挖井基础铁路桥墩的抗震性能影响参数分析  

Analysis on the influence parameters of seismic performance for railway bridge pier in digging well foundation

作　　者：王义 陈兴冲[1] 张熙胤[1] 丁明波[1] 张永亮[1] 刘正楠[1] Wang Yi;Chen Xingchong;Zhang Xiyin;Ding Mingbo;Zhang Yongliang;Liu Zhengnan(College of Civil Engineering,Lanzhou Jiaotong University,730070,Lanzhou,China)

机构地区：[1]兰州交通大学土木工程学院,兰州730070

出　　处：《应用力学学报》2020年第6期2544-2550,I0016,共8页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金项目(51968039,51768036,51808273)。

摘　　要：基于拟静力试验结果,建立了挖井基础桥墩的有限元模型,对水平往复荷载作用下挖井基础桥墩的受力特征及影响参数进行了研究,分析桥墩配筋率、含箍率和轴压比对桥墩位移延性系数、抗力增大系数和屈后刚度比的影响。研究结果表明:建立的有限元模型可较好地模拟地震作用下挖井基础桥墩的力学行为,试验及分析结果均表明在较小的墩顶位移作用下,基础周围土体也将表现出明显的非线性;提高桥墩主筋配筋率可显著提高挖井基础桥墩的极限承载能力和极限位移,减缓屈后刚度的退化,提高桥墩含箍率对挖井基础桥墩承载力和变形能力的影响并不显著;轴压比对挖井基础桥墩的变形能力和承载力影响显著,随着轴压比的增大,桥墩的位移延性系数和抗力增大系数减小,屈后刚度的退化减缓。As a kind of bridge foundation,the proportion of digging well foundation in railway bridge is increasing.As a rigid foundation,the digging well foundation has good performance under static action,while the existed seismic damages show that it is not perfectly safe under earthquake action.Based on the pseudo-static test results,the finite element model of the bridge pier on digging well foundation is established,the stress characteristics and influence parameters of the bridge pier under horizontal reciprocating load are studied,the influence of reinforcement ratio,stirrup ratio and axial compression ratio on the displacement ductility coefficient,resistance increase coefficient and flexion stiffness ratio is analyzed.The results show that the following facts,the mechanical behavior of the pier under the action of earthquake can be well simulated by the finite element model,and the test and analysis results show that the soil around the foundation will also show significant nonlinearity under the action of small pier displacement.The ultimate bearing capacity and ultimate displacement of bridge pier can be significantly improved and the degradation of post-flexion stiffness is reduced by increasing the reinforcement ratio of main reinforcement of bridge pier,the bearing capacity and deformation capacity of the pier are not significantly affected by stirrup ratio of the pier.Axial compression ratio has significant influence on the deformation capacity and bearing capacity of digging well foundation pier,the displacement ductility coefficient,resistance increase coefficient and degradation of post-flexion stiffness of the pier decrease with the increase of axial compression ratio.

关 键 词：挖井基础桥墩 受力特征 基础-土相互作用 参数分析 拟静力试验 

分 类 号：U442[建筑科学—桥梁与隧道工程]