• 한국농공학회지
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• 제18권4호
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• pp.4265-4273
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• 1976

1. Fine aggregates of concrete are very important for the construction works and construction cost determination. Most of fine aggregates are from the river sand, but the amount of storage in the river side is steadily decreasing due to continuous construction works. Therefore, another source of fine aggregates is needed to meet increasied demand of sand. 2. Beach sand is a possible source of fine aggregates. But rust of steel bar is caused by CL-chemical of beach sand. Therefore, desalinization of beach sand is requested to get durable reinforced concrete. Economical methods of desalinization are as follows. (a) Flooding and drainage method. (b) Washing of beach sand with water supply and mixing. (c) Spreading of beach sand on the land and leaching by rain water for a few month. 3. Hardening of concrete with beach sand is accelerated due to salt, Thus early stage strength increase leads to make cracks. Also later stage strength decreases and durability becomes worse. By using appropriate admixture, the quality of concrete can be improved.

• 한국건설관리학회논문집
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• 제11권1호
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• pp.142-150
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• 2010

본 연구는 교육시설물의 부위별 공사비 및 유지관리비 분석을 목적으로 수행되었다. 이를 위해 BTL 사업으로 발주된 서울지역에 위치한 초등학교 4곳을 사례 대상으로 선정하였다. 이렇게 선정된 사례 대상을 바탕으로 부위별 체계 정립을 위한 모델을 제시하였으며, 정립된 부위별 체계에 따라 공사비 및 유지관리비를 분석하였다. 이에 따라 부위별 공사비 분석표와 유지관리비 분석표 그리고 교육시설물의 적정 공사비 및 유지관리비를 제시하였다. 상기와 같은 목적과 방법에 따라 진행된 본 연구의 결론을 요약하면 다음과 같다. 1)사례 대상 학교 4곳의 부위별 공사비 산정에 따른 평균 금액 비율을 살펴보면 다음과 같다. 총 공사비 6,666백만원 대비 구조체 47.15%, 건물외부 8.34%, 건물내부 23.37%, 전기 소화 5.74%, 급수 위생 4.27%, 난방 급탕 5.25%, 옥외시설 1.36%, 토목 4.51%를 차지하는 것으로 분석되었다. 2)사례 대상 학교 4곳의 부위별 유지관리비 분석에 따른 평균 금액 비율을 살펴보면 다음과 같다. 총 유지관리비 4,309백만원 대비 건물외부 11.02%, 건물내부 41.81%, 전기 소화 14.81%, 급수 위생 11.22%, 난방 급탕 12.76%, 옥외시설 5.75%, 토목 2.63%를 차지하는 것으로 분석되었다.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.411-414
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• 2015

The purpose of this study is to conduct a comparative analysis between Korea and the United States of the supply process of unit modular housing at both the factory production phase and the transportation and lifting phase, as part of an attempt to invigorate the unit modular housing market in Korea. Unlike the practice in the United States, one of Korea's unique characteristics is that the floor is constructed with reinforced concrete and hot water heating system. To do this, the wet method in Korea is used that includes concrete placement, curing and constructing hot water floor heating system at the factory production phase, which results in a longer production time and also requires the lifting of heavier loads. In the United States, interior and exterior finishing works of modular housing are performed by different companies, and the distance between the unit module factory and the construction site is quite far. This kind of dualized production structure may cause confusion when it comes to schedule management, procurement management, and stock management. Moreover, problems caused by external environmental factors such as wind and rainfall were reported in the course of long-distance transportation. The results of this case comparison are expected to provide fundamental data that will reduce the amount of trial and error in the unit module production, transportation and lifting work in Korea, which has a comparatively small number of unit modular housing cases.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.364-367
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• 2011

The levels of unemployment and poverty are extremely high and two of South Africa's most pressing problems. There is also a widely acknowledged need for housing and municipal infrastructure (water supply, sewerage, streets, storm water drainage, and electricity, refuse collection). From a theoretical perspective supported by experience elsewhere in Africa, there are reasons for considering that properly formulated employment creation programmes based on the use of labour-intensive methods could be established to construct and maintain the required physical infrastructure, thus creating employment, skills and institutional capacities. Over the past 30 years several projects have been initiated in South Africa to counter unemployment and poverty. Given the socio-economic conditions and political objectives (regarding development, employment creation and alleviation of poverty), it is anticipated that future large-scale construction projects will be proposed by the public sector (National, Provincial and Local Government). The paper will first examine the main tenets of the implementation of development projects through the use of labour-intensive construction and a description of progress elsewhere in Africa and their potential contribution which public works programmes could make to alleviate the poverty and unemployment problems. The research will then analyse the successes and challenges that have been experienced in South Africa in relation to the implementation of development projects over the past 30 years. The paper closes with recommendations and lessons for the future.

• 한국측량학회지
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• 제18권2호
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• pp.111-120
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• 2000

상수, 하수, 전기 그리고 가스 등의 시설물들은 우리 생활에 필요한 도시기반시설로서 대부분 지하에 매설되어 있어 지상시설물에 비해 효율적인 관리가 어렵다. 지하시설물 관리소홀로 발생하는 도시재난을 방지하고 도로굴착 중복공사에 따른 예산낭비와 교통체증을 감소시키기 위해서는 지하시설물에 대한 조사 탐사 및 데이터베이스 구축과 함께 지하시설물 데이터를 효율적으로 관리하기 위한 응용시스템 개발이 요구된다. 전주시는 국가지리정보체계 사업의 일환으로 1998년 12월부터 상수도 지하시설물 전산화 사업을 실시하여 시가화 구역 39.6$km^2$내 80 mm 이상의 상수관 물량 402.89 km 대한 조사/탐사 작업을 수행하였다. 또한 80mm 이하 537 km관에 대해서는 별도의 조사/탐사작업을 수행하지 않고 급수카드를 기초로 데이터베이스를 구축하였다. 또한 기존의 각 부서별 업무프로세스를 GIS 시스템을 활용할 수 있는 체계로 수정하였고 업무프로세스를 기반으로 상수도 지하시설물 관리시스템을 개발하였다. 개발된 상수도 지하시설물 관리시스템은 기본도관리, 상수도검수, 관로관리 및 관로조회, 공사관리, 운영관리 그리고 도면관리등의 하위시스템으로 구성되어 있다. 본 연구에서는 지하시설물 조사/탐사 과정 및 방법 그리고 조사/탐사 과정중 발생한 문제점을 도출하고 개발한 상수도 지하시설물 관리시스템을 구성하고 있는 각각의 서브시스템들의 기능들을 제시하였다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1254-1259
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• 2009

The purpose of this study is to analyze elemental maintenance costs for educational buildings. The adapted research method selected three school buildings in Seoul as BTL projects. On the basis of the selected case, the study suggested a model to establish a system for each parts and to estimate analyzed maintenance costs through that system. According to the analysis, the study proposed a partial maintenance costs standard and analyzed proper maintenance costs. The results of this study are as follows 1) The system is divided into 8 large-groups and 24 small-groups for the analysis elemental maintenance costs. 2) The average rations followed by analysis of partial maintenance costs of the three school buildings are as followings, the total maintenance costs are analyzed 3,992 million won and each part of average rations is exterior of building 10.9%, interior of building 41.58%, electricity & fire fighting facility 14.22%, water supply & healthy facility 11.39%, heating & water supply facility 12.93%, landscape 6.3%, civil engineering works 2.69%.

• 한국해양공학회지
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• 제34권5호
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• pp.361-370
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• 2020

We developed a heavy-duty work class ROV trencher named URI-T (Underwater robot it's trencher) that can conduct burial and maintenance tasks for underwater cables and small diameter pipelines. It requires various supporting systems, including a dynamic positioning (DP) vessel, launch and recovery system (LARS), A-frame, and winch in order to perform burial tasks because of its dimensions (6.5 m × 5.0 m × 4.5 m, 20 t) and the tough working environment. However, operating a DP vessel has disadvantages as it is expensive to rent and operate and it is difficult to adjust the working schedule for some domestic coast construction cases. In this paper, we propose a method using a barge instead of a DP vessel to avoid the above disadvantages. Although burying the cable and pipeline using a barge has lower working efficiency than a DP vessel, it can save construction expenses and does not require a large crew. The proposed method was applied over two months at the construction of the water supply in Yokji-do, and the results were verified.

• 한국환경생태학회지
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• 제9권1호
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• pp.42-48
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• 1995

충청북도 제천시의 상수도 취수를 목적으로 건설하는 취수장 예정지를 중심으로 평창강의 담수어류상을 1994년 9월 25일과 1994년 10월 7일부터 1994년 10월 9일까지 두 차례 조사하고 하천 유지수량의 변동이 어류의 생태에 미치는 영향을 조사하였다. 6개 조사 지역에서 총 6과 21속 28종의 담수어류가 관찰되었으며 천연기념물 및 한국 특산종이 많이 관찰되었다. 평창강은 사행천으로 다양한 담수어류가 서식하기에 적합한 환경과 유지수량을 갖는다. 취수를 위한 급격한 유지 수량의 감소는 평창강의 담수어류가 대부분 멸종할 우려가 매우 높다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 가을 학술발표회 논문집
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• pp.41-48
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• 2000

Most land development projects and large scale civil works require a great amount of sand. And sand is also the most favorable material for soft ground improvement. The demand for sand is soaring rapidly due to increased number of projects regardless of its limited supply. Therefore, it is not difficult to predict that sand may become depleted and no longer be available as ground improvement material in the near future. Against this backdrop, developing an inexpensive sand-substitution material with an efficient accessibility will be necessary and urgently called for. So quick lime could be recommended as the substitutional material for sand. Quick lime is now preferred by forward developed nations. If Korea is able to take advantage of its abundant supply, economical efficiency could be achieved through massive production as well as being able to take advantage of utilization of natural resources. In this respect the purpose of this paper was to estimate improvement effect of soft ground though in-situ construction of quick lime pile. In-situ construction was peformed in road construction site of soft clay and in this study quick lime from Dan-yang that was estimated prominently in aspect of engineering characteristics was used. Quick lime piles were installed by 1.5m, 2.0m, 3.0m spacing to confirm improvement effect according to spacing and installed piles are 0.4m in diameter, up to 5m in length and the density of quick piles installed is 1.4 t/㎥. Vibrating wire pore water pressure cell was installed to confirm consolidation characteristics in surrounding of quick lime piles and both laboratory test and field test were carried out to confirm strength increase. In conclusion, soft ground improvement by quick lime piles was confirmed.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2008년 추계학술발표대회 논문집
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• pp.475-478
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• 2008

In Korea, there has been a tendency that multi-family housings are constructed by providers such as constructors or real estate agents for the economical benefits and selling efficiency, using standardized plans, load-bearing wall system, water-based construction method, and uniformized formworks. Especially, the traditional installation works which service equipments are buried into structures cause serious problems such as shortening building life span, increasing times of remodeling during specific period (100 years) and wasting resources. Also the unilateral way of massive distribution by providers for multi-family housings is not appropriate to meet the various social needs of residents. To solve these problems, it is necessary to build long-life housing which can be easily separated installations, interior and exterior finishings from structural parts. Therefore, this paper will examine the present administrative law and the civil law in order to find negative factors that can be obstructions for providing long-life housings and set the direction to revise the regulations.