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2024 Vol.23, Issue 2 Preview Page

Research Article

Dynamic Behavior of Pier-Type Quay Walls Due to Ground Improvement During Earthquakes

지진 시 지반개량에 따른 잔교식 안벽의 동적 거동

Hyeonsu Yun1
,
Seong-Kyu Yun2
,
Gichun Kang3*
윤 현수1
,
윤 성규2
,
강 기천3*
1Non-Member, Ph.D. Student, Department of Civil Engineering, Gyeongsang National University, 501 Jinjudae-Ro, Jinju 52828, Republic of Korea
2Member, Research Professor, Engineering Research Institute, Gyeongsang National University, 501 Jinjudae-Ro, Jinju 52828, Republic of Korea
3Member, Associate Professor, Department of Civil Engineering, Gyeongsang National University, 501 Jinjudae-Ro, Jinju 52828, Republic of Korea
*Corresponding Author
30 June 2024. pp. 29-42
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Abstract

The 2017 Pohang earthquake caused damage to quay structures due to liquefaction. Liquefaction occurs when effective stress is lost due to an increase in excess pore water pressure during an earthquake. As a result, the damage caused to the pier-type quay wall was identified and the damage caused by liquefaction was analyzed. In addition, in the case of improved ground, damage occurred due to liquefaction of the lower sand layer due to the difference in stiffness from the soft rock layer, so additional numerical analysis was performed assuming non-liquefaction ground. There are several factors that affect the increase in excess pore water pressure ratio, such as the relative density of the ground and the magnitude of the input seismic acceleration. Therefore, this study performed numerical analysis for Cases 1 to 3 by increasing the magnitude of the input acceleration, and in the case of improved ground, damage occurred due to liquefaction of the lower sand layer, so the analysis was performed assuming non-liquefaction ground. As a result, the improved ground requires additional reinforcement when there is liquefied ground below, and the horizontal displacement of the pier-type quay piles was reduced by about two times.

Keywords
Earthquake
Liquefaction
Pier-type quay wall
Dynamic behavior

2017년 포항지진으로 인해 액상화 현상에 의한 안벽구조물에 피해가 발생하였다. 액상화는 지진 시 과잉간극수압 증가로 인해 유효응력이 소실되어 발생하게 된다. 이에 따른 잔교식 안벽의 피해 발생 부분을 규명하며 액상화로 인한 피해를 분석하였다. 또한 개량지반의 경우 연암층과 강성차이로 인해 하부 Sand 층의 액상화 현상으로 인해 피해가 발생하여, 비액상화 지반으로 가정하고 추가적인 수치해석을 수행하였다. 과잉간극수압비의 증가에 영향을 주는 요인으로는 지반의 상대밀도 및 입력 지진가속도의 크기 등 여러 가지 원인이 있다. 따라서 본 연구는 입력가속도의 크기를 증가시켜 Case 1~3에 대해 수치해석을 수행하였고, 개량지반의 경우 하부 Sand층의 액상화 현상으로 인한 피해가 발생하여 비액상화지반으로 가정하여 분석을 수행하였다. 결과적으로, 개량지반은 하부 액상화지반이 있을 경우 추가적인 보강이 필요하며, 잔교식 안벽 말뚝의 수평변위가 약 2배 감소하는 현상이 나타났다.

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Information
  • Publisher :Korean Geosythetics Society
  • Publisher(Ko) :한국지반신소재학회
  • Journal Title :Journal of the Korean Geosynthetics Society
  • Journal Title(Ko) :한국지반신소재학회 논문집
  • Volume : 23
  • No :2
  • Pages :29-42
  • Received Date : 2024-03-07
  • Revised Date : 2024-05-03
  • Accepted Date : 2024-05-09
  • DOI :https://doi.org/10.12814/jkgss.2024.23.2.029
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