2005 Fiscal Year Final Research Report Summary
Frequency-domain method for evaluation of earthquake input energy to building structure-soil systems
| Project/Area Number |
16560496
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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 | KYOTO UNIVERSITY |
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Principal Investigator |
TAKEWAKI Izuru Kyoto Univ., Dept of Urban and Environmental Eng., Professor, 工学研究科, 教授 (20155055)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAZAKI Masahiro Kyoto Univ., Dept of Arch.& Arch Eng., Lecturer, 工学研究科, 講師 (60240826)
KANNO Yoshihiro Kyoto Univ., Dept of Urban and Environmental Eng., Assistant Professor, 工学研究科, 助手 (10378812)
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| Project Period (FY) |
2004 – 2005
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| Keywords | earthquake inpu energy / critical excitation method / structure-pile-soil system / uncertainty analysis / earthquake-resistant design / surface ground amplification / input around motion |
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| Research Abstract |
The purpose of this project is to develop a new frequency-domain method for evaluation of earthquake input energy to structure-soil systems (or structure-pile-soil systems) in order to develop more reliable earthquake-resistant design methods for building structures. The following results have been obtained in this project.
1. A new critical excitation method is developed for soil-structure interaction (SSI) systems. The input energy expression can be of a compact form via the frequency integration of the product between the input component (Fourier amplitude spectrum) and the structural model component (so-called energy transfer function). With the help of this compact form, it is shown that the formulation of earthquake input energy in the frequency domain is essential for solving the critical excitation problem and deriving a bound on the earthquake input energy for a class of ground motions. The energy dissipated in structures and ground (or radiated into ground) can be captured appropriately with the present formulation.
2. Exact higher-order sensitivities of the input energy to the SSI system are derived with respect to uncertain soil stiffness and damping parameters by taking full advantage of the frequency-domain method. The exact higher-order sensitivities facilitate to express the input energy variation due to uncertainty of ground stiffness and damping and to find the most unfavorable combination of the uncertain parameters leading to the maximum energy input.
3. The earthquake energy input rate is treated as a new measure of criticality. The key for finding the new random critical excitation is the interchange of the order of the double maximization procedures with respect to time and to the PSD function. Extension of the proposed method is discussed to a more general ground motion model, i.e. non-uniformly modulated non-stationary models, and to a more general problem for variable envelope functions and variable frequency contents.
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Research Products
(22 results)
