The invention relates to a construction method for backfilling of an assembled secondary lining of a submerged tunnel, which belongs to the technical field of
rail transit engineering construction. It is characterized in that: after the
assembly of each ring segment is completed, the bean-gravel construction is carried out in the gap between the back of the prefabricated segment and the primary support structure of the main line; the order of the bean-gravel filling is from bottom to top, left and right symmetrical; Install an
airbag seal at the end of the
pipe ring. The
airbag seal is inflated and pushed against the wall of the
cave. When the equipment moves forward, the
airbag deflates, and the mounting seat drives the airbag forward; after assembling 20 rings, the ring is prefabricated with
cement slurry The bean gravel gaps filled behind the segments are fully filled to form a closed ring. When grouting,
grout is injected vertically through the holes, and one hole is injected every five rings; the ring is sealed once every 20 rings, and the ring is sealed by
chemical grouting. The invention can control the
subsidence of the ground surface, enhance the waterproof ability of the assembled tunnel, prevent the segments from floating up and sideways, and is convenient for construction, high in safety, short in construction period and low in cost.