# Evolution Process of Toppling Deformations in Interbedded Anti-Inclined Rock Slopes
## 5 Conclusions  
This study investigates the evolutionary process and failure mechanisms of anti-inclined interbedded rock slopes under long-term gravity through base friction physical model tests. The primary conclusions of this study are as follows:  
(1) The toppling of interbedded anti-inclined rock slopes is a composite mode formed by the overturning of hard rock blocks and the bending of soft rock columns. Specifically, hard rock blocks slide and overturn along the existing cross joints, resulting in block-flexure toppling. Soft rock columns undergo continuous bending deformation, resulting in flexural toppling. Throughout the deformation process, both toppling modes occur simultaneously, mutually promoting and constraining each other for coordinated development.  
(2) The degree of constraint provided by adjacent rock columns highly influences the potential of toppling motion. The initiation of toppling requires overcoming the interlayer shear forces. Contractional strain parallel to the THS causes open space between the layers, thus facilitating forward rotation. As interlayer contact is restored, further rotation is resisted by increasing interlayer shear forces, and the slope deformation becomes self-stabilized.  
(3) The destruction of the toe blocks often triggers further motion of rock masses beyond their self-stabilized configuration. Toppling fracture zones are gradually formed by tracing tensile fractures and existing cross joints through multiple layers. When multiple-fracture zones connect and form a throughgoing failure surface, an integral movement of fractured rock masses occurs along the failure surface, resulting in slope instability.  
(4) The evolution of an anti-inclined rock slope can be recognized as occurring in four stages. These stages are initial shearing, free rotation, creep rotation, and finally the progressive failure stage. Unlike conventional toppling failures, the ultimate failure surface typically lies above the THS, and the landslide deposits are composed mainly of highly toppled rock masses.  
Conceptualization, Y.N. and Y.S.; methodology, Y.N.; investigation, Y.N., T.D., P.X., F.D. and B.Z. ([PERSON]); resources, B.Z. ([PERSON]); data curation, Y.N., T.D., P.X., F.D. and B.Z. ([PERSON]); writing--original draft preparation, Y.N.; writing--review and editing, Y.S. and J.V.S.; supervision, Y.N. and Y.S.; project administration, Y.N.; funding acquisition, Y.N. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the National Natural Science Foundation of China (Grant No. 42307220), the Xi'an Association for Science and Technology Youth Talent Support Program (Grant No. 959202413094), the Fundamental Research Funds for the Central Universities, CHD (Grant No. 300102264103), and the Postdoctoral Research Project Funding of Shaanxi Province (Grant No. 2023 BSHEDZZ210).  
Not applicable.  
The data presented in this study are available on request from the corresponding author.  
The authors would express their sincere appreciation to anonymous reviewers and editors for their valuable comments and suggestions.  
The authors declare no conflicts of interest.  
The following abbreviations are used in this manuscript: