• 제목/요약/키워드: General Conditions of the Construction

검색결과 278건 처리시간 0.026초

부체도로 포장의 단면 설계 지침 개발 연구 (The development of pavement section and thickness design guidelines for rural access roads)

  • 황성도;권수안;이문섭;김담륭;이상염
    • 한국도로학회논문집
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    • 제19권2호
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    • pp.113-126
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    • 2017
  • PURPOSES : This study proposes standards for rural access road pavement section and thickness design considering existing access road construction conditions; the study also proposes a complementary policy that can be used for design convenience. METHODS : Various literature review and case studies had been performed in terms of rural access road section and thickness design, both domestically and internationally, and this was followed by domestic rural access road field surveys. KPRP and KENLAYER were used to analyze the commonalities and predict the remaining life. Data on real cost is used to select an appropriate construction method through economic analysis. RESULTS : The economic efficiency of concrete pavement ($15{\times}15$) was the highest in terms of economic efficiency of performance life and traffic volume. In the case of asphalt pavement, it is considered that the most economical method is to implement micro-surfacing method four times as a preventive maintenance method (once every 10 years and 4.5 years for asphalt concrete pavement and MS construction method, respectively). Repairable asphalt pavement is advantageous for areas where heavy vehicles are expected to pass. In the case of other general areas, it is considered economical to place concrete ($15{\times}15$) pavement. However, as analytical results on its performance life are unavailable, it is to be considered for study in the future. CONCLUSIONS : This study proposed interim design guidelines based on various domestic and international design guidelines and case studies. However, in order to develop the final design criteria applicable to the field, it is necessary to (a) estimate the bearing capacity of the lower level of the pavement at various sites, (b) estimate the daily traffic volume, (c) implement advanced low-cost pavement technologies, and (d) propose maintenance standards and techniques for long-term performance.

Innovation and craft in a climate of technological change and diffusion

  • Hann, Michael A.
    • 복식문화연구
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    • 제25권5호
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    • pp.708-717
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    • 2017
  • Industrial innovation in Britain, during the eighteenth and nineteenth centuries, stimulated the introduction of the factory system and the migration of people from rural agricultural communities to urban industrial societies. The factory system brought elevated levels of economic growth to the purveyors of capitalism, but forced people to migrate into cities where working conditions in factories were, in general, harsh and brutal, and living conditions were cramped, overcrowded and unsanitary. Industrial developments, known collectively as the 'Industrial Revolution', were driven initially by the harnessing of water and steam power, and the widespread construction of rail, shipping and road networks. Parallel with these changes, came the development of purchasing 'middle class', consumers. Various technological ripples (or waves of innovative activity) continued (worldwide) up to the early-twenty-first century. Of recent note are innovations in digital technology, with associated developments, for example, in artificial intelligence, robotics, 3-D printing, materials technology, computing, energy storage, nano-technology, data storage, biotechnology, 'smart textiles' and the introduction of what has become known as 'e-commerce'. This paper identifies the more important early technological innovations, their influence on textile manufacture, distribution and consumption, and the changed role of the designer and craftsperson over the course of these technological ripples. The implications of non-ethical production, globalisation and so-called 'fast fashion' and non-sustainability of manufacture are examined, and the potential benefits and opportunities offered by new and developing forms of social media are considered. The message is that hand-crafted products are ethical, sustainable and durable.

5 · 16 군정기 지방행정 환경변화와 모범부락조성사업에 대한 고찰 (A Study of the Local Administration Environment Change and 'Mobum Burak Development' in 5 · 16 Military Government Period)

  • 서만용;박수영
    • 농촌지도와개발
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    • 제20권3호
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    • pp.643-678
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    • 2013
  • 본 연구의 목적은 5 16 군정기 지방행정의 많은 환경변화 속에서 각 도가 추진한 '모범부락조성사업'을 통해 초기 농촌마을개발사업에 대한 모습, 특히 지방행정이 사업의 주체가 되기 위해 추진한 방법을 검토하여 시사점을 찾는데 있다. 군정기(1961~1963) 지방행정은 시군을 기초자치단체로 하는 행정체계 개편, 국가기획제도 도입, 지방세제 개편, 새로운 농촌기구 설립으로 인한 농촌지도 다원화 등의 여러 변화요인을 맞게 되었다. 이러한 환경 속에서 지역의 개발행정 주축은 지방자치단체로 옮겨져 갔고, 각 도는 '보고가는 마을(전북)', '빛나는 마을(충남)'등의 각종 명칭으로 모범부락조성사업을 추진하였다. 또한 내무부는 지역개발의 장기적인 종합계획으로서 군 건설계획의 작성과 추진을 지시하였다. 본 연구는 국가 정책을 중심으로 한 농촌지역개발사에서 도 단위의 지방사를 발굴하고 이를 지방행정 환경변화와 연계하여 분석하였다는 측면에서 향후 관련 연구의 기초자료로 활용될 수 있으리라 판단된다.

선형 부착성 점탄성 접촉모형의 DEM 적용 및 해석적 방법을 이용한 검증 (Implementation and Verification of Linear Cohesive Viscoelastic Contact Model for Discrete Element Method)

  • 윤태영;유평준
    • 한국도로학회논문집
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    • 제17권4호
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    • pp.25-31
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    • 2015
  • PURPOSES: Implementation and verification of the simple linear cohesive viscoelastic contact model that can be used to simulate dynamic behavior of sticky aggregates. METHODS: The differential equations were derived and the initial conditions were determined to simulate a free falling ball with a sticky surface from a ground. To describe this behavior, a combination of linear contact model and a cohesive contact model was used. The general solution for the differential equation was used to verify the implemented linear cohesive viscoelastic API model in the DEM. Sensitivity analysis was also performed using the derived analytical solutions for several combinations of damping coefficients and cohesive coefficients. RESULTS : The numerical solution obtained using the DEM showed good agreement with the analytical solution for two extreme conditions. It was observed that the linear cohesive model can be successfully implemented with a linear spring in the DEM API for dynamic analysis of the aggregates. CONCLUSIONS: It can be concluded that the derived closed form solutions are applicable for the analysis of the rebounding behavior of sticky particles, and for verification of the implemented API model in the DEM. The assumption of underdamped condition for the viscous behavior of the particles seems to be reasonable. Several factors have to be additionally identified in order to develop an enhanced contact model for an asphalt mixture.

Estimation of liquid limit of cohesive soil using video-based vibration measurement

  • Matthew Sands;Evan Hayes;Soonkie Nam;Jinki Kim
    • Geomechanics and Engineering
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    • 제33권2호
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    • pp.175-182
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    • 2023
  • In general, the design of structures and its construction processes are fundamentally dependent on their foundation and supporting ground. Thus, it is imperative to understand the behavior of the soil under certain stress and drainage conditions. As it is well known that certain characteristics and behaviors of soils with fines are highly dependent on water content, it is critical to accurately measure and identify the status of the soils in terms of water contents. Liquid limit is one of the important soil index properties to define such characteristics. However, liquid limit measurement can be affected by the proficiency of the operator. On the other hand, dynamic properties of soils are also necessary in many different applications and current testing methods often require special equipment in the laboratory, which is often expensive and sensitive to test conditions. In order to address these concerns and advance the state of the art, this study explores a novel method to determine the liquid limit of cohesive soil by employing video-based vibration analysis. In this research, the modal characteristics of cohesive soil columns are extracted from videos by utilizing phase-based motion estimation. By utilizing the proposed method that analyzes the optical flow in every pixel of the series of frames that effectively represents the motion of corresponding points of the soil specimen, the vibration characteristics of the entire soil specimen could be assessed in a non-contact and non-destructive manner. The experimental investigation results compared with the liquid limit determined by the standard method verify that the proposed method reliably and straightforwardly identifies the liquid limit of clay. It is envisioned that the proposed approach could be applied to measuring liquid limit of soil in practical field, entertaining its simple implementation that only requires a digital camera or even a smartphone without the need for special equipment that may be subject to the proficiency of the operator.

백제 사찰 조영계획 고찰 (A Study on the Master Plan of the Temple Site of Baekje Period)

  • 탁경백
    • 건축역사연구
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    • 제20권4호
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    • pp.7-28
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    • 2011
  • This study intends to investigate the measuring scales, locations and scales through arrangement plans for a research on construction plans. Through an analysis of the artifacts-measuring scales, the relation of two scales found, which further helped suppose the measuring scales applied during the foundation period. Southern dynasties-scale was still used even after the capital was transferred to Sabi till Tang-scale was introduced. Tang-scale was used for Buddhist temples mostly founded in the 7th century. On the other hand, Goguryo-scale seemed to be used almost at the same period as Southern dynasties-scale used, but it seemed that Goguryo-scale disappeared earlier than Southern dynasties-scale. The locations of Buddhist temples could be classified into mountains, flatlands and mountain valley. Buddhist temples founded in mountains were mostly small-sized, but ones located on flatlands could secure flat fields through mounding operations. In addition, through location conditions of Neungsa and Wangheungsa, it was possible to find out the district setting of Sabi Capital Castle. Finally, the expansion range of Buddhist temples were found to be towards the east and the west. As for the scales of temples according to such conditions of location, it was found a similarity in Temple sites. In general, it was possible to assume that the scales of Buddhist temples tended to be expanded along with spatial expansion and there were regular systems in Buddhist temples related to the Royal family. Through the analysis of arrangement plans between individual buildings, it was found that the basic arrangement of Gate-Pagoda-Main Hall-Lecture Hall was preserved, but the proportion of distances between individual buildings varied depending on cases. As a result, there were differences between scales of entire building sites, construction subjective influences and master plan for each location of a Buddhist temple.

국내 농업용 지하댐의 현황 및 활용 사례 (Current Status and Application of Agricultural Subsurface Dams in Korea)

  • 용환호;송성호;명우호;안중기;홍순욱
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제22권3호
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    • pp.18-26
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    • 2017
  • The increasing frequency of droughts has been increasing the necessity of utilizing subsurface dams as reliable groundwater resources in areas where it is difficult to supply adequate agricultural water using only surface water. In this study, we analyzed the current status and actual conditions of five agricultural subsurface dams as well as the effect of obtaining additional groundwater from subsurface dams operated as one aspect of the sustainable integrated water management system. Based on the construction methods and functions of each subsurface dam, the five subsurface dams are classified into three types such as those that derive water from rivers, those that prevent seawater intrusion, and those that link to a main irrigation canal. The classification is based on various conditions including topography, reservoir location, irrigation facilities, and river and alluvial deposit distributions. Agricultural groundwater upstream of subsurface dams is obtained from four to five radial collector wells. From the study, the total amount of groundwater recovered from the subsurface dam is turned out to be about 29~44% of the total irrigation water demand, which is higher than that of general agricultural groundwater of about 4.6%.

곡선교의 받침특성에 따른 주행차량하중분배 특성분석 (Analysis of Moving Vehicle Load Distribution of Curved Steel Box Girder Bridges considering Various Support Conditions)

  • 김상효;이용선;조광일
    • 한국강구조학회 논문집
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    • 제14권6호
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    • pp.711-720
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    • 2002
  • 본 연구에서는 곡선교에서 주행차량에 의한 동적 응답을 보다 정밀하게 구현할 수 있는 3차원 해석 모형을 개발하였다. 원심력에 의한 차량의 롤링운동에 따른 차량의 쏠림현상을 구현하여 곡선교의 대표적인 응답특성인 편경사와 곡률반경에 따른 동적응답과 받침의 변화에 따른 동적 응답 특성을 규명하였으며, 2가지 지점조건에 대하여 주행차량에 의한 곡선교의 동적 특성을 비교 분석하였다. 또한 이와 함께 곡선교에서 어떤 파라미터가 하중 분배에 가장 효율적인가를 비교 분석하였다. 동적해석결과 받침이 외측에 배치된 경우가 중앙에 배치된 경우보다 더 유리하게 분석되었으며, 여러 가지 조건에 따라 하중분배 특성이 다르게 나타남을 알 수 있었다.

성토지지말뚝으로 지지된 성토지반내 펀칭전단파괴 (Punching shear failure in pile-supported embankment)

  • 홍원표;홍성원;송제상;이재호
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.369-378
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    • 2010
  • In this study, a computer program to predict the behavior of laterally loaded single pile and pile groups was developed by using a beam-column analysis in which the soils are modeled as nonlinear springs by a family of p-y curves for subgrade modulus. The special attention was given to the lateral displacement of a single pile and pile groups due to the soil condition and the cap rigidity. The analysis considering group effect was carried out for $2{\times}2$ and $3{\times}3$ pile groups with the pile spacing 3.0B, 4.0B and 5.0B. Based on the results obtained, it is found that the overall distributions of deflection, slope, moment, and shear force in a single pile give a reasonable results irrespective of cap connectivity conditions. It is also found that even though there are some deviations in deflection prediction compared with the observed ones, the prediction by present analysis simulates much better the general trend observed by the centrifuge tests than the numerical solution predicted by PIGLET.

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Housing Policy for Low-income Households (Ger Areas) in Mongolia: Based on Generic Characteristic of Developing Countries

  • Ishdorj, Saruul;Lee, Hyun-Soo;Park, Moonseo
    • 국제학술발표논문집
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    • The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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    • pp.138-145
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    • 2017
  • As that experienced in other developing countries, Mongolia has already faced multilateral side issues for two decades due to economic growth that created Ger areas or internationally 'Slum', public housing and living conditions for low-income citizens, on the basis of rapid migration from rural areas to urban. Ger areas appear to be the main cause of environmental pollution problems and impending comfortable living conditions of the city's residents by covering more than half area of Ulaanbaatar city. Also, the spread of the Ger areas has many side issues such as prevention of urban development and unaesthetic. Most inhabitants of the areas are on low-incomes, and living in the detached houses or felt yurts (Ger) usually build within a low budget, by themselves or unprofessional people, and by using materials of poor quality. Therefore, Ger areas are an inevitable issue that requires effective, proper and immediate housing policy coordination under the government and even the housing market. Unfortunately housing policies, laws, and projects adopted by Mongolian government have shown inefficient results. The government housing policies, unlike other developing countries did not target low-income households' housing which is the priority issue for two decades. But only in 2014, the Long-term housing policy with the strategy for affordable housing initiated the housing policy for low-income households. This policy has five main broad directions such as redevelopment of Ger area, the land readjustment, public rental housing, new settlements and new city and reconstruction for old apartments, which are rather general and would require tremendous financial resources if each of the directions is implemented simultaneously without prioritization. Therefore this research aims to suggest the efficient and adequate housing policy direction for the low-income households in Ger area based on achievement of other developing countries' strategies, performances and generic characteristic with explanatory models. Also, this research adopts a literature analysis method that uses various research reports, related papers in domestic and international journals, and theses by experts, researchers, public institutions, and agencies.

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