| 摘要 |
PURPOSE:To easily excavate a tunnel with an elliptic cross section by forming the cross section of an excavator casing into an elliptic shape, and installing semicircular reciprocating cutters on its excavating face inclinatorily to the excavation direction vertically symmetrically. CONSTITUTION:Semicircular cutters 11 are fitted on the excavating face 2a of the casing 2 of a shield excavator 1 vertically symmetrically while excavating faces 11a are inclined by an angle alpha to the excavation direction. Cutters 11 are arranged and installed in an elliptic shape when viewed from the front of the excavation direction. Cutters 11 are reciprocated to excavate a tunnel. The tunnel with an elliptic cross section can be excavated by the shield construction method. |
