| 摘要 |
PURPOSE:To improve the water stopping properties of a small-sectional tunnel contacting section and the strength of a core by installing a trapezoidal drum cutter and a ring cutter at the front end of a shield excavator having a trapezoidal section, excavating the ground in a trapezoidal shape and forming the cylindrical underground core. CONSTITUTION:A shield excavator body 14 is disposed at the front end of the shield frame 12 of a shield excavator 10 having a trapezoidal section, and a shield jack 18 is mounted to the rear section of the shield excavator body 14 and propulsion is controlled. Trapezoidal drum cutters 26, 28 and ring cutters 32, 32 are set up at the front end section of the main body 14, and a service pipe line 84 and a soil removing pipe 86 are arranged to the upper and lower sections of a partition wall section 14A. Water is conveyed from the service pipe line 84 while motors 38, 38 are driven, the drum cutters 26, 28 and the ring cutters 32, 32 are turned, and the ground is excavated in a trapezoidal sectional shape. Excavating muck is discharged from the soil removing pipe 86 together with soil and sand. Accordingly, a cylindrical underground core having high water stopping properties can be constructed. |
