Numerical Simulation Analysis Of Particle Flow About Pressed Spin Head Of Pile Test In The Sand

Pressed spin head of pile (hereinafter referred to as spin head of pile) is a new type head of pile which is similar to the spiral pile. It can improve the bearing capacity of piles through the spiral blade to increase the contact area with ground. Spin head of pile caps in the bottom of prefabricated pile and can be buried in the soil with the force of pressing pile. Spin head of pile has inherited the advantages of high bearing capacity of the spiral pile, while avoiding the pile torsional problem in the process of pressing pile.Currently, the particle flow analysis techniques which is used in geotechnical engineering have been widely accepted by scholars at home and abroad, and was gradually applied to the buried simulation analysis of straight piles. But for the numerical simulation of the screw piles buried process is still relatively little, the same thing used in the buried process of spin head of pile has not appeared in the literature. One of the key of the buried process characteristics research of the spin head of pile lies in the spin angle and impact on the surrounding soil. This paper is from the perspective of the particle flow to analyze the buried test of spin head of pile in the sand, explaining the microscopic phenomena and mechanism using particle flow software PFC3D. The main work and research results are as follows:(1) Fitting direct shear tests using PFC3D, calibrated microscopic parameters of sand.(2) Compare the process of buried into soil of "wall" and "ball" two different straight pile head model. The results show that:for the same friction coefficient, "ball" pile head due to the presence of voids between the particles, the effect of carry soil is greater than the "wall" of pile head.(3) Compare spin head of pile with one to four blades from the perspective of spin angle, soil stress distribution, particle displacement distribution, the soil plugging effect and so on.(4) Deduce theoretical spin condition of spin head of pile in soil, and get the basic conditions finally.