预应力大跨地铁站震害机理与结构优选研究

发布时间：2018-05-16 02:41

本文选题：预应力大跨度 + 地铁车站　；参考：《大连理工大学》2015年硕士论文

【摘要】：大跨地铁车站结构采用先进的预应力技术实现大空间,充分利用结构美体现现代交通建筑的特点,为乘客提供舒适的乘车环境,实现地铁车站安全性、可靠性、适用性、经济性和技术先进性有机统一,与传统的双层三跨柱岛式地铁站相比具有更大优势。然而,地铁是人流量集中区域,地铁结构一旦破坏会造成巨大的经济损失,并且地下结构的修复存在诸多困难。因此,对预应力无中柱大跨度地铁站进行地震破坏机理和抗震性能的研究具有重要的理论意义与工程应用价值。本文以预应力大跨度无中柱地铁车站结构为研究背景,考虑车站结构的预应力效应,土-结构的初始应力以及阻尼,基于大型商业有限元软件ABAQUS,用截面等效刚度法将密肋框架结构简化为二维平面应变框架结构,采用粘弹性人工边界,分别在水平和竖向地震作用下进行震害数值模拟,研究了预应力无中柱大跨度地铁站结构的地震反应特性,得出了预应力无中柱大跨度地铁车站在地震时的破坏模式和薄弱位置分布特点。主要研究内容如下：1.介绍了用于进行土-结构动力相互作用分析的土体本构、混凝土动塑性损伤本构模型及其原理；土-结构接触面的数值模型处理方法。2.比较了固定边界、粘性边界、无限元边界、粘弹性边界等边界条件动力特性；分析不同波动输入方式下自由场地的动力特性。在有限元软件ABAQUS中实现了静-动力人工边界条件的转换方法,并验证了静-动力人工边界条件转换方法的可靠性。3采用动塑性混凝土损伤本构模型,用拉压损伤因子描述混凝土在循环荷载下的非线性与疲劳性能,综合考虑了震前土-结构自重应力、钢筋混凝土预应力和地铁车站结构的阻尼效应,对土-地铁结构相互作用系统地进行了地震过程的非线性数值模拟。分析了震害发生时大跨度预应力地铁车站结构动应力反应集中,得出了该类车站结构的破坏过程、破坏形式和抗震薄弱位置,并给出了合理的解释。4将两待选大跨地铁站结构与双层三跨柱岛式地铁站结构进行对比,保证静力作用下安全可靠同时进行了地震响应分析,比较了不同位置加速度响应、裂缝的产生发展、应力响应等因素。综合评价了两个预应力大跨度地铁站的抗震性能,建议了优选结构。
[Abstract]:The large span subway station structure adopts advanced prestress technology to realize large space, fully utilize the structure beauty to embody the characteristics of modern traffic building, provide comfortable riding environment for passengers, and realize the safety, reliability and applicability of subway station. Compared with the traditional double-layer three-span island subway station, the economy and technology are organic unity. However, subway is a concentrated area of human flow. Once the subway structure is destroyed, it will cause huge economic losses, and there are many difficulties in the repair of underground structure. Therefore, it is of great theoretical significance and engineering application value to study the seismic failure mechanism and seismic performance of prestressed large-span metro stations without medium columns. In this paper, the prestressing effect of the station structure, the initial stress of soil-structure and damping are considered. Based on the commercial finite element software Abaqus, the cross section equivalent stiffness method is used to simplify the multi-ribbed frame structure to two-dimensional plane strain frame structure, and the viscoelastic artificial boundary is used to simulate the earthquake damage under horizontal and vertical earthquake respectively. In this paper, the seismic response characteristics of prestressed large-span subway station structures without medium columns are studied, and the failure mode and weak position distribution characteristics of prestressed large-span subway stations without medium columns are obtained. The main research contents are as follows: 1. The soil constitutive model, concrete dynamic plastic damage constitutive model and its principle for soil-structure dynamic interaction analysis are introduced, and the numerical model treatment method of soil-structure interface is presented. The dynamic characteristics of boundary conditions such as fixed boundary, viscous boundary, infinite element boundary and viscoelastic boundary are compared, and the dynamic characteristics of free site under different wave input modes are analyzed. The conversion method of static and dynamic artificial boundary conditions is realized in the finite element software ABAQUS, and the reliability of the static and dynamic artificial boundary condition conversion method is verified. 3. The damage constitutive model of dynamic plastic concrete is adopted. The nonlinear and fatigue behavior of concrete under cyclic load is described by using the tension-compression damage factor. The soil-structure deadweight stress, the reinforced concrete prestressing force and the damping effect of subway station structure before earthquake are considered synthetically. The nonlinear numerical simulation of soil-subway structure interaction is carried out. The dynamic stress concentration of long-span prestressed subway station structure is analyzed when the earthquake damage occurs, and the failure process, failure form and seismic weak position of this kind of station structure are obtained. A reasonable explanation is given. 4. Comparing the structure of two long span subway stations to that of double-deck three-span island subway stations, the seismic response analysis is carried out under static force, and the acceleration responses of different positions are compared. Crack generation and development, stress response and other factors. The seismic behavior of two prestressed long-span subway stations is comprehensively evaluated, and the optimal selection of structures is suggested.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U231.4;TU311.3

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