EARTH-RETAINING WALL EXCAVATING METHOD AND TUNNEL EXCAVATOR

摘要

PROBLEM TO BE SOLVED: To improve workability and safety by surely excavating a starting opening of a predetermined shape when starting a tunnel excavator in a shaft in an earth-retaining wall excavating method and the tunnel excavator. SOLUTION: A shield excavator is transferred into a starting shaft 51. A reaction force is received by a reaction force receiving facility 53 and a temporarily assembled segment S. An oil hydraulic jack 39 is extended in an earth- retaining wall supporting device 38 to bring a presser plate 40 into contact with the earth-retaining wall 54. With the earth-retaining wall 54 pressed, a location in the earth-retaining wall 54 corresponding to a protrusion 35 is cut by a workman with a drill 55 to form a through hole 56.