NUMERICAL MODELLING FOR STRESSES IN RAILWAY SUBGRADE WITH GEOCELL CONFINED BALLAST

Abstract

With the improvement in railway infrastructure, hauling capacity and speed of trains have increased. Due to this, there have been an increase in overall stresses throughout the railway substructure. In order to overcome this, various improvement techniques are being analysed. One of the improvement techniques is to confine the ballast using geocell. The decrease in subgrade stresses has been assumed to occur as a result of geocell inclusion. For the validation of this assumption, numerical modelling has been done in 2-D and 3-D, respectively. The results have shown that with the inclusion of geocell confinement and with an increase in its width, subgrade stresses have decreased. Also, it have been observed at greater width, stresses on ballast embankment slope have increased drastically. Graphical Trends of results have been found similar on comparing the 3-D and 2-D analyses results, but the difference in magnitude is high. More reliable results are observed in 3-D analysis as a 3-D models have been solved as slab instead of a beam as in case of 2-D analyses. Also, from whole analyses optimum confinement width has been determined.