JPH0475358B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides an earth pressure adjustment chamber communicating with a face chamber, an earth pressure jack that advances and retreats within the adjustment chamber to change the volume of the earth pressure adjustment chamber, and an earth pressure adjustment chamber that communicates with a face chamber. An earth pressure regulator consisting of operating equipment is installed, the face is filled with earth and sand, the shield machine is propelled by an excavation jack, and the earth and sand in the face cut by the cutter is removed by a screw conveyor. The present invention also relates to an earth pressure shield excavation method for excavating while preventing collapse of the face due to earth pressure within the face.

[Prior art] In the conventional excavation method using an earth pressure type shield machine, an earth pressure gauge is often installed on the bulkhead of the shield machine to measure the earth pressure inside the face, but the earth pressure gauge cannot be used in harsh conditions. Because the soil pressure gauge was difficult to withstand, frequently broke down, and the soil pressure gauge was difficult to repair and replace, the shield machine sometimes had to be operated blindly. Furthermore, even if such an earth pressure gauge is used, it is extremely difficult to maintain a constant earth pressure in the face chamber during shield excavation, so depending on the soil quality, the balance may be lost during excavation, leading to groundwater being drawn in or over-intake. There were many things.

For this purpose, we have published Japanese Patent Application Laid-Open No. 58-178799 and
Publication No. 55-17831 discloses a technique for making the earth pressure constant by changing the volume of the face chamber. However, in such known technology, during excavation, the volume of the face chamber is increased without removing earth to fill the face chamber with earth and sand, and then the excavation work is stopped and the earth is removed while reducing the volume within the face chamber. Excavation efficiency was poor because excavation and soil removal were separate processes.

[Problems to be Solved] Therefore, an object of the present invention is to provide an excavation method using an earth pressure type shield machine that can maintain the earth pressure in the face chamber at a predetermined value and improve the excavation efficiency.

[Means for Solving the Problems] According to the present invention, an earth pressure adjustment chamber communicating with a face chamber, an earth pressure jack that moves back and forth within the adjustment chamber to change the volume of the earth pressure adjustment chamber, and an operating device for operating the jack. An earth pressure regulator is installed, the face is filled with earth and sand, the shield machine is propelled by an excavation jack, the earth and sand in the face cut by the cutter is discharged by a screw conveyor, and the earth and sand in the face are In the earth pressure shield excavation method, in which earth pressure excavates while preventing the collapse of the face, the face chamber and earth pressure adjustment chamber are filled with earth and sand by the first excavation of the shield machine as a preparatory stage, and the shield machine is used during the excavation work. While excavating, the earth pressure is pushed out in the direction of the earth pressure chamber by the earth pressure jack to maintain the earth pressure in the face chamber at the specified earth pressure.At the same time, the earth and sand in the tunnel is discharged by the screw conveyor, and the earth pressure in the earth pressure adjustment chamber is As soon as the earth and sand are removed, the screw conveyor stops discharging the earth, and while maintaining the earth pressure in the face chamber, the earth pressure jerk is reduced and excavation continues, filling the earth pressure adjustment chamber with earth and sand.

[Description of effects] Therefore, the excavation work is performed continuously, and the earth removal work is interrupted during the contraction process of the earth pressure jack, so that the excavation efficiency can be improved. Furthermore, since the earth pressure is maintained at a predetermined value through earth removal work and the operation of the earth pressure jack, computer control becomes easy. In other words, if a large amount of earth and sand flows into the face chamber during extrusion with earth pressure jacking, the amount of earth pressure jacking per hour should be set to zero or small, and the amount of earth removed should be increased; if not much earth and sand flows in, the opposite is true. do it. Furthermore, even when earth and sand jacking is contracted, the earth pressure jacking may be operated according to the earth pressure in the face chamber. Therefore, according to the present invention, control is also easy.

[Example] The drawing shows an example of an earth pressure type shield excavator in which the present invention is suitably implemented. The cutter 2 is rotatably driven and is given thrust by a propulsion jack 3. A face chamber 4 is provided behind the cutter 2, and during excavation, this face chamber 4 is filled with earth and sand to prevent the face from collapsing. Earth is removed. As the excavation progresses, segments 6 are assembled on the wall surface.

An earth pressure regulator, generally indicated by 7, is provided to maintain the earth pressure in the face chamber 4 at a predetermined earth pressure.
The earth pressure regulator 7 has an earth pressure adjustment chamber 8 that communicates with the face chamber 4, and moves back and forth within the earth pressure adjustment chamber 8 to maintain the earth pressure in the face chamber 4 at a predetermined earth pressure. It is composed of an earth pressure jack 9 that changes the volume of the adjustment chamber 8, an operating device 10 that operates the earth pressure jack 9, and the like. The maximum volume of the earth pressure adjustment chamber 8 is approximately 10% of the volume of the face chamber 4.

Next, embodiments of the present invention will be described.

First, as a preparatory step, the face chamber 4 and the earth pressure adjustment chamber 8 are filled with earth and sand by the initial shield propulsion.

Next, excavation work is carried out, but the earth pressure in the face chamber 4 is maintained at a predetermined level by pushing out the earth and sand in the earth pressure adjustment chamber 8 in the direction of the face chamber 4 using the earth pressure jack 9. Excavation is carried out using the propulsion jack 3, and at the same time, the earth and sand in the face chamber 4 is discharged by the screw conveyor 5. In this way, the earth pressure jack 9 is pushed out, and at the same time that the earth and sand in the earth pressure adjustment chamber 8 are gone, the soil removal by the screw conveyor 5 is stopped, and while the earth pressure in the face chamber 4 is maintained,
The earth pressure jack 9 is contracted, and the propulsion jack 3 continues to excavate, filling the earth pressure adjustment chamber 8 with earth and sand. Meanwhile, the segments 6 are assembled in a known manner.

The shield machine is allowed to dig while repeating the above extrusion and contraction operations of the earth pressure jack 9.

It goes without saying that the operations of the shield machine body, such as the cutter, propulsion jack, screw conveyor, etc., and the operation of the earth pressure jack of the earth pressure regulator can be controlled in conjunction with a computer for automatic management.

[Effects of the Invention] As described above, according to the present invention, the earth pressure in the face chamber can be maintained at a predetermined pressure without interrupting the excavation work of the shield machine, so that collapse of the face can be prevented and efficient excavation can be carried out. Able to perform work. Moreover, the control is easy, as it is only necessary to control the earth pressure jack and the screw conveyor.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view showing an example of a shield excavator that implements the earth pressure shield excavation method according to the present invention. 1...Shield excavator, 2...Katsuta, 3...
Propulsion jack, 4...Face chamber, 5...Screw conveyor, 6...Segment, 7...Earth pressure regulator, 8...Earth pressure adjustment room, 9...Earth pressure jack, 1
0... Operation device.

Claims (1)

[Claims] 1 An earth pressure regulator consisting of an earth pressure adjustment chamber that communicates with the face chamber, an earth pressure jack that moves back and forth within the adjustment chamber to change the volume of the earth pressure adjustment chamber, and an operating device that operates the jack is provided, and After filling with earth and sand, the shield machine is propelled by an excavation jack, and the earth and sand in the face chamber cut with a cutter is discharged by a screw conveyor, and the excavation is carried out while preventing the face from collapsing due to the earth pressure inside the face chamber. In the earth pressure shield excavation method, as a preparatory step, the face chamber and earth pressure adjustment chamber are filled with earth and sand by the first excavation of the shield machine, and during the excavation work, while the shield machine is excavating, the earth pressure is adjusted by the earth pressure jack. The earth and sand in the face chamber are pushed out in the direction of the face chamber to maintain the earth pressure at the specified level, and at the same time the earth and sand in the face chamber is discharged by the screw conveyor, and as soon as the earth and sand in the earth pressure adjustment chamber disappears, the earth and sand are discharged by the screw conveyor. An earth pressure shield excavation method characterized by stopping the earth pressure in the face chamber, reducing the earth pressure jack and continuing the excavation, filling the earth pressure adjustment chamber with earth and sand.