系杆拱桥稳定性分析  

Stability Analysis of Tied Arch Bridge

作　　者：李子特[1,2] 王根会 LI Zite;WANG Genhui(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Gansu Province Transportation Planning Suvey&Design Institution,Lanzhou 730030,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070 [2]甘肃省交通规划勘察设计院股份有限公司,甘肃兰州730010

出　　处：《甘肃科学学报》2023年第3期108-112,139,共6页Journal of Gansu Sciences

基　　金：甘肃省重大科技专项计划项目(19ZD2GA002)。

摘　　要：研究各种设计工况下的系杆拱桥的稳定性,以一座混凝土系杆拱桥为例,依据结构弹性屈曲理论,求解了系杆拱桥的主要屈曲模态,分析了横撑设置位置及设置形式对稳定性的影响,分析了系杆拱桥施工阶段和运营阶段静力稳定性的最不利荷载工况并求解了稳定特征值,采用一阶模态下附加初始缺陷的非线性分析方法求解了地震工况下的稳定性。分析结果表明:拱肋横桥向屈曲为系杆拱桥的主要失稳模态,屈曲时横向最大位移点在拱肋结构的等分点处;横撑形式及布设位置对横向稳定性的提高有显著作用,“一”字撑、“K”字撑、“米”字撑提高作用依次提升;系杆脱架阶段为施工阶段失稳的最不利工况,对称满跨布载为运营阶段失稳的最不利工况;E1、E2地震工况下屈曲特征值较恒载作用下分别降低了7.4%、13.3%,在高震区的动力稳定性应引起重视。The purpose of this paper is to study the stability of tied arch bridge under various design conditions.Taking a concrete tied arch bridge as an example,according to the structural elastic buckling theory,the main buckling modes of tied arch bridge are solved,and the influence of the setting position and form of cross brace on the stability is analyzed.The most unfavorable load cases of static stability of tied arch bridge during construction and operation are analyzed,and the stability eigenvalues are solved.The stability under seismic conditions is solved by using the nonlinear analysis method with initial defects under the first-order mode.The results show that the transverse buckling of arch rib is the main instability mode of tied arch bridge,and the maximum transverse displacement point is at the bisection point of arch rib structure.The form and layout position of cross brace have a significant effect on the improvement of lateral stability,and the improvement effects of straight brace,K-brace and decussate brace(米shape)are increased in turn.The tie bar off frame stage is the most unfavorable condition for instability in the construction stage,and the symmetrical full span load distribution is the most unfavorable condition for instability in the operation stage.The buckling eigenvalues under E1 and E2 earthquake conditions are reduced by 7.4%and 13.3%respectively compared with those under dead load.Attention should be paid to the dynamic stability in high frequency earthquake areas.

关 键 词：系杆拱桥 稳定性 屈曲模态 横撑 施工和运营 非线性 

分 类 号：U448.22[建筑科学—桥梁与隧道工程]