土—桥梁动力相互作用的有限元模型研究

发布时间：2018-04-21 10:35

本文选题：土-结构动力相互作用 + 浅基础　；参考：《西南交通大学》2015年硕士论文

【摘要】：土-结构动力相互作用是结构设计的重要因素,也是结构动力响应分析的关键问题。论文基于有限元方法,着重研究不同的土体条件、基础形式对土-结构的动力相互作用的影响,旨在探讨适用于分析独塔斜拉桥动力响应的有限元模型。论文先后对浅基础、桩基础及某独塔双索面斜拉桥展开讨论,研究内容包括：1.基于弹性地基梁理论,采用子结构法研究土-结构动力相互作用,讨论土体条件、基础形式、基础尺寸等对土-结构系统动力刚度和阻尼的影响；2.介绍了现有浅基础的土-结构动力相互作用简化分析模型,其中包括：固结模型、六弹簧模型和刚性盆式模型,对比分析现有模型对结构动力响应的影响,结果表明,由于刚性盆式模型同时考虑了基底剪力和基础侧面的被动土压力,其理论基础和计算结果更接近实际情况；3.介绍了桩基础的土-结构动力相互作用简化分析模型,其中包括：嵌固模型、修正m法模型、刚性盆式模型,对比分析现有模型对结构动力响应的影响,结果表明,修正后的m法模型考虑了土层的分层,且没有简化群桩,对群桩的旋转阻抗和阻尼的影响最小；4.将上述改进后的六弹簧模型和刚性盆式模型用于斜拉桥的动力响应分析,分析中借用浅基础的算法虑了承台与土体的动力相互作用,同时也考虑桩基与土体的动力相互作用,对比分析可知,土-结构动力相互作用对斜拉桥下塔柱和主梁横向受力影响较大；矩形承台的形状、刚度对桥梁的动力分析有影响。
[Abstract]:Soil-structure dynamic interaction is an important factor in structural design and a key problem in structural dynamic response analysis. Based on the finite element method, this paper focuses on the influence of different soil conditions and foundation forms on the soil-structure dynamic interaction. The purpose of this paper is to explore a finite element model suitable for analyzing the dynamic response of single-tower cable-stayed bridges. In this paper, the shallow foundation, pile foundation and a single tower and double cable plane cable-stayed bridge are discussed successively. The research contents include: 1. Based on the theory of elastic foundation beam, the influence of soil condition, foundation form and foundation size on the dynamic stiffness and damping of soil-structure system is studied by substructure method. This paper introduces the existing simplified analysis models of soil-structure dynamic interaction of shallow foundation, including consolidation model, six-spring model and rigid basin model. The influence of the existing models on the dynamic response of the structure is compared and analyzed. Since the rigid basin model takes into account both the base shear force and the passive earth pressure on the side of the foundation, the theoretical basis and the calculated results are closer to the actual situation. This paper introduces the simplified analysis model of soil-structure dynamic interaction of pile foundation, including: embedded model, modified m model, rigid basin model. The influence of existing models on the dynamic response of structure is compared and analyzed. The modified m-method model considers the delamination of the soil layer and does not simplify the pile group, and the effect on the rotation impedance and damping of the pile group is minimal. The improved six-spring model and rigid basin model are applied to the dynamic response analysis of cable-stayed bridge. The dynamic interaction between pile cap and soil is considered by using the algorithm of shallow foundation in the analysis, and the dynamic interaction between pile foundation and soil is also considered. The comparison and analysis show that the soil-structure dynamic interaction has a great influence on the lateral force of tower column and main beam under cable-stayed bridge, and the shape and stiffness of rectangular cap have influence on the dynamic analysis of the bridge.
【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】：U441.3;TU435

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