This study investigated the impact of soil-structure interaction on multi-degree-of-freedom structures using the shallow-foundation Winkler model, known as the BNWF model. The model’s period was determined through eigenvalue analysis and compared to results obtained from FEMA’s formula. Results indicated that considering the soil, the structure’s period increased by up to 8.7% compared to the fixed-base model, aligning with FEMA’s calculations. Furthermore, with adequate ground acceleration, roof displacement increased by 3.4% to 3.8%, while base shear decreased by 4% to 10%. However, roof displacement and base shear increased in some earthquake scenarios due to spectral shape effects in regions with extended structural periods. Foundation damping effects, determined through the foundation’s moment-rotation history, grew with higher ground acceleration. This suggests that accounting for period elongation and foundation damping can enhance the seismic design of multi-degree-of-freedom structures.

1. 서 론
2. 해석모델
    2.1 구조물 모델
    2.2 기초 모델
    2.3 입력 지진파
3. 해석 결과
    3.1 주기 증가 효과(Period lengthening effect)
    3.2 지붕층 변위 및 층 변위
    3.3 밑면 전단력 및 층전단력
    3.4 각 기초별 반력
    3.5 기초 감쇠 효과(Foundation damping)
4. 결 론
REFERENCES

• 김동관(청주대학교 건축공학과 부교수) | Kim Dong Kwan (Associate Professor, Department of Architectural Engineering, Cheongju University)
• 김호수(청주대학교 건축공학과 교수) | Kim Ho Soo (Professor, Department of Architectural Engineering, Cheongju University)
• 민지희(청주대학교 건축공학과 석사과정) | Min Ji Hee (Master’s Student, Department of Architectural Engineering, Cheongju University)
• 박진영(서울대학교 건축학과 석박사 통합과정) | Park Jin Young (Ph. D. Candidate, Department of Architecture and Architectural Engineering, Seoul National University) Corresponding author