悬索桥主缆与鞍座抗滑移安全系数的确定方法  

Method for Determining Anti-slip Safety Factors Between Main Cable and Saddle in Suspension Bridge

作　　者：张清华[1] 程震宇[1] 贾东林[1] 保义 ZHANG Qing-hua CHENG Zhen-yu JIA Dong-lin BAO Yi(Department of Bridge Engineering, Southwest Jiaotong University, Chengdu 610031, Sichuan, China Department of Civil, Architectural, and Environmental Engineering, Missouri University of Science and Technology, Rolla MO 65401, Missouri, USA)

机构地区：[1]西南交通大学桥梁工程系,四川成都610031 [2]密苏里科技大学土木建筑与环境工程系,密苏里罗拉mo65401

出　　处：《中国公路学报》2017年第7期41-49,共9页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(51578455;51378431;51178394);"十二五"国家科技支撑计划项目(2011BAG07B03);中央高校基本科研业务费专项资金项目(2682014CX078)

摘　　要：为准确评估主缆与鞍座间的抗滑移安全性,确保多塔悬索桥结构受力安全,对主缆与鞍座间的摩擦抗力特性进行了研究。通过分析索股间微元体的应力-应变关系,建立侧向压力和索股拉力间的微分方程,推导了主缆索股和鞍座侧壁接触面间的侧向压力表达式,并据此建立了主缆与鞍座间的摩擦抗力方程,提出了悬索桥主缆与鞍座之间的抗滑移安全系数确定方法。通过模型试验结果对摩擦抗力方程进行了验证,并对主缆与鞍座抗滑移安全系数的确定方法以及鞍座设计参数对于抗滑移安全系数的影响进行了探讨。结果表明:所提出的摩擦抗力方程能够准确确定鞍槽内设置和不设置竖向摩擦板2种典型情况下主缆与鞍座间的实际摩擦抗力;现有的抗滑移安全系数定义方法物理含义模糊,计算值偏于保守,无法计入鞍座参数优化对提高抗滑移安全性的影响,可能对多塔悬索桥的结构设计造成困扰;所提出的抗滑移安全系数表达式,物理意义明确,便于工程应用,可以作为确定抗滑移安全系数的依据;主缆与鞍槽接触面间的摩擦因数和鞍座结构设计参数是主缆与鞍座间摩擦抗力的重要影响因素,改善鞍座设计参数和设置竖向摩擦板是提高主缆与鞍座抗滑移安全性的有效途径。To precisely evaluate the anti-slip safety between the main cable and the saddle and guarantee the structure safety of multi-pylon suspension bridge,characteristics of the frictional resistance between the main cable and the saddle were investigated.The differential equation between lateral pressure and tension force of strands was established by analyzing the stressstrain relation of micro-body between strands. Meanwhile,a frictional resistance equation between the main cable and the saddle was established based on the lateral pressure expression.The method for determining anti-slip safety factors between the main cable and the saddle was proposed.The frictional resistance equation was validated by results of the model test.Moreover,determination methods of anti-slip safety factor as well as the influence of saddle design parameters on the anti-slip safety factor were discussed.The results indicate that the actual frictional resistance between the main cable and the saddle can be precisely determined by the proposed frictional resistance equation for the saddle with or without vertical friction plate.The existing way of defining anti-slip safety factor with ambiguous physical meaning and conservative values can＇t consider the influence of optimized saddle parameters on the improvement of anti-slip safety.These problems obstruct the overall design of the multi-pylon suspension bridge.The anti-slip safety factor expression with clearer physical significance is convenient for engineering application and can be taken as the major basis for determining antislip safety factor.The coefficients of friction between the main cable and the saddle as well as the saddle design parameters influence the frictional resistance to some extent.It is effective to improve the anti-slip safety through optimal saddle design parameters and the installation of vertical friction plates.

关 键 词：桥梁工程 多塔悬索桥 摩擦抗力方程 抗滑移安全系数 鞍座 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]