Stability and Countermeasures for a Deposit Slope with Artificial Scarp: Numerical Analysis and Field Monitoring

Abstract

This paper presents the results of the stability analysis of a deposit slope with an artificial scarp in a tunnel exit and an evaluation of the effectiveness of four proposed reinforcement schemes. A typical slope section was used to study the deposit slope stability and retaining mechanisms of the reinforcement systems. A series of two-dimensional (2D) finite element models (FEM), combined with a strength reduction technique, was established using the Phase2 software. According to field monitoring results, the horizontal displacements of the front, middle, and rear of the slope decreased gradually, and the safety factor increased successively. The front of the deposit slope was in a state of limit equilibrium as a result of the artificial scarp formed by long-term manual excavation. Anchors and concrete frame beams provided stress compensation and improve the stability of the deposit slope, and front prestressed anchor cables and stability piles strengthened the mechanical properties of the rock and soil masses and provided resistance at the front of the deposit. Rear stability piles prevented the front of the deposit from being pushed and the middle and rear of the deposit from being pulled and provided resistance at the front of the deposit. The field monitoring also showed that the deformation of the deposit slope was effectively controlled. The study results provide insights into the effectiveness of measures for reinforcing and maintaining the stability of deposit slope with artificial scarps.