• Explosives and Blasting
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• v.24 no.1
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• pp.39-48
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• 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 Korean Recycled Construction Resources Institute
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• v.7 no.2
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• pp.78-83
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• 2012

Steel fiber reinforced shotcrete in tunneling construction has some problems in terms of constructability, durability and lots of rebound wastage. In order to resolve these problems, this pater proposes polyamide fiber reinforced shotcrete technology. And this paper presents the results of experimental construction of the polyamide fiber reinforced shotcrete technology. The results of the study are as follows. 1. The polyamide fiber reinforced shotcrete suggested in this paper shows outstanding mechanical performance that meets various Korean tunnel construction design criteria. 2. In addition, the results of experimental constructions show that the polyamide fiber reinforced shotcrete creates less rebound and wasted product than the steel fiber reinforced shotcrete. Based on the above results, it is concluded that the polyamide fiber reinforced shotcrete technology can be used as economical and environmentally friendly construction of tunnel.

• Journal of the Korean Geosynthetics Society
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• v.13 no.4
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• pp.11-20
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• 2014

The behaviors and stability of reinforced subgrade with short geogrid were examined and evaluated during construction. First of all, analytical approach for the minimum length of geogrid was performed to guarantee stability during construction loading state. Secondly, the economic aspects for reinforced subgrade were compared with between domestic standards applying with 0.7 H reinforcement length and new way to mix short and long reinforcement. Full scale railroad subgrade was constructed with the size of 5 m high, 6m wide, and 20m long to verify the stability of the subgrade with the length of 0.3 H, 0.35 H, 0.4 H reinforcement. Total 51 sensors were installed to measure settlement, bulging, and the change of stress of the subgrade. It is concluded that the reinforced subgrade with short(0.35H, 35% of height) geogrid had stability within allowable level of deformation and stress increment during construction.

• Tunnel and Underground Space
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• v.20 no.6
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• pp.434-445
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• 2010

Underground compressed air energy storage (CAES) system in a lined rock cavern is considered one of the promising large-scale energy storage technologies. In this study, permeabilities of concrete lining block and its construction joint, which are the major components of an air tightness system of the undeground CAES, were measured from a model experiment. From the experiment, it was found that intrinsic permeability of construction joint was larger than that of concrete block by the order scale of $10^1{\sim}10^4$, so that it would be very important to control the quality of construction joints in-situ in order to secure air tightness of storage system. And the permeability of construction joint could be decreased as low as that of the concrete block by pasting an acryl-type adhesive on bonding surfaces. Higher degrees of water saturation of the concrete block resulted in the lower permeability, which is more preferable in the viewpoint of air tightness of storage cavern.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.283-291
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• 2011

The purpose of this study was to identify the public's preferences of different types of debris barriers and the impacts of construction materials, design, size, and planting on landscape preferences. On-site survey was carried out in Mt. Palgong during on December, 2009 and a total 122 visitors' data were analyzed. A total of 82 students Yeungnam and Donga University were also questioned in the classes during on December, 2009. Survey results showed that the debris barrier constructed with natural materials such as stone were more preferred and the level of planting around the debris barrier impacted most on the landscape preferences. The results imply that the importance of eco-friendly construction materials and methods has been increased in term of not only environmental conservation but also people's preferences. Therefore, the factors for enhancing landscape of debris barrier should be considered synthetically in terms of construction material, design, size, and planting level.

• Journal of the Korea Institute of Building Construction
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• v.17 no.4
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• pp.361-367
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• 2017

The success of building construction projects is dependent on the cooperative ability of site organization members, which related with an organizational communication level. Therefore, the purpose of this study is to study the influence of site organization's communication on the performance of building construction projects. The results of this research are revealed that the communication quality has positive influence on the performance of building construction projects, and the information sharing has negative influence based on the results of the multiple regression analysis. So it needed to improve the performance in building construction projects that the information is shared with a normal level. the communication quality should be also raised in the project site organization. This study is expected to help to structure the site organizational management system in the building construction projects.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.05a
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• pp.47-48
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• 2019

Currently, the government has made a lot of efforts to improve construction productivity but there are few studies which measure between safety perception level and productivity in the South Korean construction industry. Therefore, the objective of this study is to analyze correlation between safety perception level of domestic construction companies and construction productivity. To achieve the objective, first, the concept of safety perception level was defined. Second, the safety perception level and construction productivity were investigated in the case projects. Third, correlation analysis was conducted between safety perception level and productivity. As a result, it was concluded that a high level of safety perception of executive and manager would increase construction productivity. In addition, To improve the safety perception level in the construction company, it is suggested that the provision safety resources for managements and the equal communication system between workers and managements and the development safety education tools considering the worker's experience. In the future, these findings can be utilized to develop future evaluation tools for a safety perception level in domestic construction company.

• Journal of the Korea Institute of Building Construction
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• v.19 no.1
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• pp.87-93
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• 2019

In recent years, BIM services have been used in many construction projects. However, they are raising the question that there are many differences between what was initially proposed and what was actually done. In the IT sector, a method called as SLA is used to perform an assessment of the services delivered to the IT service project. In this respect, this study intends to introduce this method into building construction projects to use BIM in order to propose evaluation criteria and the evaluation process for SLA-based BIM service. The BIM service assessment process and criteria presented are judged to help introduce consistent and systematic BIM services in construction projects.

• Journal of Korean Society of Transportation
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• v.23 no.8 s.86
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• pp.129-138
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• 2005

Since Successive introduction of BMS(Bus Management System) into the local governments has been able to collect each bus data on the road and valuate the bus operation by the quantitative index not qualitative index. we need a study on punctuality index for evaluation of service level for bus operation using bus location information. We propose punctuality index for bus operation using time-space diagram and valuate the index by application to real bus data.

• Journal of the Korea Concrete Institute
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• v.28 no.4
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• pp.481-488
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• 2016

Concrete member has been subjected to dead and live loads in use, and the induced stress can affect not only structural but also durability behavior. In mass concrete construction, construction joint are required, however cold joint usually occur due to poor surface treatment and delayed concrete placing. The concrete with joint is vulnerable to both shear stress and chloride ingress. This paper presents a quantitative evaluation of cold joint and loading conditions on chloride diffusion behavior. With increasing tensile stress from 30% to 60%, chloride diffusion coefficient gradually increases, which shows no significant difference from result in the sound concrete. However chloride diffusion coefficient under 30% level of compressive stress significantly increases by 1.70 times compared with normal condition. Special attention should be paid for the enlarged diffusion behavior cold joint concrete under compressive stress.