三塔悬索桥施工控制的若干问题和地震响应分析

发布时间：2018-10-31 12:10

【摘要】：近年来,跨海、跨江工程成为桥梁工程的热点话题,多塔多跨悬索桥在跨海通道的建设中优势明显。在多塔多跨悬索桥中,三塔悬索桥方案备受桥梁工程师的青睐。三塔悬索桥可减小主跨跨径,降低主缆拉力,综合性能好于同跨度的双塔悬索桥。以施工控制和地震响应为研究方向,本文的前半部分分析了一座大跨度三塔悬索桥桥塔施工控制中的若干问题；后半部分对其自振特性,尤其是地震荷载下的时程响应和行波效应问题进行了研究。本文的主要工作包含以下几个方面：(1)以正装计算法为理论基础,模拟了桥塔建造的全过程,跟踪计算了整个过程中桥塔及临时支撑结构的应力与变形,为施工工序和临时结构的设计和施工提供了计算依据,以保证施工中间状态和成桥后的力学指标符合设计要求。(2)建立以“鱼骨梁”模型为基础的有限元模型,分析成桥状态下三塔悬索桥的自振特性。将计算得到的该桥前十阶自振频率与振型与同类型的悬索桥相比较,得出三塔悬索桥自振特性的相同与不同之处。(3)采用一致激励的方法,讨论纵向波+竖向波、横向波+竖向波与三向波这三种地震波组合形式对地震时程响应的影响,并计算分析了三向地震波输入下三塔悬索桥地震时程响应的特点。结论表明三塔悬索桥加劲梁的横向刚度较差,中塔内力约为边塔的2-3倍。(4)最后,本文研究了视波速取值范围为360m/s-2160m/s的地震波的行波效应对三塔悬索桥地震响应的影响。结论认为行波效应对结构的影响依赖于视波速的选取,实际工程中应根据场地地质条件选取合适的视波速。
[Abstract]:In recent years, cross-sea and cross-river projects have become a hot topic in bridge engineering, and the advantages of multi-tower and multi-span suspension bridges in the construction of cross-sea passage are obvious. In multi-tower multi-span suspension bridge, three-tower suspension bridge is favored by bridge engineers. The three-tower suspension bridge can reduce the span of the main span and reduce the tension of the main cable. The comprehensive performance of the three-tower suspension bridge is better than that of the double-tower suspension bridge with the same span. Taking construction control and seismic response as the research direction, some problems in the construction control of a long-span three-tower suspension bridge tower are analyzed in the first half of this paper. In the latter part, the natural vibration characteristics, especially the time-history response and traveling wave effect under earthquake load are studied. The main work of this paper includes the following aspects: (1) the whole construction process of the bridge tower is simulated, and the stress and deformation of the bridge tower and temporary supporting structure are calculated in the whole process based on the formal calculation method. It provides calculation basis for the design and construction of construction process and temporary structure, so as to ensure that the intermediate state of construction and the mechanical indexes after completion of the bridge meet the design requirements. (2) the finite element model based on the "fishbone beam" model is established. The natural vibration characteristics of three tower suspension bridges are analyzed. By comparing the first ten natural frequencies and modes of the bridge with the same type of suspension bridge, the similarities and differences of the natural vibration characteristics of the three-tower suspension bridge are obtained. (3) the vertical wave of longitudinal wave is discussed by using the method of consistent excitation. The influence of three seismic wave combinations of transverse wave vertical wave and three-direction wave on the seismic time-history response is analyzed and the characteristics of seismic time-history response of the three-tower suspension bridge under the three-direction seismic wave input are calculated and analyzed. The results show that the lateral stiffness of the stiffened beam of the three-tower suspension bridge is poor, and the internal force of the middle tower is about 2-3 times that of the side tower. (4) finally, In this paper, the influence of traveling wave effect of seismic wave on seismic response of three-tower suspension bridge with apparent wave velocity range of 360m/s-2160m/s is studied. The conclusion is that the influence of traveling wave effect on the structure depends on the selection of apparent wave velocity, and the appropriate apparent wave velocity should be selected according to the geological conditions of the site in practical engineering.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U448.25;U442.55

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