The vertical frictional resistance generated during the deformation of anti-slide pile can form anti-moment or push-pull resistance

which can contribute to landslide prevention. The impact of the vertical frictional resistance on the internal forces and deformation of anti-slide pile socketed section is studied. On the base of elastic foundation coefficient method “K method” and small deformation assumption

the vertical frictional resistance is considered proportional to the relative displacement of pile and rock mass

then the mechanical model and the bending deformation differential equations of anti-slide pile are established. And the corresponding solution process is derived. The effects of the vertical frictional resistance on anti-slide pile are analyzed by the calculation of anti-slide pile in Majiagou landslide #1. It is found that the counter torque formed by vertical frictional resistance can reduce the pile deformation and internal forces

the shear force is affected by the counter torque mostly

followed by the deformation

and little influence is brought to the bending moment. The anti-slide pile model which has taken the vertical frictional resistance into account can improve the problem of excessive shear force when using the current method

and make the design more reasonable.