1994 Volume 4 Pages 275-280
In Narita sand layer, direct underground docking of two shield machines was performed using partitive docking hoods. Since the ground is liquescent, chemical grouting was necessary as a auxilliary watertight measure to prevent inflow of sand and grand water at the openings between machine and partitive docking hoods. Newly developed evaluation method using the Elastic Finite Element Analysis was applied, in order to estimate the minimum chemical grouting area. Thereafter, grouting and following direct docking was executed, though inflow of grand water was observed. Thus, the performance of this evaluation method as well as the critical watertight devices previously equipped with the docking shield machines should be thoroughly assessed, as indicated in this paper.