EARTH RETAINING METHOD AND EARTH RETAINING STRUCTURE OF WIDTH EXPANDING OBJECT PART OF SHIELD TUNNEL

PROBLEM TO BE SOLVED: To solve the problem of forcibly stopping traffic of a vehicle due to being unable to use a main track shield tunnel for sending out a bent pipe and a freezing pipe to the outside of the main track shield tunnel from the inside of the main track shield tunnel, that is, for using the main track shield tunnel as a work base at work, in arranging work of the bent pipe and the freezing pipe in width expanding work of a shield tunnel. SOLUTION: In this earth retaining method of a width expanding object part of the shield tunnel, the work base (pilot shield tunnels 3 and 4) is formed in the ground in the extension direction of the shield tunnel 1; and an earth retaining construction material (continuous walls 6 and 7 and a continuous roof 8) is sent out to a position surrounding the width expanding object part X of the shield tunnel 1 from the inside of the work base; to construct an earth retaining structure 4 of the width expanding object part X of the shield tunnel 1. COPYRIGHT: (C)2006,JPO&NCIPI