• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.2
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• pp.87-92
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• 2011

This paper describes a study on the permeability reduction of the riverbed ground during urban railway tunnel construction. The research is mainly concentrated on the study of the grouting or injection methods among permeability reduction methods which can be adapted in the riverbed ground. The design technology of grouting methods considering the long term hydro-geological behaviour in the riverbed, was suggested. Two injection methods namely, Natural Durable Stabilizer (N.D.S) and Space-Multi Injection Grouting (S.M.I) methods, were introduced as new approach methods which could be adapted to modify the riverbed ground. In order to evaluate the performance of the improved ground by the N.D.S and S.M.I method, a series of pilot tests including the field and laboratory permeability tests, were carried out in the river crossing tunnel construction sites. The results obtained from pilot test program, were also reviewed. The results, the grouting efficiency of the S.M.I method using the non-alkalimeter silica sol is better than that of N.D.S method using cement. In addition, it is anticipated that the current research results are contributed to develop the grouting design technology.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.141-144
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• 2010

건설공사 프로젝트는 기획, 설계, 시공, 운영 및 유지관리 등 각 단계의 다양한 참여 주제에 의해 프로젝트가 진행되고 각 분야 간 원활한 의사소통을 통한 협업으로 일을 진행해 나간다. 그러나 각 단계별 커뮤니케이션이 원활히 이뤄지기가 힘들며, 이러한 단계별 분절의 가장 큰 이유 중 하나가 실제적 결과물은 3차원 기반인 것에 비해, 그 과정이 2차원 CAD 시스템에 의존하는 결과와 과정의 격차 때문이다. 그로 인해 각 관련 분야에서 발생되는 정보의 불확실성, 부정확성, 표현의 애매모함 등으로 인해 재작업 및 불필요한 작업이 빈번히 발생하여 전체적인 공정의 지연 및 비용의 문제, 결과물의 품질에 대한 문제가 발생하고 있다. 또한 도면에서의 한계점인 거리감, 공간감 등 실제 사람이 느끼는 Scale감을 알 수 없어 공간에 대한 이해도가 떨어지는 한계점을 극복하지 못하고 있으며 1인칭 작업운영 방식으로 인하여 협업 설계과정에서 원활한 팀워크를 유도 할 수 없다. 따라서 본 연구에서는 협업설계 과정에서 기본설계 단계를 지원하는 설계 도구로서 건축모델의 단순 시각화에서 벗어나 가상공간에서 몰입형 VR 시뮬레이션을 구현하기 위하여 프로토타입 응용을 개발 하였고, 이것을 "Digital Studio"에 구현하여 즉각적인 공간 시뮬레이션을 통하여 실제 시공 전에 문제점들을 검토 및 보완하고 전체적으로는 생산성 향상과 설계 과정 중 오류를 최소화하기 위한 VR시뮬레이션 시스템의 제안 및 Viewer 모듈을 개발 하였다.

• Journal of the Society of Disaster Information
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• v.19 no.1
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• pp.1-9
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• 2023

In order to carry out construction work, it is urgent to introduce a proper wage system so that the cost burden of projects that have been won due to bleeding competition among original government buildings based on low-priced bids can be transferred to subcontractors. Purpose: Construction with illegal multi-level industrial structure needs to improve the wage reduction environment leading to order (100%) → original contractor (80%) → subcontractor (65%) → load contractor (65%) and aims to ensure wages for end workers. Method: Investigate the current status of labor cost appropriate payment plan in the construction industry, and investigate the case of the appropriate wage system (P.W) in the United States. In addition, the effect and direction of the appropriate wage system are presented. Result: Individual minimum wage security was also mentioned in the Constitution, and many researchers suggested that only the introduction of an appropriate wage system could solve the problem of reducing worker labor and ensure quality and safety. Conclusion: The proper wage system in the construction industry will block illegal multi-level and illegal foreign work, improve the labor environment in the construction market, create an influx of young workers, and have a significant impact on the construction industry's competitive structure, safety, and quality.

• Land and Housing Review
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• v.15 no.2
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• pp.125-137
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• 2024

A conventional Design for Safety (DfS), introduced to eliminate potential hazards in the design phase proactively, has encountered persistent challenges, such as perfunctory risk assessments and hazard identifications based on 2D drawings and inefficient workflow processes. This study proposes a BIM-based approach to Design for Safety (DfS) to address the limitations of conventional methods, aiming to enhance efficiency and achieve practical safety management benefits. The proposed workflow process for BIM-based DfS has been refined and validated for on-site applicability through various case studies, including risk assessments during the design phase and field applications for safety management activities during the construction phase. Specifically, the critical process of risk assessment within the DfS methodology has also been transitioned to a BIM-based approach. This BIM-based risk assessment process has been evaluated through case studies, encompassing safety reviews for structural design, construction equipment operation, and construction methodology with sequence in design projects. Additionally, the proposed BIM-based DfS has demonstrated exceptional on-site applicability and efficiency, as validated by the application of a BIM deliverable embedded in DfS information for CDE-based daily activity briefing, VR-based safety training, AR-based mitigation measures inspections, and other safety management activities in the construction phase.

• Korean Journal of Construction Engineering and Management
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• v.19 no.3
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• pp.61-69
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• 2018

The buildings are getting enormous and more complex as well as the requirement of the owner which wants diverse and efficient. Moreover advanced management is necessary for construction services and a new method of delivering project is now required. In order to expand the delivering method and the construction industry, we have to introduced the CM at Risk method. However, despite the fact that six years have passed already the CM at Risk regulation was introduced, the contract amount in significantly lower than that of the CM for fee, and also there is no CM at Risk project in the public sector. As a result, three pilot projects are currently underway for the LH(Korea Land & Housing Corporation) in order to set up a CM at Risk for the public sector. However, detailed regulations related to CM at Risk have not yet been implemented in Korea. Therefore, in this study, I am trying to understand the risks that could incur when practitioners participate in the three pilot projects that are currently underway and employed in the public sector wherein the CM at Risk is normally introduced. Based on the results of this study, It will be able to utilize as a basic data for future CM at Risk delivery system improvement and enactment.

• Journal of the Korea Institute of Building Construction
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• v.16 no.5
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• pp.429-436
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• 2016

Because of the shortage of construction workers due to The rising labor costs and an aging labor force, construction time has been extended. As a solution, The construction time of high-rise buildings can be reduced by adopting precast concrete construction methods. Most relevant studies have focused on the development and structural analysis of such methods and not on their construction management. Therefore, this study focused on the construction management of the hollow precast concrete column (HPC) method. The objective of this study was to evaluate the performance of HPC formulations through the analytic hierarchy process and benefit-cost analysis. After a gap analysis of the available literature and expert interviews, the evaluation criteria were selected. A questionnaire survey was administered to professionals with ample experience in precast concrete construction for the pair-wise evaluation of the benefit and costs of the HPC method. The results show that the benefits of the HPC method outweighed its costs. Therefore, the HPC method is a suitable substitute for the half-slab method.

• Journal of the Korea Institute of Building Construction
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• v.18 no.2
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• pp.151-159
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• 2018

Accident rate in the construction industry of South Korea is increasing every year, and it represents the highest percentage among industries. This shows that activities performed to prevent safety accidents in the country are not efficient when it comes to reduce the accident rate. In order to resolve this issue, a model for the prediction of human accidents should be established. In addition, it is required a quantification study based on pattern of human accidents. Therefore, the objective of this study is to quantify uncertainty of human accidents risk and predict how to change in various circumstances by using Monte Carlo Simulation. To achieve the objective, first, pattern of human accidents was defined. Second, insurance claim payout and information of human accidents during 14 years in construction site were collected. Third, descriptive analysis is conducted to determine the characteristics of the accident pattern. Fourth, to quantitatively analyze the pattern of the human accidents, the population of each accident occurrence and payout were estimated. Finally, estimated populations was analyzed according to characteristics of distribution by using Monte carlo simulation. In the future, this study can be used as a reference for developing the safety management checklist in construction site and development of prediction models of human accident.

• Korean Journal of Construction Engineering and Management
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• v.10 no.2
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• pp.65-74
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• 2009

It is expected that the number of apartment complexes in Korea that are over 20 years old will rapidly increase to more than 3,500,000. Consequently, the remodeling of these buildings is being revitalized throughout the country. Among the requirements for such remodeling, the expansion of parking lots has considerable weight. When enlarging a parking lot, the access route from an underground floor to the main building (i.e., the means of entry into the main building) determines the possibility of vertical enlargement for elevators, the size of the parking lot, the construction period, and construction expenses, etc. When enlarging an underground parking lot of an apartment complex, the access between the main building and the parking lot, as well as the inhabitants' requirements for entering the main building, are generally determined based on the designer's experience, rather than on the exact estimation of the peculiarity of the complex. In order to resolve such a problem, when enlarging an underground parking lot, a systematic and rational method is needed for selecting the means of entry into the main building. In this study, a selection model is derived for the method of selecting an access route into the main building when constructing an underground parking lot, in order to provide a reasonable decision-making process. A research method was investigated for determining the access route into the main building when enlarging a parking lot. On the basis of research carried out through in-depth interviews with experts, the characteristics for each means of entry into the main building were analyzed and the factors affecting the selection of the access route were deduced. The affecting factors selected were construction efficiency, convenience efficiency and economic efficiency. Weight values were then estimated for the selected affecting factors by applying the AHP method. Results showed that convenience efficiency, which gained the highest value, is the most important factor in selecting the means of entry into the main building. The most suitable means of entry into the main building was also suggested after estimating the applicability of the site by selecting complexes with remodeling possibility. This study will be applied as a reference for selecting the means of entry into the main building when constructing an underground parking lot particularly for older apartment complexes.

• Journal of Korean Tunnelling and Underground Space Association
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• v.16 no.3
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• pp.299-310
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• 2014

Nationally, tunnel and underground constructions are necessary for the environmental sustainability and the efficient use of land space. For the importance of eco-friendly circumstances, 2-arch or large road tunnel has been designed so far. However, such a 2-arch or large tunnel has problems in terms of cost, constructability, construction period, and maintenance. Therefore, in this study, tunnel behavior and stability of rock pillar according to the pillar width and cover depth for parallel tunnels are investigated by performing FE analysis and using empirical formula. According to the results, Rock pillar is reinforced for distributed vertical load by Tie-Bolt due to unpredicted ground deformation, and the reinforced rock pillar's behaviour from the FE analysis shows a quite good agreement with field measurement. According to ground conditions, if the pillar width of the parallel tunnels is reduced, it can be more efficient in use of the tunnel space compared to previous tunnels.

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.31-41
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• 2015

The telecommunication industry has been considered as a national fundamental infrastructure. However, due to the rapid evolution of technology and the change of industry market conditions, the telecommunication infrastructure needs no more huge space for facility and it leads its use to the mixed-use development based on private investment. This study intends to examine the financial feasibility of the development project for the optimal alternative use of telecommunication facility purpose site as a case study based on two types: contributed acceptance and multi-level designation. The NPA and IRR has been analyzed by the simulation of stochastic variables including rent price and its variation rate, vacancy rate, construction cost, capitalization rate and discount rate. The research finding indicates that the two types of development are satisfied with the financial feasibility and it is noteworthy that the rent price turns out to be the most critical factor for the project. Accordingly, it is expected that these research finding can be applied for providing the solid cases of financial feasibility analysis for the development project in limited use of telecommunication facility purpose site.