• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.18 no.10
• /
• pp.1014-1023
• /
• 2008

Subway electric trains need to be faster for accommodation of long distance passengers. The faster run of the existing trains results in deterioration of ride quality due to noise and vibration. To reduce the noise and vibration of the electric train, a running test of the electric train was performed and an ADAMS/Rail model was set up to verify the running test results. The experimental results show that the sources of the cabin noise and vibration basically comes from the irregularity of the railroad track and the deterioration of the connection part between cabin and bogie. Consequently for mitigation of noise and vibration of the electric train, the redesign of the center pivot with softer stiffness and the minimization of rail irregularity are necessary. the frequent maintenance of the train will lead to better comport.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1996.04a
• /
• pp.80-85
• /
• 1996

Predictions of vibration induced by subway operation has been studied through comparison between the measurement values and the estimated values which proposed by other scientists to determine the adequacy of each equation. It was found from this study that the Wilson's prediction equation gives the best overall approximation value although the peak frequency band lies somewhat higher than that obtained from measurement.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.05a
• /
• pp.738-742
• /
• 2005

Ground vibration at Gil-dong in Seoul induced by the 5th ling of Seoul Subway is predicted using various prediction methods and compared with measured vibration. Also, several issues on the improvement of prediction methods are discussed. Furthermore, as an alternative vibration source, measured vibration acceleration level(VAL) on the tunnel wall of the Bundang line of Seoul Subway is applied to the prediction of the VAL at the location mentioned previously. Then requirements accompanied to the suggestion of the new vibration source appropriate to the condition of Seoul Subway.

• Explosives and Blasting
• /
• v.21 no.1
• /
• pp.49-58
• /
• 2003

현재 발파의 수행은 채석, 채굴 및 지하철과 도로, 건축, 토목공사 등 다양한 분야에 적용되고 있다. 이에 따라 발파특성의 연구와 관련하여 다양한 이론이 도출되고 있고 사용되지만 발파에 의한 공해인 진동 및 소음의 문제가 대두되면서 또한 이들의 취약점을 보완하기 위해 다양한 공법들이 시행되고 개선되어지고 있다. 본 연구에서는 기존의 발파공법과 Air tubes를 이용한 발파공법을 비교하므로 화약의 사용량을 보다 감소시키고, 기존 전색의 길이를 줄이므로 폭약의 투사면적을 증대시켜 진동 및 폭음을 감소시키고 상대적으로 양호한 파쇄입도를 얻고 상부의 대괴를 최소화하는데 목적이 있다. 따라서 발생하는 진동 및 발파폭음을 크게 감소시킬 수 있으므로 기존 노천발파 및 진동, 소음에 민감한 도심지 발파에서 그 이점을 활용하여 보다 안전적이고 경제적인 발파작업을 수행하는데 연구의 목적이 있다.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.773-778
• /
• 2008

The subway noise in curved line is affected not only by rail condition but also wheel condition and dynamic characteristics. The railway curving noise can be divided into 2 categories. The first is noise depending on the vehicle speed, and the second is the one independent on vehicle speed. In this study the noises were reviewed by using eigen-mode of wheel and waterfall plot which shows noise level in time-frequency domain. And also those were reviewed in viewpoint of stick-slip noise and wheel flange contact noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 1996.10a
• /
• pp.402-407
• /
• 1996

Noise and vibration induced by subway operation is one of the major problem for the residents living nearby railway tracks. Many scientists and engineers have been working on the more accurate prediction of noise and vibration to provide the better residential environment. Some prediction equations were determined to compare the measurement value of a noise obtained from the inside of a residential area. It was observed that the condition of a soil type is one of the major parameter which should be considered to obtain the more accurate prediction value of a noise.

• Journal of Korean Tunnelling and Underground Space Association
• /
• v.6 no.4
• /
• pp.345-356
• /
• 2004

Open-cut method has been widely used to construct underground structures, but it causes several problems such as traffic congestion and public resentment resulting from severe construction noise and ground settlement. In many cases, it is very difficult to build underground structures safely due to the unknown locations of buried facilities such as water pipes, drainage pipes, gas pipes and high-pressure cable conduits etc. Also in open-cut method, moving buried facilities causes additional cost and extension of construction period. Therefore, this paper is to present a case study in which Tubular Roof construction Method (T.R.c.M.), a newly developed construction method for underground structures using slab steel pipes and PC wall trench, is applied for the construction of a subway tunnel in Seoul. As a result, it is found that T.R.c.M. is a construction method by which tunnels can be constructed safely without any effect on the surrounding environment and traffic flow due to the minimized construction vibration and noise.

• Journal of the Korean Society for Railway
• /
• v.11 no.1
• /
• pp.13-18
• /
• 2008

In this study, unsteady wind pressure analyses on platform screen door (PSD) have been conducted considering the flow intereference effects between the moving train and the configuration of subway station. The major role of PSD prevents passenger accidents, wind pressure, polluted dust and noise when the train is entering the station platform. Computational fluid dynamic method with moving gird algorithm has been adopted to accurately predict unsteady pressure levels exerted on the PSD. Closed and open type station configuration are considered. Also, wind pressure levels for passing and stopping drive motion of the entering train are presented and practically compared each other.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.14 no.4
• /
• pp.86-93
• /
• 2010

The wear of railway track affects loss of rough ride, noise or vibration of train and traveling safety. Moreover as the track is worn away, this promotes destruction of structural mechanism of rail track which can bring about increasing of rail track maintenance cost drastically. For this reason, it is very important and interested research subject to design railway track structure and to analyse train movement mechanism based on systematic analysis of the reasons causing rail wear possible in real field. In this research, for the efficient maintenance, Life Cycle Performance of rail track and maintenance characteristics are computed considering some track components such as track type, contracting type, sleeper type and roadbed type. Time - Wear probabilistic distribution relationship as well as multiple regression analysis based on time, curvature and wear data are computed to predict the service life remainder of railway track and to be adapted to safety assessment.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.1
• /
• pp.17-23
• /
• 2013

In a subway vehicle, a lateral damper is used for compensating the lateral stiffness deterioration due to the air-spring as a secondary suspension. This lateral damper can reduce the lateral vibration of the carbody. When the damping force of the lateral damper is lowered, the running stability and ride quality of the subway vehicles worsens and the lateral motion of the carbody is increased. In this study, the lateral displacement variation of the carbody according to the damping force of the lateral damper was analyzed by multi-body dynamics to solve the abnormal impact problem during vehicle operation. Furthermore, the noise and vibration due to abnormal impact were considered. An adequate damping coefficient of the lateral damper for the subway vehicle treated in this paper was suggested for preventing abnormal impact.