• Journal of the Korea Institute of Building Construction
• /
• v.21 no.3
• /
• pp.213-219
• /
• 2021

Change orders that occur frequently during the construction phase, af ect the construction performance in terms of cost, time, quality, safety and environment, and place a huge burden for stakeholders of given projects. This study analyzed the causes of change orders and their impact on the basis of 721 cases and a questionnaire of 164 domestic U.S. military construction participants in a total of 24 U.S. military projects. Important factors for change orders in the US military construction projects were engineering change due to design errors (348 cases, 48.3%), user requests change(86 cases, 11.9%), and different site conditions (69 cases, 9.6%). In addition, due to the change orders, construction cost increased by 6.56% on average and construction period was extended by 21.1% compared to the original schedule. As a result, it is anticipated that domestic construction companies can obtain a better understanding of change orders and construction performance, which may be difficult due to accessibility and limitations to military facilities. Also, it is proposed a successor study that guides in the right direction for the U.S. Military Construction.

• Explosives and Blasting
• /
• v.24 no.1
• /
• pp.39-48
• /
• 2006

The various alternatives to reduce the construction period and cost in the wide and long tunnel have been attempted recently. However, the concrete lining forming process after finishing tunnel excavation may delay construction period considering the specific conditions of the wide and long tunnel. The concrete lining is indispensible for the road tunnel. For this reason, the blasting-lining synchronizing study had been carried out to reduce construction period in the Gyea-Ryong Tunnel. Lining models were installed at four different distance conditions the floor of the tunnel. After model installation, hundreds of blasting vibration measurements and concrete material tests were performed to calculate the safe distance between blasting point and concrete lining form. The study also introduces a method which can obtain the better ability of construction by improving working environment with the ventilation and the relocation of tunnel equipments in the working places.

• Journal of the Korea Institute of Building Construction
• /
• v.9 no.6
• /
• pp.161-168
• /
• 2009

In an architectural construction, underground construction is a critical path forming a major part of the total construction period and cost, and particularly in big cities, its size has been increasing every year. A basement wall currently constructed in the field needs a large functional work force, and the construction is under progress by the Euroform and Soldier system, which is disadvantageous in terms of the construction period. Therefore, in this research, non-supporting forms which are applicable to the buildings construction were developed, based on the non-supporting forms partly used in some civil engineering works. In addition, the size of a form was assumed and its economical efficiency was compared to that of the Euroform and Soldier system which is used most in construction fields, and the results were analyzed. The study results showed that the construction cost of composite non-supporting forms was higher than that of the Euroform and Soldier system by about 8%, and the construction cost of non-composite non-supporting forms were lower than that of the Euroform and Soldier system by about 9%. However, in the case of composite non-supporting forms, the amount of concrete and reinforcing rods remarkably decreased in structural construction, so it has the effect of an economical cost reduction compared to the construction cost of existing walls by about 35%

• 한국터널공학회:학술대회논문집
• /
• 2005.04a
• /
• pp.175-186
• /
• 2005

터널공사에서 숏크리트는 가장 중요한 지보재 이므로 시공중 품질관리를 위한 압축강도시험은 매우 중요하다. 현장 타설 숏크리트의 압축강도는 실험실조건에 비하여 낮은 값을 갖고 있어 현장강도 시험은 필수적이나, 적절한 시험방법의 부재로 인하여 코어채취에 의한 압축강도시험이 적용되고 있다. 이 방법은 적절한 샘플채취와 초기강도 측정에 큰 문제점을 가지고 있다. 따라서, 본 논문에서는 공기압식 핀관입시험법을 고찰하였으며, 압축강도시험의 단점을 해소할 수 있는 점하중강도시험법의 적용성을 검토하였다. 또한, 향후 연구계획으로써, 현장강도시험기법으로 선정된 공기압식 핀관입시험기의 적정성 평가와 숏크리트 압축강도시험을 대체할 수 있는 점하중강도시험의 적용성 분석계획을 제시하였다.

• Korean Journal of Construction Engineering and Management
• /
• v.16 no.6
• /
• pp.101-111
• /
• 2015

The modular construction method has been getting more attention followed by global eco-friendly trend as the domestic construction industry has focused more on remodeling and extension work. The modular construction method is an industrialized construction system which is not likely as the existing construction method it manufactures more than 70% modules at the factory then assembling can be completed in a short amount of time on site. The modular construction method has various strengths; shortening of construction period by on-site work decrease, weight pressure reduction by usage of light steel frames and cost saving by repetitive manufacturing. However, it is currently not expanded due to the existing commercialized construction method. Therefore, this research is in order to help the related authorities make decisions to select the construction method and motivate expansion of modular construction method which can be utilized effectively in the extension works. The intention of this research is to stress differentiation from other construction methods in construction period, construction expenses, labor and forces by comparing and analyzing actual cases, to inform competitiveness of modular construction method by concrete effect analysis and to support adoption of the modular construction method into the domestic industry.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2008.11a
• /
• pp.521-524
• /
• 2008

The main goal of construction projects from the past has been enhancing efficiency by reducing cost and time. Compared to this, it is true that for a long time not much attention was paid to safety management. For this reason, safety management is much behind cost and time management but nevertheless, not much improvement has been made. The current safety management is only focused on managing after an occurrence based on knowledge like safety standards and rules. Even though safety accident is reducing in domestic construction projects, the extent of a accident is getting greater because construction projects are getting more complex and sophisticated. Moreover, the actual loss due to accident is increasing and the severeness of a hazard is getting worse. Therefore, to improve the current conditions of safety management, we propose a more effective safety management program. This program is a safety managing method using virtual reality. Property, entity, safety library is applied and finally, aims to continuously manage and prevent rather than deal with an accident/disaster after it happens.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.3
• /
• pp.1165-1171
• /
• 2013

The oversea construction contract amount has sharply increased since 2003. The contractor's capability for EPC and project management is a key factor for a successful industrial construction project. Construction performance measurement and evaluation is needed to improve contractor's project management capability. Therefore, this paper proposes the construction performance benchmarking program for oversea industrial projects. Performance metrics consists of project cost, schedule, quality, and safety. Data from 10 oversea industrial projects were collected and analyzed. Also, this paper describes the process for development of the benchmarking program and lessons learned from industry are summarized. Finally, this paper recommends how sustainable benchmarking program should be established and implemented.

• Korean Journal of Construction Engineering and Management
• /
• v.10 no.3
• /
• pp.22-31
• /
• 2009

In the buildings of educational facilities ordered by BTL projects, the competent authorities, private business, and users of school get to have a deep conflict, due to extra expenses resulted from shortening of construction period and establishment of temporary school building, and inconveniences users of school have to undergo during semester. This study aims at solving immediate problems in the aspect of construction method, proposing several alternative plans, including RC construction method generally applied to construction of the existing school, and modular construction method that is emerged as an alternative method for educational facilities lately, along with the method of construction appropriate for BTL projects of educational facilities, calculating cost of construction required for each alternative plan, analyzing and evaluating period of construction.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.242-245
• /
• 2003

Most engineering tasks require collaboration between many users in major hospital Construction Projects that have many risks. Loss of cost and change orders occurred in factors such as information exchange, misunderstandings, advanced Technology in hospital projects. Moreover, changes in context, costs, requirements, deadlines, etc. require negotiation of issues that may modify important project characteristics. Each part of the major hospital construction projects have been rapidly changed technology of equipments. Therefore it is a major challenge to make a high level of communication and to have mutual understanding. The objective of this paper is to reduce risks for the design process and construction process of hospital projects.

• Korean Journal of Construction Engineering and Management
• /
• v.20 no.4
• /
• pp.104-113
• /
• 2019

Construction dispute about Extension of Time are complexly intertwined with various issues. The duration delay analysis defines the impact the issue has on the duration variation. And The international court and the arbitrator use the results of the analysis as a basis for reasonable duration judging. However, most of the domestic Construction sites have not established a business process for Extension of Time litigation. Therefore, Analysis data are collected after the occurrence of the dispute, there is not enough basic data of analysis almost. This study sought to improve the management efficiency by organizing information requirement for delay analysis and suggesting a reasonable business process. As a result of applying the proposed process to actual construction duration extension disputes, about 33% of practitioners, 46% of contractors, and 48% of legal advisors were satisfied with the process application site And Matrix validation was 91% identical. This study suggests that it is possible to increase the efficiency of the construction duration analysis work used as a basis in the construction dispute. Finally, the Computer based system design for this process should continue in the future.