Limit analysis approach for stability of embankments on homogeneous soft soil

The stability analysis is performed for the embankments founded on the ground of a homogeneous soft soil. The soft soil is assumed to fail along an arc-shaped surface. The undrained shear strength of ground soil is considered to increase linearly with depth. The embankment material is assumed to fail along a log-spiral surface. The cohesion and internal friction angle parameters are adopted for describing the shear strength of embankment soil. An approach for the stability analysis is thus derived by using the upper-bound theorem. It can be used to calculate the non-dimensional stability numbers and stability charts for the determination of the minimum factor of safety and the critical slip surface of embankment. A case study is carried out by using the proposed approach. The calculated minimum factor of safety satisfies the measured failure condition. A good agreement is also obtained between the minimum factor of safety and the critical slip surface calculated using the proposed approach and those calculated using the slice approach and the variational approach of limit-equilibrium analysis.