摘要
基于子结构离散/整合技术构建一种新的悬浮隧道简化分析模型,研究跨度范围内支撑锚索的刚度及不均匀性对自振特性与移动荷载响应的影响。将管体沿跨径划分为多段梁单元,将支撑锚索等效为具有不同约束刚度的弹性支撑,建立多节段管体整体振动方程,动力响应采用多模态Galerkin截断获取。采用Morison方程研究水动力荷载,考虑移动荷载响应。研究结果表明:频率分布与锚索数目、支撑刚度相关,频谱图存在多阶频率汇集现象;位移峰值出现在移动列车经过该位置时刻,位移、内力与锚索数目、浮重比及刚度不均匀性密切相关;当锚索支撑数目减少、浮重比增大且支撑刚度变大时,弯矩、剪力的上下限值均变大;所提出的将锚索等效为竖向弹性支撑、采用子结构离散/整合技术建立悬浮隧道动力模型的方法是可行的,基于该模型的结构自振特性、移动荷载响应的分析及与有限元结果的对比验证了该方法的正确性,可为进一步确定锚索支撑式悬浮隧道结构的合理支撑刚度提供借鉴。
A simplified substructure model of the submerged floating tunnel(SFT)was established by using the substructures'isolating/assembling technique.The effects of the intermediate supporting cables'stiffness and their non-uniformities of the SFT on the free vibrations and the responses by the moving loads were studied.The tube was divided into multiple beam-segments in span-range,and the supporting cables were considered as elastic supports with different stiffnesses.The global vibratory equation of multiple tube segments was built.The responses were ascertained by using the Galerkin truncation with multiple modes.The hydrodynamic load was simulated by the Morison equation,and the responses of moving loads were considered.The results show that the frequency distribution is related to the supporting cables'number and stiffness,and there is an aggregation phenomenon in the frequencies spectrum.The peak displacement occurs when the moving train passes the position,and the displacement and internal forces are closely related to the supporting cables'number,the buoyancy-weight ratio(BWR)and the non-uniformity of supporting stiffness.When the supporting cables'number decreases,the BWR increases and the supporting stiffness increases,the upper/lower limits of bending moment and shear force all increase.The proposed method of establishing the dynamic model of SFT by using substructures'isolating/assembling technique is feasible.And its correctness is verified based on the natural vibration characteristics,the responses by moving loads and the comparison with the results from the finite element method.It provides reference for further determining the reasonable stiffness of the supporting cables for the SFT.
作者
潘权
易壮鹏
杨胜江
颜东煌
杨聪
PAN Quan;YI Zhuangpeng;YANG Shengjiang;YAN Donghuang;YANG Cong(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China;Guizhou Transportations Construction Group Co.Ltd.,Guiyang 550001,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2022年第10期4132-4141,共10页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(52278139,52278141,51878073)
湖南省自然科学基金资助项目(2022JJ30612)
长沙市科技计划项目(kq2202204)
湖南省教育厅科学研究项目(19A004)
长沙理工大学土木工程重点学科基金资助项目(18ZDXK02,18ZDXK14)。
关键词
悬浮隧道
子结构简化模型
锚索刚度不均匀性
浮重比
自振特性
移动荷载响应
submerged floating tunnel(SFT)
simplified substructure model
non-uniformity of cables'stiffness
buoyancy-weight ratio
natural vibration
response caused by moving loads
