• Journal of the Korea Safety Management & Science
• /
• v.17 no.3
• /
• pp.53-63
• /
• 2015

This study highlights empirically the relationship among major constructs such as accident, fear and anxiety emotion, self-efficacy, and negative spillover of work, focused on the railway drivers. The differentiated factor of this study is in that the experience of accident was posed as exogenous variable. The main statistical tool was Regression. Hypothesis tests based on 201 samples verified that the experience of accidents showed a significant effect on negative spillover of work mediated by fear and anxiety, with moderating effect of self-efficacy between fear and anxiety and negative spillover of work. However, the moderating effect was shown as increasing the degree of negative spillover of work, since the drivers recognized their fear and anxiety accrued by accident experience as uncontrollable. This findings suggest the need for mitigating driver's negative emotion - fear and anxiety - through an introduction of practice such as exemption of settlement obligation in accident site and lowering of the penalty for accident responsibility.

• Structural Engineering and Mechanics
• /
• v.84 no.5
• /
• pp.591-604
• /
• 2022

A gravity wall combined with an anchoring lattice frame (a combined retaining structure) is adopted at a typical engineering site at Dali-Ruili Railway Line China. Where, the combined retaining structure supports a soil deposit covering on different inclined rock slopes. With an aim to investigate and compare the effects of inclined rock slopes on the response of combined retaining structure under seismic excitation, three groups of shaking table tests are conducted. The rock slopes are shaped as planar surfaces inclined at angles of 20°, 30°, and 40° with the horizontal, respectively. The shaking table tests are supplemented by dynamic numerical simulations. The results regarding the horizontal acceleration response, vertical acceleration response, permanent displacement mode, and axial anchor force are comparatively examined. The acceleration response is more susceptible to outer structural profile of combined retaining structure than to inclined angle of rock slope. The permanent displacement decreases when the inclined angle of the rock slope increases within a range of 20°-40°. A critical inclined angle of rock slope exists within a range of 20°-40°, and induces the largest axial anchor force in the combined retaining structure.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.26 no.2
• /
• pp.153-167
• /
• 2024

Recently the ground settlement has been increasing in urban area according to development. And, this may attribute a groundwater level drawdown. This study presents an analysis of groundwater level drawdown for circular vertical shaft excavation of ｢◯◯◯◯ double track railway build transfer operate project｣. And, in-situ monitoring data and numerical analysis were compared. So, if we examine the groundwater level drawdown in design, ground conditions should be applied so that the site situation can be reflected. And, groundwater level should be considered a seasonal measurement in order to apply the appropriate groundwater level. It was confirmed a similar predicted value to groundwater level drawdown of in-situ monitoring data.

• Economic and Environmental Geology
• /
• v.38 no.2 s.171
• /
• pp.155-163
• /
• 2005

For an unbiased TF (Tansfer Function) estimations we investigate geomagnetic TF derived from ICHEON and YONGIN sites, employing RR (Remote Reference) and SNS (Signal Noise Separation) techniques. The Rh technique, which requires synchronized field variations recorded at a clean remote site, is a reliable method to minimize the bias of TF by uncorrelated noises in magnetic channels. Meanwhile, SNS technique based on the assumption of noise-free remote data can improve the signal-noise level by separating signal TF and noise TF, which is successfully applied to the environments with strong correlated noises. In this study, TF at YONGIN is analyzed using geomagnetic data from ICHEON site as a remote reference, which seem to have somewhat better data quality. The application of Rh technique reduces the bias of TF, which appears in single site robust estimation, and makes curves in the amplitude and phase of TF more smooth as frequency. Futhermore, in order to investigate noise source quantitatively, SNS technique is applied. The results of SNS suggest that dominant noise source seems to be located at western region of YONGIN. This noise source is considered to originate from railway system such as KTX and national subway. which passes through the west regions of YONGIN.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.12
• /
• pp.3632-3637
• /
• 2009

In this paper, we describe the performance results of the field installation test which is required to practicalize the single-phase MJ81 Switch Point Machine. This product has passed the certified test through performance improvement of driving parts in order to use 3 phase MJ81 Switch Point Machine, which is localized by taking over technology from Alstom and Cogifer when constructing Seoul-Busan rapid-transit railway, without change of the electrical equipment at track-side in domestic existing lines which single-phase 220V is used. KRRI and Samsung SDS have localized the single-phase MJ81 Switch Point Machine to improve the speed and safety of the conventional lines through the existing railway technology development project. For practicalization of this, we should, however, verify the performance through not only field installation test in real lines but also interface test with the interlocking. In this paper we verify the practicality of the domestic single-phase MJ81 Switch Point Machine through analysis on the performance result of the field installation test as well as the research contents for this test. Thereby, in Feb 2009 we have received an order from the Korea Rail Network Authority and are currently installing the single-phase MJ81 Switch Point Machine.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.72-79
• /
• 2010

The significant of continuous welded rail (CWR) management is growing because KORAIL has the plan to convert the whole of conventional railway lines into CWRs through continuous activities since constructed the CWR track with 1.8km in Gyeongbu line in 1966. The CWR recently is needed a efficient management method because it is difficult to manage the CWR by the poor of technic and equipment, limited maintain labor force and shorted the maintain work time of CWR caused by industrialization, greenhouse effect and global warming In this point, The 70ton Tenser's which is using in the rail site has been analysised with no extra tenser's capacity in case of the under low temperature and exceed the length of 1km as a result of reviewing the CWR-related rules and standards, a series of records of safety accidents, operation obstacles, and the situation of broken rails published by KORAIL, existing rail temperature measurements, and CWR researches. Therefore avoid the excessive plan of the first set-up section, choice the proper time in the normal temperature that is possible to weld the rail, turning the difference of rail temperature and Installation temperature down is desirable.

• Journal of the Korean Society for Railway
• /
• v.19 no.1
• /
• pp.38-45
• /
• 2016

The power transformation system of High Speed rolling stocks like KTX-Sancheon has shown excellent control capacities in the areas of riding comfortability, switching efficiency, safety and energy consumption due to technical developments in power-electronics, high speed & large scale integrated semiconductors and microprocessors. However, harmonics from IGBT, a high speed switching device used in the Convertor & Invertor equipment of rolling stocks have given rise to various problems in transformer substations, signaling systems, data transmission systems and facility monitoring systems. Especially, TI21 non-insulated track circuits have malfunctioned due to the influence of returning current harmonics which were generated at around of integer times of the number of power transformation equipment in the frequency domain. This paper, measures and analyzes various schemes to analyze the traveling path of the returning current harmonics generated due to the relationship between the rolling stocks and track circuits on site. Ultimately, theseschemes will be used to design high speed rolling stocks, AF track circuits and a common grounding network.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.1498-1508
• /
• 2009

Recently, the expansion of roads are necessary because the population and vehicles have rapidly increased, but those are restricted because of the limited site. JES(Jointed Element Structure) method is the method of the new cross-structure, which is element-traction method which draws and excavates elements under the existing structure with high accuracy within a short time. Also JES(Jointed Element Structure) method has a facility of the economical execution, a small effect on the train-service during construction period and no limit of the crossing length under the trade In this study, the tractive force and settlement are compared with the upper element, side wall element and the lower element respectively in the section which the JES method is applied In the case of element located at left side wall, the tractive force measured by a guage is double or more than the tractive force calculated by a formula. It is expected that many boulder contented in the ground contrary to the site investigation data cause high tractive force. For comparison of the settlement, the settlement as excavating the upper element is the largest in all steps. It is expected that this is the same as the cause of high tractive force. Also in this study, the practical use of the JES method when some under pass structures are extended in the future is studied.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.11 no.1
• /
• pp.51-57
• /
• 2011

Irregular distributions of limestone cavity in Gang-Won province area may cause unexpected accidents from reduced serviceability or failure of structure. It is requested that an appropriate ground reinforcement method should be used to improve bearing capacity of structure, and the method should also be satisfied with environmental requirements. Among several methods used for foundation constructions in cavity area, Rod Jet Pile(RJP) method has been widely used. While the RJP method was used to improve bearing capacity for the railway bridge foundations, water pollutions of drinking water as well as fishery located adjacent to this project area were occurred. The main reason of the water pollution was cement runoff used in cement mortar during injecting material in RJP method. Laboratory tests were performed to prevent water pollution. The compaction mortar method using low movable material was selected for this project. The quality of water at a fishery adjacent to the site and the compressive strength of cores taken from the construction site were measured. Test results show that the water pollutions was minimized, and the average compressive strength of foundation material was over 5 MPa. As a result of this study, compaction mortar method can be used to ensure the bearing capacity of foundation and to prevent environment pollutions.

• Journal of the Korean earth science society
• /
• v.31 no.5
• /
• pp.448-453
• /
• 2010

The population of House sparrow (Passer domesticus), once a very common bird, has declined markedly in most parts of the world including India. Sparrows were distributed widely in the district Hoogly, West Bengal, India. However over the past few decades, they became not so common in this part of the wo rld. A study has been conductedto establish the database for their current population and to assess the possible causes of their decline at Bandel ($22^{\circ}$52'22''N/$88^{\circ}$22'53''E) placed beside the river Hoogly from September 2008 to May 2009. After prolonged searching, a relatively dense population of sparrow (total subject 270) was found in busy areas of railway station and a nearby market in Bandel. The behavior of these birds was studied extensively from early morning to late night. The noise level of the area varied from 35 to 95 dB with an average of 70.6 dB from 04:30 am-10:30 pm, IST. It was also observed that the sparrows took rest on the site of the tree where the illumination level was low (30-45 lux). Sparrows residing at the Bandel station are habituated with the loud noise, being undisturbed by passing trains. Thus, it can be concluded that in spite of heavy noise of trains, crowdy travelers, and lack of nest sites, they remain at the station because of availability of food in the nearby roadside market. Based on this observation, sound pollution and availability of food are not responsible for their decline.