Topological self-locking sandwich structure, pipeline single ring and submarine explosion-proof pipeline

The invention provides a topological self-locking sandwich structure, a pipeline single ring and a seabed anti-explosion pipeline, and belongs to the technical field of ocean pipeline engineering. The topological self-locking sandwich structure comprises a first building block and a second building block which are in inferior arc shapes, first splicing faces are symmetrically arranged on the two opposite sides of the first building block in the circumferential direction of an arc, and second splicing faces are symmetrically arranged at the two ends of the first building block in the circumferential direction of the arc; third splicing faces are symmetrically arranged on the two opposite sides of the second building block in the arc circumferential direction, the third splicing faces are matched with the first splicing faces, and fourth splicing faces are symmetrically arranged at the two ends of the second building block in the arc circumferential direction. The first building block and the second building bl