JPS6130118B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention pressurizes and fills mud into the excavation chamber between the bulkhead and face provided at the tip of the shield propulsion tube, and excavates the face using a rotary cutter pivotally supported on the bulkhead. ,
In an underground excavation method in which excavated material is discharged together with mud water from a discharge pipe provided in a bulkhead, a roller bit revolving around the rotation axis of the cutter provided in the excavation chamber and a pressure propulsion operation of the propulsion pipe are used. This method relates to the shield excavation method, which is characterized by crushing gravel mixed in the excavated material, and involves crushing large lumps of excavated soil and discharging them together with muddy water from a discharge pipe, thereby preventing the large lumps from pressurizing muddy water and inhibiting shield excavation. The purpose is to eliminate.

To explain the embodiment of the present invention shown in the drawings, a partition wall 2 is provided at the tip of a shield propulsion tube 1,
An excavation chamber 3 is formed between the partition wall 2 and the tip end blade 1' of the propulsion tube 1. Inside this excavation chamber 3, a rotary shaft 4 is provided which is pivotally supported on the partition wall 2, and a plurality (4) cutter arms 5 extending in the radial direction are provided at the tip of the rotary shaft 4, and a cutting blade 6 is provided on the arm 5 for rotation. A cutter 7 is formed. Further, a muddy water supply pipe 8 is connected to the upper part of the partition wall 2, and a muddy water discharge pipe 9 is connected to the lower part thereof. A mud water pressure pump is connected to this water pipe 8 and further extended to the mud water tank. The discharge pipe 9 is extended rearward and opens at the top of a screen for separating crushed pieces of a large mass of excavated soil, and the excavated earth from which crushed pieces have been separated by the screen is discharged by a discharge device. A support shaft 10 extending parallel to the rotating shaft 4 is provided on the inner surface of each of the four cutter arms 5, and a roller bit 11 is freely supported on the support shaft 10. As shown in FIGS. 1 and 2, the roller bit 11 is perpendicular to the support shaft 10 and has a plurality of ∧-shaped circular blades 12 with different diameters arranged in a stepped manner, with the circular blade 12 on the side closer to the cutter arm 5 The diameter of circular blades 12 which are small in diameter and gradually move away from the same arm 5 are successively arranged to have a large diameter. On the inner circumferential surface of the shield propulsion tube 1, circular blades 13 having a ∧-shaped cross section are successively provided as shown in FIG. The rear end of the propulsion tube 1 fits into the tip step of the hume tube 14 and comes into contact with the step surface 15, and the jack moves the hume tube 14 to the left in FIG. 1, causing the propulsion tube 1 to move in the propulsion direction. Press and slide. In the figure, numeral 16 indicates a cutting blade provided on the distal end surface of the rotary shaft 4, 17 is a prime mover of the rotary shaft 4, and 18 is a speed reducer.

In the present invention, the shield propulsion tube 1 is replaced by a hume tube 14.
It is attached to the tip of a large diameter pipe such as, and propelled into the ground by a hydraulic jack, and the muddy water is sent under pressure from the water pipe 8 to the excavation chamber 3 formed between the face 19 and the bulkhead 2, and the same chamber 3 is filled with pressurized muddy water. The muddy water is discharged from the discharge pipe 9 while maintaining the state. In this state, the rotary cutter 7 is rotated and at the same time the shield propulsion tube 1 is
When propelled to the left in FIG. 1, the face 19 is excavated and the excavated material such as earth and sand enters the pressure mud, is stirred by the revolving roller bit 11, and is discharged from the discharge pipe 9 along with the mud. When a large lump of gravel 20 or the like from underground enters the pressure mud water in the excavation chamber 3, the gravel 20 is moved between the revolving roller bits 11 and 11 or between the propulsion pipe 1.
The roller bit 11 enters between the inner circumferential surface of the roller bit 11 and the roller bit 11, and due to the revolution and rotation of the roller bit 11 and the movement of the roller bit 11 (movement to the left in FIG. The gravel 20 is crushed by the bit 11 in the above operation and is discharged from the discharge pipe 9 along with the excavated material and muddy water.

Conventionally, if the excavated material contains large chunks of gravel, etc., they cannot be crushed by the rotating cutter, so they settle inside the excavation chamber or clog the discharge pipe, forcing the pressurized mud water shield propulsion work to be interrupted. I didn't get it.

Since the present invention is based on the method described above, large chunks of gravel 20 and the like contained in the ground are automatically crushed in the pressurized mud filling excavation chamber 3 and discharged from the discharge pipe 9 together with mud and excavated material. It has the effect of propelling the shield propulsion tube 1.

[Brief explanation of the drawing]

FIG. 1 is a side view showing the shield excavation method of the present invention, and FIG. 2 is a front view of a rotary cutter. 1... Shield propulsion tube, 2... Bulkhead, 19... Face,
3... Excavation chamber, 7... Rotating cutter, 9... Discharge pipe, 4
...Rotating shaft, 11...Roller bit, 20...Gravel.

Claims (1)

[Claims] 1 Filling the excavation chamber 3 between the bulkhead 2 and the face 19 provided at the tip of the shield propulsion pipe 1 with mud under pressure,
The face 1 is cut by a rotary cutter 7 pivotally supported on the bulkhead 2.
In the underground excavation method, in which the excavated material is excavated along with muddy water from the discharge pipe 9 provided in the partition wall 2, a roller bit 11 that revolves around the rotating shaft 4 of the cutter 7 provided in the excavation chamber 3; The above propulsion tube 1
Gravel mixed in the excavated material due to the pressing operation of
A shield drilling method characterized by crushing 0 etc.