Reinforcing structure of sand foundation

The utility model discloses a reinforcing structure of a sand foundation. Comprising a formed drill hole drilled to the bottom depth of a sand layer, a steel grouting floral tube located in the center of the formed drill hole, a first-section graded fine-crushed stone column filled in the space between the formed drill hole and the steel grouting floral tube and as high as the sand layer, and an inorganic grouting material plugging column filled in the top of the first-section graded fine-crushed stone column. The first-section graded fine stone column is located at the top of the inorganic grouting material plugging column, the second-section graded fine stone column is located at the top of the inorganic grouting material plugging column, and the steel grouting floral tube and the first-section graded fine stone column are filled with the low-carbon grouting liquid. By the adoption of the structure, low-carbon grouting liquid is evenly injected into a sand soil layer through the steel grouting floral tube,