PROBLEM TO BE SOLVED: To provide a tunnel excavating method which need not stop tunnel excavating work on a face but can carry out the excavating work by using an efficient jumbo for carrying out the boring work inclusive of coring, in parallel with the excavating work.;SOLUTION: According to the tunnel excavating method, the jumbo has a plurality of boring booms, and a boring machine which can carry out coring at high speed is attached to one of the booms. Then, normal boring and coring work in advanced boring are carried out in parallel with.;COPYRIGHT: (C)2002,JPO
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