• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1342-1347
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• 2011

Advantages of the deeply underground subway are underground space efficiency, high speed, decrease of noise and vibration. However, when fire occurs in the deeply underground subway station, large casualties are occurred like Daegu subway station fire due to the increase of evacuation distance. In this study, a numerical analysis was performed by using the fire and evacuation analysis program FDS+EVAC for smoke movement and evacuation in Beotigogae station among the deeply underground subway station. Heat release rate of carriage fire was set 10MW and the fire growth rate was ultrafast. As a result, the smoke move to the exit at 1085 second. The total evacuation time took 956 second.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.488-493
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• 2001

CWR technology is generally believed to contribute to the increase of train speed and bring a variety of significant advantages, such as the decrease in track works, noise and vibration as well as the improvement of passenger comfort. In CWR technology, welding is considered to be one of the most important element technologies. Among the various welding methods, thermit welding is the most frequently used one for site welding since the operation is simple and the instruments are light as well as easy to deal with. However, it could cause interference with safety operation of trains since thermit welding points, are essentially made of castings and there are potentialities of defects according to the operation conditions, the environment of the site as well as the dexterity of the worker. This study tries to describe the characteristics of thermit welding, defect-causing factors and defect-detection methods at welding points.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.2
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• pp.131-140
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• 2022

Installing Continuous Welded Rail (CWR) is one of the economical ways to resolve the challenges of noise, vibration, and the open-deck steel railway bridge impact, and the SSF method using the interlocking sleeper fastener has recently been developed. In this study, the method employed for determining the optimum vertical stiffness of the sleeper pad installed under the bridge sleeper, which is utilized to adjust the rail height and absorb shock when the train passes when the interlocking sleeper fastener is applied, is presented. To determine the optimal vertical stiffness of the sleeper pad, related existing design codes are reviewed, and, running safety, ride comfort, track safety, and bridge vibration according to the change in the vertical stiffness of the sleeper pad are estimated via flexible multi-body dynamic analysis,. The flexible multi-body dynamic analysis is performed using commercial programs ABAQUS and VI-Rail. The numerical analysis is conducted using the bridge model for a 30m-long plate girder bridge, and the response is calculated when passing ITX Saemaeul and KTX vehicles and freight wagon when the vertical stiffness of the sleeper pad is altered from 7.5 kN/mm to 240 kN/mm. The optimum stiffness of the sleeper pad is calculated as 200 kN/mm under the conditions of the track components applied to the numerical analysis.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1069-1073
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• 2011

When the train is running on the small curved line, there would be severe contact between the rail and wheels, which cause noise and vibration as well as abnormal wear on the rail and the wheels. In order to solve these problems, the steering bogie has been developed. To verify steering performance of the steering bogie, steering angles of two trains, one is the advanced EMU with the steering bogie, another is a conventional EMU with the conventional bogie, were measured while running on the small curve. this comparing test shows that the steering bogie has much higher steering performance than the conventional bogie on the same curved line. To verify more performance data of the steering bogie, further testing and monitoring will be done with the advanced EMU in the test track.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.618-622
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• 2007

In the past decades, complain about ground vibration and noise induced by pile driving has been quickly increased. Because of that, auger The role of train has expanded as mass transportation according to the increase of train passenger. The train operation personnel are more emphasis on the safety of train operation due to the increase of train's role. The reason is that the train transports many people daily. So, if there is natural disaster, such as earthquake, flood, high temperature, and so on, it will become disaster. Therefore, this paper introduces and proposes wayside detection system, which can be helpful for the safety assurance of train operation.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.584-589
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• 2008

A bi-modal tram has been developing to consist of articulated-two cars propelled by CNG hybrid (series type) in Korea since 2003. All wheels are driven by electrical motors independently, which can eliminate differential gears to reduce turning radius and make low floor to provide the old and the handicapped with easy access. In the bi-modal tram, therefore, reduction gear unit is key technology to make low floor and drive wheels independently. This study was aimed at performance evaluations of the reduction gear unit for the bi-modal tram. Oil leakage, oil temperature, vibration, acoustic noise in idle operations were measured for the reduction gear unit of the bimodal tram.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.555-560
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• 2003

Korean High Speed Train(KHST) has been tested on the high speed test line in Osung site of Korea High Speed Rail Construction Authority (KHRC). since it was developed as G7 Project Plan In 2002. This paper introduces the dynamic test devices in KHST and shows the comparison between the results of test and theoretical computing results which derive from the new model for KHST dynamic behavior. Previous computer simulation model for KHST was developed to review wether the vehicle system was satisfied with the dynamic performance requirements during the design procedure. But It should be applied the results of the parts test for suspension elements in order to compare between the results of computation and real test. Using VAMPIRE Program made by AEA Technology in UK. the new model also was modified. This paper shows that the static wheel loads calculated from new model is similar to test results. For test on high speed line, we prepared the test devices for evaluating the dynamic performances. which was consisted of the accelerometers( based on Kisler Co.) and the data aquisition systems (based on National instrument Co.), and test program coded by LabView 6i program. These lest devices and programs are flexible to extension the channels for adding sensors and connect to the ethernet network. The acceleration of car bodies, bogie frames and axle boxes were compared between the results of computation and test at 150km/. This paper shows that the results of test were high in high frequency band range but similar frequency band range. It might be considered that these differences were caused by the test which did not performed at constant speed for comparison analysis. Also. It will be able to understand the differences and make better results through a lot of tests planed in future.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.426-436
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• 2006

The use of the CWR track has increased consistently in the worldwide. Because the use of CWR track not only reduces the track maintenance cost, noise and vibration, but increases the life cycle of track components. Therefore, to increase train speed, improve riding condition and secure running stability, the necessity of study on making CWR is increasing. This study includes the development of a thermal buckling theory in the evaluation of curved track stability. The lateral stability of curved CWR is studied for track buckling prevention through the parameter studies. It studied the lateral buckling of the curved CWR track on the 3-D nonlinear analysis. The parameters include rail size, cant, track curvature.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.179-186
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• 1998

Three phase squirrel cage induction motor is generally adopted as a traction motor to drive high speed trains because of its robustness for surrounding environment and easy maintenance. In the design of traction molar, reduction of weight is very important in order to reduce kinetic energy to accelerate the vehicle. Therefore, in this paper, design variables of a preliminary designed traction motor to minimize its weight is determined using the optimization technique. Before the optimization process, rotor slot number is determined to reduce vibration and noise by the analysis of magnetic force. As a result, a design example to reduce weight by 12% than that of the preliminary designed motor is presented.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1203-1208
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• 2007

In the past decades, complain about ground vibration and noise induced by pile driving has been quickly increased. Because of that, auger drilled piling methods have frequently used specially in urban area. However, the present auger drilled piling methods induce inevitable ground disturbance as well as a certain degree of vibration and noise due to the final hammering. For these reasons, a new auger drilled piling method is required to be developed. This paper introduces PDT(Pulse Discharge Technology) piling method and presents the characteristics of bearing capacity. The PDT piling method is to install in-situ piles using electric power so called Pulse. The pile installed by PDT appears to be able to develop shaft and end bearing capacity efficiently. This paper introduces PDT(Pulse Discharge Technology) piling method, which is the 512nd new construction technology. The PDT piling method is to install in-situ piles using electrical power so called Pulse power. The pulse power is physical value that indicates the energy change per unit time(dE/dt). Since the pulse power is to push ground, using the pulse power is enable a hole to be expanded as well as the ground to be improved by compaction. Therefore, The pile installed by PDT appears to be able to develop shaft and end bearing capacity efficiently. In this study, couples of pile loading tests were carried out to figure out whether or not the PDT piling method is applicable to constructions like rail road facility. As a result, it was concluded that the PDT piling technique meet the requirements for such a rail road related construction.