CONSTRUCTION METHOD FOR UNDERWATER SHAFT, UNDERWATER SHAFT, CONNECTION METHOD FOR SHAFT AND ADIT, AND PIT STRUCTURE

摘要

PPROBLEM TO BE SOLVED: To provide a construction method for an underwater shaft, an underwater shaft, a connection method for a shaft and an adit, and a pit structure that enable safety construction with no temporary structure and little influence on the environment. PSOLUTION: Steel pipe sheet piles 15 are erected in a seabed 19 so that upper ends are positioned in the water, a wale 25 is arranged along an inner circumference of a steel pipe well 16, and the inside of the steel pipe well 16 is excavated to form the underwater shaft 30. A J pipe 43 with a steel frame 45 is installed in the underwater shaft 30, a separating sheet 49 is set on steel pipe sheet piles 15b, and underwater concrete 63 is placed to fix the steel frame 45 and the J pipe 43 in the underwater shaft 30. The steel pipe sheet piles 15b with the separating sheet 49 are partly cut away, and a shield tunnel 75 is passed from the side of the underwater shaft 30. An arrival fitting 55 arranged at an end of the J pipe 43 is used to connect the shield tunnel 75 and the J pipe 43, and an outlet 77 is arranged at an upper end of the J pipe 43. PCOPYRIGHT: (C)2004,JPO