Computational Technology Resources - CCP

Keywords: shakedown, subgrade, concrete slab track.

Summary

Recently, the Korean Government is driving a research and development project for a high-speed railway system which is capable of operating at the maximum speed of over 400 km/h. Besides the vehicle system, the track and railroad system should also be built properly to cope with the sustainable operation of the high-speed trains. The concrete slab track system is being introduced to reduce the cost of frequent maintenance in the conventional ballast track. This introduction also demands a new geotechnical assessment of the performance of the subsoil materials. It is important that cumulative plastic strains in the total operation period can be estimated and controlled. The stress distribution in the subsoil materials beneath the concrete slab track becomes more sophisticated than the ballistic track system. The shakedown phenomena, in which the permanent deformation rate at a number of load cycles has become negligibly small and the cyclic response has become elastic, should be understood for better design of railway track.

This study, presented in this paper, investigates the pattern of the development of the shakedown plastic strains of the subsoil materials subjected to dynamic loads induced by high-speed trains on the stiff concrete slab track system. A shakedown plasticity model that captures only the envelope of the maximum plastic deformations generated during the cyclic loading process was developed. The model parameters were estimated using the empirical relationships based on the experimental data. The accumulated plastic displacement measured in a series of full-scale model tests was compared with the predicted results using the proposed shakedown model. The predicted plastic displacement shows a reasonably good agreement with the measured values. Experimental investigation, is still required, into the shakedown plastic behaviour of geomaterials used in a high-speed railway track to enhance the proposed model.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £65 +P&P)

	Computational & Technology Resources an online resource for computational, engineering & technology publications
	not logged in - login
Front Page Browse CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Proceedings ISSN 1759-3433 CCP: 99 PROCEEDINGS OF THE ELEVENTH INTERNATIONAL CONFERENCE ON COMPUTATIONAL STRUCTURES TECHNOLOGY Edited by: B.H.V. Topping Paper 134 Modeling Shakedown Plastic Strains of Subballast and Subgrade Materials in the Concrete Slab Track System of High-Speed Trains Y.H. Jung¹, C.Y. Choi² and E. Nsabimana¹ ¹Department of Civil Engineering, Kyung Hee University, Republic of Korea ²Infra-System Research Group, Korea Railway Research Institute, Republic of Korea doi:10.4203/ccp.99.134 purchase the full-text of this paper Full Bibliographic Reference for this paper Y.H. Jung, C.Y. Choi, E. Nsabimana, "Modeling Shakedown Plastic Strains of Subballast and Subgrade Materials in the Concrete Slab Track System of High-Speed Trains", in B.H.V. Topping, (Editor), "Proceedings of the Eleventh International Conference on Computational Structures Technology", Civil-Comp Press, Stirlingshire, UK, Paper 134, 2012. doi:10.4203/ccp.99.134 Keywords: shakedown, subgrade, concrete slab track. Summary Recently, the Korean Government is driving a research and development project for a high-speed railway system which is capable of operating at the maximum speed of over 400 km/h. Besides the vehicle system, the track and railroad system should also be built properly to cope with the sustainable operation of the high-speed trains. The concrete slab track system is being introduced to reduce the cost of frequent maintenance in the conventional ballast track. This introduction also demands a new geotechnical assessment of the performance of the subsoil materials. It is important that cumulative plastic strains in the total operation period can be estimated and controlled. The stress distribution in the subsoil materials beneath the concrete slab track becomes more sophisticated than the ballistic track system. The shakedown phenomena, in which the permanent deformation rate at a number of load cycles has become negligibly small and the cyclic response has become elastic, should be understood for better design of railway track. This study, presented in this paper, investigates the pattern of the development of the shakedown plastic strains of the subsoil materials subjected to dynamic loads induced by high-speed trains on the stiff concrete slab track system. A shakedown plasticity model that captures only the envelope of the maximum plastic deformations generated during the cyclic loading process was developed. The model parameters were estimated using the empirical relationships based on the experimental data. The accumulated plastic displacement measured in a series of full-scale model tests was compared with the predicted results using the proposed shakedown model. The predicted plastic displacement shows a reasonably good agreement with the measured values. Experimental investigation, is still required, into the shakedown plastic behaviour of geomaterials used in a high-speed railway track to enhance the proposed model. purchase the full-text of this paper (price £20) go to the previous paper go to the next paper return to the table of contents return to the book description purchase this book (price £65 +P&P)
Back to top	©Civil-Comp Limited 2023 - terms & conditions