Behavior of Railway Embankment Constructed on Soft Deltaic Deposits under Varying Train Speeds

Abstract

This study employs 2D finite element modeling using Plaxis to investigate the behavior of the railway embankment constructed on the active Ganges-Bramhaputra floodplain. The parametric study considers three different train speeds, 100, 120, and 170 km/hr, and two different soil profiles along different chainages, chainage 82 km+183 m (Ch1) and 84 km+102 m (Ch2) of Padma Bridge Rail Link. Pseudo-static trainloads have been applied and the settlement of the ballast bottom (BB) and embankment bottom (EB) have been determined and compared along with the factor of safety (FS). From the obtained results, the maximum settlement of EB in Ch1 ranged between 27.45 cm to 29.2 cm which is lower by 9.2 cm from Ch2 on average. For BB, greater settlements have been observed as they varied between 33.25 cm to 36.20 cm for Ch1 and 42.80 cm to 45.31 cm for Ch2. Thus in both cases, Ch2 shows greater settlements. Also in both chainages, the settlements exceed the allowable range. As the train speed increases from 100 to 170 km/hr, the increase in the settlement is noticeable for the ballast bottom but not for the embankment bottom. Considering the FS, the embankments are assessed to be safe in all considered cases with an FS> 1.2, without any significant effect of train speeds.