• 대한토목학회논문집
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• 제31권1D호
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• pp.73-82
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• 2011

일반적으로 다져진 도로기초 지반재료의 장기적인 강도나 배수 거동 평가시 불포화상태를 고려하지 않고 있다. 그래서 보조기층과 노상토와 같은 도로하부 기초에서의 불포화상태와 이력현상을 고려하는 것은 현실적이다. 따라서 보다 정량적인 불포화 지반의 평가를 위하여 흡수력과 함수특성을 평가하기 위한 적절한 장비, 재료모델, 그리고 투수계수에 대한 평가가 필요하다. 본 논문에서는 이러한 거동을 알아보기 위해서는 흙-수분 관계인 재료의 함수특성곡선 측정 자료를 통하여 불포화 투수계수를 추정하고 이를 통하여 국내 대표적인 입상재료에 대한 불포화상태에서의 수분의 이동에 대한 관찰 및 분석을 수행하였다.

• Geomechanics and Engineering
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• 제8권2호
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• pp.283-303
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• 2015

To research and analyze the differential settlements of foundations specifically, site investigations of existing railways and metro were firstly carried out. Then, the centrifugal test was used to observe differential settlements in different position between foundations on the basis of investigation. The theoretical model was established according to the stress diffusion method and Fourier method to establish an analytical solution of embankment differential settlement between different foundations. Finally, theoretical values and experimental values were analyzed comparatively. The research results show that both in horizontal and vertical directions, evident differential settlement exists in a limited area on both sides of the vertical interface between different foundations. The foundation with larger elastic modulus can transfer more additional stress and cause relatively less settlement. Differential settlement value decreases as the distance to vertical interface decreases. In the vertical direction of foundation, mass differential settlement also exists on both sides of the vertical interface and foundation with larger elastic modulus can transfer more additional stress. With the increase of relative modulus of different foundations, foundation with lower elastic modulus has larger settlement. Meanwhile, differential settlement is more obvious. The main error sources in theoretical and experimental values include: (a) different load form; (b) foundation characteristics differences; (c) modulus conversion; (d) effect of soil internal friction.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1050-1055
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• 2007

In the case of a rail road bridge extension work, especially single track to double track, the foundation of new substructure which supports the extended part of superstructure could be interfered by the exist foundation of an old bridge. When these two foundations are jointed to prevent such fatal effects of the structure as unequal subsidence of soil foundations, it is important to prove the structural behaviour of the joining surfaces between new foundation and old foundation. 3-Dimensional Finite Element Analysis Method have been studied for the solutions of the structural behaviour of the foundations. In this analysis, 'Contact Element' which allows the sliding of each adjoining member is used for the joint of the boundary surface of the old and new pier foundations. Furthermore, Material Nonlinear Behaviour Analysis also supports the accuracy of the result in this study because the foundations consist of concrete main bodies and reinforced steel bars. These detailed analyses secure the verification of the structural safety of the foundations in the extension work more firmly.

• 대한토목학회논문집
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• 제30권5D호
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• pp.505-512
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• 2010

교통하중이 작용하는 기초지반의 성능 및 도로하부 지반에서의 변형예측을 위해서는 반복적인 교통하중하에서의 장기변형 예측이 필요하다. 그러나 도로와 철도와 같은 다층시스템에서의 장기변형을 예측하는 것은 쉽지 않은 일이다. 따라서 보다 정량적인 해석을 위해서는 적절한 해석방식, 재료모형, 그리고 재료의 상수들을 통한 역학-경험적인 방식이 필요하다. 따라서 본 연구에서는 반복 교통하중에 의한 응력의존적인 기초 지반재료의 장기변형 거동 파악을 위해 반복 하중의 응력수준과 함수비 조건이 고려된 반복재하 장기변형실험을 실시한 결과를 분석하고 해석에 활용하였다. 여러 응력상태조건에서 기초 지반재료의 장기변형 특성이 반영된 유한요소해석을 실시하였고 장기변형 예측모델의 실내시험규모에서의 적용성을 평가하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.11-16
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• 2009

Better understanding of in-situ mechanical behavior of pavement foundations is very important to predict long-term effects on the system performance of transport infrastructure. In order to do that, resilient stiffness characterization of geomaterals is needed to properly adopt such mechanistic analysis under both traffic and environmental loadings. In this paper, in situ monitoring data from KHC test road was used to analyze the non-linearity of stress conditions under traffic and moisture loadings. Then, the predicted non-linear response using finite element method with a selected constitutive model of foundation geomaterials are verified with the field data.

• 한국도로학회:학술대회논문집
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• 한국도로학회 2008년도 추계학술대회 논문집
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• pp.243-250
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• 2008

• 한국지반공학회논문집
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• 제25권7호
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• pp.47-54
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• 2009

도로하부에 대한 현장에서의 역학적인 거동에 대한 이해는 교통기반시스템의 장기공용성을 예측하는데 매우 중요하다. 이러한 현장거동에서 지반재료에 대한 회복변형 거동 정량화는 교통하중과 환경조건을 고려한 역학적인 해석이 필수적이다. 따라서 본 논문에서는 한국도로공사 시험도로에서 현장자료의 계측과 분석을 통하여 선택된 도로하부 입상재료에 대한 구성방정식을 활용한 비선형 재료거동과 응력을 예측 분석하고 이를 현장자료와 비교하고 검증하였다.

• Safety and Health at Work
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• 제9권2호
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• pp.159-163
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• 2018

Background: Fatigue and sleepiness are inter-related and common among road transport drivers. In this study, sleep deprivation and fatigue among chemical transportation drivers were examined. Methods: A cross-sectional study surveying 107 drivers from three hazardous types of chemical production and transportation industries (nonflammable gases, flammable gases, and flammable liquids) was conducted. Data on sleep deprivation were collected using questionnaires of the Stanford Sleeping Scale and the Groningen Sleep Quality Scale. Fatigue was assessed using an interview questionnaire and a flicker fusion instrument. Results: Chemical drivers had a mean sleeping scale (Stanford Sleeping Scale) of 1.98 (standard deviation 1.00) and had a mean score of 1.89 (standard deviation 2.06) on the Groningen Sleep Quality Scale. High-risk drivers had higher scores in both the Stanford Sleeping Scale and the Groningen Sleep Quality Scale with a mean score of 2.59 and 4.62, respectively, and those differences reached statistical significance (p < 0.05). The prevalence of fatigue, as assessed through a critical flicker fusion analyzer, subjective fatigue question, and either of the instruments, was 32.32%, 16.16%, and 43.43%, respectively. Drivers who slept <7 hours and had poor sleep quality were found to have more fatigue than those who slept enough and well. Drivers who had a more sleepiness score resulted in significantly more objective fatigue than those who had a less sleepiness score. Conclusion: Sleep quality and sleeping hour can affect a driver's fatigue. Optimization of work-rest model should be considered to improve productivity, driver retention, and road safety.

• 기술사
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• 제19권2호
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• pp.21-25
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• 1986

Structure-borne noise due to forced vibration which is originated from subway operation and transmitted to buildings in order of rail-wood tie-concrete bed-structure-soil-building foundations-members of building results in social problem of environmental pollution. Moreover this becomes a serious problem because of the increment of surface traffic and subway operation made by meeting traffic system in crowded cities. Since subway is constructed along the principal road or through the residential area and as the worst case may be, building foundations is contact with top part of subway structure, it is possible that vibration resonance results in fatal damage of buildings. And, structure-borne vibration noise due to subway operation at late and early hours have the residents suffer from insonmia, restlessness and so on. Therefore, to satisfy the future need concerning the environmental protection, this report deals with the influence of structure-borne vibration noise on the basis of the characteristics of Seoul Subway System.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 춘계 학술발표회 논문집
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• pp.713-718
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• 2005

A methodology is developed to evaluate the vulnerability of bridge piers to scour and to help establish effective disaster measures, taking into account the locality and scour characteristics in Korea. Based on the bearing capacity of bridge foundation-ground integrating system changed by scour, this methodology is able to prioritize bridge foundations reflecting on the geotechnical factors as well as hydraulic ones. The bridge foundation vulnerability to scour is categorized into 7 groups considering the concise information of the bridge foundation-ground integrating system. A case study of implementing this method which includes the analysis of the scour depth and evaluation, and categorizing the scour vulnerability of bridge foundation is presented.