보강 혼합토의 역학적 특성(II) -섬유 혼합토-

송창섭,임성윤,Song, Chang Seob,Lim, Seong Yoon 한국환경복원기술학회 2002 한국환경복원기술학회지 Vol.5 No.6

This study has been performed to investigate the physical and mechanical characteristics of compaction, volume change and compressive strength for reinforced soil mixed with polypropylene fiber, and to confirm the reinforcing effects with admixture such as polypropylene fiber. To this end, a series of compaction test and compression test was conducted for clayey soil(CL) and polypropylene fiber reinforced soil. In order to determine proper moisture contents and mixing ratio, pilot test was carried out for natural soil and PFRS(polypropylene fiber reinforced soil). And the mixing ratio of mono-filament fiber and fibrillated polypropylene fiber admixture was 0.1%, 0.3%, 0.5% and 1.0% by the weight of dry soil. From the experimental results, it was found that the optimum moisture contents(OMC) increased with the mixing ratio of fiber, but the maximum dry unit weight and the volume change was decreased with the mixing ratio. It means that the improvement of the workability and the reduction of the weight of embankment was done by the addition of the polypropylene fiber. And, from the compression test results, it was found that the addition of the polypropylene fiber remarkably improved the compressive strength of PFRS. And it was observed in the viewpoint of strength that the fibrillated polypropylene fiber reinforced soil was more effective than the mono-filament polypropylene fiber reinforced soil.

불포화토의 투수특성

송창섭,신창섭,Song, Chang-Seob,Shin, Chang-Seob 한국농공학회 2005 한국농공학회논문집 Vol.47 No.4

In order to analyse the flow problems for an unsaturated soil, it is required to examine closely the characteristics of the coefficient of permeability which is changing with the matric suction. To this ends, a permeability test was conducted on the three samples;granular soil, cohesive soil and silty soil. The specimen was made by pressing the static pressure on the mold filled with soil and the void ratio was controled with the different compaction ratio. And the test was performed by using the modified apparatus of the steady state method which was proposed by flute (1972). The range of matric suction was 0-90 kPa. The measured results for the coefficients of permeability were analysed with the void ratio and the compaction ratio, and it was examined closely the characteristics of the permeability for an unsaturated soil.

불포화 점성토의 등방압축 상태에서 발생하는 항복곡면과 경화함수

송창섭 ( Song Chang Seob ) 한국농공학회 1997 韓國農工學會誌 : 전원과 자원 Vol.39 No.1

This paper presents yield surfaces and hardening laws for describing the state of an unsaturated soil under isotropic compression and suction changes. The yield surface is formulated within the framework of hardening plasticity using two independent sets of stress variables : the excess of total stress over air pressure and the suction. And the application of the yield surfaces and hardening laws are confirmed from the result of the experiment. To this end a series of suction-controlled isotropic tests are conducted on clayey soils. Matric suction is controlled by the axis translation technique using high air entry ceramic disk. The specimens are compacted using a half of Proctor compaction energy with 5 % lower of water content than the optimum moisture contents. From test results, existence of the yield surfaces and an application of hardening laws to samples are confirmed· by comparison between test and predicted results. And it is confirmed that LC yield locus is extened with the total plastic deformations induced by suction or stress changes, however, SI yield locus is only extended with the plastic deformations by induced suction changes.

흙-수분 특성곡선 방정식을 이용한 포화도의 예측

송창섭,Song, Chang-Seob 한국농공학회 2004 한국농공학회논문집 Vol.46 No.6

The aim of the work described in this paper was to confirm the application of the equation of the soil-water characteristic curves on an unsaturated soil. A series of suction test for unsaturated soils was conducted on the selected 4 kinds of soil using modified pressure extractor apparatus. And it was carried out to analyse The experimental parameters which can be describe the soil-water characteristics, were determined by using the data obtained from the experiment. From the results, it was found that The matric suction varied according to the grain size distribution, amount of fine grain particles and void ratio. Also it was found that the residual degree of saturation was decreased with in crease of the void ratio, but the pore size distribution index and air entry value were increased with in crease of the void ratio. And The application of the soil-water characteristic curve equation was confirmed for the various conditions and the various state by the comparison between the measured degree of saturation and the predicted degree of saturation.

일축압축강도에 의한 선행압밀응력 예측 및 분석

송창섭,김명환,Song, Chang Seob,Kim, Myeong Hwan 한국농공학회 2016 한국농공학회논문집 Vol.58 No.6

This study was to evaluate the feasibility of pre-consolidation pressure distribution characteristic of western and southern coastal region, using correlation of unconfined compressive strength and preceding research equation. Pre-consolidation of western and southern region showed similar trends undrained shear strength and pre-consolidation pressure in proportion to unconfined compressive strength. Predicted results of U.S. NAVY. (1982) equation revealed a small error western 9.7 % and southern 0.4 %. Prediction correlation results of pre-consolidation using unconfined compressive strength revealed an error western 16.8 % and southern 0.7 %. It was reported that less than 20 percent of pre-consolidation pressure prediction result of Casagrande forecasting error. Estimates of pre-consolidation pressure are possible, before the standard consolidation test, because it was reported that less than 20 % of the forecasting errors of Casagrande.

간척지 온실기초 나무말뚝의 인발저항력 예측을 위한 실내모형시험 결과 비교·분석

송창섭,김명환,장웅희,Song, Chang Seob,Kim, Myeong Hwan,Jang, Ung Hee 한국농공학회 2016 한국농공학회논문집 Vol.58 No.2

The object of this paper was to evaulate modified proposed design equation in model test result in order to estimate uplift-resistance of timber pile of reclaimed land greenhouse foundation. Uplift resistance result of model test was increased to according to increased of contact area. Uplift-resistance result of field test tend to lineary increased to according to increased of embedment depth and contact area. Results of field uplift-resistance was evaluate compare with modified proposed design equation results of model test and Effective stress method. As the Effective stress method tend to underestimate, modified proposed design equation results of model test tend to similar type. As the contact area increase, difference between field uplift-resistance results and modified proposed design equation results of model test was considered uplift-speed.

농촌용 수로의 유형에 따른 토사 퇴적량 예측

송창섭,임성윤,Song, Chang Seob,Lim, Seong Yoon 한국농공학회 2014 한국농공학회논문집 Vol.56 No.6

Development of the economic methods and the design of the standard sections needs the more project fund and land than ever leads to the objection of enlarging canal arrangement to need economic construction method development and standard design for supporting it. The objective of this study was to evaluate the performance of selected sediment reduction methods to reduce sediment discharges from drain and irrigation of different land types (Mountain, Flatten, Reclaimed land). This study was carried out to analysis for the soil loss and sediment of drain and irrigation by comparing RUSLE method and amount of sediment from amount of dredging data of Korea Rural Corporation. The results of study were analyzed and summarized as follow. Size of soil sediment from the upper region of drain and irrigation of mountains bigger than lower region. But in case of flatten and reclaimed land, size of soil sediment from the upper and lower region of drain and irrigation did not classified. In case of comparison drain and irrigation without classifying of land type, size of soil sediment from irrigation is bigger than drain.

불포화의 흙-수분 특성곡선 방정식의 개발

송창섭 ( Song Chang Seob ),임성윤 ( Lim Seong Yoon ),김명환 ( Kim Myung Hwan ) 한국농공학회 2003 한국농공학회 학술대회초록집 Vol.2003 No.-

The purpose of this paper was to derive soil-water characteristic curve equation for uns -aturated soil. To this end, a series of suction measured test was conducted on the selected 4 kinds of soil which is located in Korea, used the modified pressure plate apparatus. From the test results, it was proved that characteristic curve changes according to grain size distribution, size of void and fine grained soil contents. Residual degree of saturation(Sr) was decreased with void ratio and changed with fine gr -ained soil contents, parameter A and hr was increased with void ratio. Soil-water characteristic curve equation based on the test result was suggested by void ratio or grain size distribution.

기계화 경작로의 포장공법 개발

송창섭 ( Song Chang Seob ),리신호 ( Rhee Shin Ho ),오무영 ( Oh Moo Young ),성찬용 ( Sung Chan Yong ) 한국농공학회 2000 한국농공학회 학술대회초록집 Vol.2000 No.-

The aim of the work described in this paper is to develope a pavement method for farm road. To this ends, a series of material test are conducted on in-situ soil which was mixed additives-coarse aggregate, polypropylene fiber, excellent soil compound etc. With the laboratory test results, in-situ pavement test was conducted during two years. The serious problem of the pavement is not appeared up to this time. And the measurement of field data is continued presently. The majority merits of this pavement method is low cost and using environmental materials.

불포화토의 흙-수분 특성곡선

송창섭 ( Song Chang Seob ),임성윤 ( Lim Seong Yoon ),김명환 ( Kim Myeong Hwan ) 한국농공학회 2003 한국농공학회 학술대회초록집 Vol.2003 No.-

The purpose of this paper was to investigate the soil-water characteristic curves for unsaturated soil. To this ends, a series of suction measured test was conducted on the selected 4 kinds of soil which is located in Korea, used the modified pressure plate apparatus. From the test results, the water contents, degree of saturation and volumetric water contents was analyzed with the suction. And was drawn the soil-water characteristic curves was drain from the test results for various factors