• Proceedings of the KSR Conference
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• 2003.10b
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• pp.104-110
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• 2003

Precast concrete slab track has been already turned out to be more efficient than cast-in place concrete slab track in view of the easiness of construction and the quality control of concrete. Thus, there is a great need to bring in the precast slab track system. In order to develop the realistic precast slab track system that is well conformed to our circumstances, the performance criteria of slab track, and the state-of-the art of precast slab track systems that are used in other countries are briefly discussed here.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1423-1429
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• 2010

We proposed a design procedure for Korean Precast Slab Track system. Korean Precast Slab Track system cannot use the same design procedure to German slab track system because of different shapes and some problems. We identified the problems of German slab track design system that cannot simulate effects of loads. This proposed procedure is implemented for the commercial software of ABAQUS. Using this procedure, one can consider uncombined effects between slab panel and hydraulic sub base, effect of close sleepers.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1659-1663
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• 2011

Precast concrete slab track is a track structure to be installed by transporting and assembling precast concrete slabs manufactured at the factory. This method can improve concrete quality, provide easy maintenance and reduce construction time, compared with in-situ concrete track. However, the concrete slabs being continuously connected in longitudinal direction, due to the temperature change between summer and winter, the openings at slab joints have occurred. Thus, in this study, to identify the cause of this opening of slab joint, the joint opening caused by temperature drop in the longitudinally continuous precast concrete slab track has been predicted using three-dimensional finite element analysis, and compared with field measurements. Based on the proven model, the slab joint opening, and the stress pattern of concrete slab and steel reinforcement according to concrete slab-base friction properties, concrete-reinforcement bond properties, and prestressing were analyzed.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.256-260
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• 2010

It has been proved that precast slab track has advantage of rapid construction speed and good quality compared to in-situ concrete slab track. A korean precast slab track, which is named as a K-PST, was developed and had been installed on the embankment and explored on the air. The developed track system consists of precast track panel and underpouring layer which is made of cement-asphalt mortar. Consequently, poor filling of underpouring layer directly could affect on the long-term performance of the track system. As a preliminary study, the effect of the poor infilling of the underpouring in precasst slab track system on structural behavior was investigated through FEM analysis.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.213-218
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• 2002

A new German high speed railway slab track was investigated. The construction objective was to provide a durable and maintenance free track system consisting of precast concretepanels of consistently high quality and highest achievable accuracy in track geometry. The System on the basis of precast panels similar to the slab track system constructed on the line Dachau- Karlsfeld in 1997.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.955-960
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• 2004

In this study, three dimensional FE analysis of concrete slab track has been performed in order to develop the realistic design of precast concrete slab track. The precast slab track system including the precast concrete slab panel and the grout layer is modeled using the three dimensional solid element with crack softening effect. The input load is computed from the one dimensional beam element model constituting the rail and several discrete springs. To investigate the effect of the longitudinal connection of slab panels, two different systems-continuous and discrete systems - are modeled. The analytical results show that the stresses of both the slab panel and the grout layer are in the range of linear elastic, and, at the interface between two adjacent panels, the primary stresses of the grout layer of the discrete system are higher than those of the continuous system. However, The overall stress levels of the grout layer are very low relative to the strength of th grout.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2435-2438
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• 2011

Steel bar is used for as a reinforcing material in a concrete slab track. Bacuase the steel re-bar could provide passes for current transition, all the cross points of steel re-bars should be insulated by using plastic materials. This is due to the loss of signal intensity of track-circuit. In this study, GFRP bars are adopted in place of the traditional steel reinforcing bars for a concrete slab track to minimize the loss of the signal intensity. In order to evaluate the replacing effect on eletrical characteristic of slab track, measurements of surface resistivity are conducted on steel and GFRP reinforced precast slab tracks. In the results, the GFRP reinforced slab strack shows the higher resistivity than the steel reinforced slab track.

• Steel and Composite Structures
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• v.24 no.1
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• pp.113-128
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• 2017

This paper highlights a study undertaken on the free vibration of a precast steel-concrete composite slab panel for track support. The steel-concrete composite slab track is an evolvement from the slab track, a form of ballastless track which is becoming increasingly attractive to asset owners as they seek to reduce lifecycle costs and deal with increasing rail traffic speeds. The slender nature of the slab panel due to its reduced depth of construction makes it susceptible to vibration problems. The aim of the study is driven by the need to address the limited research available to date on the dynamic behaviour of steel-concrete composite slab panels for track support. Free vibration analysis of the track slab has been carried out using ABAQUS. Both eigenfrequencies and eigenmodes have been extracted using the Lanczos method. The fundamental natural frequencies of the slab panel have been identified together with corresponding mode shapes. To investigate the sensitivity of the natural frequencies and mode shapes, parametric studies have been established, considering concrete strength and mass and steel's modulus of elasticity. This study is the world first to observe crossover phenomena that result in the inversion of the natural orders without interaction. It also reveals that replacement of the steel with aluminium or carbon fibre sheeting can only marginally reduce the natural frequencies of the slab panel.

• Steel and Composite Structures
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• v.25 no.4
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• pp.427-442
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• 2017

This paper presents unprecedented damped oscillation behaviours of a precast steel-concrete composite slab panel for track support. The steel-concrete composite slab track is an innovative slab track, a form of ballastless track which is becoming increasingly attractive to asset owners as they seek to reduce lifecycle costs and deal with increasing rail traffic speeds. The slender nature of the slab panel due to its reduced depth of construction makes it susceptible to vibration problems. The aim of the study is driven by the need to address the limited research available to date on the dynamic behaviour of steel-concrete composite slab panels for track support. Free vibration analysis of the track slab has been carried out using ABAQUS. Both undamped and damped eigenfrequencies and eigenmodes have been extracted using the Lancsoz method. The fundamental natural frequencies of the slab panel have been identified together with corresponding mode shapes. To investigate the sensitivity of the natural frequencies and mode shapes, parametric studies have been established, considering concrete strength and mass and steel's modulus of elasticity. This study is the world first to observe crossover phenomena that result in the inversion of the natural orders without interaction. It also reveals that replacement of the steel with aluminium or carbon fibre sheeting can only marginally reduce the natural frequencies of the slab panel.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.740-744
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• 2011

Precast slab track system(PSTS) is a concrete track laying system where the slab panels are pre-manufactured in factories and assembled and installed on-site. PSTS has been developed for the past 30 years in countries where railway technologies are advanced such as Japan and Germany to improve the various drawbacks of the in-situ concrete slab track. However, the usefulness of PSTS is being continuously approved by many other countries such as China, Taiwan, Austria, Italy, Spain, etc,. Lately, not only Japan and Germany, but also Austria, Italy and China have developed their own PSTS by collaboration between their Governments and private enterprises and are now attempting to expand their businesse soverseas. In accordance to such movement, in 2006, the Korean Railroad Research Institution and Sampyo E&C have developed a Korean PSTS by joint research. PSTS consists of concrete panel, under pouring layer and concrete base layer. Amongst these components, the panel is the main component of PSTS which supports the train load and has a great effect on the track quality, workability and economics. Therefore, a study is to be conducted to select the optimum size for the Panel of the precast slab track system panel by analyzing the various standards & forms, interpretation of finite elements of the selected model and economical analysis.