| 摘要 |
PURPOSE: To excavate a rectangular deformed section tunnel economically. CONSTITUTION: Four auxiliary cutter heads 15 are provided by shifting them to the machine main body 2 side of a main cutter head 1 so that they are faced toward both side parts at the upper and lower ends of the main cutter head 1. Also the auxiliary cutter heads 15 are installed at positions apart by a specified distance Ls from the main cutter head 1 so that they are not interfered with the cutter head and crossed at right angle to the axis Os of the main cutter head 1 and shifted. Then the outer form of the auxiliary cutter heads 15 is formed in a cylinder so that it can excavate the unexcavated part where the vertical and horizontal tangential lines of the excavating projected cross-section of the main cutter head 1 are crossed at right angle so as to form the excavating projected cross-section in square form. |
