압밀특성에 관한 연구 (I) (선행하중이 압밀특성에 주는 영향)

류능환,강예묵 한국농공학회 1976 한국농공학회논문집 Vol.18 No.4

The determination of the pre-consolidation load known to have a great effect on the consolidation characteristics of the soil have been researched and discussed in detail by many other researchers. A study was undertaken to investigate and compare the effect of pre-consolidation loads on the coefficient of permeability and the consolidation characterisics of soil through the consolidation test on the three types of soil samples. The results of this study are follows; 1. Large compression index is dependent on initial void ratio of the sample being used and the pressure-void ratio curve shows a curved linear relationship in over-consolidated area but a linear relationship in normally consolidated area.2. Settlement-time curve is S-shaped where the pressure is larger than pre-consolidation load and regardless of over-burden pressure, it is a similar straight line respectively in the secondary consolidation area. 3. Primary consolidation ratio of the sample increases almost linearly with the increase of over-burden pressure but the coefficient of volume compressibility decreases linearly with the increase of it. 4. Time factor of a certain degree of consolidation increases with over-burden pressure but the coefficient of consolidation decreases with it in over-consolidated area. There is a linear relationship between them in normally consolidated area. 5. The void ratio of completion point of primary consolidation decreases linearly with over-burden pressure. 6. The coefficient of permeability of sample decreases linearly with over-burden pressure in normally consolidated area, also it increases linearly with increment of the void ratio of the sample.

시료의 두께, 하중증가율 밀 재하시간이 압밀특성에 미치는 영향

류능환,강예묵 한국농공학회 1978 한국농공학회논문집 Vol.20 No.3

Under the various variations of the sample thickness, the load increment ratio and the load increment duration, this consolidation test of the clay in the Asan Bay was tried for the comparison with the standard consolidation test. The results gained are as follows; 1. The void ratio variations of the leached-clay samples were increasingly high, according as the sample thickness thinned and the load increment duration and the laod increment ratio increased. 2. The coefficient of consolidation were increased with the increment of the sample thickness, of the load increment ratio and of the load increment duration. Near the pre-consolidation load, the coefficient of secondary consolidation had the maximum value and lessened with the increment of the sample thicknss, and of the load increment duration 3. The value of the pre-consolidation load increased in proportion to the increment of the sample thickness and the decrease of the load increment ratio and the load increment duration. 4. The compression indices increased as the increment of load increased and decreased as the sample thickness increased. 5. The initial compression ratio increased as the sample thickness, the load increment ratio and the load increment duration decreased. The ratio of primary compression to the secondary decreased with the increment of the sample thickness and of the load increment ratio. 6. The time at the completion of psimary consolidation increased with the increment of the sample thickness and of the consolidation load, and with the decrease of the load increment ratio. 7. The compression indicses increaed as the sample thickness lessened and decreased as the load increment ratio increased. The coefficient of consolidation increased according as the sample thickness, the load increment ratio and the load increment duration went up. The settlement at the construction site should be calculated highly in proportion as the sample thickness lessened and the load increment ratio increased. The consolidation ratio is thought to be accelerated if the sample thickness and the load increment ratio becomes higher and the load increment duration longer.

밭에의 토양수분 소비기구에 관한 연구

류능환,민병섭 한국농공학회 1974 한국농공학회논문집 Vol.16 No.4

This experiment of which aim contribute to plan irrigation system so as to increase forage crop yields, was conducted to estimate evapotranspiration amount of forage crops and to find out system of consumed water in a pasture-ground. The results obtained by this study are as follows: 1. The general weather conditions which, were closely related to the evapotrannpiration of forage crops were nearly same as those of the average year with the exception that temperature of May and June were slightly low. 2. According to the investigation of potential evapotranspirations (P.E) or forage crops and its changes during growing periods, changes of tenday P.E. were high significant according to the harvesting period. P.E of Alfalfa of which yield was the largest was the biggest. Althrough the correlations between P.E. and meteorological factors were irregular oming to three-time harvesting, correlation between ten-day evapotraspiration amount and copper plated pan evaporation or solar radiation was high positive significant. 4. Predicting formulas of P.E. were led by weather factors, and also relatione between P.E. and weather factors were showed as figure. from the these formulas, P.E. may be calculated by weather factors. 5. Predicting formulas of P.E. were led by mean temperature and copper plated pan evaporation, and by mean temperature and solar radiation. As computed values and measured values showed in figure, these formulas were high signiflent. 6. In the total consumed soil water duration of 10 days which, was non-rain period from 12th to 21th of August, Alfalfa was the largest 48.1mm, second, Orchard grass 40.1mm and Fescue 37.6mm, and Ladino clover was the smallest 37.1mm, also, order of each forage crop yield amound. was same to the abov. Order of soil moisture extraction rate of soil layer of all the for forage crops dulation of ten-day was soil layer 1 which was largest, soil layer 2, 3, and 4 Reviewing the the first five-day and the second five day, in the first five-day, order of that of all the forage crops was same to the above, but in the second five-day, that of soil layer 2 or 3 was more than the of soil layer 1.

동결토의 압축강도에 관한 실험적 연구 (2)

류능환(Neung Hwan Ryu) 강원대학교 농업과학연구소 1995 강원 농업생명환경연구 Vol.6 No.-

반복하중(反復荷重),온도변화(溫度變化) 및 초기조건(初期條件)이 충적점토(沖績粘土)의 구조변화(構造變化)와 역학적(力學的) 특성(特性)에 미치는 영향(影響)

류능환 ( Ryu Neung Hwan ),류형선 ( Ryu Young Sun ),최중대 ( Choi Joong Dae ),김기성 ( Kim Ki Sung ) 한국농공학회 1992 韓國農工學會誌 : 전원과 자원 Vol.34 No.4

To estimate soil behavior and structural characteristics under the conditions of cyclic loa-ding freezing & thawing and initial state, several testing was performed and obtained follo-wing results. 1. After repeated freezing and thawing processes, original soil structure was destroyed and changed to globular structure from honeycomb or tube in its structure types. Also above processes resulted increasing the soil compression strain while decreasing the failure stress in stress-strain relationship and reached the soil structure into the mode of brittle fracture Under cyclic lading conditions, soil cluster which was originally dispersed structure colloided with each other, separated, and finally the soil failed due to the effect of overcompaction. 2. Through the stabilization processes separated by four steps, the structure of soil skeleton was changed to quite different globular type. The degree of compressibility of soil skeleton was changed to quite different globular type. The degree of compressibility of soil was decree-sed in the normally consolidated zone, while the strength against external load increased due to soil particle stabilization. 3. Soil stress-strain characteristics were largely influenced by repeated up and down proce-sses of temperature. The maximum deformation was obtained in the case of temperature between 0~10℃ by the reseon of particle cluster reformation. 4. Soil compressibility was largely influenced by the optimum moisture content. Under freezing process, swelling could be found and its magnitude was proportional to the density of soil. 5. Density of soil was decreased as increasing the number or repeated freezing and thawing processes and the largest decreasing rate was found at the first turning point from freezing to thawing cycle.

화강암 풍화토의 동상 발현 및 융해에 따른 변형 거동에 관한 연구

류능환 ( Ryu Neung Hwan ),최중대 ( Choi Jung Dae ),류영선 ( Ryu Young Sun ) 한국농공학회 1995 韓國農工學會誌 : 전원과 자원 Vol.37 No.3

Natural ground is a composite consisted of the three phases of water, air and soil paircles. Among the three components, water as a material is well understood but soil particles are not in foundation engineering. Especially, weathered granite soil generally shows a large volumetric expansion when they freeze. And, the stability and durability of the soil have shown decreased with repetitive freezing and thawing processes. These unique charcteristics may cause various construction and management problems if the soil is used as a construction material and foundation layers. This project was initiated to investigate the soil's physical and engineering characteristics resulting from freezing and freezing-thawing processes. Research results may be used as a basic data in solving various problems related to the soil's unique characteristics. The following conclusions were obtained: The degree of decomposition of weathered granite soil in Kangwon-do was very different between the West and East sides of the divide of the Dae-Kwan Ryung. Soil particles distributed wide from very coarse to fine particles. Consistency could be predicted with a function of P₂₀₀ as LL=0.8 P₂₀₀+20. Permeability ranged from 10^-2 to 10^-4cm/sec, moisture content from 15 to 20% and maximum dry density from 1.55 to 1.73g /cm³ By compaction, soil particles easily crushed, D₅₀ of soil particles decreased and specific surface significantly increased. Shear characteristics varied wide depending on the disturbance of soil. Strain characteristics influenced the soil's dynamic behviour. Elastic failure mode was observed if strain was less than 10^-4/s and plastic failure mode was observed if strain was more than 10^-2/s. The elastic wave velocity in the soil rapidly increased if dry density became larger than 1.5g /cm³ and these values were V_p=250, V_g=150, respectively. Frost heave ratio was the highest around 0℃ and the maximum frost heave pressure was observed when deformation ratio was less than 10% which was the stability state of soil freezing. The state had no relation with frost depth. Over freezing process was observed when drainage or suction freezing process was undergone. Drainage freezing process was observed if freezing velocity was high under confined pressure and suction frost process was occurred if the velocity was low under the same confined process.

압밀특성(壓密特性)에 관(關)한 연구(硏究) (I) (선행하중(先行荷重)이 압밀특성(壓密特性)에 주는 영향(影響))

류능환 ( Neung Hwan Ryu ),강예묵 ( Yea Mook Kang ) 한국농공학회 1976 韓國農工學會誌 : 전원과 자원 Vol.18 No.4

The determination of the pre-consolidation load known to have a great effect on the consolidation characteristics of the soil have been researched and discussed in detail by many other researchers. A study was undertaken to investigate and compare the effect of pre-consolidation loads on the coefficient of permeability and the consolidation characterisics of soil through the consolidation test on the three types of soil samples. The results of this study are follows; 1. Large compression index is dependent on initial void ratio of the sample being used and the pressure-void ratio curve shows a curved linear relationship in over-consolidated area but a linear relationship in normally consolidated area. 2. Settlement-time curve is S-shaped where the pressure is larger than pre-consolidation load and regardless of over-burden pressure, it is a similar straight line respectively in the secondary consolidation area. 3. Primary consolidation ratio of the sample increases almost linearly with the increase of over-burden pressure but the coefficient of volume compressibility decreases linearly with the increase of it. 4. Time factor of a certain degree of consolidation increases with over-burden pressure but the coefficient of consolidation decreases with it in over-consolidated area. There is a linear relationship between them in normally consolidated area. 5. The void ratio of completion point of primary consolidation decreases linearly with over-burden pressure. 6. The coefficient of permeability of sample decreases linearly with over-burden pressure in normally consolidated area, also it increases linearly with increment of the void ratio of the sample.

초기함수비, 비표면적, 풍건 및 동결·융해작용이 흙의 액성한계에 미치는 영향

류능환 ( Ryu Neung Hwan ) 한국농공학회 1996 韓國農工學會誌 : 전원과 자원 Vol.38 No.5

The purpose of The work described in this paper is to clear up the initial moisture content, specific surface, air drying and freezing-thawing process on liquid limit of clayey soils distributed widely at estuary of three main rivers in the west coast. To this end, a series of tests were conducted on clayey soils samples with natural state and treated state. From the test results, the liquid limit was decreased with decrement of initial moisture content, air drying process, and freezing-thawing cycles and increased with increment of specific surface. The specific surface which influenced on the liquid limit is over 25㎡/g, and their relationships are well formulated. Air drying process is expected to improve the engineering properties of the soils such the pro-water properties were changed to anti-water proper-ties through lowering of water holding as resulted to incline from A-7-5 to A-5 on the soil classificaction plastic chart. The freezing-thawing process decreased 20% of liquid limit, especially under the first cycle of the behavious, as a result of above mentioned reasons, phase change of soil-water system brought the decrement of specific surface and affected to the liquid limit.

재생굵은골재와 산업부산물을 사용한 재생콘크리트의 특성

성찬용,류능환 강원대학교 부설 석재복합신소재 제품연구센터 2004 석재연 논문집 Vol.9 No.-

The purpose of this study was to obtain the basic data for the development of block utilizing recycled aggregate and industrial by-product. The unit weight, compressive and flexural strength, ultrasonic pulse velocity, dynamic modulus of elasticity and durability factor were decreased with increasing the content of recycled coarse aggregate. But, the absorption ratio was increased with increasing the content of recycled aggregate. The unit weight was 2,237~2,307 kgf/㎥, the absorption ratio was 2,96~4.12%, the compressive strength was 415~532 kgf/㎠, the flexural strength was 75~96 kgf/㎠, the ultrasonic pulse velocity was 4,350~4,949m/s, the dynamic modulus of elasticity was 390×10³~465×10³ kgf/㎠ and the durability factor was more than 60 in the freezing and thawing 300 cycles. Accordingly, this recycled coarse aggregate can be used for high strength concrete and block manufacture. 본 연구는 재생굵은골재와 산업부산물을 활용한 블록을 개발하기 위하여 플라이 애시와 고로슬래그 미분말을 결합재 중량의 20%를 대체하고, 재생골재의 혼입율을 5종류로 하여 총 10종류의 콘크리트에 대하여 단위용적중량, 흡수율, 압축강도, 휨강도, 초음파진동속도, 동탄성계수 및 내구성 지수에 대하여 구명하였다. 단위용적중량, 압축강도, 휨강도, 초음파진동속도, 동탄성계수 및 내구성 지수는 재생골재의 사용량이 증가할수록 감소하는 경향을 나타내었고, 흡수율은 증가하는 경향을 나타내었다. 재생골재를 100%까지 사용하여도 압축강도는 415 kgf/㎠ 이상, 휨강도는 75 kgf/㎠ 이상, 내구성 지수는 60이상으로 나타나, 고강도 콘크리트 및 블록 제조에 활용이 가능할 것으로 생각된다.

폐석재와 석분을 사용한 식생블럭 제품 개발

성찬용,류능환,연규석,윤준노,김영익,남기성,노경희,박일순 강원대학교 부설 석재복합신소재 제품연구센터 2002 석재연 논문집 Vol.7 No.-

본 연구는 폐석재와 석분을 사용하여 친환경적인 식생블럭 제품을 개발하기 위하여 폐석재의 입경과 석분의 첨가량을 각각 3종류씩 총 9종류의 식생블럭에 대하여 단위중량, 공극율, 투수량, 압축강도, 쪼갬인장강도, 휨강도, 내산성, 알카리농도에 대하여 구명하였다. 단위중량, 강도, 내산성은 골재의 입경이 작을수록 석분의 혼입량이 많을수록 크게 나타났으며, 공극율과 투수량은 작게 나타났다. 강도는 중성화 처리 유무에 따라 4∼5% 정도의 미소한 차이가 나타났다. 알카리 농도는 중성화 약품처리, 수중용출, 야외폭로 순으로 효과가 크게 나타났으며, 이는 식생블럭의 중성화 방법 선택에 매우 중요한 내용이라 할 수 있다. 또한, 식생상태는 공극율과 골재의 입경이 큰 식생블럭이 생육에 유리한 것으로 나타났다. This study was performed to develop the environment-friendly plantable block and to evaluate unit weight, void ratio, permeability, strength, acid-resistance and value of pH by the change of the grading of waste stone and the addition amount of stone dust. The unit weight, strength, acid-resistance is increased with small size of waste stone with increase of the addition amount of stone dust. But, the void ratio and permeability is decreased. The strength of neutral plantable block is decreased approximately 4-5% than that of the normal plantable block. The decreased effect of pH increased in order to neutral treatment, underwater leaching and field exposure. It is very important contents in neutral method selection of plantable block. Also, the planting state is grown rapidly with increase of the void ratio and of the waste stone size, approximately.