本文以簡化模型模擬方形基礎與層狀土壤互制系統，探討其在水平與旋轉外力作用下之動態行為，並經最佳化分析建立最佳簡化模型，復由各土壤基礎互制系統之最佳簡化模型，歸納出通用簡化模型，以適用於其他層狀土壤，達到降低分析時間之目的。
本研究針對表面基礎及埋置基礎土壤互制系統，分別進行頻率域與時間域分析，探討通用簡化模型之準確性與適用性：(1)頻率域分析結果，以動態反應放大係數，與理論解、國際學者之簡化分析與SASSI程式分析結果相互驗證。研究結果顯示，僅需以2種水平單元與4種旋轉單元組合，建立6組通用簡化模型，即可進行最佳化分析；抑或直接針對土壤基礎互制系統適用之一組通用簡化模型進行分析，無須對6組通用簡化模型進行最佳化分析。(2)時間域分析結果，以通用簡化模型模擬實際土壤-基礎系統，分別以簡諧載重、強制載重與隨機載重，三種外力形式探討基礎的位移與旋轉角，並與SASSI相互驗證。研究結果顯示本文建立之通用簡化模型不論於頻率域或時間域中，皆能有效模擬方形基礎與層狀土壤系統承受水平與旋轉外力作用下的互制行為。

This thesis proposes a simplified model to simulate an interaction system including a square foundation and layered soils. Dynamic behavior of the square foundation subjected to horizontal forces and rocking moments is also investigated herein. An optimal simplified model is established to simulate the layered soils through an optimization process in this study. According to the optimization results, the generic simplified model is identified so that it can be applied to various types of layered soils for saving computational time.
In this study, the frequency-domain and time-domain analyses were carried out for the surface and the embedded foundations mounted on soil media. The accuracy and applicability of the generic simplified model were discussed in two aspects: (1)Frequency-domain analysis results: The dynamic magnification factors at discrete frequency ratio are verified with the theoretical solutions obtained by international scholars and the SASSI program. The research results show that the optimization analysis can be carried out considering only two types of horizontal units and four types of rotational units to establish 6 groups of generic simplified models. On the other hand, a group of generic simplified models can be directly established for the soil-foundation interaction system without analyzing the six groups of generic simplified models. (2)Time-domain analysis results: The generic simplified models are used to simulate the actual soil-foundation system in this thesis. The time-history responses of displacements and rotation angles at the foundation top are investigated considering three types of external forces: a simple harmonic loading, a tri-harmonic loading, and a random loading. The time-history responses are verified with the numerical results from SASSI program. The analyzed results indicate that the generic simplified models established in this study can effectively simulate the interaction behavior of the square foundation and the layered soil subjected to horizontal and rotational forces in both of the frequency and the time-domains.

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