• Journal of KIBIM
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• v.11 no.4
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• pp.10-19
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• 2021

In the evaluation for ordering BIM-based projects (Design Build) of Korean National Railway, criteria of BIM-based smart construction technology are assessed. Unlike the existing assessment criteria, performance resources and detailed assessment guidelines have been added by this research. The purpose of this study is to propose qualification assessment standards according to specific guidelines when evaluating on the phase of bidding for BIM-based projects. In the study, an improved evaluation standard (draft) was arranged based on two consultation meetings and surveys of related companies, applied to existing projects with the companies that won the bid, and validated. As more specific and added criteria compared to the existing standards, it could reduce the difficulty of evaluation for BIM capability and lay the foundation for railway BIM-based project management.

• Structural Monitoring and Maintenance
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• v.5 no.1
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• pp.67-78
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• 2018

The stability of cutting slope influences the safety of railway operation, and how to identify the stability of the slope quickly and determine the rational monitoring plan is a pressing problem at present. In this study, the attribute recognition model of risk assessment for high cutting slope stability in the heavy haul railway is established based on attribute mathematics theory, followed by the consequent monitoring scheme design. Firstly, based on comprehensive analysis on the risk factors of heavy haul railway loess slope, collapsibility, tectonic feature, slope shape, rainfall, vegetation conditions, train speed are selected as the indexes of the risk assessment, and the grading criteria of each index is established. Meanwhile, the weights of the assessment indexes are determined by AHP judgment matrix. Secondly, The attribute measurement functions are given to compute attribute measurement of single index and synthetic attribute, and the attribute recognition model was used to assess the risk of a typical heavy haul railway loess slope, Finally, according to the risk assessment results, the monitoring content and method of this loess slope were determined to avoid geological disasters and ensure the security of the railway infrastructure. This attribute identification- risk assessment- monitoring design mode could provide an effective way for the risk assessment and control of heavy haul railway in the loess plateau.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.427-436
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• 2009

This paper introduced Railway Network Design Problem (RNDP) to provide priority decisions on high-speed railway investment scenarios defined by various network segments and train systems. The RNDP optimizes the objective functions of minimize total travel time. Results show that the priority of high-speed railway investment is found to be East-west, West-coast, and South-coast line respectively. An entirely new line built with 400km/h is found to be the best alternative to East-west line. Regarding West-coast and South-coast line, the combined alternative of upgrading Geolla and Kyeonjon line with 200km/h and building a new line with 400km/h and 350km/h for remains of each line is the best.

• Journal of the Korean Society for Railway
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• v.20 no.4
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• pp.550-557
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• 2017

Owing to the established international standards for reliability and safety management of railways and the third-part conformity assessment implementation, quantitative risk assessment focusing on communication system related to railway safety has being implemented. The quantitative risk assessment starts from the establishment of quantitative RAMS requirements; the risk has to be maintained under an acceptable safety level. This paper introduces the risk assessment process based on international standards ; risk assessment was conducted using failure data for railway facilities for about 5.5 years. In addition, based on the results, a scientific risk management method for railway facilities is suggested.

• Journal of the Korean Society for Railway
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• v.16 no.4
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• pp.298-304
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• 2013

This paper systematically analyzes the dynamic effects of structure approaches which are expected to have direct effects on train loads - according to the train's acceleration as the area under consideration is located in a section where acceleration of high speed railway vehicles and the train's operating speed happens. In addition, through an examination of the dynamic train loads, dynamic behavioral characteristics of embedded structures and structure approaches were analyzed and a numerical analysis has been carried out in order to evaluate the performance of track subgrade and the safety of the structure. As a result, we reach the conclusion that the dynamic effects by train loads is low, but somewhat high vertical acceleration occurs.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.1
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• pp.71-76
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• 2017

In BIM design, the construction and use of a library are very important. Since the existing contents can be re-used, the design can be executed more effectively and efficiently. Unlike the construction, the civil engineering, in particular, the railroad sees an inappropriate development and standardization of libraries. Thus, this study aims to develop and standardize the 3D object library in the railroad facility. We first gather and analyze the railroad facility breakdown structure and relevant drawings. We then match the items of analyzed standard drawings and the breakdown structure items. It was reviewed whether the library was required according to all items, and if required, it was reviewed what software was proper. Available software were found to be Civil 3D, Revit, etc. Based on this analysis, we will design the attribute items and specifications of the 3D railroad infrastructure library, as well as construct the library thereof.

• Structural Monitoring and Maintenance
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• v.1 no.1
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• pp.131-157
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• 2014

Special track systems used to divert a train to other directions or other tracks are generally called 'railway turnout'. A traditional turnout system consists of steel rails, switches, crossings, steel plates, fasteners, screw spikes, timber bearers, ballast and formation. The wheel rail contact over the crossing transfer zone has a dip-like shape and can often cause detrimental impact loads on the railway track and its components. The large impact also emits disturbing noises (either impact or ground-borne noise) to railway neighbors. In a brown-field railway track where an existing aged infrastructure requires renewal or maintenance, some physical constraints and construction complexities may dominate the choice of track forms or certain components. With the difficulty to seek for high-quality timbers with dimensional stability, a methodology to replace aged timber bearers in harsh dynamic environments is to adopt an alternative material that could mimic responses and characteristics of timber in both static and dynamic loading conditions. A critical review has suggested an application of an alternative material called fibre-reinforced foamed urethane (FFU). The full-scale capacity design makes use of its comparable engineering characteristics to timber, high-impact attenuation, high damping property, and a longer service life. A field trial to investigate in-situ behaviours of a turnout grillage system using an alternative material, 'fibre-reinforced foamed urethane (FFU)' bearers, has been carried out at a complex turnout junction under heavy mixed traffics at Hornsby, New South Wales, Australia. The turnout junction was renewed using the FFU bearers altogether with new special track components. Influences of the FFU bearers on track geometry (recorded by track inspection vehicle 'AK Car'), track settlement (based on survey data), track dynamics, and acoustic characteristics have been measured. Operational train pass-by measurements have been analysed to evaluate the effectiveness of the replacement methodology. Comparative studies show that the use of FFU bearers generates higher rail and sleeper accelerations but the damping capacity of the FFU help suppress vibration transferring onto other track components. The survey data analysis suggests a small vertical settlement and negligible lateral movement of the turnout system. The static and dynamic behaviours of FFU bearers appear to equate that of natural timber but its service life is superior.

• Journal of the Korean Society for Railway
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• v.16 no.3
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• pp.202-206
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• 2013

A submerged floating railway is an innovative tunnel infrastructure passing through the deep sea independent of wave and wind so that high speed trains can run on it. It doesn't depend on water depth and is cost effective due to modular construction on land. The construction period can be reduced drastically. This paper introduces the concept design of a submerged floating railway, and for securing safety, proposes a method to analyze the structural behavior of the body in case of collision with a submarine. The theory of a beam with an elastic foundation was used to calculate the equivalent mass of the body so that the perfect elastic collision could be applied to calculate the collision velocity. The maximum deformation and bending moment was analyzed based on energy conservation. To verify the results, a collision analysis using a finite element analysis code was made. Comparing the results confirmed that this simplified collision analysis method gives enough accurate deformation and bending moment to be used for actual estimation in the initial design stage.

• Journal of KIBIM
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• v.12 no.4
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• pp.116-127
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• 2022

Building Information Modeling, which was applied mainly in the construction sector, is expanding to the road sector, and the government recently recommends preparing individual application guidelines considering the characteristics of detailed fields such as railways, ports, and complexes through BIM implementation guidelines. Compared to general construction projects, a lot of the works such as signals, electricity, and power, and the railway BIM 2030 roadmap has been presented to apply BIM to railway construction projects that require business consultation and work environment review with various local governments, and pilot projects are in operation. Unlike a general building, in which the construction begins after the detailed design is completed, in the railway project, the detailed design of other works proceeds along with the roadbed construction. Because construction and design work together, railways need to coordinate detailed engineering interfaces such as trajectories, signals, and power, and the application of BIM in design interface coordination has the advantage of maximizing the effectiveness of pre-review. Overseas railway construction projects actively used BIM to adjust design interfaces and had a collaboration process to modify BIM models and create construction details from the revised models through regular meetings with suppliers. Therefore, this study aims to derive the factors necessary for establishing a BIM collaboration environment based on a survey of practitioners as a preliminary step for establishing the BIM collaboration process of the railway construction project.

• Journal of Korean Society of Transportation
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• v.32 no.6
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• pp.589-599
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• 2014

This paper analyzes the forecasting errors of traffic volumes by comparing forecasted volumes for the opening year with the observed ones in the years after the urban railway construction in the metropolitan areas. The result shows that the average inaccuracy of traffic volumes for each station was estimated at around 7.27. Based on the confirmed factors of demand estimation errors, this study seeks for an alternative method to reduce estimation errors in feasibility studies. It is noted that there is a tendency that the inaccuracy varies by regions and the longer construction period or the shorter station spacing is, the overestimation increases. If urban railway projects are proceeded as planed, therefore, the level of the inaccuracy for traffic volume forecast will be decreased. In addition, thanks to the theoretical progress, recent estimation results show higher accuracy than before. In that sense, when we introduce the new railway line, it is necessary to make an accurate and realistic demand forecast based on actual outcomes and tendency of the previous estimation. The limitation of our study is that we only cover the errors of the initial period, the opening year and deal with the exogenous variables. Further research including other variables which might be considered to cause overestimation or errors would be needed for increasing the estimation accuracy of traffic volumes.