• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2007.11a
• /
• pp.971-976
• /
• 2007

In the U.S., utility damages or utility delay caused by conflicts during the underground utility relocation is one of the weighty problem in the construction industry. Also, in domestic case, delay and additional cost caused by underground utility(i.e, electricity, communication, gas, water supply and sewerage) relocation has been happened so that there is an increase of claims for responsibility between owners and contractors. However, there is insufficient survey for the recent circumstance of additional cost for delay and design changes caused by utility relocation and shortage of enough research for solving and analyzing of causes and their ripple effect. This research presents a result of the study about the best practices of FHWA(Federal Highway Administration), SHAs(State Highway Agencies) and the utility companies managing utility relocation. Also, it presents the basic concept of SUE(Subsurface Utility Engineering), the most reliable tool of FHWA presented, and investigates the developing status about SUE in Korea. At the end of this paper, this research proposes a practical and more applicable study about the efficient utility relocation focusing on local industry.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2019.11a
• /
• pp.48-49
• /
• 2019

The number of disputes over defects after completion of construction work in apartment buildings is increasing every year. In this situation, the prediction of reasonable defect repair costs is very important. In this paper, we are going to collect basic data for predicting defect repair costs through the correlation analysis of the construction period and defect repair cost of apartment houses. For this purpose, first of all, the construction period and defect repair cost of apartment houses were analyzed to analyze the construction period for each type of work, the construction period for each project type, and the construction period for each standard calculation. Next, the correlation between defect repair cost and the independent variables of the candidate was conducted. According to the analysis, the ratio of framing air, the ratio of finishing air, and the number of delay days showed strong correlation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.11
• /
• pp.110-117
• /
• 2017

In the construction of high-rise residential buildings in which the finishing works are done repetitively in each housing unit, the construction period and cost can be reduced, while maintaining the quality, if the work process is properly managed in order for the resources to be input continuously. Time management methods such as the Bar Chart, CPM and LOB are not appropriate, due to the difficulties involved in the diagraming of repetitive works and applying them to the project. The Tact method also has difficulties in maintaining a constant work flow and needs significant effort and cooperation from the subcontractors to allocate the resources consistently. Partitioning, base works for finishing, floor mortar plastering and the final finishing work are done sequentially in residential buildings projects, and there are many repetitive activities which differ in terms of the work method, work area and productivity. If these repetitive activities are synchronized or converged toward the last work area, the goal of process management can be achieved effectively. Therefore, a process planning method for the finishing works of residential building projects is proposed, which takes into consideration elements, such as the sequential relation between the activities in each housing unit and classification of repetitive works in terms of their management method, work area and production rate, for the continuous input of resources into the housing units.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.23 no.3
• /
• pp.1-8
• /
• 2019

Steel elevator pit was developed for the purpose of minimizing the excavation, simplifying the construction of the frame and economical efficiency by improving the problems that occurred in the existing reinforced concrete. It is common to apply conventional RC method through excavation to underground structures such as underground floor collector well and elevator pit. In recent years, the use of steel collector well and steel elevator pits to reduce construction costs by minimizing the materials of steel and concrete has been continuously increasing. The steel elevator pit is an underground structure and then the performance of the welding part and the structure system is important. Specimen with only steel plate and concrete without studs could support the load more than 3 times than the specimen with deck only. Therefore, even if there is no stud, the deck (steel plate) rib is formed and the effect of restraining the steel plate and the concrete during the bending action can be expected. However, since sudden fracture in the elevator pit may occur, stud bolt arrangement is necessary for the composite effect of steel plate and concrete. It is expected that the bending strength can be expected to increase by about 15% or more depending with and without stud bolts.

• Korean Journal of Construction Engineering and Management
• /
• v.3 no.4 s.12
• /
• pp.93-103
• /
• 2002

The reinforcement concrete work is the work affected by structural safety, durability, and schedule with form work. The domestic reinforcement concrete works have mainly worked the process of re-barfabrication/assembly on site. Finally it have low productivity. Then this paper analyzed waste factors and the process of re-bar fabrication/assembly on site for the productivity improvement and value-added productivity improvement. Waste factor analysis aims at maximizing value-added by the value analysis of re-bar fabrication and assembly on site. Finally, Value-AddingActivity(VAA)ismuchlessthan non-value adding activity. Especially, Non-Value-Adding Activity(NVAA) generates waste such as the activity steps, labors, equipments, materials, time, and soon. And it was non-flow production, over production, and analyzed into having to shift value. This paper aimsat maximizing value-addingactivity and minimizingnon value-addingactivity through waste factor analysis in process for the improvement of value added productivity.

• Explosives and Blasting
• /
• v.30 no.1
• /
• pp.17-28
• /
• 2012

Building demolitions at urban area make some inconvenience to neighborhood through generating noises, ground vibrations, and dusts. For this reason, various methods to control such environmental impacts have been being designed and practiced. Among the methods, the use of explosive demolition is rapidly increasing because it can minimize the inconveniency as well as decrease the working time and cost. In this respect, the old Sung-Nam city hall, which was a Rahmen structure comprised of beams, slabs and columns, was decided to be demolished by explosive demolition. This paper shows that explosive demolition can be the most suitable way of removing old buildings eco-friendly, safely, and economically by showing the observation results obtained from the actual demolition operation for the Sung-Nam city hall.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.18 no.1
• /
• pp.1-12
• /
• 2016

When utilizing a Tunnel Boring Machine (TBM) for tunnelling work, unexpected ground conditions can be encountered that are not predicted in the design stage. These include fractured zones or mixed ground conditions that are likely to reduce the stability of TBM excavation, and result in considerable economic losses such as construction delays or increases in costs. Minimizing these potential risks during tunnel construction is therefore a crucial issue in any mechanized tunneling project. This paper proposed the potential risk events that may occur due to risky ground conditions. A resistivity survey is utilized to predict the risky ground conditions ahead of the tunnel face during construction. The potential risk events are then evaluated based on their occurrence probability and impact. A TBM risk management system that can suggest proper solution methods (measures) for potential risk events is also developed. Multi-Criterion Decision Making (MCDM) is utilized to determine the optimal solution method (optimal measure) to handle risk events. Lastly, an actual construction site, at which there was a risk event during Earth Pressure-Balance (EPB) Shield TBM construction, is analyzed to verify the efficacy of the proposed system.

• Korean Journal of Construction Engineering and Management
• /
• v.6 no.5 s.27
• /
• pp.89-101
• /
• 2005

The early phase of construction projects, communication among the related participants has great influence on the further transaction of the projects. However, important decision making are made by the experience of the field managers in practice without the method for systematic analysis. For example, in building construction project, selection process for construction method has been executed by decision making of some architects dependent on their experience. As a result, there have been frequent construction method alterations during the construction process and delay of duration, addition of cost, etc have followed accordingly. The main reasons of such a mal-functional transaction are due to the absent of the reasonal procedure of decision making reflecting the characteristics of construction project. Therefore, there is a need for an supporting tool and production design for the selection of rational construction method. The objective of this study is to propose production design process and decision making model in relation to various influent factors at the early phase of construction projects. To achieve these objectives, this study 1)analyzes the prior theory about production design, 2)we have studied about selection process for optimal construction method through constraint analysis in structural works, 3)performs a case study to embody the problems of the production design, and 4)proposes a cooperative committee model for supporting production design by analyzing the results of case study and interviewing experts. It is anticipated that the effective tool of proposed model would be able to improve communication among the related participants and systematically accumulate data that might be used in similar construction projects.

• Korean Journal of Construction Engineering and Management
• /
• v.24 no.3
• /
• pp.12-19
• /
• 2023

In the case of the construction industry, the relationship between process and cost should be appropriately distributed so that the finished product can be delivered at the minimum fee within the construction period. At that time, it should be considered the size of the bridge, the construction method, the environment and production capacity of the factory, and the transport distance. However, due to various reasons that occur during the construction period, problems such as construction delay, construction cost increase, and quality and reliability degradation occur. Therefore, a systematic and scientific construction technique and process management technology are needed to break away from the conventional method. The prefab(Pre-Fabrication) is a representative OSC (Off-Site Construction) method manufactured in a factory and constructed onsite. This study develops a resource and process plan optimization system for the process management of the Nodular girder, a prefab bridge girder. A simulation algorithm develops to automatically test various variables in the personnel equipment mobilization plan to derive the optimal value. And, the algorithm was applied to the Paju-Pocheon Expressway Construction (Section 3) Dohwa 4 Bridge under construction, and the results compare. Based on construction work standard product calculation, actual input manpower, equipment type, and quantity were applied to the Activity Card, and the amount of work by quantity counting, resource planning, and resource requirements was reflected. In the future, we plan to improve the accuracy of the program by applying forecasting techniques including various field data.

• Journal of Korean Society of Steel Construction
• /
• v.21 no.5
• /
• pp.545-552
• /
• 2009

An experimental study was performed on the yLRC composite column. Its external surface was manufactured with y-shape steel sheets and L-shape steel angles, and concrete was poured inside in the field. This composite column has improved the section capacity due to the composite action of steel and concrete, and provides good efficiency in reducing the terms of construction works because of its abridged formworks. The stub column specimens (three small and three large specimens) were tested through concentrical axial loading, and the effect of the width-to-thickness ratio of the steel angle on the column axial strength was examined. The axial strength and behavior of the composite columns were analyzed, and a formula for predicting the axial load capacity was proposed.