Prefabricated assembly type subway foundation pit supporting structure

The utility model discloses a prefabricated assembly type subway foundation pit supporting structure which comprises a plurality of prefabricated assembly type rectangular vertical shafts, a coping beam, a compaction grouting body layer, a plurality of sleeve valve pipes, a plurality of anti-overturning anchor rods and a low-grade concrete layer. The prefabricated assembly type rectangular vertical shaft is arranged in a foundation pit and comprises a plurality of layers of rectangular well frames which are sequentially spliced from top to bottom. And the capping beam extends towards the outer side of the foundation pit to form an extension section. The compaction grouting body layer is located at the bottom of the foundation pit. The multiple anti-overturning anchor rods are evenly distributed on the outer side of the foundation pit with the foundation pit as the center and arranged on the extending section of the coping beam in a penetrating mode. The sleeve valve pipes are evenly distributed between the fo