• Smart Structures and Systems
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• v.30 no.5
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• pp.479-500
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• 2022

In this study, a new type of isolation bearing is proposed by combining S-shaped steel plate dampers (SSDs) with a spherical steel bearing, and the seismic control effect of a five-span standard high-speed railway bridge is investigated. The advantages of the proposed S-shaped steel damping friction bearing (SSDFB) are that it cannot only lengthen the structural periods, dissipate the seismic energy, but also prevent bridge unseating due to the restraint effectiveness of SSDs in the large relative displacements between the girders and piers. This study first presents a detailed description and working principle of the SSDFB. Then, mechanical modeling of the SSDFB was derived to fundamentally define its cyclic behavior and obtain key mechanical parameters. The numerical model of the SSDFB's critical component SSD was verified by comparing it with the experimental results. After that, parameter studies of the dimensions and number of SSDs, the friction coefficient, and the gap length of the SSDFBs were conducted. Finally, the longitudinal seismic responses of the bridge with SSDFBs were compared with the bridge with spherical bearing and spherical bearing with strengthened shear keys. The results showed that the SSDFB can not only significantly mitigate the shear force responses and residual displacement in bridge substructures but also can effectively reduce girder displacement and prevent bridge unseating, at a cost of inelastic deformation of the SSDs, which is easy to replace. In conclusion, the SSDFB is expected to be a cost-effective option with both multi-stage energy dissipation and restraint capacity, making it particularly suitable for seismic isolation application to high-speed railway bridges.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1163-1167
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• 2004

This study attempts to analyze the flexural behavior of RC beams strengthened with tiber sheets according to the KCI strength method and nonlinear flexural analysis. Also based on these methods, analysis and design programs are developed by the visual basic programming language. Programs include the influence of concrete tensile capacity and failure strain of fiber sheets.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.135-140
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• 2003

Recently Light Rail Transit(LRT) systems, especially full automatic systems are strongly issued by many provinces and major cities due to it's own characteristic for economical, environmental and sufficient transportation capacity. But LRT design criteria should be modified according to Rolling Stock's properties. -size, arrangement of bogie and wheel, power of traction motor etc, This thesis suggest for basic standard design criteria of Rubber Tired Light Rail Transit system.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.319-326
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• 2000

It is investigated character of the dynamic behavior at over excavation zone of roadbed using crushed stone instead of lean concrete. It is considered that behavior of roadbed using PENTAGON-3D and Baber's equation. Typical load of sine wave type using impact factor is compared to moving load system to examine relationship in using PENTAGON-3D case. Variations of this paper are material properties of roadbed, train velocity, subgrade bearing capacity. Using variations, safety of roadbed is estimated by dynamic behavior character.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.385-390
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• 2005

A specimen with residual stress due to welding was analyzed by three-dimensional cohesive zone model. The residual stress distribution was calculated by simulating welding process, and cohesive elements were located along crack propagation planes. Crack growth is possible since two planes of the cohesive element are separated beyond a maximum load carrying capacity. Stress fields around a crack tip are compared for specimens with and without residual stresses. Load-displacement curves and crack growth behaviors are also examined.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1902-1907
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• 2007

This paper suggests improvements in travel cost function of transit assignment model by analysing existing model. Two types of travel cost function are widely used for congested public networks. The one is used for strictly restricting public transport capacity. Another is non-decreasing function such as BPR function. In this paper, we analyse two types of travel cost function in case of intercity rail. The characteristics of intercity rail are different from those of public transit in urban area. Therefore travel cost function must be differently applied in each case.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.722-729
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• 2010

Deciding peak-time demand will be most important factor to decide facilities' capacity of complex transfer centers. Concentration of demand is growing more and more in urban railroad that has 3 minutes headway by using MOE of 15 minutes demand. It is far from reality. Moreover there are various demand and reflection of business facilities' demand and commerce facilities' demand is being requested in complex transfer centers. This study focused on it and suggested demand calculation method about facility design of complex transfer centers.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1713-1718
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• 2010

An ultimate strength evaluation of the through plate girder bridge using nonlinear inelastic analysis is presented. In this method, separate member capacity checks after analysis are not required, because the stability and strength of the structural system and its component members can be rigorously treated in analysis. The method captures the inelastic redistribution of internal forces throughout a structural system, and allows an economic use of material for highly indeterminate steel bridges.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.356-358
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• 2002

The automatic/driverless operation which are great important techniques in metro railway are required to increase higher safety, greater reliability, and transport capacity. This paper describes the method to develop the ATO software system. The software design is based on VxWorks, a Real Time Operating System.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1538-1545
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• 2004

In the train schedule plan corresponds to a master plan for transport services. This service plan must be constructed to minimize operational cost or maximize revenue considering transportation demands and resource capacities in the operation company, and it includes several sub-planning activities such as train operation frequency plan, train schedule plan, train capacity assignment plan, and rolling stock requirement plan. In this paper, we present profitability evaluation system for the current train schedule plan. The proposed system can be used for evaluating profitability by estimating train service revenue considering customer demands.