• 한국농공학회지
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• 제30권3호
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• pp.69-81
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• 1988

The Repeated Load Triaxial and Oedometer Tests to the weathered granite & silty clay soil have been fulfilled to investigate their dynarnic characteristics. The results obtained are summarized as follows ; 1. In the relation between the repeated triaxial compression and the oedometer test, the recoverable strain of weathered granite soil showed a tendency to decrease by the increase of the repeated loads number(N), and that of silty clay showed approximately constant values while the total strain increased continuously. 2. The changes of plastic strain was dependent to the level of deviator stress which is the most important element in the calculation of soil deformation under repeated load condition. And there was a significance of 10% between the level of stress and plastic strain. 3. When the soil was aimost dried or saturated to 100%, the deformation by the repeated loads was small. However the deformation showed peak around the saturation of 50%. 4. When the deformation was predicted by the repeated triaxial load tests of a laboratory, it is desirable to introduce the threshold stress concept in the calculation of deformation of subgrade of the pavement. 5. The improved design equation (Eq. 16) introducing the modulus of conversion(Fo), which is based on the Boussineq' s theory, is considered to be rational in the design of flexible pavement. From the above results, the deformation to the repeated traffic loads could be predicted by the repeated triaxial tests on the pavement materials or undisturbed soil layers, therefore it is think that the durable and econornic pavement could be constructed by reflecting that to the design.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.475-482
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• 2005

Many public facilities including roadway, railway, and embedded pipe lines in this country have been damaged by the repeated freezing and thawing of the soil during winter and spring every year. However, there are only few research results in field of frozen ground in this country. Also, there are no the formulation of the reasonable equation for frost penetration depths and of the criterion for identifing potentially frost-susceptible soil in design manual of pavement yet. Through this study it is anticipated to asses the frost action problem in roadway, railway, and water suppply lines and to establish the design criterion about pavement in seasonal cold region.

• 한국도로학회논문집
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• 제15권5호
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• pp.47-55
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• 2013

PURPOSES : The purpose of this study is to investigate the optimal joint positions which can minimize distresses of concrete pavement containing box culvert with horizontally skewed angles. METHODS : The concrete pavement containing the box culvert with different skewed angles and soil cover depths was modeled by 3 dimensional finite element method. The contact boundary condition was used between concrete and soil structures in addition to the nonlinear material property of soil in the finite element model. A dynamic analysis was performed by applying the self weight of pavement, negative temperature gradient of slab, and moving vehicle load simultaneously. RESULTS : In case of zero skewed angle ($0^{\circ}$), the maximum tensile stress of slab was the lowest when the joint was positioned directly over side of box culvert. In case there was a skewed angle, the maximum tensile stress of slab was the lowest when the joint passed the intersection between side of the box culvert and longitudinal centerline of slab. The magnitude of the maximum tensile stress converged to a constant value regardless the joint position from 3m of soil cover depth at all of the horizontally skewed angles. CONCLUSIONS : More reasonable and accurate design of the concrete pavement containing the box culvert can be possible based on the research results.

• Geomechanics and Engineering
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• 제11권5호
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• pp.625-638
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• 2016

This paper presents field study and numerical modeling results for a single-cell low-fill concrete box culvert under a flexible pavement subjected to traffic loading. The culvert in the field test was instrumented with displacement transducers to capture the deformations resulting from different combinations of static and traffic loads. A low-boy truck with a known axle configuration and loads was used to apply seven static load combinations and traffic loads at different speeds. Deflections under the culvert roof were measured during loading. Soil and pavement samples were obtained by drilling operation on the test site. The properties of the soil and pavement layers were determined in the laboratory. A 3-D numerical model of the culvert was developed using a finite difference program FLAC3D. Linear elastic models were used for the pavement layers and soil. The numerical results with the material properties determined in the laboratory were compared with the field test results. The observed deflections in the field test were generally smaller under moving loads than static loads. The maximum deflections measured during the static and traffic loads were 0.6 mm and 0.41 mm respectively. The deflections computed by the numerical method were in good agreement with those observed in the field test. The deflection profiles obtained from the field test and the numerical simulation suggest that the traffic load acted more like a concentrated load distributed over a limited area on the culvert. Elastic models for culverts, pavement layers, and surrounding soil are appropriate for numerical modeling of box culverts under loading for load rating purposes.

• 한국도로학회논문집
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• 제7권4호
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• pp.103-112
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• 2005

도로포장구조체에서 하부구조의 함수비는 포장공용성에 중요한 영향을 미칠 수 있다. 최근 들어 많은 연구자들이 현장 계측을 통한 포장하부구조의 함수비를 주기적으로 측정하기 위해서 TDR(Time-Domain Reflectometry) 함수량계를 사용하고 있다. 일반적으로 TDR 함수량계는 흙의 타입, 입도, 밀도, 온도 등에 의해 오차가 유발된 수 있기 때문에, 현장의 흙을 사용하여 TDR 함수량계의 실내보정실험을 반드시 수행해야 한다. 본 연구에서는 LTPP(Long Term Pavement Performance) 구간의 노상재료와 보조기층재료에 대하여 TDR 함수량계(CS616) 실내보정실험을 수행하였으며, 이 결과로부터 TDR 함수량계의 보정모델을 개발하였다. 또한 현장데이터의 분석을 통해, 함수량계가 동결의 발생여부, 부동수의 양, matric suction 등을 판단하는데 활용될 수 있음을 확인하였다.

• 한국물환경학회지
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• 제25권2호
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• pp.181-192
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• 2009

In this study, the hydrological properties of permeable pavement were analyzed by the experiment and the numerical simulation. The numerical model used was a modified SWMM especially for considering the hydrological response of permeable pavement. The parameters of modified SWMM were revised by the experimental results, and then the practicability was evaluated through the comparison of the experimental and numerical simulation results. In the experiments, three different rainfall intensities such as 65 mm/hr, 90 mm/hr, 95 mm/hr were supplied for 4 hrs, and the hydraulic properties including surface outflow, subsurface outflow, ground water level, soil water contents were measured for 10 hrs. The results showed rainfall intensity effected directly on surface outflow volume and subsurface outflow volume was more effected by ground water level than rainfall intensity. The ground water level and the soil water contents were under estimated as compared with the experimental data except the portion of occurring direct runoff. The surface and subsurface outflow discharge were simulated very well in comparison with the experimental data. Consequently, the modified SWMM could be used very effectively to evaluate the hydrological property of permeable pavement.

• 한국도로학회논문집
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• 제8권1호
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• pp.45-54
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• 2006

1970년대 이후로 국내 건설 산업은 건설위주의 정책으로 지속적인 성장을 이루어 왔지만 이로 인한 환경문제가 심각하게 대두되고 있다. 아스팔트 및 시멘트 콘크리트포장으로 이루어진 도시지역은 열을 흡수하여 국지적인 열섬효과를 만들어 도시지역의 기온을 상승시키는 원인이 되고 있다. 이러한 문제점의 대안으로 최근에 기존 포장에 비해 흡수열량과 방출열량이 적은 흙을 주재료로 하여 특수한 경화재와의 혼합물을 사용한 도로 포장공법이 개발 사용되고 있다. 본 연구에서는 아스팔트콘크리트와 시멘트콘크리트 및 습식교반경화토를 대상으로 시험포장을 실시하고, 현장계측을 통하여 포장형식에 따른 포장체의 온도를 측정하여 온도특성을 규명하였다. 연구 결과, 시험포장에서 계측한 결과를 분석하여 대기온도에 따른 포장표면온도와 포장체 내부에서의 온도를 추정할 수 있는 관계식을 제시하였다. 대기온도 변화에 따른 포장체 내부온도 변화는 아스팔트콘크리트포장에서 가장 큰 변화를 나타내는 반면, 습식교반경화토포장에서는 큰 변화를 보이고 있지 않다. 따라서 기존 포장에 비해 흡수열량과 방출열량이 적은 습식교반경화토를 이용하여 공원 산책로, 농로, 관광지 도로, 자전거전용 도로 등과 같은 도로에 적용하게 되면 도시지역의 기온상승을 방지함과 동시에 인체에 무해하고 환경친화적인 도로를 제공할 수 있을 것으로 판단된다.

• 한국건설순환자원학회논문집
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• 제4권3호
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• pp.276-283
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• 2016

레드머드는 보오크사이트 원광석에서 생산되는 알루미나의 선광과정에서 발생되는 무기질 부산물이다. 인 레드머드를 활용하고자 하는 연구가 국내에서 이루어지고 있다. 강알카리성의 레드머드를 건설산업용 촉진제로서 활용하고자 하는 연구로서 알칼리활성화 슬래그-레드머드 시멘트가 국내외적으로 발표되고 있다. 본 논문은 순환골재 대체율에 따른 알칼리활성화 슬래그-레드머드 건식 흙포장재의 최적함수율, 압축강도, 흡수율, 백화발생 특성에 대하여 비교 검토하였다. 그 결과 순환골재 대체율이 증가할수록 알칼리활성화 슬래그-레드머드 흙포장재의 최적 함수비, 물흡수계수, 백화면적은 증가하고 압축강도는 감소하였다.

• 대한토목학회논문집
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• 제36권3호
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• pp.545-550
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• 2016

본 연구에서는 말뚝기초의 실내모형시험을 통해 연약지반상의 경량포장체용 기초로서의 적합성을 분석 및 평가를 목적으로 하고 있다. 안전성 평가를 위해 실내모형시험용 경량포장체용 말뚝기초모형을 실제 포장체 사이즈의 1/30으로 축소한 모형을 이용하여 시험을 실시하였다. 지반 조건은 연약지반을 모사하여 모델링하였고, 말뚝은 마찰군말뚝으로 실험하였다. 제한된 실험으로부터 측정된 모형포장체의 침하량은 Case A는 0.86 mm, Case B는 0.70 mm, Case C는 0.50 mm로 측정되었다. 측정된 말뚝기초 모형의 실험값을 실제 크기로 환산하였을 때의 최대침하량과 부등침하량은 각각 25.8 mm와 10.8 mm로 도로교 설계기준에 의거하여 최대부등변위량인 50 mm와 부등변위량 20 mm를 넘지 않는 것으로 보이며 침하량을 기준으로 안전성을 평가 할 경우 안전한 것으로 판정되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.374-379
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• 1998

Nowadays, as the traffic volume is higher, the more pavement are expanded and constructed. In korea, the most of the pavement system were covered with an asphaltic concrete or portland cement concrete, so it need the new system of pavement to protect the natural environments. The objectives of this study are to investigate properties and applications of Soilcrete using FGC soil stabillizer and then to evaluate the benefits to be gained by Soilcrete pavement, when a pavement system of existing are replaced by Soilcrete, for example, environmental advantages, cost savings, ultimately.