• Journal of KSNVE
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• v.3 no.3
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• pp.202-208
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• 1993

도시 주거지의 소음은 주로 자동차와 철도 등에 의한 교통소음이 주류를 이룬다. 저소음 차량 개발 등 국가적 차원의 노력은 차량소음을 줄이는 원천적이고 장기적 대책이 되겠지만 방음벽의 설치가 현실적으로는 최선의 방법이 될 수 있다. 이러한 제반 여건을 감안하여 대전시 중촌동 일원에 새로 건설되는 고가도로 구간의 인근에 거주하는 사람들의 소음대책을 위해 도로교통 소음 및 철도소음에 대한 영향을 컴퓨터 시뮬레이션 기법을 이용하여 예측하였으며, 이 결과에 따라 방음벽을 설치하였다. 또한 방음벽 설치시 주민의 여론을 수렴하여 방음벽은 투명방음판과 흡음형 방음판을 조합하여 설치하였다. 교통소음에 대한 컴퓨터 예측결과에 따라 설치된 방음벽에 대한 효과는 방음벽이 설치된 후 실측을 통하여 상호 비교하고 주민의 반응에 대해서도 알아보았다.

• Journal of the Korean Society for Railway
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• v.9 no.1 s.32
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• pp.29-35
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• 2006

Trains in LRT(Light Railway Transit) system usually have shorter car length than metro's because of their smaller passensers demand. Therefore it is very likely that the load condition of LRT system in abnormal operation, in case of which trains are in close proximity by system broke or train rescue works, could be worse rather than in normal operation, in spite of rare probability of abnormal operation. In this study, the target reliability indexes of several abnormal operations are estimated in accordance with the occurrence probabilities of each abnormal operation case and the reliability index of normal operation presented by the specification. From the indexes, load factors for the abnormal operation cases are estimated and the safety evaluation is performed for Yong-in LRT project.

• Journal of the Korean Geosynthetics Society
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• v.21 no.4
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• pp.41-53
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• 2022

In the excavation work like blasting/excavator work bordering on the urban railway, the dynamic safety of railway structures like tunnel, open-cut box structure and elevated bridge was investigated by numerical analysis in this study. The practically presented criteria on influential zones at the blasting work in the construction industry was numerically checked in cases of the precise vibration-controlled blasting (type II) and the small scale vibration-controlled blasting (type III) and it was shown that the criteria on blasting work methods needed to be supplemented through continuous field tests and numerical analyses. The influence of excavation vibration by mechanical excavators was especially investigated in case of earth auger and breaker. The numerical analysis of tunnel shows that the criteria on vibration velocities from the regression analysis of field test values was conservative. The amplification phenomenon of excavating vibration velocity was shown passing through the backfilling soil between the earth auger and the open-cut box structure. It was shown that the added-vibration on the superstructure of elevated bridge was occurred at the bottom of pile like earthquake when the excavator vibration was arriving at the pile toe. The systematic and continuous research on the vibration effect from excavating works was needed for the safety of urban railway structures and nearby facilities.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1445-1456
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• 2011

This paper presents the research of Low Pass Filter(hereinafter called "LPF") which is the part of Chopper Gate Control Unit on the electric rolling stock. Chopper Gate Control Unit controling the propulsive equipments of electric rolling stock consists of several electronic parts, PCB, Power Supply, Gate Circuit Amp, Freon Cooling Device, and has been used the parts made by japan manufacturer Mitsubish. But these parts recently have been more broken down and slow down performance because of long-term use, deterioration. Most of the malfunctions are low performance of LPF. Furthermore, it is physically impossible to repair LPF. Because it is molding type part and no longer manufactured. Also it needs high cost for custom-building. Therefore, it is now making up for through self-developed LPF and operating on Busan metro 1st after on-board testing. This research performed the PS Pice simulation testing, analysis of self-developed LPF performance and the wave form characteristic by multi-function synthesizer, spectrum analyzer, oscilloscope.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1479-1485
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• 2012

The development of a technique for the real-time sensing of a curve section is very important for active rolling-stocks in order to improve the curving performance. However, conventional methods using expensive track inspection equipment or various complex sensors are not practicable to be applied to commercial vehicles. Therefore, we have proposed a new method to estimate the curve radius of a curve section. This method uses the relative displacements occurring between the body and the bogie when the rolling-stock is running on a curve. To verify the validity of this method, we conducted a vehicle dynamics simulation and test using a real vehicle on a test line. The results confirmed the validity of the proposed method. We expect that this method will be effectively applied in studies of active rolling-stocks to increase the curving performance using active control technology.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3518-3527
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• 2013

The new developed train(HEMU-430X) faces running at high speed over 400km/h. But The Korea railway design code gives guidelines below 350km/h speed. Honam HighSpeed Railway was also designed based on the design standard below 350km/h. Existing infra structures have to be reviewed at high speed running and the design guideline for the speed over 350km/h should be prepared as soon as possible. This paper presents (1) the simulation results of composite steel girder bridge(Kaya Bridge of Seoul-Pusan HighSpeed Railway), (2) values measured at this bridge and the comparison with simulation results, and (3) the prediction of Yonjung bridge being constructed in Honam HighSpeed Railway.

• Journal of the Korean Society for Railway
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• v.11 no.1
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• pp.54-60
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• 2008

In the trackbed design using elastic multilayer model, the stress-dependent resilient modulus $(E_R)$ is an important input parameter, that is, reflects substructure performance under repeated traffic loading. However, the evaluation method for resilient modulus using repeated loading triaxial test is not fully developed for practical purpose, because of costly equipment and the significantly fluctuated values depending on the testing equipment and laboratory personnel. The this study, the paper will present an indirect method to estimate the resilient modulus using dynamic properties. The resilient modulus of crushed stone, which is the typical material of sub-ballast, was calculated with the measured dynamic properties and the range of stress level of the sub-ballast, and approximated with the power model combined with bulk and deviatoric stresses. The resilient modulus of coarse grained material decreases with increasing deviatoric stress at a confining pressure, and increases with increasing bulk stress. Sandy soil (SM classified from Unified Soil Classification System) of subgrade was also evaluated and best fitted with the power model of deviatoric stress only.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.353-356
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• 2008

This study was performed to estimate the dynamic behavior for Bi Prestressed Concrete Girder(Bicon girder) which could introduce effectively prestressed forces into concrete girders. Dynamic behavior of PSC girder must be verified because it becomes not only slim but also long and a railway bridge which loaded regularly has risk of resonance especially. Forced vibration test using a vibration machine was executed for 20m railway bridge girder specimen to acquire dynamic characteristics(natural frequency, damping ratio) and test results showed the natural frequency of 6.632Hz and the damping ratio of 1.43%

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.482-484
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• 2007

철도차량이 운행될 때 회생제동 구간에서는 회생에너지가 발생한다. 1500[V] DC급전시스템에서 회생된 에너지는 가선 전압을 상승시킨다. 상승된 가선전압은 급전시스템에 악영향을 주기 때문에 회생에너지를 활용하는 방법을 이용하여 가선전압을 안정화 한다. 회생에너지 활용방법의 하나인 회생에너지 저장 시스템을 적용할 때 고려해야 될 사항은 회생에너지의 발생양이다. 회생에너지의 양이 적어 활용가치가 떨어지는 구간에서는 적용하지 않기 때문에 회생량에 대한 사전 정보가 필요하다. 회생에너지의 양은 실측을 통해 얻을 수 있지만 측정을 위한 시간이나 고가의 장비를 사용해야하는 단점이 있다. 본 논문에서는 회생에너지 예측이 가능한 직류지하철 시스템의 모델링을 통해 실측시 발생하는 시간 및 비용적인 문제점을 해결할 수 있다. 회생에너지의 예측은 시뮬레이터를 이용하여 구배 및 곡선, 차량 데이터 등의 운전특성을 바탕으로 이루어진다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.9
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• pp.1249-1256
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• 2018

For the screening factor of the tunnel and overbridge structure in the electrified railway, the ITU-T regulation denotes only a theoretical estimation method, and the actual numeric values are notified differently by the official announcement of each nations. In this study, the factors which can affect the screening factor are investigated and analysed by FEM and a suitable calculation method based on multi-conductor line theory for the current pre-estimation formula for the induction noise voltage in the national notice is presented. The case studies are performed using the real data of the tunnel and the overbridge of the electrified railway, and a satisfactory formula for the determining of screening factor is derived.