独塔斜拉桥动力特性及地震响应研究

发布时间：2019-06-01 07:39

【摘要】：武汉黄陂后湖大桥主桥为独塔单索面预应力混凝土展翅箱梁斜拉桥，跨径组成为90+128m。独塔斜拉桥主梁、桥塔、桥墩的连接方式，决定了结构体系内部构件传力的有效性。对不同塔、梁、墩连接形式的独塔斜拉桥进行动力特性和抗震性能的分析具有实际应用意义，本文依此主要做了以下研究工作。 (1)对独塔斜拉桥的总体布置和不同结构体系的相关特点进行了论述。 (2)对不同结构体系独塔斜拉桥动力特性分析中的建模方法进行了研究。以武汉黄陂后湖大桥（刚构体系、边跨设置辅助墩）为背景，改变塔、梁、墩的边界条件，采用有限元结构分析软件midas Civil建立了刚构模型一、半漂浮模型、漂浮模型、塔梁固结模型，同时建立了边跨不设置辅助墩的刚构模型二，依此形成两种不同模式的对比。采用多重Ritz向量法对五种不同模型进行了动力特性分析，并比较了特征值的差异性。 (3)采用规范加速度反应谱作为输入的谱曲线，对五种不同模型进行了反应谱分析。以刚构模型一为例计算了八种（一维三种，二维两种，三维三种）不同组合下独塔斜拉桥的地震响应，得到了地震响应的一般规律。计算了五种不同模型在工况六（纵桥向+0.3横桥向+0.3竖向）作用下的地震响应，并分别比较了不同控制截面的位移和内力响应的差异性。 (4)采用修正的Taft波作为地震动输入，对五种不同模型进行了一致激励作用下的动态时程分析。以刚构模型一为例计算了八种不同组合下独塔斜拉桥的地震响应，并比较了地震动态时程响应规律与反应谱得到的规律的差异性。计算了五种不同模型在工况六（纵桥向+0.3横桥向+0.3竖向）作用下的地震响应，，并分别比较了不同控制截面位移和内力响应与反应谱位移和内力响应的差异性。考虑到地震作用的随机性，两种方法计算的结果有比较明显的差异，为安全起见，对此类独塔斜拉桥进行地震响应分析时应将两种方法相结合，综合权衡以得到比较满意的结果。
[Abstract]:The main bridge of Wuhan Huangpi Houhu Bridge is a single tower single cable plane prestressed concrete spread wing box girder cable-stayed bridge with a span composition of 90 128 m. The connection mode of main beam, tower and pier of single tower cable-stayed bridge determines the effectiveness of force transmission in the internal members of the structural system. It is of practical significance to analyze the dynamic characteristics and seismic performance of single-tower cable-stayed bridges with different tower, beam and pier connections. The following research work has been done in this paper. The main contents are as follows: (1) the general arrangement of single tower cable-stayed bridge and the related characteristics of different structural systems are discussed. (2) the modeling method in dynamic characteristic analysis of single tower cable-stayed bridge with different structural systems is studied. Based on the background of Wuhan Huangpi Houhu Bridge (rigid frame system, edge span with auxiliary piers), the boundary conditions of tower, beam and pier are changed, and the rigid frame model 1 and semi-floating model are established by using finite element structural analysis software midas Civil. The consolidation model of tower beam is established, and the rigid frame model 2 with no auxiliary piers is established, according to which the comparison of two different modes is formed. The dynamic characteristics of five different models are analyzed by using multiple Ritz vector method, and the differences of eigenvalues are compared. (3) the response spectra of five different models are analyzed by using the canonical acceleration response spectrum as the input spectral curve. Taking rigid frame model 1 as an example, the seismic responses of eight kinds of single tower cable-stayed bridges under different combinations (one-dimensional and three-dimensional, two-dimensional and three-dimensional) are calculated, and the general law of seismic response is obtained. The seismic responses of five different models under the action of working condition 6 (vertical bridge 0.3 horizontal bridge 0.3 vertical) are calculated, and the differences of displacement and internal force responses of different control sections are compared respectively. (4) using the modified Taft wave as the input of ground motion, the dynamic time history analysis of five different models under uniform excitation is carried out. Taking rigid frame model 1 as an example, the seismic response of single tower cable-stayed bridge under eight different combinations is calculated, and the difference between seismic dynamic time history response law and response spectrum is compared. The seismic responses of five different models under the action of working condition 6 (vertical bridge 0.3 horizontal bridge 0.3 vertical) are calculated, and the differences between displacement and internal force response of different control sections and response spectrum displacement and internal force response are compared respectively. Considering the randomness of seismic action, the results calculated by the two methods are obviously different. For the sake of safety, the two methods should be combined in the seismic response analysis of this kind of single-tower cable-stayed bridge. Comprehensive trade-off to obtain satisfactory results.
【学位授予单位】：武汉理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441.3;U448.27

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