• 제목/요약/키워드: River Crossing

검색결과 84건 처리시간 0.031초

하천통과 지하구조물의 누수 보수 대책 (A Case Study on Repairing Work of Leakage of River-crossing Underground Structure)

  • 이종은;최석원;노현창
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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    • pp.801-809
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    • 2000
  • Until recently as a method of repairing leaking problem, generally urethane series were used for many structures as subway, box culvert etc. However the lacking of sufficient penetration capacity have made it difficult to repair such structures completely. Now, we could achieve enhanced quality of repairing work by using new material which was compounded of urethane series and cement series properly. This material can penetrate concrete structure efficiently and move interactively with the structure in case of the thermal expansion. Besides of this, we could prevent expecting leakage through several improvements on the aspects of design, materials and site implementation.

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노량행궁의 복원을 위한 기초연구 (A Basic Study for the Restoration of Noryang Temporary Palace)

  • 구욱희
    • 대한건축학회논문집:계획계
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    • 제34권5호
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    • pp.109-118
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    • 2018
  • Noryang Temporary Palace was a place where king Jeongjo (1752-1800) would have lunch after crossing the Temporary Palace River on his way to Hwaseong Temporary Palace to worship at Hyeonryungwon, the tomb of his father, Sadoseja. The government offices in charge of ship bridge construction 'Jugyosa' and 'Byeoljangso' were located in the Temporary Palace. The central buildings of the Haenggung Palace, which ranged up to Yongyangbongjeojeong, were arranged to observe both 'Jugyosa' and 'Byeoljangso' from the Temporary Palace by lifting the ground from Sammun Gate to Yongyangbongjeojeong. Yongyangbongjeojeong, the center of Noryang Temporary Palace, features the style of royal palace architecture and functions of housing architecture. The 'Jugyosa' and 'Byeoljangso' buildings had eight quarters. According to the records, in addition, 15 wood sheds, 5 rice hubs, 3 barns, 1 side gate quarter, 1 front gate, 70 separate sheds, 2 suragan temporary buildings, oesammun gate and hongsalmun gate were found. Such architectural layout is matched with the Temporary Palace Jugyohwaneodo Painting.

하천개수 전·후 하천공간의 생태기능 평가방법에 관한 연구 (A Study on Evaluation of Ecological Function before and after River Improvement)

  • 홍일;김지성;신형섭;김규호
    • 한국수자원학회논문집
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    • 제47권4호
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    • pp.397-409
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    • 2014
  • 본 연구에서는 과거 자연하천에서 개수 후 현재 정비하천으로 변화된 하천공간의 생태기능을 비교 평가할 수 있는 방법을 제안하고 그 적용성을 검토하였다. 생태기능 평가는 하도 중심의 물리구조와 하천공간의 생태연결성으로 구성하였고, 각각 4개와 2개 평가항목을 토대로 평가기준에 따라 정량화 하였다. 평가방법의 적용은 하천개수 전인 1918년과 대규모 하천개수사업이 종료된 현재의 만경강 하천공간에 204개 격자와 7개 하도구간을 설정하고 GIS 분석기능을 활용하여 수행하였다. 그 결과, 물리구조와 생태연결성은 각각 평균 2등급에서 4등급, 2등급에서 3등급으로 감소한 것으로 나타났다. 물리구조의 주된 악화 원인은 직강화와 그에 따른 하천 횡단구조물의 건설에 의한 것으로 파악되었고, 생태연결성 악화는 도로와 철도 등에 의한 선적 단절요인이 토지이용에 의한 면적 단절요인보다 비교적 더 크게 작용한 것으로 확인되었다. 특히, 생태기능이 높은 격자들을 기준으로 하천공간을 살펴볼 때, 1918년의 생태 연결성은 하천을 축으로 분포되어 있었음을 알 수 있으나, 2007년은 제방 축조와 도시화된 지역의 증가로 산포하는 경향을 나타났다.

지상 전투차량의 수상 추진 시 동적 안정성에 대한 연구 (Syudy on the dynamic Stability of Ground Armored Moving Vehicle during cruising river)

  • 안태술;이경훈
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.252-255
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    • 2008
  • In this study, the characteristics of crossing a river of Ground Armored Vehicle (GAV) were evaluated by numerical method and real size tests. 3-D hybrid mesh systems were constructed by 3-D models of the GAV, and a commercial software, FLUENT, was used in numerical analysis. In order to deal with multi-phase problem (air and water), Volume Of Fluid (VOF) method was used, and Moving and Deforming Mesh (MDM) was adapted for unsteady motion of GAV. There were two steps in this research. Firstly, stability of the GAV which cruised a river was evaluated by changing several shapes of water-proof-front-wing of the GAV in steady state, and compared results (free surface shape and drag value in 10km/h) with those of real size tests. Secondly, results of unsteady analysis considering weight and moment of inertia of the GAV were presented. There were showed a maximum velocity with a designed water jet and dynamic stability including pitch, roll, and yaw moment. Based on these results, the optimal shape of water-proof-front-wing of the GAV was determined for a proto-type of the GAV.

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Preliminary Report on the Breeding of Robust and Resistant-NPV and High Quality Silkworm Race 'Shengming No.1' for Summer-autumn Rearing

  • Zhao, Yuan;Chen, Kepin;Yao, Qing;Wu, Yang-Chun;Zhang, Jian;Guo, Xijie
    • International Journal of Industrial Entomology and Biomaterials
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    • 제13권2호
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    • pp.85-95
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    • 2006
  • Seveval Chinese and Japanese varieties with good characters were used in the breeding. After 5 years (15 generations), a pair of robust and high quality silkworm variety with NPV resistance was bred by means of a combination of crossing and pedigree selection complemented by the selection of NPV resistance. The variety was identified jointly nationwide in 2003 and 2004, and appraised by National Mulberry and Silkworm Appraising Committee. Results are as follows: its cocooning rate is over 93%, shell rate 23-25%, filament length 1200-1300 meters, reelability 75-88%, Length of non-broken cocoon filament 900-1100 meters, raw silk rate 17-19%, neatness 95-97 points, and cocoon crop, cocoon shell weight and raw silk weight per 10000 larvae is higher than those of the control variety by 7-10%, 14-19% and 14-18%, respectively. The variety is not only robust, resistant to high temperature and NPV, easy to rear, uniform in hatching, molting and maturing, but also lays more eggs, and its fecundity is high. It is suitable to rear in the Yangtze River Basin, the Yellow River basin and the Pearl River basin of China.

교각 주변 유목 집적 및 거동 특성 3차원 수치모의 (Three-dimensional Numerical Simulation of Driftwood Accumulation and Behavior Around Bridge Piers)

  • 박문형;김형석
    • Ecology and Resilient Infrastructure
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    • 제7권4호
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    • pp.336-344
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    • 2020
  • 홍수 시 하천횡단구조물 주변에 유송잡물들이 집적되어 수재해로 인한 피해 가능성이 증가하기 때문에 이에 대한 예측기술 및 검토가 필요하다. 본 연구에서는 3차원 흐름과 유목 거동을 해석할 수 수치모형을 활용하여 교각 주변에서 유목의 집적 및 거동 특성을 검토하였다. MPS기반 유목 해석 모형은 구체의 개수에 민감한 것으로 나타났다. 수치모의결과 유목의 길이비와 접근유속은 유목 집적 특성에 주요한 인자인것으로 나타났지만 유목의 밀도의 영향은 미미한 것으로 확인되었다. 이 연구를 바탕으로 하천횡단구조물 주변의 유목의 집적에 의한 위험성 평가 지표를 수립하는데 기여할 수 있을 것으로 기대된다.

230KV 2회선승 111M 높이 철탑설계 (I) (강폭 12km인 Bangladesh Jamana강 횡단용) (The design of 111m high steel towers with 220kv double circuits crossing 12 km wide Bangladesh River)

  • 이재숙
    • 기술사
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    • 제15권4호
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    • pp.12-24
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    • 1982
  • East Parts of Bangladesh have been benifited by low cost energy generated by domestic natural gas but West parts where energy generated by imported fuel. Bangladesh Government authority has very much concerned to transmit the low cost electricity to the West from the East for past several years. To solve such concerns, cross-country 230kv double circuits Power transmission line was proposed, however there was a big obstacle for the realization of this line to cross the Jamuna river which has 12 km long width with a deep muddy river bed. A consultant engineering firm named Merz-Mclellan anyway finalized this plan and a world-wide bid was announced on June 31, 1979. Due to the expected difficulty to construct the towers on sea like area, only three construction groups have participated. including a Korean joint venture organization of Samsung-Korean Developement corporation-Kolon Electric Machinery company. After 3 months bid evaluation, contract was awarded to Korean Consosium and KEM Co was in charge of designing steel towers with anchor bolts and base plates beside to electrical engineering field. Then KEM Co have faced and over-comed many unenpected technical difficulties such as forced eccentricity joint on base plate, distorsion issue of 60mm thick plates welding, threading anchor bolts, tad heat treatment of some anchor bolts, disagreement from Consultant Engineer on multiplying factor of leg stresses for 45$^{\circ}$ wind and on reducing O.L.F for wind loads on cables for such 1220km long spans. After spending two years long period for designing and engineering towers, base plates, and anchor bolts, first shipment of tower was finally realized on Nov. 8, 1981 and on the other hand KDD has proceeded concrete caisson work on schedule at Jamuna river site and expected to complete tower erection and stringing of cables within this year of 1982 which was original completion target.

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중·소하천에서 물리적 구조의 교란과 하안식생 귀화율의 관계 (The Relationship between Disturbances of Hydromorphological Structures and Naturalized Plants Ratio in Small and Mid-sized Streams)

  • 천예준;최윤의;홍선희;전진형
    • 한국환경복원기술학회지
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    • 제16권1호
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    • pp.207-225
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    • 2013
  • Current ecological stream restoration is focusing on recovery of physical characteristic and ecological functions of individual stream. For effective stream restoration, the relationship between stream environment and riparian flora should be investigated. The purpose of this study is to analyze the relationship between disturbance of hydromorphological structures and naturalized plants ratio in small to mid-sized streams. For the study sites, Gwanpyeong stream, Dongdal stream, and Yongchoo streams were chosen as 'reference stream' while, Gunnam stream, Anchang stream, and Hwa stream were chosen as 'damaged stream'. The hydromorphological structures of streams were evaluated with LAWA and flora of the streams were completely enumerated to calculate naturalized plants ratio. The result showed that there was a significant correlation between the outcome of LAWA and naturalized plants ratio(r=0.675, p<0.01). The result of factor analysis of LAWA identified three factors, 'River front and land use', 'River bed materials and structures', and 'Crossing structure and bar'. Among the factors of hydromorphological structures given by the result of factor analysis, 'river front and land use' and 'bed materials and structures' have statistically significant relationship with naturalized plants ratio($R^2$=0.470, p<0.01). Given this results, quantitative analysis on the relationship between disturbance of hydromorphological structures of streams and naturalized plants ratio could provide some essential information for stream restoration. Also, as this study figured out major factors of hydromorphological structures that affect naturalized plants ratio, it might help monitor ecological states and current problems of small and mid-sized streams.

Application of the Artificial Neurons Networks for Runoff Forecasting in Sungai Kolok Basin, Southern Thailand

  • Mama, Ruetaitip;Namsai, Matharit;Choi, Mikyoung;Jung, Kwansue
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2016년도 학술발표회
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    • pp.259-259
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    • 2016
  • This study examined Artificial Neurons Networks model (ANNs) for forecast flash discharge at Southern part of Thailand by using rainfall data and discharge data. The Sungai Kolok River Basin has meant the border crossing between Thailand and Malaysia which watershed drains an area lies in Thailand 691.88 square kilometer from over all 2,175 square kilometer. The river originates in mountainous area of Waeng district then flow through Gulf of Thailand at Narathiwat Province, which the river length is approximately 103 kilometers. Almost every year, flooding seems to have increased in frequency and magnitude which is highly non-linear and complicated phenomena. The purpose of this study is to forecast runoff on Sungai Kolok at X.119A gauge station (Sungai Kolok district, Narathiwat province) for 3 days in advance by using Artificial Neural Networks model (ANNs). 3 daily rainfall stations and 2 daily runoff station have been measured by Royal Irrigation Department and Meteorological Department during flood period 2000-2014 were used as input data. In order to check an accuracy of forecasting, forecasted runoff were compared with observed data by pursuing Coefficient of determination ($R^2$). The result of the first day gets the highest accuracy and then decreased in day 2 and day 3, consequently. $R^2$values for first day, second day and third day of runoff forecasting is 0.71, 0.62 and 0.49 respectively. The results confirmed that the ANNs model can be used when the range of collected dataset is short and real-time operated. In conclusion, the ANNs model is suitable to runoff forecasting during flood incident of Sungai Kolok river because it is straightforward model and require with only a few parameters for simulation.

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