Experimental and numerical analysis of rainfall-induced slope failure of railway embankment of semi high-speed trains

Abstract

Safety and maintenance of railway tracks has been very crucial, for sustainable economic development of many nations. Almost the entire Indian railway tracks were built over the raised earth embankments. These embankments are susceptible to slope failure due to numerous reasons. One of the major cause is seepage and surface runoff during rainy (monsoon) season. Erosion by gullying has regarded as most significant failure scar. Various researches had studied the embankment failure due to rainfall. However, the gullying effect on the slope failure has been missing in these studies. Hence, in this study slope stability analysis of the railway embankment has been performed considering the gullying. Embankment of Dedicated Freight Corridor (India) has been taken up in this study. The present study has three sections (a) Field observation, (b) scaled laboratory modelling, and (c) FEM-based numerical analysis. The effect of vegetation, degree of compaction, and the intensity of rainfall on the slope stability has been evaluated. Effect of gullying has incorporated through change in shape and dimension of embankment. It has been found that vegetation significantly reduced the gully formation and also the less compacted slope experienced more gullies formation as compared to the more compacted slope. While varying the rainfall intensity from 20 to 100 mm, it has been observed that without consideration of gully higher FOS (factor of safety) was reported. Moreover, FOS decrease with increase of rainfall from 20 to 100 mm and becomes constant after that.