Abstract: The axial stress and axial displacement distribution curves of the concrete core mixing single pile are researched by ANSYS software; and the differences of the single pile ultimate capacity of concrete core mixing pile between different concrete core pile length and area replacing ratio are analyzed; then the single pile ultimate capacity of concrete core mixing pile is compared with that of concrete pile. The different seismic response analyses in time domain is performed with 3-D finite element method, taking into account of the interaction among pile-soil-superstructure. The differences between composite foundation of concrete core mixing pile and pile foundation in seismic response are analyzed. Some parameters influencing the aseismic behavior of composite foundation of concrete core mixing pile are studied. The results show that the core pile shaft friction undertakes the mass of vertical load of the pile; and it is found that there are an optimum core pile length and area replacing ratio for the concrete core mixing pile. The maximum bending moment and shear force of concrete core mixing pile are greater than pile foundation’s under the same seismic response. The maximum moment of concrete core mixing pile lies in the (0.2-0.4) L; the effect degree of area replacing ratio on bending moment and shear is greater than concrete core pile length’s effect; the effect of elastic module of cement-soil is slight.

Key words: concrete core mixing pile, composite foundation, finite element method, dynamic analysis, ANSYS