방조제 축조에 따른 침하량 연구(Ⅳ)

장병욱 서울대학교 농업개발연구소 2000 농업생명과학연구 Vol.4 No.-

When a sea-dike is constructed on soft soils, loss by running flow, replacement by quarry and consolidation settlement of clay ground must be made clear to estimate the amount of quarry accurately. Because the study on the ground deformation is incomplete, most of design does not slough off existing practice. In this study, development of ground deformation analysis system, development of consolidation settlement analysis system for soft ground and development of measuring management and analysis system under a sea-dike constructed on soft soils were performed. In the fourth year study, development of settlement section estimation system, program, and development of mesh generator pre-processor and pre-processor program were performed.

畓에서의 有效雨量에 關한 硏究

金成俊,朴承禹,張秉郁,權純國,鄭夏禹 서울大學校 農科大學 1986 서울대농학연구지 Vol.11 No.1

In this study, a daily water balance model for effective rainfall in paddy fields is descrived, and compares the results with field data. The model was used to simulate seasonal effective rainfall for ideal plots with different irrigation scheduling. The followings are a summary of this study results: 1. Effective rainfall during irrigation season of paddy fields in 1985 ranged from 172.3mm at 4cm ridge to 206.7mm at 6cm ridge. They were 63.1% and 75.7% of total precipitation during that span, respectively. The water balance model simulated that 60.5% and 69.5% precipitation may be considered to be effective rainfall. 2. Daily rainfall appears to be important to the ratios of effective rainfall to the total. 3. Measured and estimated effective rainfall had a high correlation. R=0.9805

시멘틱 공유를 위한 MDA기반 지하공간정보 온톨로지 모델 개발

이상훈(Lee Sang Hoon),장병욱(Chang Pyoung Wuck) 대한공간정보학회 2009 대한공간정보학회지 Vol.17 No.1

최근 이질적인 정보의 폭발적인 증가와 다양한 관리주체별로 생산, 축적되는 공간정보의 특성으로 인하여 공간정보의 재사용과 공유가 어려운 실정이다. 국가공간정보체계의 하나인 지하공간정보도 공간분석을 위해서는 지형도, 지질도, 지하시설물도 등 여타 공간정보와 공유가 필수적이다. 그러나, 기존 표준 혹은 데이터웨어하우스에 의한 공유방법은 시멘틱 이질성을 고려할 수 없다. 본 연구는 지하공간정보의 시멘틱 공유를 위해 일반개념, 측정스케일, 공간모델을 포함한 온톨로지 레이어 모델을 개발하였다. 또한, 기존의 수작업에 의존하는 온톨로지 개발방법론이 아닌 MDA기반 방법론을 적용하여 직관적이며 환경변화에 쉽게 대응할 수 있는 메타모델(UML Profile)을 개발하였다. 개발된 온톨로지 모델의 시멘틱 품질은 Pellet 추론엔진을 통해 검증하였다. 본 연구를 통해 시멘틱 공유를 증진시키고, 온톨로지의 지식표현 능력을 이용하여 GIS 전문가시스템 개발이 가능할 것으로 기대된다. Today, it is difficult to re-use and share spatial information, because of the explosive growth of heterogeneous information and specific characters of spatial information accumulated by diverse local agency. A spatial analysis of subsurface spatial informa-tion, one of the National Spatial Data Infrastructure, needs related spatial information such as, topographical map, geologic map, underground facility map, etc. However, current methods using standard format or spatial datawarehouse cannot consider a se-mantic hetergenity. In this paper, the layered ontology model which consists of generic concept, measuremnt scale, spatial model, and subsurface spatial information has developed. Also, the current ontology building method pertained to human experts is a expensive and time-consuming process. We have developed the MDA-based metamodel(UML Profile) of ontology that can be a easy under-standing and flexiblity of environment change. The semantic quality of devleoped ontology model has evaluated by reasoning engine, Pellet. We expect to improve a semantic sharing, and strengthen capacities for developing GIS experts system using knowledge representation ability of ontology.

불포화 점성토의 체적변화에 대한 연구

장병욱 ( Chang Pyoung Wuck ),길상춘 ( Gil Sang Choon ) 한국농공학회 1998 韓國農工學會誌 : 전원과 자원 Vol.40 No.5

This study was performed to evaluate the characteristics of volume change is unsaturated clayed soil. The medium-plastic clay was selected and compacted by 50% of Proctor standard compaction energy at 6% higher moisture content than its OMC. A series of isotropic compression tests and triaxial shear tests were performed. The results of the study are summarized as follows. At each matric suction, when the matric suction was increased, the yield stress was increased and slope of volume change was decreased. The more net mean stress was, the less the quantity of volume change was. In shear test, the volumetric strain was much rapidly changed in large matric than in low matric suctions. But the effect of matric suction to volume change disappeared under high net mean stress. At lower deviator stress the more matric suction was, the higher volume change was. But As the matric suction was increasing, the behavior of the unsaturated clayey soil was similar to that of saturated clayey soil. Volume change in the unsaturated clayey soil can be represented as a unique plane in three-dimensional space, which is the axes of net mean stress, matric suction and void ratio.

Evaluation of Engineering Properties of Soft Clay in the Daebul Reclaimed Area

Chang, Pyoung-Wuck The Korean Society of Agricultural Engineers 1995 韓國農工學會誌 : 전원과 자원 Vol.37 No.5

To identify the soft marine clay of the Daebul reclaimed area, the south western part of Korea, and determine their engineering properties, a series of the laboratory and field tests are conducted. The main findings are summarized from laboratory and field investigations. It is also formulated the basic geotechnical characteristic data for the porject area. The established correlations for the engineering properties are reviewed and their applicabilities are studied.

Permeability Characteristics of Sand- Bentonite Mixtures

Chang, Pyoung-Wuck,Chae, Yong-Suk The Korean Society of Agricultural Engineers 1997 韓國農工學會誌 : 전원과 자원 Vol.39 No.2

Abstract A series of permeability tests was performed on the mixtures with specific mixing rates of sand and bentonite using modified rigid-wall permeameter. Sand-bentonite mixtures were permeated by organics, ethanol and TCE. Permeability of bentonite with several mixing rates had a tendency to decrease up to initial one pore volume and permeability was thereafter converged to a constant value. When sand-bentonite mixtures was permeated by water, permeability was decreased at the beginning but it was thereafter converged to a constant. Among several mixing rates, permeability was greatly decreased at 15% of mixing rate. When sand-bentonite mixtures with 15% mixing rate was permeated by ethanol, permeability was about 10 times larger value than permeability of water. Peameability was shown greater values when permeated by TCE (TrichloroEthylene) followed by ethanol. Suitable mixing rate of sand-bentonite for a liner of waste landfills was detected.

바닥사석충의 통수에 따른 성토제체 침윤선 변화 연구

이행우 ( Lee Haeng-woo ),장병욱 ( Chang Pyoung-wuck ),장웅희 ( Chang Woong-hee ),정인영 ( Chung In-young ) 한국농공학회 2004 한국농공학회 학술대회초록집 Vol.2004 No.-

본 연구는 방조제에서 바닥사석충의 유·무 및 성토충의 길이에 따라 성토충의 침투특성에 미치는 영향을 파악하기 위하여 수리모형실험을 실시하였으며, 아울러 흐름상태가 다른 바닥사석충의 흐름을 정확히 해석하는가를 알아보고자 수치해석으로 성토충의 침윤선을 계산하여 실측치와 비교분석하였다. 본 연구의 결론은 다음과 같다. 1) 성토충에서 측정한 수두와 수치해석으로 계산한 수두가 차이를 보였으며, 이는 바닥사석충의 흐름특성이 흙속의 흐름과는 상이한 것으로 판단된다. 2) 바닥사석충의 유·무에 따라서 성토충의 침투특성이 크게 차이가 났으며 또한 바닥사석충의 길이에 따라서 방조제 침투안정에 영향을 미치는 것으로 나타났다. 3) 향후 연구를 위한 제안으로 방조제의 실제에 부합하는 침윤선 계산 및 침투안정해석을 위하여 바닥사석충의 흐름특성 및 수두손실에 대한 연구가 필요함. One of the major role of the sea dike is protecting farmlands from the storm surges and tidal wave attacks. Furthermore, sea dike makes a bit easier to reclaim the landside of the sea dike and supplies water to the farmland and factory. Although water in the landside of the sea dike is likely to non salt water, it is practically allowed and maintained some extent of salt concentration because of the construction of bottom riprap. Flow in the bottom riprap is an interesting topic to study in order to maintain water with minimum salt concentration in the fresh water. Generally, the change in phreatic line has affected to the overall stability and it may cause a piping and sliding of the sea dike. This paper presents the change in phreatic line through flow in bottom riprap in the sea dike. This study is performed and compared to seepage analysis and prototype hydraulic model test results.

Evaluation of Engineering Properties of Soft Clay in the Daebul Reclaimed Area

( Chang Pyoung Wuck ) 한국농공학회 1995 韓國農工學會誌 : 전원과 자원 Vol.37 No.-

To identify the soft marine clay of the Daebul reclaimed area, the south western part of Korea, and determine their engineering properties, a series of the laboratory and field tests are conducted. The main findings are summarized from laboratory and field investigations. It is also formulated the basic geotechnical characteristic data for the project area. The established correlations for the engineering properties are reviewed and their applicabilities are studied.

모래의 진동(振動)다짐에 영향을 주는 인자(因子)에 대한 연구(硏究)

장병욱 ( Chang Pyoung Wuck ) 한국농공학회 1987 韓國農工學會誌 : 전원과 자원 Vol.29 No.2

效果的인 모래의 다짐 方法으로 振動에 의한 方法이 널리 使用되고 있다. 이 硏究의 目的은 모래의 振動 다짐시 영향을 주는 因子의 個別的인 效果를 分析하고 各 因子들이 複合되어 振動다짐에 주는 效果를 분석하는 것이다. 이 硏究에서는 振動時間, 加速度, 過載荷重, 含水比, 試料의 다짐전 密度등을 變化시켜가며 振動테이블 위에서 제작된 試料를 다짐하였고 試驗結果는 相對密度의 變化에 의하여 分析하였다. 振動다짐의 效果는 다짐加速度 振動數 및 모래의 粒度에 따라 變하며 過載荷重이나 振巾은 比較的 적은 영향을 주는 因子였다. 加速度가 1g 보다 큰 경우 다짐效果는 振動이 시작되는 初期에 發生하였고 그 후는 緩漫하게 振動效果가 나타났다. 效果的인 다짐을 위하여는 最適加速度와 最適 過載荷重의 選擇이 重要하며 最適値보다 큰 경우는 다짐의 效果가 減少한다. 乾燥된 모래와 飽和된 모래 모두 같은 最適加速度에서 最大의 다짐效果를 나타냈다. 각 因子 즉 加速度, 振動數, 單位重量, 含水比, 均等係數, 有效粒徑, 過載荷重 및 振動時間 등의 效果를 複合하여 振動다짐의 效果를 相對密度의 變化로 나타낼 경우 ΔD_R=38.0∧^0.14의 關係를 얻었다.

pH 변화에 따른 점토의 투수특성

장병욱 ( Chang Pyoung Wuck ),강상욱 ( Kang Sang Uk ),김성필 ( Kim Seong Pil ),차경섭 ( Cha Kyung Seob ) 한국농공학회 2002 韓國農工學會誌 : 전원과 자원 Vol.44 No.6

A series of physical properties and rigid wall permeability tests were performed on two clays to investigate changes in permeability characteristics of clays with various pH values. Results of the study are as follows. As pH values were increased, coefficients of permeability of S-clay(clay fraction 18%) and J-clay(clay fraction 30%) were decreased in 3 and 4 times, respectively. Variation of coefficient of permeability of J-clay was considerably related to clay fraction. It can be said that coefficient of permeability of clays tested was increased, as pH values were decreased. This was because of increase in effective voids caused by decrease in thickness of diffused double layer, that is, change in soil structures and effective grain sizes.