大跨度钢—混组合梁斜拉桥地震反应分析

发布时间：2018-05-01 03:27

本文选题：钢混组合斜拉桥 + 索力优化　；参考：《合肥工业大学》2017年硕士论文

【摘要】：本文以目前中国最大跨径、最大联长的钢混组合梁斜拉桥-望东长江公路大桥为工程背景,对其进行恒载索力优化、动力特性分析、地震反应分析,主要工作及结论如下:(1)总结钢混组合梁斜拉桥的发展历程,及其相较于钢斜拉桥、混凝土斜拉桥的一些静力、动力方面良好受力性能。明确斜拉桥抗震分析意义,及关键影响因素。总结抗震计算的主要方法,并判断能否适用于大跨径斜拉桥计算分析,及计算结果是否有所局限。(2)在ANSYS中进行结构的离散,根据梁、塔、索各自不同的受力特点选择对应的单元类型,建立全桥的有限元模型。(3)利用零位移法、最小弯曲应变能法、一阶优化法对组合梁斜拉桥恒载索力进行优化分析,结果表明一阶优化法就线形、主梁、主塔内力、拉索应变分布方面均取得非常好的优化效果。(4)建立墩底固结模型及集中质量模型,对比分析桩土相互作用对结构动力特性的影响,计算结果表明,桩土相互作用对结构有着显著影响。(5)对斜拉桥进行单独的顺桥向、横桥向及与竖向地震共同作用下结构的响应进行反应谱分析,结果表明竖向地震对结构顺桥向地震的轴力、弯矩、位移均有较大的影响。(6)对斜拉桥进行顺桥向、横桥向及于竖向地震共同作用下结构响应进行非线性时程分析,结果表明顺桥向地震反应为半漂浮体系抗震设计关键因素,且要考虑竖向地震影响,结构内力、位移时程明显表现出长周期结构的特征。(7)本文基于m法,将桩土相互作用等效为水平布置的弹簧,并就进行时程分析研究了其对地震响应的影响,结果表明,不考虑桩土相互作用,主塔的动力响应将被低估。(8)本文对流体粘滞阻尼器对望东长江公路大桥的减震效果进行了分析,主要分析了阻尼系数对减震效果的影响,结果表明,流体粘滞阻尼器可以明显降低结构位移响应,塔底弯矩响应。
[Abstract]:In this paper, the steel-concrete composite girder cable-stayed bridge, Wangdong Changjiang Highway Bridge, which has the largest span and the longest connecting length in China, is used as the engineering background. The optimization of the dead load cable force, the analysis of the dynamic characteristics and the analysis of the seismic response are carried out in this paper. The main work and conclusions are as follows: 1) summarize the development course of steel-concrete composite beam cable-stayed bridge, and compare with steel cable-stayed bridge, concrete cable-stayed bridge has good static and dynamic behavior. The significance of seismic analysis of cable-stayed bridge and the key influencing factors are clarified. This paper summarizes the main methods of seismic calculation, and determines whether it can be applied to the calculation and analysis of long-span cable-stayed bridges, and whether the calculation results are limited. The finite element model of the whole bridge is established. The zero displacement method, the minimum bending strain energy method and the first order optimization method are used to optimize the cable force of the composite girder cable-stayed bridge. The results show that the first order optimization method has achieved very good optimization results in terms of linear shape, main beam, internal force of main tower and strain distribution of cable. 4) the consolidation model and concentrated mass model of pier bottom are established. The effect of pile-soil interaction on the dynamic characteristics of the structure is analyzed. The calculated results show that the pile-soil interaction has a significant effect on the structure. The response spectrum of the structure under the action of transverse bridge and vertical earthquake is analyzed. The results show that the axial force, bending moment and displacement of the vertical earthquake have a great influence on the axial force, bending moment and displacement of the structure. The nonlinear time-history analysis of the structural response under the interaction of horizontal bridge and vertical earthquake shows that the seismic response along the bridge is the key factor in the seismic design of semi-floating system, and the influence of vertical earthquake should be considered, and the internal force of the structure should be taken into account. Displacement time history obviously shows the characteristics of long-period structure.) based on m method, the pile-soil interaction is equivalent to a horizontally arranged spring, and the influence on seismic response is studied by time-history analysis. The results show that, Without considering the pile-soil interaction, the dynamic response of the main tower will be underestimated.) in this paper, the damping effect of fluid viscous damper on Wangdong Yangtze River Highway Bridge is analyzed, and the effect of damping coefficient on the damping effect is analyzed. Fluid viscous dampers can significantly reduce the displacement response of the structure and the bending moment response at the bottom of the tower.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U442.55;U448.27

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