• Tunnel and Underground Space
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• v.7 no.1
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• pp.51-57
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• 1997

This study provides the results of two different blasting methods applied at the H Telcon construction site in Yeon-dong, Cheju Island. One is the traditional blasting method without bottom-hole stemming and the other with bottom-hole stemming using the materials such as sand, polystyrene and sawdust in 5~10 cm lengths. The effect of these materials on vibration level was studied. Assuming that safety criterion of vibration level be 0.5cm/set, 95% confidence limit line of measured data shows that maximum charge weight per delay could be increased in the following order; traditional methed, polystyrene stemming, sand stemming, sawdust stemming.

• Journal of Construction Engineering and Project Management
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• v.5 no.3
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• pp.18-28
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• 2015

Bidding and contract systems are used for public construction projects to select contractors following fair competition principles and to execute national budgets effectively. Many challenges have arisen due to a lack of transparency and fairness and because bidding practices have been luck-based. Few comprehensive or comparative analyses have been conducted on the performance and limitations of bidding and contract systems, and empirical analyses designed to improve policies on and the practice of such systems are lacking. This study empirically analyzed current bidding and contract systems to seek ways of improving them. The study proposes several alternatives to resolve the problems with and irrationalities of the current system: 1) improving bidding and selection systems by changing them from a luck-based price competition into a technical merit- and value-based competition; 2) improving the assessment criteria to meet the current market level of bid and winning prices; 3) adjusting contractual responsibilities and sharing structures to meet the current trend; and 4) strengthening the competitiveness and expanding the social responsibility-based procurement systems of construction companies.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.401-404
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• 2002

To manage a construction project efficiently, it is essential to ensure the practical usage in construction management. The purpose of this study is to develop a practical model, which will increase the efficiency of management. The followings are the method of this study: (1) Establishing a breakdown structure based on integration of CBS and WBS which is well acquainted (2) Developing and systemizing managerial standards and processes on such activities as calculating and marking progress rates & schedule, summarizing cost by activities level, making out project analysis reports. This study shall contribute to raising the efficiency in construction management after being verified in a pilot project and being developed into construction management system.

• Journal of the Korean Society of Safety
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• v.30 no.3
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• pp.73-79
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• 2015

In consideration of current circumstances which management activities for safety performance on construction sites are mostly controlled by safety personnel, it is necessary to maintain qualified safety personnel those who are experienced and have adequate ability. This is a major factor in order to prevent any of work related incident in the construction site. However, the existing standard which enforces certain number of safety personnel in the construction site aligning with respective contract amount could lead to difficulties for proactive safety management. So, it is required to get improvement on the existing standard. In nominating the proper number of safety personnel, it would be more efficient to consider the level of risk for characteristic of work itself and the total number of manpower mobilized in respective construction work, rather than to follow the existing standard of manpower ratio as per the contract amount. Hence, this study aims to propose several plans which enable to improve the existing standard for assignment of safety personnel on construction sites.

• Journal of the Korean Society of Safety
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• v.28 no.5
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• pp.35-40
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• 2013

Recently reclamation land is largely developed to utilize the land according to economic growth. The soil of landfill is soft, low shear strength, which makes it difficult to use the equipment. A large movement is occurred on the utility tunnel under construction. The inclined land with high water level and underground facilities are widely distributed and the excess pore water pressure may occur under construction similarly to this study. Some different conditions are made to design result, such as 4m of soil piling near the construction area, heavy rainfall during 2nd excavation that may cause flow liquefaction. To analyze the cause of transverse lateral movement, Three dimensional analysis are performed to four load cases, which is original design condition, flow liquefaction by heavy rainfall, unsymmetric lateral soil pressure, and both of them simultaneously. Ten steps of full construction stage, 1st excavation for utility tunnel, construction of utility tunnel, 1st refill, piling soil from 1m to 4 m, 2nd excavation for drainage culvert, liquefaction around the utility tunnel, construction of drainage culvert and 2nd refill, are take into account to investigate the cause of movement.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.53-54
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• 2012

This study is aimed at utilizing LCA processor with BIM LOD, eliciting the problems of the existing environmental assessment by constructing the database for environmental values of green buildings. For these objects, environmental load database of BIM construction material and evaluation process are presented, after matching BIM family based environmental load database which is available during evaluation stage, input-output tables and Korea LCI database to standard item code of public procurement service. It is a important factor in environmental assessment of building to develop database unit of standard item code for BIM and construction material. Thus, the results of this study are expected to provide basic data for improving effectiveness of construction through BIM based environmental load evaluation database. Furthermore, the provided environmental load database unit for construction material is considered to be available as basic information for BIM study by suggesting a processor connecting BIM with LCA and along with this, continuous examination on the connection process is needed.

• Explosives and Blasting
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• v.22 no.3
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• pp.43-55
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• 2004

Use term of tower style construction exceeds recently. Accordingly, according to construction safety diagnosis result, achieve removal or Improvement construction. But when work removal, must shorten shut down time. Therefore, removal method of construction to use blasting demolition of construction is very profitable. Influence construction and equipment by blasting vibration and occurrence vibration caused by felling impact. Is using disadvantageous machine removal method of construction by and economic performance by effect of such vibartion. Therefore, this research studied techniques to forecast vibartion level happened at blasting demolition and vibration reduction techniques by use a scaled model test.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.9
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• pp.797-804
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• 2010

In case of the construction equipment using by the military camp, such equipments are different from those equipments using at general construction site, of which muffler(silencer) is attached at the passenger seat side, since such equipments are obsoleted, it is great part that a considerably loud noises are continuously diffusing. When working, such noise can be influenced a lot of effects to those working soldiers nearby the equipment, and though it is really terrible loud noise as much as can arise a civil complaints by neighboring civilians, but because its specialty of the military, it is real state that there are many difficulties in establishing an effective soundproof countermeasure due to study shortage and lack of the relevant material regarding to military construction equipment. Accordingly, this study has ever grasped the characteristics of noise by its each frequencies and by distances about those 9 kinds of construction equipments using chiefly by the military camp. As the result, it was known that the military construction equipment is generating the loud noise which can influence bad effect to the workers, and such high sound pressure level of low frequency band can harm even to far distance.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.04a
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• pp.113-118
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• 2007

Now a performance process of Demolition works is 'Before-Removal & After-Classification' method in Korea. This method is short of demolition time, but construction wastes contained substances lower recycling rate of construction, raise expenses of reclamation & treatment. Then the government has decided upon a positive 'Before-Classification & After-Removal' method, and substantially raise a recycling rate of construction wastes. Therefore, this study makes an investigation into state of internal and external demolition field through evaluating technological level, we make a proposal of dismantling method from there. Also, we put dismantling to the test in an apartment by proposed work process. As the result, it made a term of works increased for removing interior material. To solve this problem, we need to develop tools and methods of construction that can remove efficiently. From now on, we continuously need to study a breakdown system of dismantling, analysis of dismantling process and general system by inspecting entire demolition process. And we have to study details for making a specific thesis of method of removing interior material which was based on developing a suitable partial demolition machine and dismantling works.

• Journal of the Korea Safety Management & Science
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• v.16 no.4
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• pp.31-40
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• 2014

While Korea had achieved radical growth of construction industry, it also had accumulated problems in material, human and economical loss due to its low quality of safety level. Therefore, not only enterprises but also the nation is putting in a great deal of efforts for construction safety. However, its effect is not satisfiable. This research aims for change of construction cite by introduction of professional Safety Patrol Management System(SPMS) and consideration of its necessity. To consideration of its necessity, we compared and anaylzed average numbers of indicated dangers and safety accident incidences in each construction cites and we researched changes in worker's safety sense. It will establish the suitable design standards and suggest the basic database for estimating disaster and accident ratio.