A three-dimensionally-adjustable spike for securing a post comprises: two C-shaped walls, two wrench-accessible openings formed in the two C-shaped walls, a base molded to the two C-shaped walls, two post-elevating struts welded to the base, post-clamping screws screwed into the two C-shaped walls and the post, convex bolts each having a convex bolt bottom, concave upper washers each having an upper concave surface engaging with the convex bolt bottom, concave lower washers each having a lower concave surface, convex locking nuts each having a convex nut top engaging with the lower concave surface for three-dimensionally adjusting and securing the stanchion base and the post perpendicularly to the ground, a hammer plate, plate nuts welded to the hammer plate for stationarily securing the convex locking bolts to the hammer plate, spiral blades, offset spiral shovels, and a spike welded to the spiral blades, the offset spiral shovels, and the hammer plate.