Pile foundation structure applied to loose geological structure

The utility model relates to the technical field of roadbed construction, and discloses a pile foundation structure applied to a loose geological structure, the pile foundation structure comprises a soft soil layer, two pile cylinders are arranged in the soft soil layer, a plurality of sliding holes are formed in the outer wall surfaces of the pile cylinders, and arc-shaped sliding plates are slidably connected to the interiors of the sliding holes; the outer surface of the gravity knocking column is in contact with the side slope of the arc-shaped sliding plate, so that the arc-shaped sliding plate extends outwards and enters the soft soil layer, and when the gravity knocking column reaches the bottom of the interior of the pile barrel and enables all the arc-shaped sliding plates to extend into the soft soil layer, a user injects high-pressure grout into the pile barrel at the moment; the high-pressure grout can enter the second grouting hole through the first grouting hole, so that the high-pressure grout