Abstract: Based on the energy equilibrium, the computational formula of critical buckling length of multi-layer rock slope is derived. Considering interlayer and cross joints, the numerical manifold method is used to simulate the buckling evolution process of Malvern hills slope in New Zealand, and the theoretical calculation and numerical simulation results are compared with the field measured data. The results show that numerical manifold method can accurately simulate slope buckling failure process by preforming interlayer and cross joints. The process of slope buckling deformation and instability failure can be divided into interlayer dislocation-slight bending, slope toe traction-sharp uplift and accelerated sliding-landslide formation. Under the long-term action of self-weight, the evolution of slope buckling from formation to failure mainly includes three stages: initial bending, sharp bending and landslide formation. The angle between cross joint and slope normal is defined as β. Among the four kinds of cross joints with the angle β of 0°, 15°, 30° and 45°, the slope with 45° cross joint is most prone to slipping and bending deformation, the degree of buckling is the largest, and the number of time steps of slipping and bending is the least. When β is in the range of 30°−45°, the numerical simulation results are in good agreement with the reality.

Key words: layered slope, buckling failure, numerical manifold method, cross joint