Abstract: To further study the load transfer mechanism of the tapered pile, the pile-soil stress analysis model of tapered pile is established by using FLAC3D finite-difference software. The differences of load carrying characteristics between the tapered pile and the uniform-section pile are compared and analyzed. The influence of the taper angle on the load transfer mechanism of tapered pile between pile and soil is emphatically discussed. The results show that: the decreasing rate of axial force along the depth increases rapidly with the increase of the tapered angle; the shape of the inclined side wall changes the load transfer mechanism of the pile shaft. The proportion of the side load sharing of the tapered pile is as high as 89.3%, and the external load is mainly carried by the friction resistance of pile-soil interface; Under the same settlement of pile top, the pull-down displacement of the surface soil around the tapered pile is significantly greater than that of the uniform-section pile, and the larger the taper angle is, the higher the displacement will be. This special pile-soil interaction mechanism is the main source of the excellent load carrying capacity of the tapered pile.

Key words: Tapered Pile, Numerical Analysis, Load Transfer Mechanism, Load-Sharing Ratio, Mechanism of Pile-Soil Interaction