• 제목/요약/키워드: scouring

검색결과 232건 처리시간 0.026초

Mechanism for Bank Erosion and Local Scouring in Estuary of the Hangang River

  • Lee, Samhee;Han, Hyeongjun;Choo, Jeongho
    • 한국습지학회지
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    • 제16권4호
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    • pp.453-462
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    • 2014
  • The levee and bridge pier in estuary of the Hangang River are exposed in a dangerous condition due to bank erosion and local scouring occurred since the summer season in 2011. At first, it is presumed that the high sandbar formed in river channel of the study area was an important element in the occurrence of bank erosion and local scouring. It can be presumed that the record-breaking depth of freezing due to cold wave for the long term during the winter season between 2010 and 2011 as well as the heavy intensive rainfall of 2011 had a decisive effect on the first damage of A section. The second damage of B section mainly occurred around the bridge pier constructed on the high water channel before it was washed away during the winter season between 2011 and 2012. It is considered that the second damage was caused by ice formation and ice floes.

교각세굴을 고려한 말뚝기초의 해석 (Analysis of Piled Piers Considering Riverbed Scouring)

  • Jeong, Sang-Seom;Suh, Jung-Ju;Won, Jin-Oh
    • 한국지반공학회논문집
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    • 제18권3호
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    • pp.43-50
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    • 2002
  • 본 연구에서는 지반말뚝, 말뚝-말뚝캡, 그리고 말뚝-유체간의 상호작용 해석을 수행하여 교각세굴을 고려한 말뚝기초의 거동을 해석하였다. 지반-말뚝의 상호작용은 비선형 하중전이곡선(p-y, t-z, 그리고 q-z 곡선)을, 말뚝-말뚝캡의 상호작용에서는 군말뚝의 배열과 말뚝-말뚝캡 사이의 구속조건을 고려하였다. 말뚝유체의 상호작용은 세굴에 의한 지반의 강성 저하를 고려하여 지반-말뚝의 상호작용에 포함하여 해석하였다. 그 결과 세굴심이 깊어질수록 말뚝에 발생하는 최대 휨모멘트의 값이 증가함을 알 수 있었으며, 이를 바탕으로 세굴에 따른 군말뚝의 안정성 평가에서는 지반-말뚝 및 말뚝-말뚝캡의 상호작용을 고려한 해석을 수행하는 것이 바람직함을 알 수 있었다.

Polyester 섬유직물에 함유된 불순물이 염색성에 미치는 영향 (The Effects of Impurities of Polyester Fiber Fabric on the Dyeing Property)

  • 박민식;장철민;엄재영;김삼수;허만우
    • 한국염색가공학회지
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    • 제10권1호
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    • pp.43-50
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    • 1998
  • In order to investigate the effect of contained impurities of polyester fiber fabric on the scouring and dyeing property, 3 kinds of polyester fabrics were heat-set treated at $160-200^\circ{C}$ and evaluated its scouring and dyeing property by through with soxhlet extraction and K/S value of the dyed fabric derived from the surface reflectance. The impurities such as oiling and sizing agent are adhered more strongly on the polyester fabric surface by heat setting temperature. In scouring test, the removal of the these re-adhered impurities on the polyester fabric is very difficult in comparing with unheat-set treated polyester fabric. It is also confirmed that the remained impurities on the polyester fiber decreased its dyeing property.

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무용제형 저기포성 정련제의 제조에 관한 연구 (A Study on the Preparation of Solvent-Free Low Foaming Scouring Agents)

  • 근장현;김승진;함현식;박홍수
    • 공업화학
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    • 제4권4호
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    • pp.760-769
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    • 1993
  • Polyoxyethylene(30) octadecylbenzylammonium chloride(POAC), propylene oxide와 ethylene oxide의 블럭 공중합체[p(PO-b-EO)glycol], Sedlan FF-200(FF-200) 및 polyoxyethylene(10) nonylphenyl ether의 술폰산-아민축합물 (PSAC) 등을 블렌딩하여 무용제형 저기포성 정련제 (LFSA)를 제조하였다. LFSA로서 여러 가지 물성시험을 해 본 결과 FF-200/POAC/p(Po-b-EO) glycol/PSAC/water(20g/10g/5g/5g/60g) 혼합물(LFSA-5)은 세정력, 침투력, 유화력, 알칼리 안정성 등이 양호하였으며, 수질오염에 대한 영향이 크지 않았다. LFSA-5의 정련효과는 정련전 후의 염색온도에 따른 염착률의 변화로서 확인하였는데, 정련전 PET 직물인 경우는 $70^{\circ}C$에서 4.5%의 염착률을 나타낸데 반하여, LFSA-5로서 정련된 직물은 1.3%의 염착률을 나타냄으로써 LFSA-5의 정련효과가 양호함을 알 수 있었다. 또한 LFSA-5는 Ross and Miles법에 의한 거품 생성 직후의 기포력이 포고 6mm로 나타났고, Ross and Clark법에 의한 기포력이 $30^{\circ}C$에서는 포고 300mm 이하로, $80^{\circ}C$에서는 20mm를 각각 나타내어 양호한 저기포성 정련제임이 입증되었다.

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N/C 복합소재의 CPB/Silket 일욕 전처리 (Simultaneous CPB/Silket Treatment of N/C fabric)

  • 최연지;박종호;김성동
    • 한국염색가공학회:학술대회논문집
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    • 한국염색가공학회 2008년도 제39차 학술발표회
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    • pp.47-48
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    • 2008
  • New scouring agent which was stable up to 50% NaOH 350g/l has been developed for simultaneous CPB/silket treatment of N/C union fabric. The physical and dyeing properties of N/C union fabric treated with new scouring agent were measured. Fabric scoured and Mercerized by one bath CPB/silket process showed almost the same degree of Mercerization and K/S value with two bath process.

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Investigation of the Effect of Continuous Finishing on the Mechanical Properties and the Handle of Wool Fabrics

  • Sun D.;Stylios G.K.
    • Fibers and Polymers
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    • 제7권3호
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    • pp.245-249
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    • 2006
  • The effect of scouring, bleaching and dyeing on the low stress mechanical and surface properties of wool woven fabrics was studied. Fabric properties were measured by the KES-FB system. In general, mechanical properties of the treated fabrics are greatly affected by scouring, moderately by dyeing and least by bleaching.

Analysis of Visual Sensibility Evaluation of Naturally Colored Organic Cotton: Identification of Reliability and Proper Scouring Method

  • Park, Jang-Woon;Chang, Yoon;Hong, Won-Gi;Lee, Myung-Eun;Han, Ah-Reum;Chae, Young-Joo;Cho, Gil-Soo;You, Hee-Cheon
    • 대한인간공학회지
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    • 제30권2호
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    • pp.311-317
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    • 2011
  • Objective: The present study was intended to identify (1) the intra- and inter-rater reliabilities of a visual sensibility evaluation protocol and (2) the effects of NaCOC color and scouring method on the visual sensibility of NaCOC. Thirty female participants(20s & 30s) were participated in the visual sensibility evaluation of NaCOC. Background: Interests in naturally colored organic cotton(NaCOC) increase rapidly in parallel with the social trend of eco-friendly living and wellbeing. Method: Three color sets (ivory, green, and coyote-brown) of NaCOC specimens including one untreated and four treated specimens($Na_2CO_3$; NaOH; enzyme; boiling water) were examined in the study. The visual sensibility evaluation was conducted by the test-retest method using nine pairs of bipolar visual sensibility adjectives(bright-dark; clear-murky; heavy-light; vivid-subdued; warm-cool; fresh-stale; strong-weak; showy-plain; and luxurious-cheap). Results: As a result of reliability of a visual sensibility evaluation protocol, inter-rater variability(average SD=1.06) of visual sensibility evaluation was more than 1.4 times the intra-rater variability(average SD=0.74). However, both the sensibility evaluation reliabilities did not show any systematic pattern of changes. Lastly, ANOVA and post-hoc analysis showed that preferred scouring methods for a visual sensibility adjective pair significantly vary depending on NaCOC color. Application: Both the reliability of visual sensibility evaluation protocol and the analysis of proper scoring method of NaCOC in the study would be useful information to design the affective textile.

ECH(Epichlorohydrine)으로 처리한 리오셀 직물의 피브릴레이션 경향 및 염색성에 관한 연구 (Fibrillation tendency and Dyeing characteristic of Lyocell treated with Epichlorohydrine)

  • 박지양;김신희;박영환;전동원
    • 한국염색가공학회지
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    • 제18권4호
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    • pp.20-27
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    • 2006
  • Lyocell is a not only environmentally-friendly but also very advantageous fiber. When Lyocell is soaked in water, its wet tenacity does not decrease and elongation and moisture regain of it are better than cotton. However, one drawback of lyocell is its fibrillation. The fibrills of lyocell were generated during wet process such as scouring and dyeing deteriorates the dyeing color depth and the appearance of fabric. The purpose of this study was to decrease the fibrillation tendency of lyocell fabric using crosslinking agent, epichlorohydrine(ECH). The effects of NaOH scouring and ECH crosslinking were observed. The different types of ECH addition methods to lyocell and the various concentrations of ECH in crosslinking reaction onto dyeing characteristic and fibriallation were investigated. Weight loss and whiteness index of crosslinked lyocell by ECH were examined. K/S values of ECH treated lyocell fabrics dyed with reactive dye were measured and SEM images of untreated and treated lyocells were observed extensively to define the fibrillation tendency. The results were as follows ; 1) ECH treatment showed the effect of weight loss and scouring because ECH crosslinking reaction was conducted in alkaline condition. 2) The increase in ECH concentration from 5 to 30% does not affected K/S value changes. 3) ECH crosslinking can effectively prevent the fibrillation tendency of lyocell.

Reflection Characteristics of Eco Block on Seabed

  • Kim, Jeong-Seok;Lee, Joong-Woo;Kang, Seok-Jin;Lee, Yong-Hun
    • 한국항해항만학회지
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    • 제38권4호
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    • pp.421-427
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    • 2014
  • In order to protect coastal facilities mainly from wave and current actions, the self-locking eco blocks constituting elements of protecting shore structures against scouring were designed. These blocks are adapted to the sloping bottom, coastal dunes, and submerged coastal pipelines, counteracting the destructive and erosive impulse action. A series of laboratory experiments has been conducted to investigate the reflection of water waves over and against a train of protruded or submerged shore structures and compare the reflecting capabilities of incident waves including wave forces. In this study the hydraulic model experiment was conducted to identify the performance of newly designed water affinity eco blocks to keep the coast slope and bottom mound from scouring by reduction of the wave reflection and to convince stability of the block placement. Revised design of each block element was also tested for field conditions. From the result of experiments, the field applicability of the developed blocks and placement was discussed afterward.

방향성 파랑의 입사에 따른 이안제 제두부의 안정성에 관한 기초적 연구 (A study of stability at the head of a breakwater with directional waves)

  • 김홍진;류청로
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2001년도 추계학술대회 논문집
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    • pp.144-149
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    • 2001
  • The failure at the head section of rubble-mound detached breakwaters is more important than other failure modes. because this initial failures will occur the failure of the trunk section and lead to the instability of the structure. The three-dimensional failure modes are discussed using the experimental data with multi-directional waves considering the failure modes occurring around the head of the rubble-mound detached breakwater. The spacial characteristics of failure mode around the rubble-mound structures can be summarized as follows: 1) It was clarified that the failure modes at the round head of a detached breakwater are classified as failure by plunging breaker on the slope, failure by direct incident wave force and failure by scouring at the toe of the detached breakwater. 2) The failure mode was found in the lower wave height than the design wave by the breaker depth effects. It is clarified that the structure monitored was safely designed for the design wave but the failure was occurred by the reason of breaker waves and scouring processes at the toe 3) It was observed that scouring at the toe developed in the region where steady stream due to vorticity was generated and the spatial variation of scour at the toe of the round head was predominated by incident wave direction.

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