Karst tunnel supporting structure based on keel support and supporting method thereof

The invention belongs to the technical field of tunnel construction, and particularly relates to a karst tunnel supporting structure based on keel supporting and a supporting method thereof.The karst tunnel supporting structure comprises a filter layer fixedly connected with the inner side of an initial lining, the inner side of the filter layer is provided with a keel supporting structure, and the keel supporting structure penetrates through the initial lining and the filter layer and is fixedly connected with a soil layer; a plurality of confluence prefabricated slabs are clamped between the keel supporting structures and the filtering layers in the length direction, the two sides of the confluence prefabricated slabs communicate with the keel supporting structures, open grooves are formed in the two sides of the bottom end of the tunnel correspondingly, drainage structures are fixedly connected into the open grooves, and the drainage structures communicate with the bottom ends of the keel supporting struct