2001 Fiscal Year Final Research Report Summary
Proposal for Modeling Nonlinear Sloil-Structure Interaction System Considering Amplification Effect of Surface Layers
| Project/Area Number |
12650574
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Building structures/materials
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| Research Institution | Kobe University |
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Principal Investigator |
KUSAKABE Kaoru Kobe Univ., Faculty of Engineering, Professor, 工学部, 教授 (80027250)
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| Co-Investigator(Kenkyū-buntansha) |
MAEDA Yukinori Kobe Univ., Faculty of Engineering, Research Associate, 工学部, 助手 (00116253)
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| Project Period (FY) |
2000 – 2001
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| Keywords | surface layer / complex stiffness / nonlinear earthquake response analysis / ground compliance / impedance / pile foundation / rational function / 地盤-建物連成系 |
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| Research Abstract |
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.
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Research Products
(24 results)
