区公路工程技术研究中心开放基金项目(GSGZJ-2018-01)。

摘　　要：锚跨索股索力的控制影响着悬索桥主缆线形及安全。由于锚跨索股较短,边界条件、拉杆特性、索股抗弯刚度和锚头质量等因素对索力测试精度有一定程度影响。根据结构实际构造特点基于解析法建立锚跨索股的力学模型,索股和拉杆分别采用不同的欧拉梁的振型函数。根据能量守恒定律,采用瑞利法推导得到索股索力与自振频率的显式关系式。建立考虑散索鞍影响的符合锚跨索股实际构造特点的精细化有限元模型,通过有限元计算分析并结合实测数据对公式进行了验证。研究结果表明:提出的公式适用于悬索桥锚跨索股采用预应力锚固系统的情况,具有较高的精度。在应用公式通过实测频率计算索力时应考虑索股锚头质量的影响;空缆等索股索力较小时应首先识别出索股抗弯刚度,并考虑抗弯刚度对锚跨索股索力的影响。The control of anchor span cable force influences the shape and safety of the main cable for suspension bridges.On account of the short cable strand in anchor span,the test accuracy of cable force is influenced by boundary conditions,connecting rod characteristics,bending stiffness of cable strand and anchor head quality.According to the actual structural characteristics of cable strands in anchor span,the mechanical model is established for calculating the cable force.In the model the cable strand and the connecting rod adopt different Euler beam vibration mode functions.According to the law of conservation of energy,the explicit relationship between cable force and natural frequency is derived by Rayleigh method.A refined finite element model considering the influence of the splay saddle is established,which conforms to the actual structural characteristics of the anchor span cable strand.The formula is verified by the finite element calculation and the measured data.The results show that the formula is suitable for the prestressed anchorage system in suspension bridges.The calculation results have high precision.When the formula is used to calculate the cable force through the measured frequency,the influence of the mass of the anchor head should be considered.When the cable force of the cable strand is small,the bending stiffness of the cable strand should be first identified,and the influence of the bending stiffness of the cable strand should be considered.

关 键 词：悬索桥 锚跨索股 频率法 振型函数 瑞利法 

分 类 号：U448.25[建筑科学—桥梁与隧道工程] U443.38[交通运输工程—道路与铁道工程]