鋼製魚礁의 效率性에 關한 實驗的 硏究

이익효(Ik Hyo Lee),서성호(Seang Ho Seo),조원제(Won Je Cho) 전남대학교 수산과학연구소 2001 수산과학연구소논문집 Vol.10 No.-

All the artificial fish reefs which have been installed in Korea between 1971 and 1999 are made of reinforced concrete(RC). In general it takes about three years after installation to swarm fishes effectively. In addition, according to field investigations, the RC fish reefs often lose their functions due to damage during installation and insecurity to hydrodynamic forces generated by current and water waves. On the other hand, a different type of fish reef made with steel-framed structures, as an alternative of the RC reef, was developed in Japan about three decades ago. The steel fish reef has many advantages including: (1) capability of manufacturing in a large-scale, and (2) cost-effectiveness in comparison with the RC fish reef. In this study, a real-scale model consisting of steel-framed structures is fabricated in order to investigate and demonstrate efficiency of the steel fish reef, and installed in the vicinity of Sori island, Yosu, Chonnam, Korea. Then, its effect and durability have been investigated by periodic diving works.

Sinker Block 하부의 지반조건 변화에 따른 배수터널의 안정성에 관한 연구

이익효 ( Ik-hyo Lee ),정만 ( Mahn Chung ) 한국환경기술학회 2013 한국환경기술학회지 Vol.14 No.5

Recently, while construction of underground structures is increasing, research needs on the stability of underground structures is growing. There are external factors affecting underground structures such as changes in the upper part of the load and earthquake. Therefore, underground structures design review is required because it is associated with the stability of the structure. Therefore, this study was conducted about stability analysis of outlets segments located at the bottom of SINKER block when occurring external factors. The stress and displacement that occurred in outlets segments by upper load and earthquake has been analyzed and the analysis of seismic analysis by applying dynamic analysis has been performed.

폐기물 재활용 측면에서 고로슬래그 미분말과 아라미드 섬유를 이용한 차수그라우트재 개발

이익효 ( Ik-hyo Lee ),김대현 ( Dae-hyeon Kim ) 한국환경기술학회 2018 한국환경기술학회지 Vol.19 No.5

The grouting method is used for reinforcement and waterproofing of soft ground and restoring foundation and increasing bearing capacity of the structured damaged by subsidence and uneven subsidence due to lowering or rising of groundwater level and vibration at reservoir or dam. The purpose of this study is to improve the tensile strength and lateral force by using aramid fiber and to develop the high strength soil improvement method and to recycle the waste tent and clothes afterwards to improve the economic efficiency and the recycling rate of general waste. For this purpose, blast furnace slag powder, cement, and aramid fiber were used in this study. Gel-time and uniaxial compression tests were carried out on the homoge gel to confirm the effect of the improvement of the strength of the grout material. The results of laboratory tests showed that the uniaxial compressive strength of homo-gel increases with the increase in contents of fiber demolition agent and processing rate of surface agent, suggesting that the bridging activity caused by aramid fiber in cement material promotes uniaxial compressive strength.

Flat TDR과 Purdue TDR의 비교실험

이익효 ( Ik-hyo Lee ),김완민 ( Wan-min Kim ),김대현 ( Daehyeon Kim ) 조선대학교 공학기술연구원 2016 공학기술논문지 Vol.9 No.4

In order to improve a typical type of TDR (Time Domain Reflectometry) that requires soil disturbance for compaction control, we developed a Flat type TDR Probe. A laboratory experiment was conducted on two sandy soils to assess the applicability of the Flat TDR system. The reliability of measured values with the Flat TDR was evaluated by comparing the moisture content and dry density of soil with those of Purdue TDR. Based on the comparison of the values, it turns out that the flat type TDR can be used as an alternative to measure the dry density and water content of soil.

人工魚礁 設置方法에 關한 硏究

Ik Hyo LEE(李益孝) 전남대학교 수산과학연구소 1998 수산과학연구소논문집 Vol.7 No.-

For the installation of the artificial fish reefs on sea-beb, the hanging down method use floating crane is desirable for the case that the artificial fish reefs can collide each other. To choose a proper floating crane for this installation situation, its capabilities such as working radius and water depth shall be considered as well as its basic weight capacity.

人工魚礁地盤의 液狀化 豫測方法

Ik hyo Lee(李益孝),Seok Choi(崔石) 전남대학교 수산과학연구소 1996 수산과학연구소논문집 Vol.5 No.-

This paper describes the method to estimate analytically liquefaction for the purpose of the enhancement of artificial fish reefs stability under the consideration of wave conditions as well as soil propertise of seabed. The main results are as follows : 1) The stability of artificial fish reefs is closely related to the seabed liquefaction. 2) Effects of propagation coefficient(α) and drainage coefficient (C) on seabed liquefaction were remarkable. The seabed was more easily liquefied as the propagation coefficient (α) increases because of the difficulty of water pressure propagation toward the seabed while it was more difficult to be liquefied as the drainage coefficient(C) increases because of easy drainage. 3) Not to occur the liquefaction phenomena when the wave height H increase, the water depth should be increased. The amplitude of water pressure, Pₒ, is becoming larger with wave height and then the larger Pₒ is, the easier the liquefaction occurs. 4) Considering items of artificial fish reefs, seabed and wave characteristics, some techniques to find whether the liquefaction occurs or where the liquefaction occurs were analytically suggested at Fig. 7.

지하유류비축공동(地下油類備蓄空洞)에서 Water Curtain의 효율성(?率性)에 관한 연구(硏究)

정형식,이익효,Chung, Hyung Shik,Lee, Ik Hyo 대한토목학회 1983 대한토목학회논문집 Vol.3 No.3

지하유류비축공동(地下油類備蓄空洞)의 성패(成敗)는 공동상부(空洞上部)에 충분(充分)한 수두(水頭)를 유지(維持)하여 공동주위(空洞周圍)의 수밀성(水密性)을 보장(保障)하는 데 있다. 공동상부(空洞上部)에 충분(充分)한 수두(水頭)가 유지(維持)되면 저장(貯藏)된 유류(油類)의 Gas가 누출(漏出)되지 않으며, 인접공동(隣接空洞)이 비어있을 때에도 이곳으로 유류(油類)는 이동(移動)되지 않는다. 본(本) 연구(硏究)에서는 전기상사모형실험(電氣相似模型實驗)을 통(通)하여 수평(水平) 및 수직(垂直) Water Curtain을 설치(設置)하여 Gas 누출(漏出)과 유류이동(油類移動)을 방지(防止)하려 할 때 효과적(?果的)인 Water Curtain의 위치(位置), 인접공동간격(隣接空洞間隔) Water Curtain 수두(水頭), Bore-hole 간격 등이 검토(檢討)되었다. 연구결과(硏究結果) 공동(空洞)의 간격(間隔)이 좁으면 수직(垂直) Water Curtain은 꼭 설치(設置)되어야 하며, 공동간격(空洞間隔)이 공동(空洞) 높이의 2배 이상 커지면 수직(垂直) Water Curtain은 필요(必要)없다는 것이 입증(立證)되었고 유류이동(油類移動)을 방지(防止)하는데 필요(必要)한 수평(水平) 및 수직(垂直) Water Curtain의 위치(位置), Water Curtain 수두(水頭), Bore hole 간격 등이 도표(圖表)로 주어졌다. The successful oil storage in the underground cavern is dependent on how to keep the water-tightness around the cavern by the groundwater. If the water-tightness is not secured, gas bubles will leak out and oil migrate to the adjacent empty cavern. An electrical analogy method was employed in studying the influences of the position of horizontal and vertical water curtains, the head of water curtain and the intervals of the cavern spacings and boreholes on the gas leakage and the oil migration into the adjacent empty cavern. The result shows that if the cavern spacing is narrow, the vertical water curtain should be established and if the cavern spacing is more than twice the cavern height, its establishment is not necessary. All the detailed factors required to prevent the oil migration are shown on graphs.

광양만 해역 축소로 인한 COD 확산 변화에 관한 수치실험

정만 ( Mahn Chung ),이익효 ( Ik-hyo Lee ) 한국환경기술학회 2014 한국환경기술학회지 Vol.15 No.4

This numerical experiments is to perform a change of the COD diffusion by the before and after development in Gwangyang bay which was reclaimed more than its half. The numerical experiments were executed using RMA-2 and RMA4 model of the finite element method. As a result, it turned out that the COD diffusion range of the before Gwangyang bay reclaimed were widely formed during the ebb and flood tide than the after Gwangyang bay reclaimed. And during the flood tide, the 0.2mg/L line of equivalent concentration were floated by the maximum flood flow to the northwest of the Myodo. The after Gwangyang bay reclaimed, the COD diffusion range were largely reduced by the effect of the Gwangyang Steel Mill land and Baealdo during the ebb and flood tide. And during the neap flood flow, the 0.2mg/L line of equivalent concentration were floated along the east shore line end of the Gwangyang Steel Mill land by the effect of Sumjin river outflow.

Liquefaction in Seabeds and Stability of Coastal Structure Foundations

Hong-Yoon Kang(강홍윤),Ik-Hyo Lee(이익효) 한국해양공학회 1998 한국해양공학회지 Vol.12 No.1

해안구조물 설치시 기초지반의 안정성 해석을 위해 파랑에 기인한 액상화 메카니즘을 과잉간극수압 (excess pore pressure) 현상과 관련하여 논의하였다. 과잉간극수압 발생 메커니즘에 있어서 두 가지 형태, 즉, 변동과잉간극수압 (Oscillatory excess pore pressure) 및 잔류광잉간극수압 (Residual excess pore pressure) 각각에 기인한 액상화의 특성을 구명하였다. 또한, 과잉간극수압 및 해저지반의 액상화 가능성에 대한 평가공정을 제시하였는데 이는 모형실험과 현장관측자료에 의해 그 적용성이 검증되었다. 이러한 평가공정 (Assessment Procedures)은 특수성 해저/기초 지반의 액상화를 추정하는데 이용될 수 있다. 해안구조물 기초 설계 및 해저지반의 안정성 평가시 액상화의 가능성 또는 과잉간극수압의 적절한 평가ㆍ고려가 무엇보다 중요하다고 사료된다.

강우시 뒷채움재의 투수특성에 따른 보강토옹벽의 거동

김대현(Daehyeon Kim),이익효(Ik-Hyo Lee),김선학(Sun-Hak Kim),서준형(Joon-hyeong Seo),이광기(Gwang-Ki Lee) 한국철도학회 2012 한국철도학회논문집 Vol.15 No.3