This study examines the seismic failure of RC low-rise building structures having irregularities at the ground story during the 15 November 2017 Pohang, Korea, earthquake, Mw = 5.4, which is the second strongest since the government began monitoring them in 1978 in South Korea. Some 2,000 private houses were damaged or destroyed in this earthquake. Particularly, serious damage to the piloti story of RC low-rise residential building structures of fewer than five stories was observed within 3 km of the epicenter with brittle shear failure of columns and walls due to severe torsional behavior. Buildings below six stories constructed before 2005 did not have to comply with seismic design requirements, so confinement detailing of columns and walls also led to inadequate performance. However, some buildings constructed after 2005 were damaged at the flexible side of the piloti story due to the high torsional irregularity. Based on these results, this study focuses on the problems of the seismic torsion design approach in current building codes.

A B S T R A C T
 1. 서 론
 2. 저층 RC 비틀림 비정형 건축물의 손상 분석
  2.1 4층 RC 필로티 건축물 (C Building)
  2.2 5층 RC 필로티 건축물 (F Building)
  2.3 3층 RC 모멘트 저항 골조 건축물 (H School)
  2.4 4층 RC 벽식 건축물 (K Building)
 3. 저층 RC 비틀림 비정형 건축물의 거동 특성
  3.1 비틀림 비정형 건축물의 거동 특성과 비틀림 설계법의 문제점
  3.2 RC 기둥의 전단 파괴 특성
  3.3 RC 얇은 벽체의 파괴 특성
 4. 결 론
 REFERENCES

• 황경란(고려대학교 건축사회환경공학부) | Hwang, Kyung Ran Corresponding author
• 이한선(고려대학교 건축사회환경공학부) | Lee, Han Seon