• 한국지반환경공학회 논문집
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• 제16권2호
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• pp.5-13
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• 2015

본 연구에서는 36개의 CFRD에 대한 계측자료(38개 지점)를 통해 댐 축조단계에서 얻어지는 계측자료를 이용하여 담수 후 댐의 정부침하량 및 내부침하량 예측기법을 제안하였다. 전체 데이터에 대한 분석 결과, 댐체의 정부침하량 및 시공 중 최대 내부침하량은 댐체의 높이 및 간극비에 비례하였다. 그러나 내부침하량과 댐 높이에 대한 반대수지 상에서의 선형회귀분석 결과는 간극비에 따른 차이 없이 대단히 유사함을 확인하였다. 또한 CFRD의 시공 중 내부침하량을 통해 정부침하량의 예측이 가능하였으며, 댐체가 조밀할 경우 연직변형계수가 크게 평가됨과 동시에 계곡형상의 영향을 많이 받는 것으로 나타났다. 본 연구결과는 향후 CFRD의 설계, 시공, 장기적 유지관리를 위한 유용한 도구가 될 것으로 사료된다.

• 한국지반환경공학회 논문집
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• 제15권11호
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• pp.21-27
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• 2014

본 연구에서는 37개의 CCRD에 대한 계측자료(46개 지점)를 통해 댐 축조단계에서 얻어지는 계측자료를 이용하여 담수 후 댐의 정부침하량 및 내부침하량 예측기법을 제안하였다. 전체 데이터에 대한 분석 결과, 담수 후 시간경과에 따라 정부침하량이 함께 증가함이 확인되었으며, 댐 코어의 재료를 조립질과 세립질의 2가지 유형으로 구분한 댐 높이와 시공 중 최대 내부침하량의 관계로부터 조립질 재료를 사용 시의 내부침하량이 다소 크게 평가되었다. 또한 내부침하량은 댐 높이에 비례하여 증가하였으며, 댐 코어로서 세립질 재료를 사용하는 경우의 정부침하량이 상대적으로 크게 평가되었다. 본 연구결과는 향후 CCRD의 설계, 시공, 장기적 유지관리를 위한 유용한 도구가 될 것으로 전망된다.

• 한국농공학회논문집
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• 제52권4호
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• pp.45-52
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• 2010

The purposes of this research are to analyze the internal settlement behavior of Concrete Faced Rockfill Dam (CFRD) typed 'D dam' and to evaluate the stability of the 'D dam' during dam construction using internal settlement measurements and results of numerical analysis. The field measurements were obtained during dam construction period. The numerical analysis was also carried out for the same construction period. The numerical analysis focused mainly on prediction of stress and displacement behavior of 'D dam' during dam construction stage using input parameters obtained from laboratory tests, i.e. large triaxial tests. The behavior of 'D dam' was evaluated to be stable from comparing the results of field measurements and numerical analysis. A simple empirical equation is also presented to predict final settlement at the completion of dam construction, using settlement measurement monitored during dam embankment.

• 한국농공학회논문집
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• 제54권4호
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• pp.73-81
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• 2012

In this study, the settlement data of 32 center cored rockfill dams (total 39 monitored data) were collected and analyzed to develop the method to predict the crest settlement of a CCRD after impounding by using the internal settlement data occurred during construction. An artificial neural network (ANN) modeling was used in developing the method, which was considered to be a more reliable approach since in the ANN model dam height, core width, and core type were all considered as input variables in deriving the crest settlement, whereas in conventional methods, such as Clements's method, only dam height is used as a variable. The ANN analysis results showed a good agreement with the measured data, compared to those by the conventional methods using regression analysis. In addition, a simple procedure to use the ANN model for engineers in practice was provided by proposing the equations used for given input values.

• 한국지반공학회논문집
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• 제21권7호
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• pp.91-105
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• 2005

본 연구에서는 대곡댐의 계측자료에 의한CFRD의 축조에 따른 거동분석을 통하여 댐체가 받는 하중의 변화에 따른 침하 변형 거동을 분석하였으며, 외국의 CFRD 계측 결과와 비교 분석하였다. 대곡댐의 깊이에 따른 침하량 분석 결과, 전체적인 거동양상이 일반적인 CFRD 거동과 잘 일치하는 것으로 평가되었다. 또한, 38개 CFRD의 계측자료 분석 결과 변형계수, 간극비, 형상계수 등은 댐체의 침하 거동을 예측하는데 중요한 인자임을 확인하였으며 최대 층별 침하량이 작을수록 간극비는 낮게 나타났다. 최대 층별 침하량과 댐 높이의 관계에서 0.001에서 0.01사이에 상관계수를 갖는 댐이 26개로서, 일반적인 CFRD는 대략적으로 평균하였을 경우 최대 층별 침하량과 댐 높이는 0.005의 상관계수를 갖는 것으로 나타났다. 간극비가 낮은 경우 변형계수가 높았으며 형상계수는 4 이하로 나타났고 간극비가 높은 경우 상대침하율이 상대적으로 컸으며 형상계수도 4 이상으로 나타났다.

• Geomechanics and Engineering
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• 제20권1호
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• pp.19-28
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• 2020

The spatial variability of geotechnical properties can lead to the uncertainty of settlement for frozen soil foundation around the oil pipeline, and it can affect the stability of permafrost foundation. In this paper, the elastic modulus, cohesion, angle of internal friction and poisson ratio are taken as four independent random fields. A stochastic analysis model for the uncertain settlement characteristic of frozen soil foundation around an oil pipeline is presented. The accuracy of the stochastic analysis model is verified by measured data. Considering the different combinations for the coefficient of variation and scale of fluctuation, the influences of spatial variability of geotechnical properties on uncertain settlement are estimated. The results show that the stochastic effects between elastic modulus, cohesion, angle of internal friction and poisson ratio are obviously different. The deformation parameters have a greater influence on stochastic settlement than the strength parameters. The overall variability of settlement reduces with the increase of horizontal scale of fluctuation and vertical scale of fluctuation. These results can improve our understanding of the influences of spatial variability of geotechnical properties on uncertain settlement and provide a theoretical basis for the reliability analysis of pipeline engineering in permafrost regions.

• Advances in Computational Design
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• 제3권1호
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• pp.35-47
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• 2018

Design of settlement space is a complicated process while reasonable spatial layout bears great significance on the development and resource allocation of a settlement. The study proposes a weighted L-system generation algorithm based on CA (Cellular Automation) model which tags the spatial attributes of cells through changes in their state during the evolution of CA and thus identifies the spatial growth mode of a settlement. The entrance area of the Caidian Botanical and Animal Garden is used a case study for the model. A design method is proposed which starts from the internal logics of spatial generation, explores possibility of spatial rules and realizes the quantitative analysis and dynamic control of the design process. Taking a top-down approach, the design method takes into account the site information, studies the spatial generation mechanism of settlements and further presents a engine for the generation of multiple layout proposals based on different rules. A optimal solution is acquired using GA (Genetic Algorithm) which generates a settlement spatial layout carrying site information and dynamically linked to the surround environment. The study aims to propose a design method to optimize the spatial layout of the complex settlement system based on parametric generation.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.349-354
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• 2005

In this study, settlement characteristics of 23 CFRD was investigated from monitoring data and the method to estimate the crest settlements considering internal settlement during constructions was proposed. Moreover, crest settlement smaller than 20cm and deflection of face slab smaller than 20cm are not considered to be critical to the stability of large dam whose height is over 40m. Therefore, we assigned the region as safe zone that can be used as a guideline of maintenance of dam. These estimated data can be used in the design, construction and long-term maintenance in domestic CFRD hereafter.

• Geomechanics and Engineering
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• 제12권2호
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• pp.313-326
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• 2017

Based on the reliability theory and limit analysis method, the roof stability of a shallow tunnel is investigated under the condition of surface settlement. Nonlinear Hoek-Brown failure criterion is adopted in the present analysis. With the consideration of surface settlement, the internal energy and external work are calculated. Equating the rate of energy dissipation to the external rate of work, the expression of support pressure is derived. With the help of variational approach, a performance function is proposed to reliability analysis. Improved response surface method is used to calculate the Hasofer-Lind reliability index and the failure probability. In order to assess the validity of the present results, Monte-Carlo simulation is performed to examine the correctness. Sensitivity analysis is used to estimate the influence of different variables on reliability index. Among random variables, the unit weight significantly affects the reliability index. It is found that the greater coefficient of variation of variables lead to the higher failure probability. On the basis of the discussions, the reliability-based design is achieved to calculate the required tunnel support pressure under different situations when the target reliability index is obtained.

• 인간식물환경학회지
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• 제24권3호
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• pp.285-300
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• 2021

Background and objective: Rural migrants are an important human resource in urban and rural exchange (URE) business, therefore it is necessary to enhance their awareness and intent-to-participate. This study was to analyze the rural migrants' recognition and intent-to-participate of URE business and to propose the enhancement of them both. Methods: The questionnaire was designed to analyze the socio-demographic background, motivations, satisfaction with settlement, intent-to-persist, and intent-to-participate of URE business including tourism. The data of 144 respondents was subject to the statistical analysis. Results: The motives of migration were to enjoy leisure life after retirement, increased tiredness of city life, health problems, etc. The satisfaction with settlement was 3.67 at 5-point Likert scale. The intent-to-recommend and intent-to-publicize were 3.40 and 3.46, respectively. The intent-to-participate was 3.45, which was affected by the necessity of URE business and the support of central/local governments, and also showed a significant correlation with the satisfaction with settlement, intent-to-recommend, intent-to-publicize, tourism resources for green tourism or rural tourism, driving a car in Namhae county, and the service and price of meals. They thought the missions that the Namhae county office must focus on were to establish an internal/external public relations systems, establish a support system of central/local governments, and foster/support local leaders. Conclusion: It is necessary to improve the satisfaction with settlement and intent-to-persist, expand exchanges with local people, improve internal/external public relations systems, foster/support leaders, improve transportation in the county, enhance the service and price of meals, and develop/operate URE programs including tourism.