Core filling tubular pile cement composite foundation pile and construction method

The invention discloses a core filling tubular pile cement composite foundation pile, which comprises a core pile and a cement pile wrappring around the core pile, and is characterized in that the diameter ratio of the core pile to the outer-layer pile is 0.375-0.50, the length ratio thereof is 0.50-0.76; the cement pile is a cement pile of a repeated spraying section in a range of 2-6m on the upper part and below the core pile bottom end; expansive concrete with C30-C80 of strength grade is filled into hollows on the upper part of the core pile; the length of the core filling concrete is 6-10 times of the diameter of the core pile. The construction method of the core filling tubular pile cement composite foundation pile is characterized by comprising the following steps: the outer-layer cement pile is constructed by a high-pressure spraying, blending and stirring method; the upper end and the lower end of the core pipe are sealed; the central concentric static force is pressed into the core pile to the desig