동해안 연안침식 원인과 대응기술 개발

심재설(Shm, Jae-Seol),임학수(Lim, Hak-Soo) 한국연안방재학회 2016 한국연안방재학회 학술발표대회 논문집 Vol.2016 No.-

동해안에서 점차 심각하게 야기되고 있는 연안침식을 방지하기 위해서는 우선 연안침식의 원인과 토사이동의 메커니즘을 규명하고, 더 이상의 연안침식을 방지하기 위한 효과적인 연안정비사업을 수행해야 한다. 이를 위해 국가나 지자체의 지원으로 장기적인 연안침식 모니터링 사업이 지속되어야 하며, 연안침식 대응기술 개발과 같은 국가 R&D를 수행하여 연안정비사업의 효율성을 높여야한다. 또한, 동해안에 표사계를 설정하고 표사계 내 모래의 유입과 유출을 검토하여 연안 표사수지(Sand Budget) 체계를 작성해야 연안개발이나 인공구조물 설계시 또는 시공 후 발생 가능한 연안침식을 저감할 수 있는 방안을 마련할 수 있다. 미래 기후변화에 의한 너울성 고파랑 증가와 연안개발 또는 인공구조물 건설로 야기되는 연안침식으로부터 연안역을 보호하기 위해서는 연안통합관리 방안을 시급히 마련하여 관계기관의 공동정책이나 협동 관리체계를 서둘러서 수립해야 한다.

2018년 항만투자 계획

한국연안방재학회 한국연안방재학회 2018 한국연안방재학회지 Vol.5 No.1

제2차 연안정비기본 계획의 변경 과정을 통한 향후 과제

윤성순(Yoon, Sungsoon) 한국연안방재학회 2014 한국연안방재학회 학술발표대회 논문집 Vol.2014 No.-

연안관리법에 제23조에 따라 2009년에 수립, 고시된 제2차 연안정비기본계획의 추진과정과 그 동안의 연안의 다양한 여건 변화 등을 검토하여 변경계획을 수립하였다. 동기간동안의 연안정비사업은 연안의 보전과 친수기능 제공이라는 사업목적에 부합하는 긍정적 효과를 발휘하였지만 보다 발전된 연안정비사업의 추진체계를 위해서는 개선해야할 과제들이 도출되었다. 연안을 보다 안전하고 쾌적하게 유지하고 관리하기 위한 효과적수단으로서의 연안정비사업 의 안정적인 추진을 위해 앞으로 해결해야할 과제와 방향성을 제시함으로써 지속적인 제도의 개선과 정책의 효과를 제고하고자 하였다.

인공자갈의 연안침식 저감 능력 수리실험

김효섭(Kim, Hyoseob),이승호(Lee, Seungho) 한국연안방재학회 2016 한국연안방재학회 학술발표대회 논문집 Vol.2016 No.-

본 논문에서는 인공자갈이 가지고 있는 연안침식 저감 능력을 알아보는 수리실험을 진행하였다. 모래 해변의 경우, 외력에 의한 침식이 발생하여 모래가 외해로 빠져나가는 반면 인공자갈이 배치된 해변은 연안 인근 외력에 의한 침식을 줄이고 해안선을 보존 혹은 전진 시키며 기존보다 큰 연안경사를 유지시키는 것을 확인하였다. 인공자갈의 주원료가 되는 시멘트의 안정성 또한 인체와 환경에 유해하지 않은 것으로 조사되고 있어 인공자갈을 이용한 연안보호 공법은 연안침식 대응 공법으로써 큰 효과를 가질 것으로 판단된다.

부유식 원형구조물의 사각틀(Sideline) 계류에 따른 계류장력의 공간분포

김홍진(Hong-Jin Kim),윤준호(Joon-Ho Yoon),장효필(Hyo-Pil Jang),정종현(Jong-Hyun Jeong) 한국연안방재학회 2020 한국연안방재학회지 Vol.7 No.1

The spatial mooring tensions in sideline mooring systems for waves acting on floating collar were analyzed. In the sideline mooring system, the wave force acting on the floating collar was properly spreaded to the each mooring tension. However, the mooring tension tends to increase in the connecting and mooring ropes depending on the wave and structure conditions. The results are summarized as follows. 1. In the sideline mooring system, the sum of mooring tensions at the rear joint point was more than four times higher than the sum of mooring tensions at the front joint point. 2. The maximum mooring tension was occurred when the wave-steepness(H/L₀) was 0.05 to 0.08 and the relative diameter(B/L₀) was 0.15. 3. At the front joint point, mooring tension develops around the mooring rope connected to the anchor, At the rear joint point, high mooring tension occurred in the bridle and mooring ropes entrained with the direction of incident wave. 4. Although the load distribution is the main function of the bridle rope of the floating collar, more than 10 times of deviation may occur depending on the wave condition. Therefore this must be taken into account in the design.

이어도 종합해양과학기지의 진동 계측자료를 이용한 구조물 동특성 분석

이진학(Jin-Hak Yi),민인기(In-Ki Min),심재설(Jae-Seol Shim) 한국연안방재학회 2020 한국연안방재학회지 Vol.7 No.2

To study the ocean and meteorological issues related to global climate change and global warming, Korea is operating several ocean research stations (ORS), including Ieodo ORS, Gageocho ORS, and Sochengcho ORS in remote ocean area. In 2003, the Ieodo ORS was first constructed and in operation, and a lot of scientific studies were carried out using the observation data at Ieodo ORS. After the Gageodo ORS was attacked by Typhoon Muifa and was severely damaged to its structural members, ORSs were equipped with vibration measurement systems to monitor their structural integrities. In the case of Ieodo ORS, the vibration measurement system was instrumented in 2016. In this study, the structural dynamic characteristics of the Ieodo ORS were investigated using the vibration measurement data, including acceleration and tilt. As a result, three natural frequencies of two bending modes and torsional mode were estimated as 1.315 Hz, 1.390 Hz, and 1.590 Hz, respectively, and these natural frequencies were compared with those estimated using measurement data in 2005 and 2006 by Kim et al. (2006). It was found that the natural frequencies were decreased as about 2-3.8% due to the combined effect of structural degradation and the increase of mass of equipment. Long-term measurement data were also analyzed to obtain the variation of dynamic characteristics according to the environmental effects such as temperature and excitation force. It was also found that the dynamic characteristics of Ieodo ORS are not affected by temperature and tidal level while they are significantly affected by the level of excitation force, i.e., the amplitude of vibration responses can be used to account for the effect of excitation force indirectly.

사동항 2단계 동방파제의 해양환경을 고려한 시설계획

안성욱,심상효,손건목 한국연안방재학회 2014 한국연안방재학회지 Vol.1 No.2

탁도 측정을 통한 점착성 유사의 플록형성 분석

김동현(Dong Hyun Kim),유형주(Hyung Ju Yoo),이승오(Seung Oh Lee) 한국연안방재학회 2020 한국연안방재학회지 Vol.7 No.2

In many estuaries and rivers, the contaminants such as heavy metals have became serious threat to ecosystem including human communities since eagerly development of heavy industrialization. It was found that such materials tended to bound with cohesive sediments, and this bond mechanism is affected by hydraulic characteristics, for instance, turbulence intensity. To understand the complex relationship with the sediment-bond mechanism and hydrodynamics, the study for flocculation which includes the bond between sediment particles without heavy metals should be preceded as the first step. In this study, the flocculation of single sediment (Kaolin) was analysed through laboratory experiments in which the rotational jar-flow was generated and 3D numerical simulation which was performed to obtain the detailed flow fields and calculate hydraulic characteristics. First, the PIV experiment was conducted for the verification of 3D numerical model. And the flocculation index (IF) was proposed to consider the relation with the external energy and average turbulence length scale through the regression approach. The results showed that the flocculation was more affected by turbulence length (eddy size) than by turbulence intensity, and there was the significant specific range of turbulence length about formation of flocculation.

석션파일 지반관입중 리프팅케이블 장력에 의한 수직도보정 효과

박해용(Haeyong Park),오명학(Myounghak Oh),강현(Hyoun Kang) 한국연안방재학회 2020 한국연안방재학회지 Vol.7 No.2

Performance on the individual length control method of lifting cables for correcting verticality during suction penetration of pile was evaluated. Model tests were performed to compare and analyze for verticality correction results and cable tension for different number of installed lifting cables and inclination condition. Model test results showed that verticality of suction piles were successfully corrected during penetration by eccentricity resulted from different cable tension induced by differently adjusted length of each cables according to inclination position. Field tests were performed to evaluate field applicability. The inclination of pile was corrected by lifting cable length control during penetration. Especially, the verticality correction at the pullout stage was more effective compared with suction penetration stage in spite of slight pullout. Therefore, individual control of lifting cables during suction penetration can be applied for verticality correction of suction pile. And the accurate verticality of pile could be achieved by adding pullout process during penetration of suction pile.

항공 및 드론 영상을 이용한 테트라포드 연안활동장소에 대한 공극률 계산 기법에 관한 연구

전호군(Ho-Kun Jeon),박주한(Ju-Han Park),양찬수(Chan-Su Yang) 한국연안방재학회 2020 한국연안방재학회지 Vol.7 No.2

In 2016 and 2019, the death rate from fall accidents at breakwater and tetrapod was 14.2% and 16.3% of whole coastal activity accidents, a higher proportion than other types of accidents. But there is no quantitative basis for assessing the risk of fallen at tetrapod. Thus this study introduces the method of calculating the porosity of tetrapod by image processing. Aerial image of the National Geographic Information Institute (NGII) and drone image was used. The target area was the tetrapod of the breakwater near Korea Maritime and Ocean University, Yeongdo-gu, Busan City, South Korea. We compared porosity results from Otsu threshold and Adaptive threshold methods. The result shows that Adaptive method gives about 2 times difference between aerial and drone image while Otsu method shows 3 times difference. It is revealed that the adaptive method can be applied with porosity measurement for tetrapod.