Abstract:The punching process is simulated by means of PFC2D and its re-development. In the simulation,piles with flat tip and tapered tip are adopted respectively. The effect of pile diameter is considered by adopting different diameters in the research of pile with flat tip. Tapered pile tips with different angles are researched as well. Results explain well the function of soil at pile tip and surrounding pile in the process of pile-soil interaction. In addition, the relationship between pile-soil macroscopical response and changes of soil mesomechanical parameters is intended to be established,which enhances the understand of punching process. Some valuable conclusions from numerical simulation are drawn as follows:(1) particles surrounding piles with different types of pile tip have different displacement behaviors;(2) pile end bearing capacities of flat pile tip and tapered pile tip will both tend towards a steady value while punching process continues;(3) pile-soil macroscopical response and changes of soil mesomechanical parameters do have close relation;(4) only a small fraction of particles locating at the contact surface of pile tip and particles have slippage relative to pile tip,while the others tumble on pile tip;and (5) pile end bearing capacity has some relations with angle of tapered pile tip.