• Title/Summary/Keyword: construction engineering

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Growth Characteristic of Pinus densiflora by Soil Generated at Civil Works Site (현장발생토 활용 식재기반 조성유형별 소나무 생육 특성 평가)

  • Oh, Deuk-Kyun;Kim, Phil-Lip;Yoon, Yong-Han;Kim, Won-Tae
    • Journal of Environmental Science International
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    • v.28 no.8
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    • pp.655-667
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    • 2019
  • This research aims to identify the possibility of developing A horizon resources that can be used for construction and civil engineering work. As such, the utility of A horizon resources was examined by establishing planting ground through a mixture of soil layers and by analyzing the growth and development of Pinus densiflora. The physicochemical and physical properties of the soil were as follows: the A horizon was sandy clay loam, B horizon was sandy loam, and the mixture of two layers appeared as sandy loam, which was identical to the B horizon. The experimental groups did not show any significant difference in their physical properties of porosity and degree of water-stable aggregates. With regards to chemical properties, the A horizon as well as the mixture of A and B horizon showed acidity while the B horizon showed alkalinity. The figures of organic matter, total nitrogen, available phosphate, and replaceable potassium were greater as the A horizon content increased, whereas the figures of replaceable calcium, replaceable magnesium, and conductivity increased as the A horizon content decreased. As a result of the growth and development of Pinus densiflora in each planting ground, the final survival rates were all above 100%. However, the tree height and the rate of growth for the diameter of root were higher in the order of A horizon > A horizon + B horizon > B horizon,indicating that the increased A horizon content is related to the growth and development of Pinus densiflora. The treatment of soil with improvement agents, used to recover the functions of in-situ soil showing poor growth and development, did not have a clear impact on the soil texture and porosity. However, the degree of water-stable aggregates increased significantly when using O horizon as the soil improvement agent among the types of in-situ soil. In contrast, all items related to the chemical properties showed significant differences following the treatment by soil improvement agents. The survival rate according to the treatment of soil improvement agents for the growth and development of Pinus densiflora was higher in the order of organic horizon = no treatment > compound fertilizer > organic fertilizer + compound fertilizer > organic fertilizer; this result was statistically significant with a marginal significance value of the log-rank test(p < 0.05).

A Study on the Time-Sectional Analysis of Apartment Housing related research in Korea (국내 아파트 관련 연구의 연구주제 시계열 분석)

  • Kim, Tae-Sok;Park, Jong-Mo;Park, Eu-Gene;Han, Dong-Suk
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.3
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    • pp.45-52
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    • 2018
  • Currently, apartments have become an important research subject for the overall area of politics, economics, and culture as well as urban architectural study. However, there are few analyses of the research trends related to the current interest in the apartment research and prediction of the future changes of an apartment in politics and industry. In this study, the research information related to the apartment has classified, and the changes in the research trends have analyzed. Based on the classified data, the first thesis and dissertation related to the apartment and changes of academic notation have discovered. In addition, future interests and future research directions through Frequency of Appearance, Degree Centrality Analysis, and Betweenness Centrality Analysis of author keywords were predicted. As a result of the analysis, 'Space,' 'Residential Mobility' and 'Apartment Complex' studies were found to be important research topics throughout the entire period. 'Han Gang Apartment,' 'Small Size Apartment,' 'Civic Apartments,' 'Jamsil,' and 'Child' were newly interested topics until 70's era. '(Super) High-rise Apartment,' 'Perception,' 'Jugong Apartment,' 'Housing Environment,' 'Housewife,' 'Apartment Layout,' and 'Busan' were newly interested topics during the 80's and 90's era. 'Apartment Price,' 'Energy,' 'Remodeling,' 'Noise,' 'Resident Satisfaction,' 'Community,' and 'Apartment Lotting-out' were newly interested topics after the year 2000. New concerns for last decade are found to be 'Super High-rise Apartment', 'Remodeling', 'Indoor'(2007), 'Apartment Reconstruction Project', 'Brand', 'AHP', 'Housing Environment'(2008), 'Ventilation'(2009), 'Apartment Lotting-out'(2010), 'Economic Assessment'(2011), 'Cost'(2012), 'Green Building', 'Apartment Sales', 'Law', 'Society'(2013), 'Floor Impact Noise', 'Seoul'(2014), 'Noise'(2015), 'Hedonic Model'(2016). In addition, following research topics are expected to be active in the future: In maturity stage of the research development is going to be 'Apartment Price', 'Space', 'Management of Apartment Housing'; the hedonic model, which is research growth and development stage, is going to be '(Floor Impact) Noise', 'Community', 'Energy.

Construction of Open-source Program Platform for Efficient Numerical Analysis and Its Case Study (효율적 수치해석을 위한 오픈소스 프로그램 기반 해석 플랫폼 구축 및 사례 연구)

  • Park, Chan-Hee;Kim, Taehyun;Park, Eui-Seob;Jung, Yong-Bok;Bang, Eun-Seok
    • Tunnel and Underground Space
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    • v.30 no.6
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    • pp.509-518
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    • 2020
  • This study constructed a new simulation platform, including mesh generation process, numerical simulation, and post-processing for results analysis based on exploration data to perform real-scale numerical analysis considering the actual geological structure efficiently. To build the simulation platform, we applied for open-source programs. The source code is open to be available for code modification according to the researcher's needs and compatibility with various numerical simulation programs. First, a three-dimensional model(3D) is acquired based on the exploration data obtained using a drone. Then, the domain's mesh density was adjusted to an interpretable level using Blender, the free and open-source 3D creation suite. The next step is to create a 3D numerical model by creating a tetrahedral volume mesh inside the domain using Gmsh, a finite element mesh generation program. To use the mesh information obtained through Gmsh in a numerical simulation program, a converting process to conform to the program's mesh creation protocol is required. We applied a Python code for the procedure. After we completed the stability analysis, we have created various visualization of the study using ParaView, another open-source visualization and data analysis program. We successfully performed a preliminary stability analysis on the full-scale Dokdo model based on drone-acquired data to confirm the usefulness of the proposed platform. The proposed simulation platform in this study can be of various analysis processes in future research.

A Study on the Documentary Filming Method for Specific Places - Focus on the documentary and - (장소 특정적 다큐멘터리의 촬영 방식 연구 - 다큐멘터리 <서울역>, <옥포 조선소>를 중심으로 -)

  • Oh, Sehyun
    • Trans-
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    • v.11
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    • pp.37-63
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    • 2021
  • This paper focused on documentaries and for specific places and described the documentary shooting methodology from the perspective of a Cinematographer. 'Old Seoul Station' and 'DSME' (DAEWOO Shipbuilding & Marine Engineering Co., Ltd.) are monumental spaces that reflect the value of Korea modernization and are shared by Koreans' collective memories, unconsciousness, and unique feelings for the place. 'Old Seoul Station' has changed its place identity to a new space called "Culture Station Seoul 284." 'DSME' is a large-scale industrial complex that still functions actively, and it is like an organism that seeks to change according to changes in its industrial structure. and observe and record images of space related to place identity and the people related to it. It shows the construction of staring into a space in a particular place and continuously recording and placing moments of experience, such as the appearance of people working and resting. If it is not recorded through this, it allows us to see intangible narratives related to volatile place identity, and enables specific place experiences through theaters. This study focuses on production theory based on examples of documentary filming methods for these specific places.

An Comparative Study on the Method of Determining Allowable Horizontal Bearing Capacity of Piles (말뚝의 허용횡방향지지력 결정법의 비교연구)

  • Lee, Seung-Hyun;Han, Jin-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.6
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    • pp.267-274
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    • 2021
  • Among several methods for determining the allowable lateral resistances of piles, the subgrade reaction method and ultimate lateral resistance method are generally used. To determine the effects of the soil conditions, pile head restraint conditions, and pile lengths on determining the allowable lateral resistances of piles, computations of the allowable lateral resistances of piles using the two methods were executed, and the computation results were compared. For piles in soft cohesive soil, the pile design is governed by the allowable lateral resistance of a pile from subgrade soil reaction method regardless of the pile head restraints conditions and pile lengths. The allowable lateral resistance of a pile from the ultimate lateral resistance governs the design as the undrained shear strength increases. Except for the case of a short pile, which is installed in loose granular soil, the allowable lateral resistance of a pile from ultimate lateral resistance governs the design of laterally loaded piles. According to this study, computation of the ultimate lateral resistance of a pile is needed, even though some opinions suggest that the design of a laterally loaded pile is satisfied only by the subgrade reaction method. The pile width barely influences the coefficient of horizontal subgrade reaction. Realistically, the effect of the pile width can be disregarded in the condition of common pile widths of 20~90cm.

Geoenvironmental Influence on the Recycled Soil from Demolition Concrete Structures for using in Low Landfilling (건설폐토석의 성토에 따른 지반환경적 영향)

  • Shin, Eun-Chul;Kang, Jeong-Ku;Ahn, Min-Hee
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.12
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    • pp.21-30
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    • 2011
  • The recycled soil that is proceeded from demolition concrete structures was analyzed by the methods of the physical and mechanical tests of soil and TCLP test to use the soil in low landfilling for the construction of an industrial complex. The laboratory test for diffusion of alkali ion in soil mass was analyzed by the methods of XRF and ICP. The fish toxicity test was also conducted to find an environmental influence. The recycled soil through the laboratory test satisfied the engineering property for low landfilling and the criteria of soil contamination. However, the solution which producted by 1:1 ratio of recycled soil and water contained the high pH concentration by alkali ion. The calcium hydroxide solution by CSH cement paste was estimated as the main reason why pH concentration is increased more than 9.0. The high pH concentration in recycled soils causes a toxicity to the livability of fishes. A diffusion area of pH concentration in the ground was analyzed by the Visual Modflow Ver. 2009 program based on geotechnical investigation. The high pH concentration in the recycled soils can be remained as high value due to cement paste in the long term period. Therefore, in the early stage of landfilling work, the mixing with the weathered granite soil is necessary to control the pH concentration.

A Study on the Characteristics of Planning of Hwa-sung from the Point of Water System (수체계로 본 수원화성 건설의 계획적 특성에 관한 연구)

  • Kang, In-Ae
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.29 no.4
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    • pp.137-147
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    • 2011
  • This study aims to find out the construction process and planning characteristics of Suwon and Hwa-sung in 18th century from the point of water system. This study has an explanatory approach. The planning intents in the water system was driven out by analyzing various planning elements in relation to water system in the process of constructing Hwa-sung in 18th century. Using Entire Map of Hwa-sung, land registration map made in 1911 and topographic map of 1/10,000 scale made in 1917, water system and interpretation of spatial structure in Hwa-sung were analyzed. The results are as follows(Planning characteristics of the water system in Haw-sung in 18th century are as follows). Firstly, in determining the spatial structure and location of Hwa-sung, water system had an important role. Secondly, integrated drainage system was planned by the organization of natural and artificial water stream. Thirdly, the main street system and land use structure were planned in relation with water system. Fourthly, territoriality of main area was planned with water stream. Fifthly, ponds were constructed for flood control and they had important role as landscape elements. Sixthly, water stream was used as intentional BiBo element. As a result of the study, the weater system of Hwa-sung in 18th century was planned by the organization of natural and artificial water stream in relation with the location of new town and wide area's spatial structure, street system, land use structure, territoriality of main area, terriflood control, water quality protection, landscape, 비보 and urban daily life.

The Engineering Characteristics of the Sludge Mixed Soil (슬러지 혼합토의 공학적 특성)

  • Kim, JungUn;Kim, MyeongKyun;Bae, WooSeok
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.5
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    • pp.43-50
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    • 2011
  • As a result of population growth and economic growth, household and industrial wastes continue to rapidly increase every year. Especially, sewage sludge produced at final stage is increasing with the constant construction and putting in good order of the sewage plant. In addition to the government's prohibition for filling up the sludge, it became more and more difficult to discharge wastes to the sea as London Dumping Convention '96 came into effect. And sewage sludge and the livestock wastes are expected to be thoroughly prohibited from discharging to the sea from 2012. So we need desperately economical and useful alternatives to compact and reuse these wastes. The purpose of this study is to evaluate the utilization of solidified sludge-soil mixture as an enhancement and covering material. To determine the proper mixed ratio of solidified sludge, this study conducted basic physical properties tests, compaction tests, uniaxial compression tests, and permeability test. It was found that the higher the ratio of solidified sludge, the lower the coefficient of permeability. Upon the results of particle size distribution, the mixed ratio of solidified sludge that meet the enhancement material condition was 59% or lower for SP granite soil and 48% or lower for SM granite soil respectively.

Recharge Potential Assessment of Artificial Recharge System for Agricultural Drought Adaptation (농업가뭄대응을 위한 인공함양 시스템의 함양능력 평가)

  • Lee, Jae Young;Kim, Gyoo Bum
    • Journal of Korean Society of Disaster and Security
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    • v.14 no.1
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    • pp.61-72
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    • 2021
  • There is an increasing need for water supply plan using sustainable groundwater to resolve water shortage problem caused by drought due to climate change and artificial aquifer recharge has recently emerged as an alternative. This study deals with recharge potential assessment for artificial recharge system and quantitative assessment for securing stable water and efficient agricultural water supply adapt to drought finding optimal operating condition by numerical modeling to reflect recharge scenarios considering climate condition, target water intake, injection rate, and injection duration. In order to assess recharge potential of injection well, numerical simulation was performed to predict groundwater level changes in injection and observation well respect to injection scenarios (Case 1~4) for a given total injection rate (10,000 m3). The results indicate that groundwater levels for each case are maintained for 25~42 days and optimal injection rate is 50 m3/day for Case 3 resulted in groundwater level rise less than 1 m below surface. The results also show that influential area of groundwater level rise due to injection was estimated at 113.5 m and groundwater storage and elapsed time were respectively increased by 6 times and 4 times after installation of low permeable barrier. The proposed assessment method can be contributed to sustainable agricultural water supply and stable water security for drought adaptation.

Strength and Earth Pressure Characteristics of Industrial Disposal Flowable Filling Materials Utilizing Backfiller (뒤채움재로 사용된 산업폐기물 유동화 처리토의 강도 및 토압특성)

  • Bang, Seongtaek
    • Journal of the Korean GEO-environmental Society
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    • v.22 no.3
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    • pp.5-13
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    • 2021
  • Due to population growth and industrial development, the amount of industrial waste is increasing every year. In particular, in a thermal power plant using finely divided coal, a large amount of coal ash is generated after combustion of the coal. Among them, fly ash is recycled as a raw material for cement production and concrete admixture, but about 20% is not utilized and is landfilled. Due to the continuous reclamation of such a large amount of coal ash, it is required to find a correct treatment and recycling plan for the coal ash due to problems of saturation of the landfill site and environmental damage such as soil and water pollution. In recent years, the use of a fluid embankment material that can exhibit an appropriate strength without requiring a compaction operation is increasing. The fluid embankment material is a stable treated soil formed by mixing solidifying materials such as water and cement with soil, which is the main material, and has high fluidity before hardening, so compaction work is not required. In addition, after hardening, it is used for backfilling or filling in places where compaction is difficult because higher strength and earth pressure reduction effect can be obtained compared to general soil. In this study, the possibility of use of fluidized soil using high water content cohesive soil and coal ash is considered. And it is intended to examine the flow characteristics, strength, and bearing capacity characteristics of the material, and to investigate the effect of reducing the earth pressure when applied to an underground burial.