Foundation treatment method for ancient collapse of karst region

The invention discloses a foundation treatment method for ancient collapse of a karst region. The foundation treatment method comprises the following construction steps that a pile hole is drilled ina foundation region, and a cement gravel pile is arranged in the pile hole; a grouting hole is drilled in the foundation region, and cement pressure grouting is carried out in the grouting hole; and the strength of the foundation region is detected in a conical dynamic sounding mode. According to the foundation treatment method, the soft stratum of a deep foundation is reinforced through cement pressure grouting, and the foundation surface is extruded through a cement gravel pile. Under the action of the cement pressure grouting, the cement grout flows into the pile hole and is combined with the cement gravel pile, and the composite foundation with high bearing capacity is further reinforced, so that the mechanical property of the soft stratum in the ancient collapse region is improved, the foundation bearing capa