Numerical Simulation and Stability Analysis Method of Sliding Failure in an Embankment Reinforced by piles in cement-improved soil

Abstract This paper proposed a stability analysis method suitable for embankments reinforced by piles in cement-improved soil through 3D finite element numerical simulation. First, the failure mode of piles in cement-improved soil in each part of the sliding range was explored. Then, based on the existing research on rigid pile calculations, the contribution of piles in cement-improved soil to resistance in different failure modes was determined appropriately through the plane analytical calculation method of the safety factor. Finally, the accuracy of the calculation method proposed in this paper was verified. The research shows that the sliding mode transitions from linear sliding in the slope to circular sliding in the foundation. The possible failure modes inside the ground are divided into two types according to location: pile bending failure inside the slope foot and soil sliding upward by overcoming the friction force at the pile‒soil interfaces, which results in excessive deformation outside. Increasing the thickness of the outer cement piles helps to delay the increase in the inner pile bending moment, which leads to tensile damage. Compared with the calculation methods that consider only a single failure mode, the safety factors calculated by the method presented in this paper are closer to those obtained via numerical simulation.