• 한국건설관리학회논문집
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• 제21권1호
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• pp.12-20
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• 2020

본 연구에서는 기본적으로 로짓모형, 즉 선택변수 모형을 사용하여 가격, 기술점수는 물론 담합여부, 경쟁정도, 제도적 요인, 공사의 특성 등이 공공공사 낙찰에 영향을 미치는지를 분석하였다. 특히 최근 논란이 되고 있는 담합여부가 낙찰에 미치는 부분에 주목하였다. 본 연구의 주요 실증결과와 시사점은 다음과 같다. 먼저 담합은 낙찰에 직접적인 영향은 미미하지만, 담합 및 비담합의 경우에 따라 입찰행태에 영향을 주는 것으로 나타났다. 두 번째로 낙찰에 영향을 주는 변수 중 설계가 계수 상으로는 가장 중요하고 유의한 요인으로 나타났다. 세 번째로 입찰참가자수로 측정된 경쟁의 정도도 낙찰에 중요한 역할을 하는 것으로 나타났다. 마지막으로 제도적 요인과 공사 특성에 따라 가격, 설계점수, 담합, 경쟁정도의 영향이 다르게 나타나, 이들도 입찰에 영향을 미치는 것으로 분석되었다.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.649-657
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• 2022

The COVID-19 pandemic has unprecedented impacts on different sectors around the globe. The effects observed in developing countries are even more severe. Some projects stopped while many have cost and time overrun issues. This paper conducted a case study on the COVID-19's effects on a hotel construction project in Nepal. The study reviewed the literature on COVID-19 and its impact on construction sectors and conducted a semi-structured interview with the project's personnel. The interview response was analysed and the contributing factors that impacted the project and its performance were identified. The paper found financial, operational, contractual, safety, and risk management issues in the hotel project. Overall, the project cost increased by 32% where the material cost increased by 35% and labor cost increased by 28%. This research discusses causes, measures, and provides a broad perspective of the problems, significant challenges, and opportunities associated with the effects of COVID-19 on the construction industry. The Owner as well as the Contractors incurred added costs because of COVID-19. The paper identified contributing factors and presented the challenges which could be used as opportunities to minimize unforeseen impacts of the pandemics in near future. The lesson learned from this case study was that the labor cost and materials cost could have been minimized if the Owner and the Contractor had established alternative resources such as using locally available labor, materials, and alternative suppliers.

• 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.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.962-967
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• 2005

Construction management requires decision-making skills. Main approaches to training construction management students are: (1) analyzing sample situations involving decision-making; and (2) teaching logical decision-making procedures. The absence of 'pressure' factors in these approaches has significant impacts on the success of the training. The approaches also lack 'dynamic' effects that help create a spontaneous plan for construction projects where unforeseen changes and interruptions may occur. To minimize the adverse effects of the existing approaches, this paper proposes a framework for developing a web-based training system. The application is delivered as a game involving decision-making on the student's part in response to developments at the job-site, and where one student competes against another in an attempt to simulate a real-world scenario.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.179-187
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• 2022

The project performances can be measured in terms of meeting the project schedule, budget, and conformance to functional and technical specifications. Numerous studies have been conducted to examine the causes and effects of change orders for both vertical and horizontal construction, respectively. However, these studies mainly focus on a single project type, so this paper examines the impact of change order for cost growth and schedule overruns using four different building types to close the gap in the change order research area. A total of 211 building projects are collected from four building types: healthcare, residential, office, and education. Statistical analyses using ANOVA tests and linear regression models are used to examine the created metric $CO/day on the cost and schedule impacts. The results found that mean $CO/day values were not statistically different among building types, and that the sum of change orders is a statistically significant predictor of $CO/day. The results will help project stakeholders mitigate the negative change orders effects can be a challenge for project managers and researchers alike.

• KIEAE Journal
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• 제1권2호
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• pp.13-19
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• 2001

Recently, With the increase of income level, many people desire to have agreeable and quiet surrounding. However, the extent and time of the exposure to construction noise and vibration is increasing, which is a factor that ruins the quietness of the surrounding and increasingly raises interests in its effects. In this point, this study attempts to survey the characteristics of construction vibration by SD(Sand drain) method in construction field. In addition, the result of study is presumed to be usable as the fundamental materials for an efficient counter-plan in case of the public resentment in relations to the construction vibration occurring henceforth.

• 한국건설순환자원학회지
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• 제19권2호
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• pp.62-65
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• 2024

• Steel and Composite Structures
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• 제26권2호
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• pp.241-253
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• 2018

Mode II fracture toughness, $K_{IIC}$, of single-ply triaxially woven fabric (TWF) composite due to tow waviness and anisotropy effects were numerically and experimentally studied. The numerical wavy beam network model with anisotropic material description denoted as TWF anisotropic was first validated with experimental Mode II fracture toughness test employing the modified compact tensile shear specimen configuration. 2D planar Kagome and TWF isotropic models were additionally constructed for various relative densities, crack lengths, and cell size parameters for examining effects due to tow waviness and anisotropy. $K_{IIC}$ generally increased with relative density, the inverse of cell size, and crack length. It was found that both the waviness and anisotropy of tow inflict a drop in $K_{IIC}$ of TWF. These effects were more adverse due to the waviness of tow compared to anisotropy.

• 한국안전학회지
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• 제33권2호
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• pp.76-85
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• 2018

The interest in the Building Information Modeling (BIM) technology has risen remarkably due to the effects on construction work period reduction, cost reduction, work safety improvement, and other factors. In civil engineering field, BIM applications mainly focus on data modeling and virtual construction. In this study, we present the BIM-based virtual construction and analyze the effects of BIM for the railway facilities so that the conventional approach to the equipment operation plan can be improved in order to prevent safety accidents which can result from unclear information during the operation plan. The BIM-based virtual construction technology is applied to establish the construction plan for the site with constraints, the installation of steel girder needs to be completed, avoiding interference with the existing high-speed railway operation within a given limited time. A virtual construction model consisting of topography, structures, equipments, and avatar was built and more detailed model, including safety guard rails, was then created. Specifications of the construction equipment were input as a database, and the virtual construction model was manipulated in the equipment operation planning. Through the BIM-based virtual construction, including the verification of alternative construction method, 311 million won was saved and the construction period was shortened by 87 days compared to the original plan. In addition, it was shown that the interest and participation of the construction workers can be increased by providing the 3D virtual scene for real construction work and various safety hazards occurring during equipment operation can be effectively removed in advance by the interactive worker education.

• 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.