Finite Element Analysis of an Unpaved Road Embankment Under Drawdown Conditions

Unpaved roads play a crucial role in transportation infrastructure, particularly in rural and developing regions where limited resources prevent the construction of paved road networks. However, the stability of road embankments is a significant issue in Bangladesh. Two major contributing factors to this problem are changes in external water levels and external loading. This paper's objective is to examine how slope behavior changes in response to these shifts. Numerical modeling was conducted using the PLAXIS-2D software, based on the two-dimensional finite element method (FEM). Slope stability analysis was performed considering different mechanical properties, such as the angle of internal friction (ranging from 20° to 35°) and cohesion (ranging from 2.5 to 10 kN/m2), along with different water levels (high water table, rapid drawdown, slow drawdown, and low water table). Additionally, investigations were conducted to assess the embankment's response to static loading. The results indicated that drawdown conditions significantly affected the embankment's stability, with permeability and drainage conditions playing crucial roles. Moreover, excessive external loading caused substantial instability, compromising the overall endurance of the embankment.