• Tunnel and Underground Space
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• v.20 no.1
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• pp.58-64
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• 2010

GLI model was verified to consider the interaction between a ground and a tunnel lining and to rationally reduce the ground load acting on the secondary lining(concrete lining) of a tunnel. In this study, the economy and the construction condition of tunnel concrete linings designed by a conventional frame model at Lot O of OO line were highly enhanced through a field design change using GLI model. For a few safe considerations, not only about 50% saving of reinforcing steel could reduce the material cost but also the wide space between bars could make it easy to pour concrete mix without voids. There was large saving effect of reinforcing steel for poor ground conditions because Terzaghi's load used in the conventional frame model produces too much high loads for those conditions.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• autumn
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• pp.465-468
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• 2003

It has taken a growing interest about environmental problems such as global warming and water pollution. Because of intensified environmental problems, it would be going on the research about environmental preservation and harmful factor reduction. Also, it makes ISO to show the quantitative data about LCA analysis. The research of LCA method in the domestic construction industry has advanced stealing from a national point of view. In this study, it would be possible to confirm the feasibility of a plan by LCA analysis. Moreover, the result of life cycle cost which deliberate the influence cost of environment in the steps of material production, construction, maintenance, and disposal has made to be 74,819,560,776 won in a plan and 78,979.469,602won in alternative. That is, it would analysis for a plan to reduce 4,159,908,826 won for alternative.

• Korean Journal of Construction Engineering and Management
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• v.7 no.1 s.29
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• pp.80-88
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• 2006

Construction graphical simulations usually do not reflect physical properties of construction equipment and material because there are restricted to the geometric model. The complete description of construction operations is difficult for graphical simulation without a physical modeling. The object of this research is to enhance the functionality of restricted simulation system to geometric model. And research is conducted to overcome the limitation of current construction graphical simulation system through the connection geometric model and physical model with the physical properties of construction equipment and material such as crane's cable oscillation. The motion equations for the oscillation of crane cable as a result of the trolley's movement and the boom's rotation were derived. The equations were solved through numerical analysis and the results were simulated visually. The realistic description with physical modeling of construction operations will contribute for ensuring preliminary against risks and improving constructability as well as the application of various fields.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.2
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• pp.297-305
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• 2016

This study aims to analyze characteristics of environmental load for the construction phase of PSC beam bridge based on Life Cycle Assessment. For detail computation of environmental load, the construction materials and energy consumption are derived from the BOQ, also connecting with environmental load by Korea LCI Database Information Network. The characteristic of environmental impact was analyzed by 25 cases and cut-off ratio was 80% to 94%. The result sorted by construction materials revealed that environmental load were 53.3% for ready-mixed concrete, 9.6% for wire rod, 7.8% for rebar, 6.8% for cement, 5.5% for plywood, and 5.2% for energy. Furthermore, the result of environmental impact revealed that 45.5% for global warming, 30.4% for abiotic resources depletion, 10.5% for human toxicity, and 8.9% for photochemical oxidant creation. In the future, we can make a decision considering environmental load based on LCA at design phase.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.377-386
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• 2015

The helical pile is a manufactured steel pile consisting of one or more helix-shaped bearing plates affixed to a central shaft. This pile is installed by rotating the shaft into the ground to support structural loads. Advantages of the helical pile are no need for boring or grout process, and ability to install a pile foundation with relatively light devices. In this study, an optimized design method for helical piles is proposed to minimize the material cost with consideration of the load bearing capacity obtained by the cylindrical shear method. The harmony search meta-heuristic algorithm was adopted for optimization process. The optimized design was verified by comparing with the 2009 International building code. It is noted that the optimization for the configuration of helical piles along with material cost proves to be an out-performed tool in designing helical pile foundation with economic feasibility.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.2
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• pp.144-152
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• 2011

The existing underground trenchless methods use reinforcing rod in steel tube to obtain structural stiffness. However, there are some problems such as inconvenience of work and expensive material fee which are resulted from limited working space and reinforcing work. To resolve these problems, a new trenchless method, namely P.S.T method (Prestressed Segment Tunnel Method), is developed which uses joint to connect the steel segment and form erection structure in underground construction. Further, installing strands for prestressing. In order to evaluate the flexural capacity of the P.S.T method structure, experiment was conducted. The parameters considered in the experiment are the span-to-depth ratio, diameter of steel tube at corner, prestressing force and welding of joint. Altogether examining the flexural behavior, the effect of deflection in structure according to different parameters has also been analysised.

• Korean Journal of Construction Engineering and Management
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• v.6 no.1 s.23
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• pp.140-150
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• 2005

Recently, quality inspection and defect management have been considered as one of the major issues for increasing customer satisfaction and corporate image in domestic construction industry. However, the quality inspection and defect management have not been performed systematically because of insufficient field managers, the excessive amount of documents, complicated work process and difficulty in communicating construction information. Therefore, the field manager could not perform the quality inspection and defect management work in time as well as the reliability of recorded quality and defect data was decreased. The primary objective of this study is to propose a quality inspection and defect management system using information technology which enables field managers to efficiently gather the information of defection in apartment housing. It is anticipated that the effective use of the proposed system would be able to imp개ve communication among the related participants and systematically accumulate data that might be used in similar construction projects.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.4
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• pp.356-362
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• 2016

Light-weight concrete uses forming agents for reducing weight and high heat insulation property. However, the forming agents make problems of decreased volume and compressive strength of the concrete. This research aims to having weight-reduction and securing heat insulation property using recycled wasted form polyurethane without any forming agents. A small quantity of admixture used for constructability and avoiding material segregation. We picked admixtures from two different companies which shows evenly dispersed of wasted form polyurethane. This research conducts a study on the effect of mixing ratio of admixture on the light-weight concrete used wasted form polyurethane. As a result of the test, increased mixing ratio of the admixtures results reduced fluidity of concrete. On the other hand, percentage of moisture content and compressive strength are increased slightly. Combustibility performance and sound insulation performance are also secured, as well.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.5
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• pp.3542-3547
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• 2015

There is commonly used the full depth excavation method of sewer pipeline maintenance in Korea. This induces couple of technical and social problems like increase of construction cost and time for excavation and backfill, increase of public complains and delay of traffic, and so force. In order to overcome these problems, lots of laboratory tests were carried out for sewer pipeline of maintenance materials with trenchless methods. The testing materials are liquid and hardened polyurethane, and polyurethane CIPP. The lab tests were followed by Korean Standard. There are no side effects, like harmless to the human body and air pollution with stink. Judging from the limited test results, all the items tested were satisfied the KS criteria.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.54-60
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• 2016

Building information modeling (BIM) has the advantage of having been utilized for various scenarios through a single model. Although extracting 2D drawings from BIM is one of the advantages, there are many difficulties when utilized in practical work. Architectural detail drawings are an important factor for expressing interior finishing materials and complicated construction methods, as well as for cost estimations. However, creating detail drawings does not have a standard, and each design company establishes its own detail drawings, so it is hard to share or exchange information in the construction industry. Therefore, this study suggests a systemized method for making detail drawings, and explains how it can be utilized as back data for quantity take-off and construction expenses linked with BIM libraries.