Abstract: The determination of the location of the most dangerous slip surface is a key work in the study of side slope stability. The change of displacement characteristics of rock and soil in the process of slope instability is the most intuitive manifestation of stability state of the side slope. In this research, the displacement field of the side slope is numerically simulated by finite element method. The imported numerical simulation results are developed through coding by a kind of programming software. The spatial displacement interpolation algorithm is then adopted to realize an accurate and efficient search to the most dangerous slip surface on the side slope. Finally, the rationality of the proposed method and coded program is verified by a classical example of 3D side slope. This method does not need to assume the shape and position of slip surface, and the predicted result is reliable and meanwhile easy to program.

Key words: displacement field, most dangerous slip surface, displacement interpolation, finite element method