제주대학교 Repository

濟州外港에서 暴風波浪荷重에 依한 砂質土地盤에 施工된 防波堤의 沈下

Metadata Downloads
Abstract
In this study, to prove the wave-induced settlement, the long-term measured settlement data at Jeju harbor caisson breakwater were analyzed. Additionally, a wave load acting on the structure and seabed was calculated using 3D-NIT (Three-Dimensional Numerical Irregular wave Tank). The
wave load data was used as an input data in geotechnical analysis program. The following conclusions were drawn.

Generally, the structure built on sand ground predominantly depends on immediate settlement. However, based on the field measurement in Jeju harbor area in which the silicate and carbonate mixed sand exists, it shows that in addition to the immediate settlement a considerable additional compression has been occurred with time due to crushing, shattering, and
rearrangement of sand particles, especially carbonate sand particles. This material related settlement has been already studied. However, the settlement data show extra unordinary settlement which is related to wave load due to storm. The study on the wave-induced settlement has not been conducted so far. In this study, we focused on the wave-induced settlement affected by Typhoon.

In Jeju harbor caisson, the settlement caused by wave load was identified. Settlement, excess pore pressure, and effective stress path histories were estimated. The ground settlement was a little different at each measured location but practically the same. Settlement at the leeside is little bigger than that at the seaside.

As seen settlement history, wave load induced settlement clearly occurred so that the effect of wave on settlement was verified. Comparing with wave distribution, the ground settlement was not occurred during regular wave condition, but the settlement increased with wave. The rapid and abruptly large settlement occurred at the maximum wave load. After the maximum wave load the settlement still continuously occurred but the magnitude is smaller than that occurred at the maximum wave load.

The change of excess pore pressure ratio showed a similar pattern to location and depth of ground. The excess pore pressure ratio reached up to 0.9 at the ground just below the toe of rubble mound. When the excess pore pressure ratio reaches up to 1 and we can define the soil becomes liquefied. The rest of area showed 0.5 of excess pore pressure ratio. This excess pore pressure ratio was not enough to induce soil liquefaction, but could decrease the effective stress and cause the ground settlement.

As seen the effective stress path in p'-q' diagram, the ground at the toe of rubble mound was the most vulnerable location. As increased the excess pore pressure, the effective stress path moved to left side. Comparing with Mohr-Coulomb failure line, the ground at the toe of rubble mound closely reached to the failure line. It indicated the decrease of ground strength.

From this study, we can clearly see the effect of wave load on settlement in coastal structure built on sandy soil so that this effect should be incorporated in design and maintenance. Additionally a study of guideline about the structure installation considering the storm wave load induced settlement should be conducted urgently.
Author(s)
김인석
Issued Date
2014
Awarded Date
2014. 2
Type
Dissertation
URI
http://dcoll.jejunu.ac.kr/jsp/common/DcLoOrgPer.jsp?sItemId=000000006661
Alternative Author(s)
Kim, In Sok
Affiliation
제주대학교 대학원
Department
대학원 토목해양공학과
Advisor
이병걸
Table Of Contents
I. 서 론 1
1.1. 연구배경 및 목적1
1.2. 논문내용 및 구성2
II. 침하에 대한 기존연구 5
2.1. 기초의 침하5
2.2. 지중응력 9
2.3. 즉시침하 20
2.4. 압밀침하 22
2.5. 모래지반의 기초침하 27
2.6. 기초 사석침하 33
Ⅲ. 제주도 해안지역 모래의 특성 35
3.1. 제주도에 분포하고 있는 모래의 분류 35
3.2. 제주도 해안지역 모래의 역학적 특성 52
3.3. 압축시험 56
3.4. 제주도 해안지역 모래의 거동특성 61
3.5. 제주도 해안지역 모래의 탄성계수 63
3.6. 제주도 해안지역 모래의 압축특성 64
3.7. 제주도 해안지역 모래의 파쇄성 66
Ⅳ. 파압 산정 및 침하량 해석 모델 69
4.1. 개요69
4.2. 파압에 의한 해양구조물아래의 지반변동 70
4.3. 파압산정 해석 모델 74
4.4. 침하량 해석 모델85
Ⅴ. 제주외항 설계 조건 97
5.1. 제주외항 지역의 기상조건 97
5.2. 제주외항 지역의 해상조건 105
5.3. 제주외항 지역의 지반조건 117
Ⅵ. 제주외항 관측 및 계측 127
6.1. 파랑127
6.2. 케이슨 침하136
Ⅶ. 파압 산정과 침하량 해석 155
7.1. 설계파 결정155
7.2. 해석단면 설정 157
7.3. 파압산정 160
7.4. 단면해석 166
7.5. 비교검토 190
Ⅷ. 결론 및 향후 연구방향 198
참고문헌 201
부 록 207
Degree
Doctor
Publisher
제주대학교 대학원
Citation
김인석. (2014). 濟州外港에서 暴風波浪荷重에 依한 砂質土地盤에 施工된 防波堤의 沈下
Appears in Collections:
General Graduate School > Civil and Ocean Engineering
Authorize & License
  • AuthorizeOpen
Files in This Item:

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.