• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.03a
• /
• pp.245-248
• /
• 2001

During the core drilling for the design of a railway bridge crossing over the inferred fault system along the river, fracture zone, extends vertically more than the bottom of borehole, filled with fault gouge was found. The safety of bridge could be threatened by the excessive subsidence or the reduced bearing capacity of bedrock, if a fault would be developed under or around the pier foundation. Thus, a close examination of the fault was required to rearrange pier locations away from the fault or to select a reinforcement method if necessary. Geophysical methods, seismic reflection method and electrical resistivity survey over the water covered area, were applied to delineate the weak zone associated with the fault system. The results of geophysical survey clearly showed a number of faults extending vertically more than 50m. Reinforcement was not desirable because of the high cost and the water contamination, etc. The pier locations were thus rearranged based on the results of geophysical surveys to avoid the undesirable situations, and additional core drillings on the rearranged pier locations were carried out. The bedrock conditions at the additional drilling sites turned out to be acceptable for the construction of piers.

• Journal of the Korean Society of Safety
• /
• v.38 no.1
• /
• pp.87-92
• /
• 2023

The number of unmanned light rail train operators is continuously increasing in Korea. In a failure event during an operation due to the nature of the unmanned operation, recovery is performed based on the remote control. However, if remote recovery is not feasible, safety personnel arrive at the train to resume the train operation. There are regulations on safety personnel and the suspension time of the train operation. However, there is currently no rule for safety personnel deployment. Currently, railway operating organizations operate in three scenarios: safety personnel on board trains, stationed at stations, and deployed at major stations. Four major factors influence the downtime for each emergency response scenario. However, these four influencing factors vary too much to predict results with simple calculations. In this study, four influencing factors were considered as random variables with high uncertainty. In addition, the Monte Carlo method was applied to each scenario for the safety personnel deployment to predict train service downtime. This study found a 17% difference in train service suspension by safety personnel deployment scenario. The results of this study can be used in setting service goals, such as standards for future safety personnel placement and frequency of service interruptions.

• Journal of the Korean Society for Railway
• /
• v.13 no.5
• /
• pp.535-540
• /
• 2010

We present an optimization model for how to assign the freight trains to transshipment tracks and allocate the containers to the freight trains in a rail container terminal. We formulate this problem as a multi-criteria integer programming to minimize the makespan of job schedule and simultaneously to maximize the loading throughput, i.e. the number of containers to be disposed per day. We also apply our model to the instance obtained from the real-world data of the Uiwang Inner Container Depot. From the experiments, we can see an improvement of approximately 6% in makespan, which means that our model can contribute to the improvement of the disposal capacity of containers without additional expansion of facilities.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1081-1099
• /
• 2010

The TVM 430 system manufactured by Ansaldo STS in France is currently used in ground signalling system for Kyungbu HSR. It transmits the speed information to the on-board signalling system in the form of continuous signal via the track, and the rolling stock in Kyungbu HSR runs with 300km/h max. operating speed by using the corresponding information. Looking from the recent international trends in HSR, reducing the travelling time and increasing of the line capacity is promoting via the improvement of train speed. In case of TGV Est, they are realizing the normal operation with 320km/h max. operating speed by using TVM SEI signalling system, which is similar to TVM 430. Furthermore, in case Honam HSL, which is under construction, is looking over faster speed than the limited one of Kyungbu HSR(i.e. over 300km/h). In this paper, it is assumed that the existing TVM 430 ground signalling system is used and train speed is improved, therefore the number of block section to be increased depending on the increase of train speed and the standard speed to be used in this case is drawn via the simulation of the train model and described the method accordingly.

• Structural Monitoring and Maintenance
• /
• v.9 no.1
• /
• pp.1-27
• /
• 2022

Extensive laboratory tests were conducted to investigate the effect of load amplitude, geogrid position, and number of geogrid layers, thickness of ballast layer and clay stiffness on behavior of reinforced ballast layer and induced strains in geogrid. A half full-scale railway was constructed for carrying out the tests, the model consists of two rails 800 mm in length with three wooden sleepers (900 mm × 10 mm × 10 mm). The ballast was overlying 500 mm thickness clay in two states, soft and stiff state. Laboratory tests were conducted to investigate the response of the ballast and the clay layers where the ballast was reinforced by a geogrid. Settlement in ballast and clay, soil pressure and pore water pressure induced in the clay were measured in reinforced and unreinforced ballast cases. It was concluded that the effect of frequency on the settlement ratio is almost constant after 500 cycles. This is due to that the total settlement after 500 cycles, almost reached its peak value, which means that the ballast particles become very close to each other, so the frequency is less effective for high contact particles forces. The average maximum vertical stress and pore water pressure increased with frequency.

• Journal of the Korean Society for Railway
• /
• v.12 no.3
• /
• pp.348-356
• /
• 2009

The objective of this paper is to estimate the DMT utility function for the transportation mode choice using SP survey. With the freight OD data the estimated utility function can be used as a basic data for forecasting DMT market. 3 alternatives of transportation mode are considered in SP survey; railway, road and DMT. The utility functions are developed according to the freight items, which are container, steel and chemical product. In this study the attribute variable are chosen as time, cost and reliability. The number of level for attribute variables are 3. The high valve is determined as +10% above the standard and the low value -20% below the standard.

• Journal of the Korean Society for Railway
• /
• v.8 no.4
• /
• pp.342-347
• /
• 2005

The Korean High-Speed Train(HSR 350x) had been developed by through 'G7-R&D project' in 1996-2002, and has been testing and evaluating it's reliability on the high-speed line until now. A number of core equipments designed and developed by using domestic technologies were boarded on the HSR 350x. In order to verify the performance of HSR 350x and core equipments such as traction system, brake system and pantograph, sophisticated testing and evaluating procedures should be considered and applied. In this paper, the tested and analysed results about the dynamic characteristics of HSR 350x pantograph are introduced in a view point of the mean contact force and it's variation trend, criterion of current collection, and up-lifting of contact wire when the MSR 350x running up to 350 km/h. Through the test and evaluation, we verified that HSR 350x pantograph had an excellent current collection performance and good dynamic characteristics as it had been designed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.11a
• /
• pp.33-42
• /
• 2005

Studies on community annoyance caused by transportation noise exposure were carried out in fifty-one areas around Gimpo and Gimhae international airports, Gyungbu and Honam railway lines and east and riverside-northen motorway to accumulate social survey data and to assess the relationship between each transportation noise level and degree of annoyance in Korea. The measurements of transpotation noise were carried out using portable precision sound level meters (B&K type 2238 and LD 812) except in aircraft noise. Aircraft noise levels were measured automatically by airport noise monitoring system, B&K type 35n Social surveys were carried out to people living around noise measurement points. Questionnaires were only aggregated by face-to-face interviews using various questions concerned with demographic factors, degree of noise annoyance, interference with daily activities and health-related symptoms. The questions of noise annoyance were answered on an 11-point numerical scale. The respondents, from 18 to 70 years of age, were randomly selected and completed the questionnaire for themselves. The total number of respondents for the questionnaires was 1,839. The results showed that community annoyance of railway noise in Korea is similar to that in Japan, but is more severe than that in European countries.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.1193-1198
• /
• 2007

The total number of passengers for Line $1{\sim}4$ operated by Seoul Metro among subways that act as foot of Seoul residents was 1.43116 billion passengers in 2006 and average of 3.921 million passengers per day. The results of analysis on safety accidents that occurred recently in subways show that various complaints on subways were reduced through the expansion of safety related facilities and training but accidents caused by negligent handling by employees including engineers are increasing on the contrary. At present time where various man-made accidents break out such as wrong handling and habits of engineers in charge of driving trains and momentary mistakes, there needs effort for active management and improvement to prevent and minimize accidents. Therefore, this study has drawn out problems through surveys on aptitude test system to engineers and compared with case studies in overseas. Thus, it attempted to minimize safety accidents in subways, and derived methods for improving safety management by focusing on improving the current aptitude test system for nurturing engineers suitable to handle railway driving in the future.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.603-609
• /
• 2008

Nowadays, double-system of TFM(Track-side Functional Modules) developed instead of single-system in use of high speed line to acquisition more availability. Safety Law for Railroad recommend to quality certification of development and general railway machines. It is important to select metrics which form the bases for testing software products. A number of package software development part do not open source cords, so testing external characteristic vectors having relationship with metrics. In this paper, review the process for the TFM Point Modules, Universal Modules and Switchers, think about the test methode of circuit boards output performance by using TFM tester and Simulators.