Abstract: The stability analysis of high rock slopes is a classical research topic in geotechnical engineering. One analysis method based on a certain hypothesis is different from others. This paper is to discuss and compare the advantages and disadvantages of various existing rock slope stability analysis methods. In addition, on the basis of traditional slope stability analysis methods, such as the limited equilibrium method and the finite element method (FEM), we propose an idea using the FEM to directly solve stability of the slope. The stress field and the deformation field of a slope at all conditions can be well simulated with landslide units which have not yet slid after excavation and support, and thus slope safety factors can be calculated based on the real stress field. Furthermore, the stability analysis of rock slopes is gradually simulated during the step-step excavating process by combining on-site monitoring with computer simulation means. An example of analytical calculation shows that the rigid body limit equilibrium method is complemented and upgraded by this new method. We solve the challenge of determining the strength reduction ratio in the strength reduction method, and deal with the uncertain mechanical direction in the overloading method. The calculated results of the slope safety factor and the stability by using the new method show good agreement with actual field measurements. This paper provides a new thought and approach for the stability analysis of complex rock slope.

Key words: high rock slope, stability analysis, safety factor, excavation process, direct solution of finite element method