Proposal for Modeling Nonlinear Sloil-Structure Interaction System Considering Amplification Effect of Surface Layers

考虑表面层放大效应的非线性土土-结构相互作用系统建模建议

基本信息

批准号：
12650574
负责人：
KUSAKABE Kaoru
金额：
$ 2.3万
依托单位：
Kobe University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

During 1995 Hyogo-ken Nanbu Earthquake we have observed conspicuous concentration of damage in an extended area as a form of the so-called damage belt whose width was very narrow compared to its length. One of causes for this damage is the complexity of the deep underground structures including the earthquake fault. Another cause is the effects of surface layers.In this study, we discussed about the amplification effect of surface layers, the evaluation of complex stiffness of surface layers and the interaction effect between soil layer and structure. Then we proposed the earthquake response analysis method considering these effects of surface layers and the soil-structure interaction when building structures are subjected to ruinous or disastrous earthquake motion like 1995 Hyogo-ken Nanbu Earthquake.The complex stiffness of surface layers is evaluated by dynamical ground compliance (DGC) and impedance of soil-embedded base or pile foundation considering surrounding nonlinear soil media. Then the complex stiffness of surface layers is expressed by using the rational function of DGC and replaced with frequency-dependent spring-dashpot system.Results are as follows ; (1) The amplification effect of surface layers strongly depends on the conditions (depth, stiffness etc.) of the surface layers. (2) Simple surface layers can easily be replaced with simple spring-dashpot system, but deep surface layers becomes to more complex spring-dashpot system. (3) We must analyze earthquake response of building structure considering the interaction effect of soil-structure, because surface layers often have bad effects on earthquake response of building. (4) Nonlinear earthquake response analysis of soil-structure interaction system becomes easier by using rational function as the complex stiffness of surface layers.

在1995年，hyogo-ken nanbu地震，我们观察到在扩展区域中显着损害的浓度是所谓的损伤带的一种形式，其宽度与其长度相比非常狭窄。造成这种损害的原因之一是深地下结构（包括地震断层）的复杂性。另一个原因是表面层的影响。在这项研究中，我们讨论了表面层的扩增效应，表面层的复杂刚度的评估以及土壤层和结构之间的相互作用效应。然后，我们提出了地震反应分析方法，考虑到地面层的这些影响以及建筑物结构经受毁灭性或灾难性的地震运动（如1995年Hyogo-ken nanbu地震）时的土壤结构相互作用。考虑到周围的非线性土壤培养基，合规性（DGC）和土壤包裹的碱或桩基础的阻抗。然后，通过使用DGC的合理函数来表达表面层的复杂刚度，并替换为频率依赖性的弹簧式仪表板系统。分子如下；（1）表面层的放大效应在很大程度上取决于表面层的条件（深度，刚度等）。（2）简单的表面层可以轻松地用简单的弹簧式仪表板系统替换，但是深层表面层变成了更复杂的弹簧式 - 钻头系统。（3）我们必须分析考虑土壤结构的相互作用效应的建筑结构的地震反应，因为地面层通常对建筑的地震反应有不良影响。（4）通过将合理功能用作表面层的复杂刚度，对土壤结构相互作用系统的非线性地震反应分析变得更加容易。