Numerical Modeling of Improvement of Soft Soil with Stone Columns under High-Speed Train Crossing

Document Type : Original Article

Authors

1 Department of Civil Engineering,, Islamic Azad University, Tehran, Iran

2 Department of Civil Engineering, Islamic Azad University, Tehran, IRAN

Abstract

Rail transport has unique advantages over other modes of transport, such as less environmental vulnerability, less pollution and more safety than other modes of transport. Due to the lack of lands with adequate load-bearing capacity, parts of the railway route are built on soft soils. These types of soil have the possibility of creating instability and subsidence of railway lines in this type of soil is one of the main concerns of engineers. These factors lead to an increase in differential settlements, reduce the speed of the train, and finally cause financial and human losses. High-speed trains are recently used in developed countries to reduce travel time, which can significantly increase the dynamic responses of components on railroad tracks, especially when the train is traveling at a critical speed. One of the ground improvement methods that have been widely used to improve soft sediments and loose fine-grained soils is the stone column method.The main purpose of this study is to investigate and control the amount of settlement and stability of soft clay bed and embankment of the railway under high-speed train crossing as two important factors in the operation and use of the railway complex. In this study, the performance of stone columns in the bed of high-speed trains to reduce soil settlements and prevent the occurrence of differential settlement in different conditions is investigated. The results showed that by increasing the length of the stone column and decreasing its diameter, differential settlement due to the passage of high-speed trains decreases. Also, increasing the stiffness of the encasing geogrid reduces the settlement. In addition, as the train speed rises, the settlement drops and the Excess pore water pressure due to the train passing increases.

Keywords

Main Subjects


[1] Thach, P. N., Liu, H. L., & Kong, G. Q. (2013). “Vibration analysis of pile-supported embankments under high-speed train passage”, Soil Dynamics and Earthquake Engineering, 55, 92-99.
[2] Leshchinsky, B., & Ling, H. I. (2013). “Numerical modeling of behavior of railway ballasted structure with geocell confinement”, Geotextiles and Geomembranes, 36, 33-43.
[3] Shahraki, M., & Witt, K. J. (2015). “Improvement of soft subgrade soil using stone columns for high-speed railway track”, In International Conference on Soft Ground Engineering (ICSGE2015), 3, 4.
[4] Indraratna, B., Nimbalkar, S. S., Ngo, N. T., & Neville, T. (2016). “Performance improvement of rail track substructure using artificial inclusions–Experimental and numerical studies”, Transportation Geotechnics, 8, 69-85.
[5] Gu, L. L., Ye, G. L., Bao, X. H., & Zhang, F. (2016). “Mechanical behaviour of piled-raft foundations subjected to high-speed train loading”, Soils and Foundations, 56(6), 1035-1054.
[6] Li, W., & Bian, X. (2016). “Dynamic performance of pile-supported bridge-embankment transition zones under high-speed train moving loads”, Procedia engineering, 143, 1059-1067.
[7] Abebe, M. S., & Qiu, H. S. (2016). “Numerical modeling of geotextile reinforcement of soft subgrade ballasted railway under high speed train”, Electronic Journal of Geotechnical Engineering, 21(12), 4327-4343.
[8] Yoo, C., & Kim, S. B. (2009). “Numerical modeling of geosynthetic-encased stone column-reinforced ground”, Geosynthetics International, 16(3), 116-126.
[9] Basack, S., Indraratna, B., Rujikiatkamjorn, C., & Siahaan, F. (2017). “Modeling the stone column behavior in soft ground with special emphasis on lateral deformation”, Journal of Geotechnical and Geoenvironmental Engineering, 143(6), 04017016.
[10] Tabchouche, S., Mellas, M., & Bouassida, M. (2017). “On settlement prediction of soft clay reinforced by a group of stone columns”, Innovative Infrastructure Solutions, 2(1), 1.
[11] Tan, X., Zhao, M., & Chen, W. (2018). “Numerical simulation of a single stone column in soft clay using the discrete-element method”, International Journal of Geomechanics, 18(12), 04018176.
[12] Hosseinpour, I., Soriano, C., & Almeida, M. S. (2019). “A comparative study for the performance of encased granular columns”, Journal of Rock Mechanics and Geotechnical Engineering, 11(2), 379-388.
[13] Remadna, A., Benmebarek, S., & Benmebarek, N. (2020). “Numerical Analyses of the Optimum Length for Stone Column Reinforced Foundation”, International Journal of Geosynthetics and Ground Engineering, 6(3), 1-12.
[14] Pandey, B. K., Rajesh, S., & Chandra, S. (2020). “Numerical evaluation of geogrid-encased stone columns in soft soil under embankment loading”, In Geo-Congress 2020: Foundations, Soil Improvement, and Erosion, Reston, VA: American Society of Civil Engineers, 543-551.
[15] Hataf, N., Nabipour, N., & Sadr, A. (2020). “Experimental and numerical study on the bearing capacity of encased stone columns”, International Journal of Geo-Engineering, 11(1), 1-19.
[16] Fayed, A. L., Sorour, T. M., & Shehata, H. F. (2017). “Study of the Behavior of Floating Stone Columns in Soft Clay Formations Using Numerical Modeling”, In International Congress and Exhibition Sustainable Civil Infrastructures: Innovative Infrastructure Geotechnology, pp. 236-251.
[17] Correia, A. G., Cunha, J., Marcelino, J., Caldeira, L., Varandas, J., Dimitrovová, Z., ... & Silva, M. (2007). “Dynamic analysis of rail track for high speed trains. 2D approach”, 5th Intl Worksop on Application of Computational Mechanics on Geotechnical Engineering, 4.
[18] Shahraki, M., Sadaghiani, M. R. S., Witt, K. J., & Meier, T. (2014). “3D modelling of train induced moving loads on an embankment”, Plaxis Bulletin, 36, 10-15.
CAPTCHA Image