Shaft bottom structure and bottom sealing construction method for ensuring bottom sealing quality of pipe jacking working shaft

The invention discloses a shaft bottom structure and a shaft bottom sealing construction method for ensuring the bottom sealing quality of a pipe jacking working shaft. The shaft bottom structure comprises an enclosing body structure which works at a position deeper than the jacking pipe working shaft and has shaft bottom elevation of 2 to 4 m, wherein a compaction grouting layer, a first underwater concrete bottom sealing layer and geotechnical cloth are sequentially laid in the enclosing body structure from the bottom to the upper part; the diameter of the geotechnical cloth is greater thanthat of the jacking pipe working shaft; four sides of the geotechnical cloth are tightly fitted with the shaft wall; a second underwater concrete bottom sealing layer is laid on the geotechnical cloth; the second underwater concrete bottom sealing layer compacts and seals the fitting part of the geotechnical cloth and the shaft wall; a wood template is laid on the second underwater concrete bottomsealing layer; a third un