• Title/Summary/Keyword: revetments

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Stability Analysis of Low Flow Revetments on External Forces (저수호안에 작용하는 외력에 의한 안정성분석)

  • Kim, Chul;Park, Nam-Hee;Kim, Dae-Young;Kim, Yun-Hwan
    • Journal of the Korean Society of Hazard Mitigation
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    • v.8 no.5
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    • pp.147-153
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    • 2008
  • Tractive forces by flowing water and ship generated waves are items that affect the stability of the low flow revetments among various external forces exerting on those revetments. Bank revetment stability by these external forces is analysed in this study. The study area is the section of the test construction area changing the artificial revetments to ecological revetments in Han river. Tractive forces are computed using the calculated flow velocity using RMA-2 model. The stability is analyzed comparing the calculated tractive forces with permissible tractive forces of the revetments in the study area. The calculated tractive forces at section number 93 is higher than permissible tractive forces in that section, so the section is estimated hydraulically unstable. The calculated tractive forces for the storm of 10th August 2007 are small compared to the permissible tractive forces in all sections. The sections are considered to be hydraulically stable, but have been eroded in some parts. The reason for the erosion is considered to have insufficient time for the plants taking root, and be exerted composite forces such as forces by ship generated waves. Ship generated waves by the excursion boats and small boats called river taxi was calculated. Wave forces by these calculated waves are computed and compared with the supporting forces of the revetment material. The external forces exerted by the ships in Han River on the revetments is very little compared with the permissible supporting forces of the revetments, so the revetments are estimated hydraulically stable. But considering the composite forces are exerted simultaneously, the stability consideration should include these composite forces.

The Analysis of Vegetation Characteristics According to Revetment Structure at Rural Small Streams (농촌지역 소하천의 제방형태에 따른 식생특성 분석연구)

  • Kim, Mi-Heui;Kang, Banghun;Kong, Min-Jae;Jeong, Myeong-Cheol;Son, Jin-Kwan
    • Journal of Wetlands Research
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    • v.17 no.4
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    • pp.359-369
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    • 2015
  • Stream ecosystems are highly valued natural resources, however, stream environments are currently under threat in several respects. We evaluated vegetation and ecological characteristics according to different revetment types. The distribution of vegetation differed with revetment type, with a 42~45 taxa found in natural revetments, and 23~38 taxa in vertical revetments. Thus, natural revetments host more diverse vegetation than vertical revetments. We also found more plants belonging to the families Labiatae and Cyperaceae growing in natural revetments than in vertical revetments. We proposed that habitat space be apportioned to introduce annual plants as part of stream restoration projects. And, we identified 7 families and 18 taxa of naturalized plants, majority taxa were either biennial or perennial. Moreover, naturalized ratio was higher in vertical(14.3%) than natural(12.1%), we proposed a plan to promote and improve natural streams and revetments. Furthermore, we applied a waterfront evaluation method developed by the Natural Resources Conservation Service of the USDA-NRCS, which confirmed that stream health can be improved in most regions by controlling naturalized plants and ensuring shrub and tree growth. We adopted a new method to remove naturalized plants and establish natural revetments to ensure shrub and tree growth to aid in small-stream restoration and improvement. In future studies, we hope to develop methods for small-stream restoration projects in rural areas.

The Actual Condition of River Revetment in Gang Won-Do (강원도 하천 호안 실태조사)

  • Choi, Han-Kuy;Jung, Young-Duk;Baek, Hyo-Seon
    • Journal of Industrial Technology
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    • v.29 no.B
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    • pp.207-213
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    • 2009
  • The propose of this study is to survey the revetments installed in Gangwon Province for identifying their characteristics. The survey showed that in eastern Gangwon Province, gabion, retaining wall and concrete blocks took about 63% or more, and in western Gangwon Province, dry wall, gabion and retaining wall, 68% or more. Gabion and dry wall had better vegetation coverage in western Gangwon Province than in eastern Gangwon Province. That is thought to be due to slope of river and under-water frequency.

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A Monitoring and Data Analysis for Close-to-Nature Pilot Creeks (자연형 소하천 모니터링 시범사업 결과 분석)

  • Yi, Sang-Kuk;Chung, Jae-Hak;Lee, Ho-Yul;Lee, Jong-Seol
    • 한국방재학회:학술대회논문집
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    • 2008.02a
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    • pp.751-754
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    • 2008
  • Recently according to increasing of damage in creeks, it has been needed to develop a close-to-nature creek improvement technique considering flood safety as well as the functions of ecosystem and scenery preservation. In this study, the monitoring on creeks in seven provinces was accomplished to develop the technique applicable to domestic creeks between 2002 and 2007. Although the riparian ecosystem was disturbed, after just finishing the improvement on pilot creeks, the result of monitoring showed that restoration rates of creeks were satisfactory by constructing close-to-nature creek revetments. However it is hard to analyze on restoration and permissible tractive force of each revetments constructed in most creeks, because of insufficient monitoring data. Therefore the feasible study on the close-to-nature creek revetments should be performed in the near future through continuous monitoring on creeks.

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Application and Assessment of New Vegetation Revetment Techniques Considering Safety against Flood and Environmental Performance (치수 안전성과 환경성을 고려한 새로운 식생호안 공법의 적용 및 평가)

  • Rhee, Dong-Sop;Ahn, Hong-Kyu;Woo, Hyo-Seop;Kwon, Bo-Ae
    • Journal of Korea Water Resources Association
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    • v.40 no.2 s.175
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    • pp.125-134
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    • 2007
  • The objective of this study was to investigate the applicability of new vegetation revetment techniques. The applicability of revetments was confirmed with respect to flood safety as well as environmental consideration. The safety against flood was examined through an in situ experiment at Dong-moon Stream located in Paju and a laboratory experiment. The environment-friendly characteristics of revetments were analyzed by using the results of a 2-year in situ monitoring. It was found that the revetments investigated in this study had a safety capability against floods and high vegetating capability. Application ranges of design factors were suggested for each revetment developed in this study.

Basic Research on Revetments Development of Erosion Protection for Coastline Creation of Hydrophilic Environment by Field Observation (현장관측에 의한 친환경 해안조성을 위한 침식방지 호안공 개발에 관한 기초적 연구)

  • Lee, Jong-Seok;Han, Jae-Myung
    • Journal of Korea Water Resources Association
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    • v.41 no.10
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    • pp.983-993
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    • 2008
  • In recent times, sea level increasing caused by abnormal weather and global warming, sea-sand dredging and complex development causes various kind of erosion damages onto the coastal area in the world. The various types of erosion control and protection methods are applied but there are no signs of fruitful effectiveness. The PC concrete protection block for shore protection structure is practically installed in globally but most of structures in the present day became villainous because of bad accessability. In this study, hydrophilic revetments for control and protection of coastline erosion will be developed in order to make up for a faculty of the shore erosion protection block with better accessibility and excellent protection ability. Experimental measurements were researched to insure for the capacity and facility on reflection coefficient, overtopping volume, and overtopping height characteristics of newly developed shore erosion protection block in model tests. As the result, hydraulic model tests show much excellent than the general step block. Field tests were carried out also to verify through vegetative test on an affinity and construction work test of control-protection on coastline erosion with actual utilization. In the latter case, deposition of sand accumulation occurred in fairly short time at the established reaches and then we can be confirmed to utilize for newly developed block as the revetments for control and protection of coastline erosion.

Research on Environmentally-Sound Erosion Control Works(I) -Environment-oriented erosion control works in Japan- (환경(環境)과 조화한 사방사업(砂防事業)(I) - 일본의 환경보전사방(環境保全砂防) -)

  • Chun, Kun-Woo;Ezaki, Tsugio
    • Journal of Forest and Environmental Science
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    • v.12 no.1
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    • pp.13-25
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    • 1996
  • In recent erosion control works, securing not only the disaster prevention space but the environmental space, harmonized with surrounding environment and abundant with biological resources, are emphasized. Inspired of by the fact that efforts to secure such spaces have been being briskly promoted in Japan since the beginning of 1990s', we compile and analyze the Japanese sources about the "environmentally-sound erosion control works" to contribute to the erosion control works of our country. Specifically, in this report, we deal with the subjects of "establishment of the comfortable river environment" and "environmentally-sound erosion control works" which includes "erosion control dam", "water channel works and revetments", "fish routes" and "water quality conservation works".

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