Ultralarge-length-diameter-ratio cast-in-place pile reinforcement cage matched with drilling core detection and drilling core detecting method

The invention discloses an ultralarge-length-diameter-ratio cast-in-place pile reinforcement cage matched with drilling core detection and a drilling core detecting method. In the cast-in-place pile reinforcement cage, a reinforcement cage main rib is used for fixedly arranging a vertical steel pipe; a bottom port of the vertical steel pipe is from the pile bottom by 1 m; a top pipe mouth of the vertical steel pipe is projected at the top of the reinforcement cage; after pile body concrete is filled, the vertical steel pipe is kept as a hollow pipe; and a drill bit of a drilling machine for drilling core detection can fall down to a position above the pile bottom by 1 m along the hollow pipe for drilling core sampling of the pile bottom of a cast-in-place pile. The vertical steel pipe is used as a guide pipe for accurate drilling core sampling to realize quick and effective detection of the thickness of pile bottom sediments and the rock-soil properties of a pile end bearing stratum of the ultralarge-length-d