Study on Reasonable Combination of Retaining Structure and Main Structure for Tunnel Shaft in the Offshore Environment

Through the investigation, the design of the combination of the retaining structure and the main structure of the large-diameter shield shaft was summarized. Combined with the characteristics of the offshore shaft, considering the difficulty in implementing underwater pouring of high-grade underground diaphragm wall, through reasonably analyzing the characteristics of chloride environmental corrosion, a reasonable solution of supporting the temporary diaphragm wall to participate in anti-floating action is proposed. For the strictness of crack control in the chloride environment, it is proposed to use the frame beam as the purlins in the excavation stage, and the waterproof problem of the construction joint is better solved. Finally, the three-dimensional calculation results confirm the stress of lining wall is reasonable.