• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.396-400
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• 2007

Various ways of automated guideway transit construction are being planned recently owing to the policies of the national government and local municipalities as well as increasing investment from the private sector. Particularly, the increase in the private investment is increasing greatly in SOC (Social Overhead Cost). This trend of promoting private sector investment must be conducted on the basis of a thorough analysis of the economic feasibility of the project from the government and construction companies in the private sector. In other words, an accurate cost analysis of initial investment cost (Construction cost), maintenance/repair cost, profit making through the operation of the concerned facilities, cost of dissolution, etc. in terms of the life cycle is very much in need. Nevertheless, the analysis of uncertainty factors and its probabilistic theory are in need of development so that they can be used in the analysis of the economic feasibility of a construction project. First of all, the actual studies on maintenance/repair cost of automated guideway transit are scarce as of yet, prohibiting an accurate computation of the cost and its economic analysis. Accordingly, this study focused on the uncertainty analysis of the economic feasibility for civil engineering structures among automated guideway transit construction projects based on the rapidly increasing investment on such structures from the private sector. For this research purpose, a cost classification system for the automated guideway transit is proposed, first of all, and the data On the cost cycle of the civil structure facilities and their unit cost are collected and analyzed. Then, the uncertainty in the cost is analyzed from the perspective of LCC. In consideration of the current status with almost no. studies on maintenance/repair of such facilities, it is expected that the cost classification system and the uncertainty analysis technique proposed in this study will greatly enhance LCC analysis and economic feasibility studies for automated guideway transit projects in the future.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.6
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• pp.17-24
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• 2020

In this study, series of nonlinear seismic analysis were performed on a reinforced concrete intake tower surrounded by water. To consider the fluid effect around the structure, analysis models were composed using an added mass and CEL approach. At this time, the implicit method was used for the added mass model, and the explicit method was used for the fluid structure interaction model. The input motions were scaled to correspond to 500, 1000, and 2400 years return period of the same artificial earthquake. To estimate the counteractivity of the fluid coupled model, models without fluid effect were constructed and used as a reference. The material models of concrete and reinforcement were selected to consider the nonlinear behavior after yielding, and analysis were performed by ABAQUS. As results, in the acceleration response spectrum of the structure, it was found that the influence of the surrounding fluid reducing the peak frequency and magnitude corresponding to the fundamental frequency of the structure. However, the added mass model did not affect the peak value corresponding to the higher mode. The sectional moments were increased significantly in the case of the added mass model than those of the reference model. Especially, this amplification occurred largely for a small-sized earthquake response in which linear behavior is dominant. In the fluid structure interaction model, the sectional moment with a low frequency component amplifies compared to that of the reference model, but the sectional moment with a high requency component was not amplified. Based in these results, it was evaluated that the counteractivity of the additive mass model was greater than that of the fluid structure interaction model.

• Korean Journal of Construction Engineering and Management
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• v.10 no.4
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• pp.111-118
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• 2009

This study is to analyze the performance of SWH(Solar Water Heating) and GSHP(Ground Source Heat Pump) systems by evaluating their energy efficiency and LCC(Life Cycle Cost) as being applied to the OO hall as a selected building in the Army. The OO hall, used as bathrooms, dining rooms, accommodations and offices, has reinforced concrete structure system with three floors above the ground and one underground, and its total floor area is approximately 2,917$m^2$. Two energy simulations are conducted to predict the yearly cooling and heating energy of the selected building: One is for analysis of an air-conditioning energy consumption using the e-Quest program, and another is for two new-renewable energy facilities as a water heating source using the RETScreen. The installed capacity of two new-renewable energy facilities is determined according to the 5% level of total standard construction cost. As a briefly result, SWH system is more energy-effective than GSHP system. Considering the break-even point, it is expected that SWH can take only 3 years 11 months to pay for itself in savings while the investment of GSHP can be recovered in more than 16 years 6 months.

• Korean Journal of Construction Engineering and Management
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• v.13 no.4
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• pp.48-59
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• 2012

Gangform, compared to the traditional forms, is a systemized form which can reduce construction duration and cost by the advantage of using it repeatedly. However, transportation and climbing process of the Gangform is highly dependant on the performance of tower crane. Gangform climbing process takes one day out of six to seven days of a structural work cycle. Tower cranes can not be used in other lifting works when they lift the Gangform during the structural work cycle, causing the delay in the construction project. Numerous efforts and researches have been done in domestic and international industry to solve such limitations of Gangform climbing process. Especially, "A Study on the Development of Automatic Gangform Climbing System for Apartment Housing Construction"has suggested a conceptual model which can climb the Gangform system without a tower crane. In this paper, the technical and economical feasibilities of previously proposed Automatic Gangform climbing system are examined by evaluating its structural stability and lifting load reduction effect.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.1
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• pp.21-26
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• 2013

In recent study, infiltration analysis considering rainfall intensity is more economical and practical than existing analysis method. Revised construction slope design standard is also stated to full-fill infiltration analysis considering rainfall for practical stability review. Infiltration analysis considering rainfall for practical stability review. But, to infiltration analysis, the process is complicated by ground impermeability and rainfall intensity. In this study, we perform infiltration analysis to charge infiltration conditions, soil type and rainfall characteristics, for more pratical stability review. Using the result, we can suggest construable condition on the assumption that soil is saturated up to surface zone.

• Korean Journal of Environment and Ecology
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• v.23 no.4
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• pp.302-308
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• 2009

For the proper tree management of Taxus cuspidata, distributed in the High 1 Ski Slope construction area in Baekwoonsan, Jeungsun-gun, Kangwon-do, the growing states of 323 trees(including transplanted 57trees) are investigated. Tree height, rootcollar diameter, D.B.H., stem condition, apical shoot, dead branch, needle growth condition, 2-year-old needle loss, root condition, tree form are investigated. Taxus cuspidata are mainly growing at the sites, high elevated mountain ridge or slopes facing north. Growing states of Taxus cuspidata, distributed in Baekwoonsan are relatively better than those of Taxus cuspidata and Abies koreana at other subalpine zone in Korea. Damaged trees are mainly due to root-removal through transplanting, root-damages by raising the ground level and digging. Several methods of Taxus cuspidata conservation were suggested.

• Journal of the Korean Institute of Gas
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• v.12 no.3
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• pp.75-80
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• 2008

According to the Integrated Notice on City Gas Safety Management Standards, materials for bedding and foundation which are around the pipe should be sands or fine grade soil without large particle that is more than 19 mm size. However, sands are mostly used at gas pipeline construction sites and this causes a shortage of sands and an increase of construction costs. It even causes the disruption of natural environment. In order to improve the standards of backfill material, we have researched regulations in other countries and investigated the pipeline construction sites to survey the present state of backfilling. We also have studied what the bedding and foundation materials affect on buried gas pipelines. Lastly, we have suggested suitable materials for bedding and foundation besides sands. We are sure this paper help the government amend the Notice about backfill materials.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.547-552
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• 2022

In this study, shape-based track management by analyzing track irregularity was studied in terms of force-based track irregularity analysis by numerical analysis of wheel-rail interaction force using by the measured vertical irregularity. The effect of the vertical irregularity of the track due to the difference in track types on the wheel-rail interaction force and the track acceleration in the connecting section of the sleeper floating track and the direct fixation track on concrete bed were analyzed. As the results of this study, the measured vertical irregularity was directly affect the vertical wheel load (the wheel-rail interaction force) and the rail acceleration, and it has been demonstrated to change consistently. In this study, the adequacy and necessity of the force-based track irregularity analysis method was verified based on the wheel-rail interaction analysis using the the measured vertical irregularity.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.2
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• pp.103-108
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• 2007

A stress measurement method of structural member using piezoelectric property and electrostatic voltmeter is presented. The electric potentials of the surface of the piezoelectric element, which are proportional to the strain ${\varepsilon}$ on the structural member, are measured by an electrostatic voltmeter during load cycling. The stress ${\sigma}$ is calculated by this strain ${\varepsilon}$. Moreover, a stress distribution measurement tape which can be used for the stress distribution measurement along a specified line on the surface of structural member is developed, and the surface potential was measured by an electric static voltmeter of non-contact type. The applicability of the stress distribution measurement tape is examined through experiments using a notched specimen under cyclic loading. The measured distributions of x, y and xy are compared with those calculated by FEM analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.4 s.56
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• pp.107-115
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• 2009

The number of railway tunnel design is increasing recently compare to a great number of highway tunnel design which had increased with a lot of highway construction in the 70's and 80's. Therefore, there is more or less difference of time between highway tunnel and railway tunnel. In this paper, numerical analysis on two kinds of tunnels, such as two-forked road highway ventilation tunnel and double track railway tunnel with 4.3m of center line, in cases of with support materials condition and without support materials condition were conducted. Finally, stability of two kinds of tunnels were compared and analyzed through comparing of principal stresses and deviator stresses in the near base rock of tunnels using results of numerical analysis.