波形钢腹板PC连续箱梁桥地震响应数值分析研究

发布时间：2018-03-13 19:18

本文选题：连续箱梁桥　切入点：波形钢腹板　出处：《东北大学》2014年硕士论文　论文类型：学位论文

【摘要】：波形钢腹板PC组合箱梁是一种以波形钢腹板替代普通混凝土腹板的新型钢—混凝土组合结构,我国从本世纪初才始于研究,其兼具自重轻、结构简单、受力明确、造型美观等优点。近年来作为生命线工程的桥梁结构的抗震性能越发受到人们的重视,有必要对这一新式桥梁形式进行动力特性和地震响应的研究。本文依托深圳南山大桥,以《公路桥梁抗震设计细则》等相关规范为基础,利用Midas Civil软件建立全桥梁单元模型,考虑结构的自重、二期恒载以及预应力,并结合抗震规范阐述的“三水准设防、两阶段设计”理念,利用反应谱法和时程分析方法进行桥梁地震响应分析。首先进行桥梁在多遇地震作用下的弹性地震响应计算,考虑水平两个方向的地震分量,根据南山大桥所在场地确定实际场地反应谱曲线,以动力特性计算结果为基础,进行反应谱分析；并采用两条实际地震波和一条人工合成地震波进行时程分析,两种分析方法结果接近且满足规范相关要求。随后,利用时程分析法,对桥梁在罕遇地震作用下的响应进行弹塑性分析。考虑材料非线性,分别采用双折线本构模型和Mander本构模型来描述钢筋和混凝土的本构关系,并由此得到桥墩截面弯矩—曲率曲线,作为判定桥墩塑性状态的工具。采用纤维铰定义桥墩塑性铰单元,以此得到地震过程中桥墩的滞回曲线。通过增大地震动峰值加速度、改变桥墩纵筋配筋率进行对比分析,计算结果说明桥墩设计偏于安全,有进一步优化的空间。最后,对比不同基础模拟方法对桥梁地震响应的影响,以此说明桩基础的模拟对于桥梁动力和地震分析的重要性。此外,通过比较波形钢腹板PC连续箱梁桥和普通混凝土腹板PC连续箱梁的地震响应,可知波形钢腹板桥型由于自重的减轻,具有更优秀的抗震性能。
[Abstract]:PC composite box girder with corrugated steel webs is a new steel-concrete composite structure with corrugated steel webs instead of ordinary concrete webs. It has been studied since the beginning of this century in China. It has the advantages of light weight, simple structure and clear force. In recent years, people pay more and more attention to the seismic performance of bridge structure, which is a lifeline project. It is necessary to study the dynamic characteristics and seismic response of this new bridge form. Based on the relevant codes such as "detailed rules for Seismic Design of Highway Bridges", a full bridge element model is established by using Midas Civil software, taking into account the weight of the structure, the dead load of the second phase and the prestress, and combining with the "three-level fortification" elaborated in the aseismic code. In the concept of two-stage design, the response spectrum method and time-history analysis method are used to analyze the seismic response of bridges. First, the elastic seismic responses of bridges under the action of frequent earthquakes are calculated, and the seismic components in both horizontal directions are considered. According to the site of Nanshan Bridge, the actual site response spectrum curve is determined, and the response spectrum analysis is carried out on the basis of the result of dynamic characteristic calculation, and two actual seismic waves and one synthetic seismic wave are used for time history analysis. The results of the two methods are close and meet the requirements of the code. Then, the elastic-plastic response of the bridge under rare earthquake is analyzed by time-history analysis. The material nonlinearity is considered. The double line constitutive model and the Mander constitutive model are used to describe the constitutive relation of steel bar and concrete respectively, and the moment curvature curve of the section of bridge pier is obtained. As a tool to determine the plastic state of the pier, the plastic hinge element of the pier is defined with fiber hinge, and the hysteresis curve of the pier during earthquake is obtained. By increasing the peak acceleration of the ground motion, the reinforcement ratio of the longitudinal reinforcement of the pier is changed and the reinforcement ratio of the pier is compared and analyzed. The results show that the design of piers is more safe and there is room for further optimization. Finally, the effects of different foundation simulation methods on the seismic response of bridges are compared. In addition, the seismic response of PC continuous box girder bridge with corrugated steel webs and ordinary concrete web PC continuous box girder is compared. It can be seen that the corrugated steel web bridge has better seismic performance because of the reduction of self-weight.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U442.55

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