Steel-plate-encased precast concrete column foot joint and construction method therefor

A steel-plate-coated assembled concrete column-base joint, comprising a prefabricated-reinforced-concrete column (2) at an upper portion and a reinforced-concrete foundation (1) at a lower portion that are vertically correspondingly spliced, the prefabricated-reinforced-concrete column (2) being pre-buried with an internal-to-column longitudinal bar (4), an internal-to-column stirrup (5) and a grouting sleeve device (6) that are circumferentially evenly distributed along a column body, the reinforced-concrete foundation (1) being pre-buried with a foundation anchoring-insertion steel bar (12), the foundation anchoring-insertion steel bar (12) being connected to the internal-to-column longitudinal bar (4) via a grout-injection material (13) filling the grouting sleeve device (6), and a splicing seam between the reinforced-concrete foundation (1) and the prefabricated-reinforced-concrete column (2) being filled with the grout-injection material (13),

• wherein the joint further comprises a coating-steel-plate sleeve (7) that is integrally prefabricated with the concrete column and encloses an exterior of a column base, a top end of the coating-steel-plate sleeve (7) is below a grout-injection hole and a grout exiting hole of the grouting sleeve device, a gap is between a bottom end of the coating-steel-plate sleeve (7) and an upper surface of the foundation, and an outside of the gap is provided with a plugging material (3), and
• the joint further comprises an annular rib plate (8) all of whose edges are horizontally and seamlessly connected to an inner wall of the coating-steel-plate sleeve (7) and whose middle portion is provided with a rib-plate opening (81), the annular rib plate (8) is located at a bottom of the coating-steel-plate sleeve and is above the bottom end of the coating-steel-plate sleeve (7) to leave a steel-plate-cylinder rim, the steel-plate-cylinder rim, the annular rib plate (8), the plugging material (3) and the upper surface of the foundation form a closed splicing-seam cavity, the annular rib plate is provided with a sleeve opening (82) that matches with the grouting sleeve device (6), the grouting sleeve device (6) sequentially passes through the sleeve opening (82) and protrudes into the splicing-seam cavity, a bottom side face of the grouting sleeve device (6) flushes with a bottom side face of the coating-steel-plate sleeve (7), and the splicing-seam cavity is filled with the grout-injection material (13).