Abstract: To address the limitations of the current reinforcement technology for multi-stage high-fill slopes, this study proposes a novel flexible supporting structure called frame-prestressed T-shaped fixed anchors (FPTA) that achieves superior reinforcement performance. Firstly, based on the asymmetric distribution of the pullout failure mode of the T-shaped anchor along the burial depth, the concept of the asymmetric failure influence height lz is introduced. A unified mechanical model for the horizontal ultimate pullout resistance of the T-shaped anchor is established, and the anchoring action is represented as the additional cohesion Δc based on the pseudo-cohesion theory. Secondly, a seismic stability analysis method for multi-stage fill slope reinforced by FPTA is developed by using the pseudo-dynamic approach combined with the upper-bound limit analysis method. This method considers the inhomogeneous and damping properties of the fill soil, the interaction between the T-shaped anchor and the soil, and the geometric characteristics of the multi-stage slope. Then, the comparative analysis between the proposed method, experimental results, and existing research serves to demonstrate the validity and reliability of this method. Finally, the effects of soil strength parameters, slope geometry parameters, supporting parameters, and seismic parameters on slope stability are elucidated. This study provides technical guidance for multi-stage fill slope reinforcement engineering projects and offers a theoretical basis for the seismic design of multi-stage fill slopes reinforced by FPTA.

Key words: seismic stability, frame-prestressed T-shaped fixed anchors, multi-stage fill slope, real-time analysis, parametric analysis