• 한국건설관리학회논문집
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• 제7권1호
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• pp.138-147
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• 2006

최근에는 주 5일 근무제도, 공기단축형 입찰제도의 도입, 후분양제도의 도입 등의 제도적 변화로 건설공사의 성공적 수행에 중대한 영향을 미치는 공사기간에 대한 관심이 증대되고 있다. 또한 건설시장의 축소와 최저가 입찰제도하에서 건설수주 경쟁은 더욱 치열해짐에 따라 적정 공사기간의 산정과 예측은 매우 중요하다. 이러한 공사기간에 대한 중요성을 인지하고 공사기간을 비교 분석하거나 예측하고자 하는 연구들이 진행되었다. 국내에서 공사기간의 비교연구는 공동주택과 사무소 건축에 국한되었고 국외에서는 통계적 분석과 시뮬레이션을 통한 공사기간의 예측에 대한 연구가 많이 수행된 반면, 건물에 대한 수요의 변화로 발생된 주상복합건물과 오피스텔건물에 대한 공사기간의 실제 사례비교에 대한 연구는 거의 없다. 이에 본 연구는 국내 건설사들의 주상복합 및 오피스텔 건물의 실적공기와 가상사례를 활용하여 공사기간을 비교 분석한 후 공기 경쟁력 확보를 위한 공사단계 별 대응현황을 분석하는 것을 목적으로 한다.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.604-605
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• 2015

To secure quality of dam construction needs appropriate construction duration. Tight construction schedule may have negative influence on infrastructure quality, work safety and maintenance cost. It is necessary to reflect proper construction duration in the planning phase. There have been standards for estimating construction duration of building and industrial complex development but dam construction have not. In order to estimate construction duration of CFRD, feasible study reports and design reports were analyzed to acquire available information. After that, considering on construction duration methods such as comparison with similar cases, approximate estimating formula, approximate quantity assumption were adapted to Critical Path items. Hence, this study present framework for construction duration estimating of CFRD in the planning phase. This framework can be applied other types of dam along the same line.

• 한국BIM학회 논문집
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• 제6권4호
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• pp.35-41
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• 2016

Learning effect is an observation that the more times a task is performed, the less time is required to produce the same amount of outcomes. The construction industry heavily relies on repeated tasks where the learning effect is an important measure to be used. However, most construction durations are calculated and applied in real projects without considering the learning effects in each of the repeated activities. This paper applied the learning effect to the repeated activities in a small sized apartment construction project. The result showed that there was about 10 percent of difference in duration (one approach of the total duration with learning effects in 41 days while the other without learning effect in 36.5 days). To make the comparison between the two approaches, a large number of BIM based computer simulations were generated and useful patterns were recognized using machine learning algorithm named Decision Tree (See5). Machine learning is a data-driven approach for pattern recognition based on observational evidence.

• 한국산학기술학회논문지
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• 제19권12호
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• pp.677-685
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• 2018

건설공사에서 공정관리는 기본적으로 가장 중요한 단계이며, 효율적인 공정관리를 위해서는 합리적 공정표 작성이 우선시 되어야 한다. 설계단계에서는 기상조건과 현장 특성을 고려한 다양한 조건과 공법의 비교 검토를 통해 최적의 공사 기간을 산정할 수 있으나, 기획단계에서 기본적인 자료(D/B) 분석만으로는 효율적 공법 선정과 적정한 공사 기간 산정이 어렵다. 따라서, 기획단계에서 기존시가지의 공동구 건설시 표준공기 분석을 위하여, 본 논문에서는 공동구 형식을 개착식 및 터널식으로 구분하고, 각 형식의 특성과 기존시가지의 조건을 고려한 공법을 선정 하도록 하였다. 합리적인 공기 계산을 위하여 외부 공사에 영향을 주는 기상조건을 고려하여 년 간 가동율을 산정 하였으며, 개착식은 RC 공법/터널식은 Shield TBM 공법에 대한 단위공정을 분석하였다. 각 단위공정을 종합하여 연장 1,200m, 환기구 200m 간격으로 가정한 공사의 표준공기를 산정한바, 개착식은 893일, 터널식은 616일이 소요되는 것으로 분석 되었다. 본 연구의 결과는 기획단계에서 보다 쉽게 공동구 형식 선정과 표준공기 산정에 도움이 될 것이며, 추후 설계단계에 연계하면 공정 및 공사비 산정이 용이할 것으로 판단된다.

• 한국농공학회지
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• 제20권3호
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• pp.4750-4770
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• 1978

Under the various variations of the sample thickness, the load increment ratio and the load increment duration, this consolidation test of the clay in the Asan Bay was tried for the comparison with the standard consolidation test. The results gained are as follows; 1. The void ratio variations of the leached-clay samples were increasingly high, according as the sample thickness thinned and the load increment duration and the laod increment ratio increased. 2. The coefficient of consolidation were increased with the increment of the sample thickness, of the load increment ratio and of the load increment duration. Near the pre-consolidation load, the coefficient of secondary consolidation had the maximum value and lessened with the increment of the sample thicknss, and of the load increment duration 3. The value of the pre-consolidation load increased in proportion to the increment of the sample thickness and the decrease of the load increment ratio and the load increment duration. 4. The compression indices increased as the increment of load increased and decreased as the sample thickness increased. 5. The initial compression ratio increased as the sample thickness, the load increment ratio and the load increment duration decreased. The ratio of primary compression to the secondary decreased with the increment of the sample thickness and of the load increment ratio. 6. The time at the completion of psimary consolidation increased with the increment of the sample thickness and of the consolidation load, and with the decrease of the load increment ratio. 7. The compression indicses increaed as the sample thickness lessened and decreased as the load increment ratio increased. The coefficient of consolidation increased according as the sample thickness, the load increment ratio and the load increment duration went up. The settlement at the construction site should be calculated highly in proportion as the sample thickness lessened and the load increment ratio increased. The consolidation ratio is thought to be accelerated if the sample thickness and the load increment ratio becomes higher and the load increment duration longer.

• Journal of Construction Engineering and Project Management
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• 제2권3호
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• pp.17-29
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• 2012

Delays are one of the biggest problems facing by the construction industry and they have significant financial and social impact in construction projects. The paper presents a framework of Delay Analysis System (DAS) with the aim of analysing the impact of delay factors in Libyan construction projects. The system has designed by integrating the possible delay factors, critical activities of a project using@risk simulator. A case study of building project was demonstrated to identify the impact of delays and the sensitivity of delay factor. The case study result showed that the project might be delayed by 97 to 103 days in comparison to the planned duration. The developed DAS is a tool for analysing and identify the impacts of delay factors and assist to construction manager to take necessary measure in reducing the delay impact. The paper provides a methodology for analysing the possible delay impact in a construction project and informing to construction manager in advance of the possible delay factors.

• 한국건설관리학회논문집
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• 제10권3호
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• pp.102-110
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• 2009

동시공학 연구는 최근까지 국내에서 인식이 부족하여 잘 활용되지 못하였고 다만 패스트 트랙에 관한 연구가 활발히 진행되어 왔다. 그러나 본 연구는 기존의 패스트 트랙 방법에서 정량적인 분석과 논리적으로 증명 및 평가하는 연구가 미비하다고 판단하여, 상위 개념인 동시공학 방법을 분석하였다. 설계단계에서 정성적인 분석이 아닌 실제 예제를 통하여 정량적인 자료를 이용하여 각 공정별 중첩이 전체 프로젝트에 미치는 영향을 명확하게 보여주는 분석방법을 제시하였다. 시뮬레이션 기법을 이용한 정량적인 분석방법을 통하여 실제 분석 결과를 가지고 의사결정에 참고 자료로 활용이 가능하도록 하였다. 사례분석 결과 중첩 비율별 공기 비용 간의 관계를 알 수 있었고 중첩 비율별 값을 가지고 공기 비용간의 정량적인 분석을 통해 최적점을 제시함으로서 의사결정이 가능토록 하였다.

• 한국산업융합학회 논문집
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• 제27권2_2호
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• pp.403-414
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• 2024

The aim of this study is to evaluate the productivity of multilayered modular housing units during the prefabrication phase. Additionally, it shows the results of productivity analysis conducted using the Web Cyclone technique. Initially, an review of literature and prior studies helped outline the comprehensive manufacturing process of laminated modular apartments, examining the range of minimum, average, and maximum work durations along with workforce size. Subsequently, the productivity of the multilayered apartments' prefabrication was assessed using the Web Cyclone technique, focusing on the workflow, duration, and personnel involved. This analysis also included a comparison of productivity against the initial plan based on the outcomes of a sensitivity analysis.

• Structural Engineering and Mechanics
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• 제20권6호
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• pp.673-693
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• 2005

A general step-by-step simulation for the time-dependent analysis of segmentally-erected prestressed concrete box-girder bridges is presented. A three dimensional finite-element model for the balanced-cantilever construction of segmental bridges, including effects of the load history, material nonlinearity, creep, shrinkage, and aging of concrete and the relaxation of prestressing steel was developed using ABAQUS software. The models included three-dimensional shell elements to model the box-girder walls and Rebar elements representing the prestressing tendons. The step-by-step procedure allows simulating the construction stages, effects of time-dependent deformations of materials and changes in the structural system of the bridges. The structural responses during construction and throughout the service life were traced. A comparison of the developed computer simulation with available experimental results was conducted and good agreement was found. Deflection of the bridge deck, changes in stresses and strains and the redistribution of internal forces were calculated for different examples of bridges, built by the balanced-cantilever method, over thirty-year duration. Significant time-dependent effects on the bridge deflections and redistribution of internal forces and stresses were observed. The ultimate load carrying capacities of the bridges and the behavior before collapse were also determined. It was observed that the ultimate load carrying capacity of such bridges decreases with time as a result of time-dependent effects.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2007년도 정기학술발표대회 논문집
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• pp.377-380
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• 2007

거푸집공사는 전체 건설공사에서 매우 큰 비중을 차지하고 있는 공종이다. 해외에서는 거푸집 공법과 관련하여 연구개발이 활발히 이러우지고 있고, 다양한 공업도 개발되고 공사비 절감노력이 이루어지고 있으며, 국내에서도 다양한 시도가 이루어지고 있다. 그러나 새로운 거푸집 공법에 대한 체계적인 연구가 부족하여 현장적용에 어려움이 있고, 특히 거푸집 공법의 일종인 PF/R 공법이 건설현장에서 적용되고 있으나, 일부 문제점들이 지적되고 있는 실정이다. 이에 본 연구에서는 PF/R과 기존의 거푸집 공법과의 비교분석을 통해 문제점을 도출하고 해결방안을 제시하였다.