불포화 정성토의 체적변화에 대한 연구

장병욱,길상춘,Chang, Pyoung-Wuck,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.

방조재 시공을 위한 강제치환심도의 추정

장병욱,우철웅,김성필,Chang, Pyoung-Wuck,Woo, Chull-Woong,Kim, Seong-Pil 한국농공학회 2005 한국농공학회논문집 Vol.47 No.1

The research has been done to obtain a empirical equation for the depth of replacement by the analysis of data collected from 8 sea-dike construction sites of south coast of Korean peninsula. The correlation analysis results show that the depth of replacement was mainly dependent upon the height of embankment and the undrained shear strength of soft soil. The suggested regression equation was quite well predicted the depth of replacement and recommended to use under certain restrictions where the embankment height was less than 10m and under 0.2 kgf/cm^{2} of the undrained shear strength of soil.

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.

보강 흙벽의 열전도 특성

장병욱 ( Chang Pyoung Wuck ),서동욱 ( Seo Dong Uk ),박영곤 ( Park Young Kon ) 한국농공학회 1999 한국농공학회 학술대회초록집 Vol.1999 No.-

The objectives of the study are to investigate thermal conductivity(TC) and coefficient of thermal transmission(CTT) according to the type of soils, the presence of reinforcement, temperature, relative humidity and to analyze experimentally the characteristics of thermal transfer of reinforced soil wall. Results are summarized as follows : 1) Clayey soil has high value of TC and CTT than sandy soil. 2) TC and CTT of unreinforced soil wall is about 6~17% higher than those of reinforced one, 3) It is found that the effect of relative humidity on the soil wall is important at the same temperature and 4) As the temperature is high , it is appeared that TC and CTT are high.

비내력벽용 보강흙의 다짐 및 강도 특성

장병욱(Pyoung-Wuck Chang),박영곤(Young-Kon Park),송창섭(Chang-Seob Song),우철웅(Chull-Woong Woo),이상호(Sang-Ho Lee) 한국토목섬유학회 2001 한국토목섬유학회 학술발표회 Vol.2001 No.4

경기도내 농업용 저수지의 제체 및 구조물의 노후도 조사 연구

장병욱 ( Chang Pyoung Wuck ),송창섭 ( Song Chang Seob ),박영곤 ( Park Young Kon ),우철웅 ( Woo Chull Woong ),원정윤 ( Won Jeong Yun ) 한국농공학회 1997 韓國農工學會誌 : 전원과 자원 Vol.39 No.4

Field inspections and laboratory tests for 31 agricultural reservoirs in Kyungki province were performed to provide basic data for maintenance and rehabilitation of agricultural reservoirs and to evaluate structural degradation of agricultural reservoirs. Results of the study are as follows: 1) From survey's results of embankments, signs of settlement and lateral movement are appeared in 17 reservoirs. Crest settlement of 20~80cm, downstream settlement of 10~90cm, and 20~160cm lateral movement of embankments are detected from settlement and movement analysis of 17 reservoirs. Crest and downstream settlements and lateral movement are greatly occurred in 20~40 years after embankment construction. 2) About 39% of total reservoirs shows seepage problems occurred in the lower part of berm and retaining wall located between embankment and spillway. Probability of seepage problems is higher at retaining wall than others. 3) Concrete strength estimated by Schmidt hammer in structures of reservoirs is a range of 100~150kgf/cm² and average deviation of concrete strength is about 10kgf/cm²· Strength difference(□S) between compressive strength estimated b:y Schmidt hammer and uniaxial compressive strength of concrete core is about ±100kgf/cm²· This difference is due to absence or presence of reinforced bar in concrete core, variable length of concrete core and limitation of Schmidt hammer. 4) About 68% of total reservoirs shows leaching, 58% alkali-aggregate reaction and 71% abrasion/frost. Leaching, alkali-aggregate reaction and abrasion/frost occurred in most reservoirs when passed 10 years after construction of structure parts.

연약지반 장기침하량 예측기법의 적용성 연구

장병욱 ( Chang Pyoung Wuck ),우철웅 ( Woo Chull Woong ),이경호 ( Lee Kyung Ho ) 한국농공학회 1998 한국농공학회 학술대회초록집 Vol.1998 No.-

The theory of consolidation has been achieved remarkable development, but associated properties are very difficult to determine in the laboratory. The theoretical shortcomings of those consolidation theories and uncertainties of associated properties make inevitably some discrepancy between theoretical and field settlements. Field settlement measurement by settlement plate is, therefore, widely used to overcome the discrepancy. Among the various methods of ultimate settlement predictions using field settlement data, hyperbolic method and Asaoka's method are most commonly used because of their simplicity and ability to give a reasonable estimate of consolidation settlement. In this paper, the applicability of hyperbolic method and Asaoka's method has been estimated by the analysis of the laboratory consolidation test and field measured data. It is shown that both hyperbolic method and Asaoka's method are significantly affected by the direction of drainage, and Asaoka's method is better to reflect the properties of the soft foundation than hyperbolic method.

Density Variation within Specimen as Affected by Vibration

장병욱(Pyoung Wuck Chang) 한국지반공학회 1987 지반 : 한국지반공학회지 Vol.3 No.3

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.