• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.04a
• /
• pp.493-598
• /
• 2000

In the rail facilities, the rail track consists of rail, tie, fastening, accessories and bed. The rail track is largely divided into Ballast Bed Track (BBT) and Concrete Bed Track (CBT) according to the type of bed. In this thesis, among Concrete Bed Track, slab track, which is used for the Japanese high speed railway, is a target of this study. Dynamic analysis by using finite element method are performed where moving train load is periodic function. Then through parametric study, some conclusions are obtained as follows. Cement Asphalt Mortar (CAM) affects contrary mechanical behavior to rail and slab greatly. Therefore, change of CAM spring coefficient should be handled with care. For slab thickness, thin slab is more profitable to reduction of vibration of rail than thick one but mechanical capacity of slab is deteriorated. Improved structural type is proposed, then structural analysis is performed for this one. This type is effective to reduction of vibration of railway system.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.03a
• /
• pp.223-230
• /
• 2001

Nine different types of the reinforced railroad roadbeds which . are located in between Suwon-Chunan station of Kyongbu line were constructed in order to increase the bearing capacity of railroad roadbed and to improve the ridability as a part of speed-up project of conventional railroad systems. Each three sections were composed of weathered granite soil, crushed stone and furnace slag(HMS25), and fully instrumented with earth pressure cells, settlement plates and geophones to monitor the behavior of roadbeds under actual train loads. Field measurement has continued since October 31, 2000 and presently with rather longer measurement interval. The measurement data such as settlement, earth pressure and vibration levels are currently under analysis process. In this paper, only cumulative measurement data of railroad roadbeds were introduced. In the near future, comprehensive measurement data and result of analysis will be presented and design technique for the reinforced railroad roadbed will be proposed as a final product of this study.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.03a
• /
• pp.525-532
• /
• 2001

In this study, performance of reinforced railroad roadbeds with the crushed stones was investigated through the real scale railroad roadbed tests. Several real scale reinforced railroad roadbeds were constructed in the laboratory with different subgrade conditions and were tested with the estimated actual train loads including the impact loading of train. The affecting factors such as settlement, earth pressure and stress change at the surface of reinforced roadbed, subgrade layers as well as surface of rails were measured. It was found through the actual testing that for the roadbed with the same thickness, the settlement and vibration level (velocity) of reinforced roadbed decreases with the increase of reaction modulus of subgrade. The settlement of reinforced roadbed with the same reaction modulus of subgrade also decreases with the increase of thickness of the reinforced roadbed.

• Proceedings of the KSME Conference
• /
• 2008.11a
• /
• pp.817-821
• /
• 2008

Wind turbine requires service life of about 20 years and each components of wind turbine requires high durability, because installation and maintenance costs are more expensive than generated electricity by wind turbine. So the design of wind turbine must be verified in various condition before production step. This paper demonstrates the application of a generic methodology, based on the flexible multibody simulation technique, for the dynamic analysis of a wind turbine and its drive train. The concern of the paper is the computation of dynamic loads of wind turbine in emergency-stop condition. The finite element model is used to analyse the dynamic behaviour of the wind turbine.

• Proceedings of the KIEE Conference
• /
• 2001.07a
• /
• pp.289-291
• /
• 2001

This paper represents the application of the Static Var Compensator (SVC) on the electric railway power supply system to compensate for the voltage drop. The high reactance of line and a heavy train load consume a significant amount of the reactive power which results the voltage drop. This paper shows that the SVC is necessary for voltage compensation in the railway power supply system and verify effectiveness of the SVC through the simulation by using PSCAD/EMTDC. In this paper, the case studies were performed with the various line length and train loads.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.268-273
• /
• 2008

The ballast, one of track components, plays an essential role as intermedium in transmitting train load to subgrade safely, and the deterioration of ballast directly effects the growth of track irregularity. So far, gravel fining of ballast track was mainly related to the repetition of train loads, but was gradually increased with using MTT(Multiple Tie Tamper) recently. Therefore, in this study, an evaluation of the abrasion and crush process of ballast particles was performed with outdoor field test by MTT works. From this study, the amount of abrasion and crush of ballast particles appeared to increase linearly with MTT works, and the gradient of particle size distribution curve appeared to deviate gradually from a criterion of aggregated ballast size distribution in high-speed railroad.

• Proceedings of the KSR Conference
• /
• 2004.10a
• /
• pp.1028-1033
• /
• 2004

The open deck steel bridge is the most common type in railway bridges. Steel I-shaped girders are connected with sleepers directly without ballast and moving train loads are transmitted directly to the girder, so this bridge has weak characteristics on impact. Therefore, considerable accelerations can cause unsatisfactory dynamic behavior of the open deck steel bridge. Especially, Impact created at rail joints can increase the dynamic response of the bridge and this phenomenon would be injurious to passenger comfort. In the present study, dynamic behavior of the open deck steel bridge which has a rail joint is estimated through experimental studies and bridge-train interaction analysis considering surface irregularities by rail joints.

• Wind and Structures
• /
• v.21 no.3
• /
• pp.311-329
• /
• 2015

A method for analyzing the coupled wind-vehicle-bridge system is proposed that also considers the shielding effect of the bridge tower with triangular wind barriers. The static wind load and the buffeting wind load for both the bridge and the vehicle are included. The shielding effects of the bridge tower and the triangular wind barriers are incorporated by taking the surface integral of the wind load. The inter-history iteration is adopted to solve the vehicle-bridge dynamic equations with time-varying external loads. The results show that after installing the triangular wind barriers in the area of the bridge tower, the bridge response and the vehicle safety factors change slightly. The peak value of the train car body acceleration is significantly reduced when the wind barrier size is increased.

• Structural Engineering and Mechanics
• /
• v.38 no.3
• /
• pp.301-314
• /
• 2011

The paper constitutes the second part of the author's study. The first part (Podworna 2010) formulates four fundamental tasks in dynamics of the bridge-track-train systems. The following cyclic moving loads are considered: a concentrated forces stream (model P), an unsprung masses stream (model M), a single-mass viscoelastic oscillators stream (model $M_o$) and a double-mass viscoelastic oscillators stream (model $MM_o$). Three problems precluding to the numerical simulations have been developed, i.e., prediction of the forced resonances, the parameters of integration of equations of motion, the output results. A computer programme was written in Pascal and numerical research in the scope of the fundamental tasks was worked out. The investigations were focused on adequacy evaluation of the moving load models, P, M, $M_o$, $MM_o$, in predicting dynamic processes in railway bridges.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.2 no.1
• /
• pp.121-128
• /
• 1998

The rail, which supports the train road, distributes the wheel loads to the tie by rail stiffness. Subway sleeper on concrete ballast is construction of PC or RC sleeper. The present, PC sleeper is constructed of line 1, 2, 3, 4 Seoul Subway and RC sleeper is planing construction for the STEDEF system on concrete ballast of the line 5, Seoul, Taegu, and Kwangju Subway. The major purpose of this study is to check influence of the angle with analysising the behavior of sleeper according to the existent or non-existent of angle. And the study is carried to check static analysis by manufacture of same model.