• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.313-313
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• 2011

오염물질은 배출원의 형태에 따라 점오염물질과 비점오염물질로 구분하고 있고 점오염물질은 생활하수, 산업폐수, 축산폐수, 환경기초시설 방류수 등으로 발생원이 명확하고 수집하여 처리 및 관리가 용이하나 비점오염물질은 배출위치가 명확하지 않으며, 강우 시 일시적으로 대량 배출되는 특징을 가진 농경지, 도로, 대지, 임야 등에서 배출되는 오염물질을 말한다. 우리나라에서 비점오염은 전체 수질오염의 42~67%(2003년)를 차지하는 것으로 나타났고, 2015년에는 전체 수질오염의 65~75%에 이를 것으로 예상되고 있다. 이 중 농업 비점오염원은 총 수질 오염량의 30%이상을 차지할 것으로 추정하고 있으나 이를 저감하기 위한 최적관리방법의 효과검증에 관한 연구는 아직 미미한 상태이다. 이에 본 연구에서는 농경지 중 밭에서 발생하는 비점오염을 저감하기 위한 기법으로 다양한 규모와 형태의 Silt Fence/식생밭두렁/침사구를 설치하여 밭 비점오염에 대한 저감효과를 평가하고 제어대책을 개발하여 최적관리기법을 제시하고 이에 대한 매뉴얼을 개발하기 위한 기초연구를 실시하려 한다. Silt Fence는 주로 건설공사현장에서 홍수유출 발생 시 인접한 하천 및 호소 등으로 유사 및 오염물질이 유입되는 것을 방지하기 위해 임시적으로 설치하는 시설로 합성 직물 필터를 나무나 금속 막대로 연결하여 등고선 방향으로 설치하는 것으로 대상 지역의 토양이 교란되기 전에 그 지역 아래쪽에 설치한다. 식생밭두렁은 밭의 이랑의 길이가 길어질수록 강우 시 빗물이 하단에 이를 때 늘어난 유량과 빠른 유속으로 토양침식이 가중되는데, 이때 30~35m간격으로 식생밭두렁을 설치하게 되면 상부와 하부의 침식정도가 유사한 경향을 보여 식생밭두렁을 설치하지 않은 지역에 비해 토양의 침식정도가 작게 나타나게 된다. 이러한 Silt Fence/식생밭두렁/침사구의 밭 비점오염의 저감효과 평가 및 제어대책 개발을 위한 기초 실험을 수행하기 위해 경상남도 사천시 용현면 선진리 일대에 시험포장을 조성 하였으며, 시험포장내에 6개의 Plot을 만들어 하단부에 포장에서의 유출수의 유량을 측정하기 위해 플룸을 설치하였고 실내실험을 통해 플룸의 수위-유량관계 곡선을 작성하였다. 포장의 토양특성을 판별하기 위해 Plot별로 토양시료를 채취하여 특성을 분석 한 결과 6개 Plot모두 모래함량이 많은 점토질 사질토로 분류되었다. 향후 강우 시 시험포장에서 발생하는 유출수의 수질을 분석하고 Silt Fence/식생밭두렁/침사구의 오염물질 저감효과를 분석하여 제어대책을 개발하게 되면 농업수자원확보를 위한 관리방안 선정을 위한 정책수립에 활용될 수 있으며 비점오염 배출을 최소화시켜 수질의 개선에 기여할 뿐만 아니라 우리나라 농업에 적합한 최적영농관리기술을 개발 할 수 있을 것으로 사료된다.

• Korean Journal of Construction Engineering and Management
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• v.13 no.3
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• pp.152-159
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• 2012

Remodeling the existing building structure by recycling has great advantages compared with reconstruction in terms of environmentally contributions and reduced use of national resources. And no matter the existing floor area ratio, extension up to 30% of the exclusive using area and short project period have made remodeling a good alternative to reconstruction. However, the residents of aged housings that were being remodeled are either abandoning the remodeling project and turning to reconstruction. The main reason is remodeling project cannot increase the number of householders. In principal, it is prohibited to increase the number of floors during remodeling due to matters of safety. That is, all remodeling construction costs are borne by the residents, which leads to great financial pressure. Therefore, in order to improve these conditions, the residents' burden of remodeling charges should be reduced, and one of the ways to do so is to increase the number of householders. In this study, there will be suggestions of alternatives, including the story increase during remodeling, and compare the burden of remodeling charges on each of the residents, between proposed alternatives and the current remodeling plans by calculating the construction costs in order to prepare a foundation for a system that will promote remodeling.

• Korean Journal of Construction Engineering and Management
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• v.9 no.6
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• pp.137-146
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• 2008

Both competent authorities and private entrepreneurs face plenty of risks when negotiating BTO(Build Transfer Operation) methods of PPI(Private Participations in Infrastructures) projects. Also, success and failure of projects largely depend on the concession agreement contract. In this study, for more efficient negotiation, major issues are examined, and quantitatively analyzed to find out not only the relationship but also the characteristics of which these issues share. Questionnaire research was conducted through both research and by experts who were divided into an ordering agency, design company and constructor. Characteristics of major issues were quantitatively analyzed using the Likert index method, ANOVA(ANalysis of VAriance) and AHP(Analytic Hierarchy Process) analysis. Case studies were examined in order to estimate construction cost, rates of return, government finance support, level of operation-revenues guarantees, estimating operational costs and usage fees. With these 6 items, relative priority, relative impression which is sensible to risk and extent of difficulty in presenting data which is objective were quantitatively analyzed by the ordering agency, design company and constructor groups. From the analysis, there were some similarities between the design company and constructor groups while there was less of similarities between the ordering agency and design company or constructor. The government is diversifying the methods of project promotion, and PPI project from infrastructure-centered to public culture facilities are being expand. The current study will provide not only supporting efficient negotiation but also revitalizing PPI projects.

• The Journal of Engineering Geology
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• v.26 no.3
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• pp.331-337
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• 2016

Radial collector wells (RCWs) have been managed by Korea Rural Community Corporation (KRC) since 1983, installing 98 wells for agriculture in rural area over the country. Among them, 20 wells were installed upstream of 5 subsurface dams and the remaining were installed regardless of the subsurface dam. Most of RCWs have been developed in 1980s and 1990s, and 83 wells have been passed more than 20 years after construction. The number of horizontal arms for RCWs varies from 9 to 28, with length and diameter being 10~30 m and 65 mm, respectively. The central caisson with an inner diameter of 3.5 m was commonly constructed to a depth of 10 m. The maximum pumping rates in RCWs, which are located at distances of 10 to 1,200 m from the river, are 2,000~10,000 m³/day. RCW has a fundamental problem that reduced pumping capacity and degraded well efficiency, due to the physical and chemical clogging. From the feasibility test for improving RCW performance, specific capacity increased to 67% after rehabilitation. TV logging for RCW horizontal arm shows that near the caisson is more severe clogging. From the results of this study, KRC has established the guidebook for monitoring and improving well efficiency through physical/chemical treatment, well logging, and hydraulic tests and managed RCWs periodically with its rehabilitation methods.

• Korean Journal of Construction Engineering and Management
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• v.13 no.1
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• pp.106-117
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• 2012

The proportion of rebar factory manufacturing which has been settled down in Korea recently seems to increase because of their strength such as high decreasing rate of rebar loss and manufacturing accuracy and the external factors such as an increase of downtown projects and a decrease of skilled workers. However, factory manufacturing using straight rebars causes a certain amount of rebar loss and an environmental problem including $CO_2$ emissions. To solve these problems, Bar in coil (BIC) has been introduced; however its application is very rare because it has not been produced so far in Korea and manufacturing machines of BIC are very expensive. Also, although BIC's application is expected to expand due to its strengths, few analysis of its application has been conducted. Therefore in this study, analysis of the BIC's characteristics and the influence to the rebar manufacturing industry are conducted for the advancement of rebar work as a basic research. To achieve this, inquiry on the present condition of rebar manufacturing industry in Korea is implemented. Then, the validation of BIC's applications by aspects of industry and the analysis of stakeholders' economical profit and loss are conducted.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.39-39
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• 2018

우리나라는 전체 국토의 약 70%가 산악지형으로 이루어져 있고 연중 강우가 6월에서 9월에 집중되는 기후적 특성을 가지고 있다. 최근 기후변화의 영향까지 더해지면서 시간당 300mm 이상의 집중호우를 보이는 이상강우가 빈번하게 발생하고 있다. 대부분의 도시지역은 하천을 중심으로 발달되어 있어 인구 및 사회기반시설의 집약정도가 매우 높고 하천변 저지대 지역에 주거 및 상업시설이 밀집되어 있다. 기후적 지역적 특성으로 인한 홍수피해를 미연에 방지하고 피해를 최소화하기 위하여 치수 중심의 수자원 관리를 위해 노력하고 있다. 하지만 우리나라의 하천관리는 시기별 하천 수량의 급격한 변동으로 어려움을 겪고 있다. 이러한 어려움을 극복하고 효율적인 수자원 관리 및 홍수피해 저감을 위해 수계를 중심으로 20개의 다목적댐을 건설하여 운영 관리 중에 있다. 특히, 홍수기 시 댐 운영은 예상 강우에 따라 적절한 예비방류와 강우 시 효율적인 댐 운영계획이 필수적이다. 본 연구에서는 강우가 집중되는 홍수기 댐 운영 시에 예상 강우량에 따라 댐 유역 내 유량 증가에 기여하는 정도를 예측할 수 있는 유출율 예측 회귀식을 개발하였다. 유출율은 강우와 유출량의 비로 지역특성, 강우특성, 관개여부, 선행강우량, 강우이동 방향 등 다양한 요인에 의해 복잡한 메케니즘을 갖는다. 단순히 예상되는 총강우량에 따른 유출율 만으로 상호관계를 정의하기가 쉽지 않기 때문에 한국수자원공사에서 개발한 댐군 홍수조절 연계운영시스템(COSFIM)인 수문학적 연계운영모형을 활용하였다. 최근 10년간 홍수기에 발생한 강우사상별 시간단위의 수문자료(총강우량, 기저유량, 유출율, 무강우일수, 강우지속시간 등) 분석을 실시하였다. COSFIM 모형을 통한 결과를 토대로 고려항목 간 교차검증을 통해 사분위수범위의 이상치 경계를 설정하고 상관분석 결과에 따라 0.5 이상의 상관성이 높은 항목을 활용하여 예측 강우량에 따른 유출율 예측 회귀식을 도출하였다. 본 연구에서 개발한 예측 강우에 따른 유출율 예측 산정식은 댐 유역에 예상되는 강우량에 대하여 하천의 유량 증가 예측 정도를 정량적으로 제시할 수 있으며, 실제 홍수기 댐 운영 시 예상 강우량에 따라 신속하고 적절한 수문 방류 계획 수립에서 용이하게 활용할 수 있을 것으로 기대한다.

• Korean Journal of Construction Engineering and Management
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• v.20 no.4
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• pp.22-33
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• 2019

The government has steadily revised and developed laws and systems for activating remodeling of apartments in response to the problems of aged apartments. However, despite such efforts, remodeling has yet to be activated. For many reasons, this study noted that there were no tools for reasonable profitability judgements and decision making in the preliminary stages of the remodeling project. Thus, the feasibility evaluation model was developed. Generally, the profitability judgements are made after the conceptual design. However, decisions to drive remodeling projects are made at the preliminary stage. So a feasibility evaluation model is required at the preliminary stage. Accordingly, In this study, a feasibility evaluation model was developed for determining preliminary stage profitability. Construction costs, business expenses, financial expenses, and generally sales revenue were calculated using the initial available information and remodeling variables derived through the existing cases. Through this process, we developed an algorithm that can give an overview of the return on investment. In addition, the preliminary stage feasibility evaluation model developed was applied to three cases to verify the applicability of the model. Although applied in three cases, the difference between the model's forecast and actual case values is less than 5%, which is considered highly applicable. If cases are expanded in the future, it will be a useful tool that can be used in actual work. The feasibility evaluation model developed in this study will support decision making by union members, and if the model is applied in different regions, it will be expected to help local governments to understand the size of possible remodeling projects.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.12
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• pp.6488-6494
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• 2013

Recently, BIM has attracted attention as a technology to improve the construction productivity. The BIM standards to be applied to the BIM project are necessary for using or connecting the current 2D-based drawing standards. To develop the standard for BIM-based QTO and cost, this paper focused on using QDBEx, which was applied to road project cost management and connecting QDBEx with IFC, which is the BIM data delivery format. The IFC schema was evaluated to determine if it is possible to use the converts to the QDBEx XML file. As a result, 66% of the whole was available to connect directly, and 17% was available to connect through the processing of instance. The remaining 17% was evaluated to determine if it was available to connect. In the future, improvements in the schema will be suggested based on these results.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.64-75
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• 2008

Since the current database systems for managing geotechnical investigation results were limited by being described boring test result in point feature, it has been trouble for using other GIS data. Although there are some studies for spatial characteristics of subsurface modeling, it is rather lack of being interoperable with GIS, considering geotechnical engineering facts. This is reason for difficulty of practical uses. In this study, we has developed subsurface spatial information model through extracting needed geotechnical engineering data from geotechnical information DB. The developed geotechnical information clustering program(GEOCL) has made a cluster of boring formation(and formation ratio), classification of layer, and strength characteristics of subsurface. The interpolation of boring data has been achieved through zonal kriging method in the consideration of spatial distribution of created cluster. Finally, we make a subsurface spatial information model to integrate with digital elevation model, and visualize 3-dimensional model by subsurface spatial information viewing program(SSIVIEW). We expect to strengthen application capacity of developed model in subsurface interpretation and foundation design of construction works.

• Journal of Energy Engineering
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• v.29 no.2
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• pp.79-84
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• 2020

In order to reduce greenhouse gas by 30% compared to BAU in 2020, research and development of zero-energy building construction technology for reducing greenhouse gas emissions in the construction industry is being conducted. With the recent implementation of the policy as mandatory through the establishment and commercialization of the zero energy building base, the government should devise measures to support and expand technology through the identification of the current status of the zero-energy building incentive system and the erasure of the erasure. In order to implement zero-energy buildings, excessive construction costs are presented as a major issue in revitalizing the supply of new and renewable energy to enhance Passive (energy efficiency grade of 1++) and achieve self sufficiency of energy (20% or higher). In this paper, the major problems and solutions for zero-energy building identification were presented in order to activate the dissemination of zero-energy buildings, and the recent policy changes resulting from the mandatory use of zero-energy buildings were analyzed.