Currently

most of studies on the mechanisms of driving and pulling for Benoto pile sleeve are focused on sleeve driving process. Yet

pulling by high-frequency vibration are deficient. Using the ALE (Arbitrary Lagrangian-Eulerian) method

the finite element-infinite element coupling model is developed to explore the pulling mechanism and influence of parameters on sleeve pulling. The results of numerical analysis show that the process of sleeve pulling by high-frequency vibration can be divided into two stages: the slow and the fast pulling stages. During sleeve pulling

the soil displacements

stresses

void ratio and excess pore water pressure all mutate near the sleeve end

and the change is more significant as approaching to the sleeve center. Therefore

the influence of soil parameters (including soil young’s modulus and soil-sleeve friction coefficient) and vibration hammer parameters (such as vibration frequency and vibration force) on sleeve pulling are investigated. When the soil is soft and the friction of the sleeve-soil is strong

the change of soil displacements and stresses variety are obvious. The parameters of the vibrating hammer only have influence on sleeve pulling speed and soil particle velocity

and hardly have any effect on soil displacements and stresses. When the vibration frequency is close to the natural frequency of soil layers

the pulling resistance is the small. The larger the vibration frequency is

the smaller the influence range of vibration.