Girth joint structure of prefabricated assembly tunnel

The invention relates to a girth joint structure of a prefabricated assembly tunnel. The tunnel is manufactured by splicing a plurality of prefabricated structure sections. A tunnel structure joint exists between two of the prefabricated structure sections. The girth joint structure is arranged on the tunnel structure joint. The girth joint structure comprises two first stainless steel plates, a second steel plate and a grouting tube, wherein the two first stainless steel plates are vertically attached to the wall faces on the two sides of the tunnel structure joint; the second stainless steel is horizontally arranged on the tunnel structure joint; the grouting tube is pre-buried in one prefabricated structure section, a grout outlet is formed in the tunnel structure joint, a grouting body is formed at the tunnel structure joint by injecting grout, and the gap of the tunnel structure joint is filled with the grouting body. The girth joint structure has the bending-resistant shear-resistant functions and can guarantee the effective transmitting ability of a joint. The gap between the two tunnel prefabricated structure sections is filled with the grout through the pre-buried grouting tube, and underwater is prevented from entering the tunnel.