STUDIES ON SEISMIC RESPONSE OF EXTENDED STRUCTURES IN IRREGULAR SITE AND THE RATIONAL DESIGN CONSIDERATIONS

不规则场地延伸结构地震响应研究及合理设计考虑

基本信息

批准号：
04555111
负责人：
TAKEMIYA Hirokazu
金额：
$ 4.22万
依托单位：
OKAYAMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1994
项目状态：
已结题

项目摘要

Presented first is the transient seismic response of alluviums with due account for the configuration and the size in view of incident wave types and the lengths, besides the stiffness contrast to the underlain far extening base. Discretization is made such that the near field of complex configuration and irregular material distribution is modeled by the finite elements (FE) and the extending far field by the boundary elements (BE). The time domain BEM-FEM hybrid computation is taken in order to give a clear interpretation to the seismic wave scattering and propagation. Parametric studies are performed aiming at aquiring the relevant soil amplification which is useful information for the structural design on irregualar allumivums.Secondly, discussed is the seismic response of an extended shield tunnel structures to be constructed at irregular sites with due account for the alluvium configuration and size and the stiffness contrast to the underlain far extending base. The BEM-FEM hybird … More formulation is taken for the total system of soil and structure in order to account for the seismic wave scattering due to the presence of the letter. Parametric studies are performed for various wave lengths of the incident SV wave, P wave with different incident angles. The structural internal forces as well as deformation are investigated.Thirdly, for the purpose of practical design procedure of shield tunnels, a simplified 3-dimensional structural model supported by Winkler type springs.is proposed. The behavior of extended buried structures in alluvium deposits with is interpreted due care to the site topography. This is examined from the comparison with the above elaborate BEM-FEM hybrid solution. The matching between these different methods is achieved when an appropriate modification factor is made to the spring constant.Finally, from the design point of view, stiffening of the surrounding sofft soil is proposed in order to avoid excessive response and for the seismic response redunction. Less

首先介绍的是冲积层的瞬态地震响应，考虑到入射波类型和长度，适当考虑了结构和尺寸，此外还进行了离散化，以便复杂结构的近场。不规则材料分布由有限元（FE）建模，延伸远场由边界元（BE）建模，采用时域边界元-有限元混合计算，以便对地震给出清晰的解释。进行了参数化研究，以获得相关的土壤放大率，这对于不规则冲积土的结构设计是有用的信息。其次，讨论了在适当考虑的不规则场地上建造的扩展盾构隧道结构的地震响应。对于冲积层的配置和尺寸以及与下面的远延伸基础的刚度对比，BEM-FEM 混合公式适用于整个土壤和结构系统，以考虑到对不同波长的入射SV波、不同入射角的P波进行了参数化研究，研究了由于字母的存在而引起的结构内力和变形。第三，以实用为目的。在盾构隧道的设计过程中，提出了由 Winkler 型弹簧支持的简化 3 维结构模型，并根据现场地形对冲积层中延伸的埋地结构的行为进行了解释。通过对弹簧常数进行适当的修正因子，可以实现这些不同方法之间的匹配。最后，从设计的角度来看，建议对周围的软土进行加固。避免过度反应和减少地震反应。