Tunneling machine and ground improvement method

Abstract

To radially expand an area in which ground improvement can be performed by a tunneling machine placed underground. [Solution] The tunneling machine includes a tunneling machine body, a cutter head section arranged forward in the tunneling direction relative to the tunneling machine body and configured to be rotatable about a rotation axis relative to the tunneling machine body, a first injection nozzle provided on the cutter head section and configured to inject ground improvement material at high pressure toward the forward side in the tunneling direction, and an injection nozzle moving mechanism configured to move the first injection nozzle in a radial direction relative to the rotation axis. The injection nozzle moving mechanism is configured to move the first injection nozzle radially outward from the radial outer edge of the cutter head section.

Description

[Technical field]

[0001] The present invention relates to a technique for carrying out ground improvement using a tunneling machine placed underground. [Background technology]

[0002] When constructing a pipeline or tunnel by excavating soil with a tunneling machine, it may be necessary to improve the ground around the excavation route. The following Patent Document 1 discloses a technique for injecting a ground improvement material at high pressure from an injection nozzle fixed to the cutter head of the tunneling machine located underground in the forward direction of excavation. This type of ground improvement technique allows the necessary ground improvement to be carried out from underground without affecting the aboveground environment. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-041707 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the ground improvement technology of Patent Document 1 leaves room for improvement. Specifically, the injection nozzle is fixed to the cutter head, and the reach of the ground improvement material injected from the injection nozzle is also short, so that only a very limited range around the tunneling machine in the radial direction can be improved. For this reason, for example, when an underground structure is located away from the tunneling machine, it is not possible to improve the ground up to that area. For this reason, a technology is required that can radially expand the range in which ground improvement can be performed by the tunneling machine placed underground. [Means for solving the problem]

[0005] The present invention has been made to solve the above-mentioned problems, and can be realized, for example, in the following forms.

[0006] According to a first aspect of the present invention, there is provided an excavator. The excavator includes an excavator body, a cutter head section arranged on the front side of the excavation direction relative to the excavator body and configured to be rotatable about a rotation axis relative to the excavator body, a first injection nozzle provided on the cutter head section and configured to inject ground improvement material at high pressure toward the front side in the excavation direction, and an injection nozzle moving mechanism configured to move the first injection nozzle in a radial direction relative to the rotation axis. The injection nozzle moving mechanism is configured to be able to move the first injection nozzle radially outward from the radial outer edge of the cutter head section.

[0007] According to this tunneling machine, the first injection nozzle can be moved radially outward from the radial outer edge of the cutter head, and the ground improvement material can be injected at high pressure from the first injection nozzle. Therefore, the range in which ground improvement can be performed by the tunneling machine placed underground can be expanded radially (e.g., upward). "Injecting the ground improvement material at high pressure toward the forward side in the tunneling direction" includes a mode in which the ground improvement material is injected at high pressure toward the forward side in a direction parallel to the rotation axis of the cutter head, and a mode in which the ground improvement material is injected at high pressure toward a direction intersecting the rotation axis of the cutter head (more specifically, diagonally forward at an angle angled radially outward).

[0008] According to the second aspect of the present invention, in the first aspect, the first injection nozzle is oriented to inject the ground improvement material at high pressure in a direction angled radially outward with respect to the rotation axis. According to this aspect, the range in which the ground improvement can be performed can be further expanded in the radial direction, compared to the configuration in which the first injection nozzle injects the ground improvement material at high pressure in a direction parallel to the rotation axis.

[0009] According to a third aspect of the present invention, in the first or second aspect, the tunneling machine includes a second jet nozzle provided in the cutter head and configured to jet fluid at high pressure toward the radially outward direction in the moving direction of the first jet nozzle. The jet nozzle moving mechanism is configured to be able to move the second jet nozzle together with the first jet nozzle. The second jet nozzle is configured to jet fluid when or before being moved radially outward from the radially outer edge of the cutter head together with the first jet nozzle. According to this aspect, by jetting fluid from the second jet nozzle, it is possible to stir the ground on the moving path when the first jet nozzle moves radially outward. Therefore, it is possible to smooth the radially outward movement of the first jet nozzle.

[0010] According to a fourth aspect of the present invention, in any one of the first to third aspects, the tunneling machine includes a partition wall that divides the inner space of the tunneling machine body into a chamber exposed to the soil and an internal space that is arranged rearward in the tunneling direction relative to the chamber and is not exposed to the soil, the partition wall having a first through hole located below the rotation axis and a second through hole located above the first through hole, a conveyor for transporting the excavated soil taken from the chamber into the internal space through the first through hole rearward in the tunneling direction, and a valve for opening and closing the second through hole. The tunneling machine is configured to open the valve and discharge mud from the chamber to the internal space through the second through hole when the ground improvement material is injected from the first injection nozzle. According to this aspect, the mud can be discharged when the ground improvement material is injected from the first injection nozzle through the second through hole located above the first through hole, rather than through the first through hole for taking the excavated soil into the internal space. Although a part of the ground improvement material injected from the first injection nozzle returns to the chamber, this embodiment can prevent the returned ground improvement material from reaching the position of the first through hole. In other words, the returned ground improvement material does not spread throughout the entire chamber, so the ground improvement material can be quickly taken into the interior space. Therefore, the solidification of the ground improvement material in the chamber can be suppressed.

[0011] According to the fifth aspect of the present invention, in the fourth aspect, the tunneling machine is configured to be able to supply mud-adding material into the chamber from the second through-hole before injecting the ground improvement material from the first injection nozzle. According to this aspect, it becomes possible to supply mud-adding material only near the second through-hole. In this case, the fluidity is increased only near the second through-hole in the chamber, so that the range of entry of the ground improvement material that has returned into the chamber can be further limited. Therefore, the effect of the fourth aspect can be further enhanced.

[0012] According to the sixth aspect of the present invention, there is provided a ground improvement method for carrying out ground improvement using an underground tunneling machine. This ground improvement method includes the steps of: arranging a cutter head unit rotatably arranged relative to the tunneling machine body at a predetermined rotation angle position on the front side of the tunneling direction relative to the tunneling machine body; moving an injection nozzle provided on the cutter head unit radially outward from the radial outer edge of the cutter head unit; and injecting a ground improvement material at high pressure from the injection nozzle located radially outward from the outer edge toward the front side of the tunneling direction. This ground improvement method has the same effect as the first aspect. A step corresponding to any one of the second to fifth aspects can be added to the sixth aspect. [Brief description of the drawings]

[0013] [Figure 1] 1 is a schematic diagram showing the internal structure of an excavator according to an embodiment of the present invention; [Diagram 2] FIG. 2 is a schematic cross-sectional view taken along line AA in FIG. [Diagram 3] FIG. 2 is a view taken along the arrow B in FIG. [Figure 4] FIG. 2 is a schematic diagram showing the procedure for carrying out ground improvement using a tunneling machine. [Diagram 5] FIG. 2 is a schematic diagram showing the procedure for carrying out ground improvement using a tunneling machine. [Figure 6] FIG. 2 is a schematic diagram showing the procedure for carrying out ground improvement using a tunneling machine. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] FIG. 1 is a schematic vertical cross-sectional view of an excavator 10 according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view taken along line AA in FIG. 1. In FIG. 2, a main shaft and a screw conveyor, which will be described later, are omitted from illustration. FIG. 3 is a view seen from arrow B in FIG. 1. In the following explanation, for convenience of explanation, the excavation direction of the excavator 10 and the direction toward the opposite side are defined as the front-rear direction. In addition, the front side in the excavation direction is defined as the front side of the excavator 10, and the rear side in the excavation direction is defined as the rear side of the excavator 10.

[0015] As shown in Fig. 1, the tunneling machine 10 comprises a tunneling machine main body 20 and a cutter head section 30. The tunneling machine main body 20 and the cutter head section 30 each have a generally cylindrical shape extending in the front-rear direction. The cutter head section 30 is disposed coaxially with the tunneling machine main body 20, on the front side of the tunneling machine main body 20. The cutter head section 30 is supported by a bearing (not shown), and is configured to rotate about a rotation axis AX relative to the tunneling machine main body 20 by the rotational driving force of a drive motor (not shown).

[0016] As shown in FIG. 1, a plurality of spokes 32 (only one spoke 32 extending in the vertical direction is shown in FIG. 1) are bridged inside the cutter head unit 30. The plurality of spokes 32 are arranged so as to extend radially from the center of the approximately cylindrical shape of the cutter head unit 30 to form a cross shape. A cutter bit 33 for cutting the ground is attached to each of the plurality of spokes 32. In the places where the spokes 32 are not bridged, a space is formed penetrating the cutter head unit 30 in the front-rear direction. The number, shape and arrangement of the spokes 32 are not particularly limited and can be arbitrarily set according to the construction conditions. In addition, instead of the spoke type, a faceplate type cutter head unit 30 with fewer openings may be adopted.

[0017] As shown in FIG. 1, a partition wall 40 is formed near the front end of the tunneling machine body 20, dividing the internal space of the tunneling machine body 20 into a chamber 24 and an internal space 25. The internal space 25 is located rearward of the chamber 24. Excavated soil enters the chamber 24 through a portion of the cutter head section 30 where the spokes 32 are not spanned. Meanwhile, the internal space 25 is isolated by the partition wall 40 and is not exposed to the excavated soil. Each piece of equipment of the tunneling machine body 20 (for example, the above-mentioned bearings and drive motor) is installed in the internal space 25. The cutter head section 30 has an internal space that is not exposed to the excavated soil.

[0018] 1, a main shaft 50 arranged coaxially with the rotation axis AX extends from the interior space 25 to the internal space of the spokes 32 at approximately the center of the partition wall 40. The main shaft 50 is fixed to the cutter head portion 30 and rotates integrally therewith.

[0019] As shown in Figures 1 and 2, a first through hole 41 is formed in the lower part of the partition 40 (below the rotation axis AX) and penetrates the partition 40 in the front-rear direction. A chamber gate (not shown) for opening and closing the first through hole 41 is provided in the first through hole 41. A screw conveyor 55 is arranged behind the first through hole 41 in the internal space 25. When the tunneling machine 10 is excavating, the screw conveyor 55 transports excavated soil taken into the internal space 25 from the chamber 24 through the first through hole 41 to the rear.

[0020] As shown in FIG. 1 and FIG. 2, a plurality of second through holes 42 penetrating the partition wall 40 in the front-rear direction are formed above the partition wall 40 (above the first through hole 41, and above the rotation axis AX in this embodiment) (only two second through holes 42 are illustrated in FIG. 1). In this embodiment, one second through hole 42 is disposed directly above the rotation axis AX. This second through hole 42 is located near the uppermost edge between the rotation axis AX and the uppermost edge of the partition wall 40. The remaining two second through holes 42 are disposed symmetrically on the left and right of the one second through hole 42 as viewed in the front-rear direction. The two second through holes 42 are located below the one second through hole 42. In the interior space 25, three valves 43 are disposed in each of the three second through holes 42, respectively, for opening and closing the three second through holes 42.

[0021] As shown in FIG. 1, the cutter head unit 30 is provided with a first injection nozzle 61 and a second injection nozzle 62. The first injection nozzle 61 injects the ground improvement material at high pressure toward the front side. In this embodiment, the first injection nozzle 61 is oriented to inject the ground improvement material at high pressure in a direction angled radially outward with respect to the rotation axis AX. However, the first injection nozzle 61 may also be oriented to inject the ground improvement material at high pressure parallel to the rotation axis AX. Any material can be used for the ground improvement material. Typically, the ground improvement material is cement-based (e.g., a mixture of sodium silicate solution and cement milk), but may also be solution-based (any ground improvement material that does not contain cement).

[0022] The second jet nozzle 62 jets fluid at high pressure radially outward. Any material can be used as the fluid. For example, the fluid may be a cement-based ground improvement material, a solution-type ground improvement material, water, a mud-adding material, etc. The jet pressure of the first jet nozzle 61 and the second jet nozzle 62 can be, for example, 30 to 245 MPa depending on the construction conditions.

[0023] In this embodiment, the ground improvement material and the fluid are respectively supplied to the first jet nozzle 61 and the second jet nozzle 62 via piping 65 (for simplicity, only one piping 65 is shown in FIG. 1, but in reality there are multiple pipings) arranged in the internal space of the cutter head unit 30. In this specification, the term "piping" refers to any hollow body made of any material (e.g., metal, resin, etc.) capable of transporting a fluid. The rear ends of the multiple pipings 65 are connected to a flow path formed inside the main shaft 50 at the front end of the main shaft 50. However, the supply paths of the ground improvement material and the fluid to the first jet nozzle 61 and the second jet nozzle 62 can be set arbitrarily.

[0024] The first injection nozzle 61 and the second injection nozzle 62 are configured to be movable in the radial direction by the injection nozzle moving mechanism 63. Specifically, as shown in FIG. 1 and FIG. 3, the first injection nozzle 61 and the second injection nozzle 62 are fixed on a support base 64. The support base 64 is connected to a rod of the injection nozzle moving mechanism 63. In this embodiment, the injection nozzle moving mechanism 63 is in the form of a hydraulic cylinder, but can be any actuator. The first injection nozzle 61 and the second injection nozzle 62 can move together in the radial direction by stroking the rod of the hydraulic cylinder toward the radial outward direction. The first injection nozzle 61 and the second injection nozzle 62 can move radially outward from the radial outer edge of the cutter head portion 30 via a notch portion 34 (see FIG. 3) formed on the side surface of the cutter head portion 30.

[0025] According to the above-mentioned tunneling machine 10, ground improvement can be performed by the following procedure. First, the cutter head unit 30 is placed at a predetermined rotation angle position according to the desired ground improvement target range. Typically, the predetermined rotation angle position is a position where the first injection nozzle 61 and the second injection nozzle 62 are located at the top, as shown in FIG. 1. Next, a mud-adding material is supplied into the chamber 24 from at least one second through hole 42 out of the plurality of second through holes 42. As a result, only the excavated soil in the chamber 24 around the at least one second through hole 42 is fluidized (shown as fluidized range 71 in FIG. 4).

[0026] Next, as shown in FIG. 4, the first injection nozzle 61 is injected obliquely forward from the first injection nozzle 61 in a state where the first injection nozzle 61 is positioned inside the radial outer edge of the cutter head unit 30, and the ground improvement of the ground improvement range 72 is performed. At this time, the ground improvement material is injected in excess, so that the injected ground improvement material returns to the chamber 24 together with the soil that has replaced the ground improvement material. For this reason, only the valve 43 provided in at least one of the second through holes 42 (the second through hole 42 used to supply the mud-adding material) among the plurality of second through holes 42 is opened, and the mud is discharged from the chamber 24 to the interior space 25 through the at least one second through hole 42. FIG. 4 exemplarily illustrates how the mud is discharged from the three second through holes 42 (however, only one of the two second through holes 42 arranged symmetrically on the left and right is illustrated). Since only the periphery of at least one second through-hole 42 used to supply the mud-adding material (i.e., fluidization range 71) is fluidized, the ground improvement material and soil that has returned to chamber 24 is quickly taken into interior space 25 without spreading throughout chamber 24 (while being prevented from moving below fluidization range 71). This makes it possible to prevent the ground improvement material from solidifying in chamber 24. In this embodiment, the ground improvement material and soil that has returned to chamber 24 is temporarily stored in sludge tank 45 via piping 44 connected to valve 43, and then transported rearward.

[0027] Next, as shown in FIG. 5, the first jet nozzle 61 is moved to the outside of the outer edge of the cutter head unit 30 in the radial direction. In this embodiment, while moving the first jet nozzle 61, the second jet nozzle 62 jets a fluid in the moving direction of the first jet nozzle 61. This makes it possible to stir the ground on the moving path of the first jet nozzle 61, and as a result, the movement of the first jet nozzle 61 can be made smooth. In an alternative embodiment, the first jet nozzle 61 may be moved after the fluid is jetted from the second jet nozzle 62. When the first jet nozzle 61 is moved a predetermined distance, the first jet nozzle 61 jets a ground improvement material to improve the ground improvement range 73 located above the ground improvement range 72. At this time, the mud is discharged in the same manner as in the ground improvement of the ground improvement range 72. In an alternative embodiment, the first jet nozzle 61 may be moved to the outside of the radially outer edge of the cutter head portion 30 while simultaneously jetting the ground improvement material from the first jet nozzle 61. In this case as well, the fluid may be jetted from the second jet nozzle 62 while the first jet nozzle 61 is being moved, or the first jet nozzle 61 may be moved after the fluid is jetted from the second jet nozzle 62.

[0028] Next, as shown in Fig. 6, the first jet nozzle 61 is moved further outward from the outer edge in the radial direction of the cutter head unit 30. At this time, too, fluid is sprayed from the second jet nozzle 62 in the moving direction of the first jet nozzle 61. When the first jet nozzle 61 is moved further a predetermined distance, the first jet nozzle 61 sprays the ground improvement material to improve the ground improvement range 74 located above the ground improvement range 73. At this time, too, sludge is removed in the same manner as in the ground improvement of the ground improvement range 72.

[0029] According to the above-mentioned tunneling machine 10, the first injection nozzle 61 can be moved radially outward from the radial outer edge of the cutter head portion 30, and the ground improvement material can be injected at high pressure from the first injection nozzle 61 after the movement. Therefore, the range in which ground improvement can be performed can be expanded in the radial direction. Also, as in the above-mentioned embodiment, the first injection nozzle 61 can be moved stepwise multiple times, and the ground improvement material can be injected from the first injection nozzle 61 at each moving position, thereby further expanding the range in which ground improvement can be performed in the radial direction.

[0030] Furthermore, since the first injection nozzle 61 injects the ground improvement material at high pressure in a direction angled radially outward from the rotation axis AX, the range in which ground improvement can be performed can be further expanded radially compared to a configuration in which the first injection nozzle 61 injects the ground improvement material at high pressure in a direction parallel to the rotation axis AX.

[0031] Furthermore, according to the tunneling machine 10, the mud can be discharged when the ground improvement material is injected from the first injection nozzle 61 through the second through hole 42 located above the first through hole 41, rather than through the first through hole 41 for taking in the excavated soil into the internal space 25. Therefore, compared to the case where the mud is discharged through the first through hole 41, the movement range within the chamber 24 of the ground improvement material and soil that have returned to the chamber 24 can be limited, and as a result, the ground improvement material and soil that have returned to the chamber 24 can be quickly taken into the internal space 25, and solidification of the ground improvement material within the chamber 24 can be suppressed.

[0032] Although the embodiment of the present invention has been described above, the above-mentioned embodiment of the invention is intended to facilitate understanding of the present invention and does not limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and the present invention includes equivalents thereof. In addition, any combination or omission of each component described in the claims and specification is possible within the scope of solving at least a part of the above-mentioned problems or achieving at least a part of the effects.

[0033] For example, the supply of the mud-adding material and / or the drainage of the mud during the injection of the ground improvement material may be performed using any of the second through holes 42 among the plurality of second through holes 42. The number of the second through holes 42 can be set to any number equal to or greater than one.

[0034] Alternatively, the mud discharge during injection of the soil improvement material may be carried out through at least one of the second through holes 42 and the first through hole 41. Even in this case, the first through hole Compared to when sludge is discharged only through 41, the range within the chamber 24 over which the soil improvement material and soil that have returned to the chamber 24 move can be limited.

[0035] Alternatively, the above-mentioned configuration for injecting the soil improvement material and the above-mentioned mud removal method using the second through-holes 42 may be carried out independently of each other. [Explanation of symbols]

[0036] 10...Drilling machine 20...Drilling machine body 24...Chamber 25...In-flight space 30...Cutter head 32...Spokes 33...Cutter bit 34...Notch 40...bulkhead 41...First through hole 42...Second through hole 43...Valve 44...Plumbing 45...Sludge tank 50...Main shaft 55...Screw conveyor 61...First injection nozzle 62...Second injection nozzle 63...Injection nozzle movement mechanism 64...Support stand 65...Plumbing 71... Fluidization range 72, 73, 74...Ground improvement range AX...rotation axis

Claims

1. A tunneling machine, The tunneling machine body, A cutter head portion is disposed on the front side of the excavation machine body in the excavation direction and configured to be rotatable about a rotation axis with respect to the excavation machine body; A first injection nozzle provided in the cutter head portion and configured to inject a ground improvement material at high pressure toward the front side in the excavation direction; a jet nozzle moving mechanism configured to be able to move the first jet nozzle in a radial direction relative to the rotation axis; Equipped with the injection nozzle moving mechanism is configured to be able to move the first injection nozzle radially outward from an outer edge portion of the cutter head portion in the radial direction, a partition wall dividing the inner space of the tunneling machine body into a chamber exposed to the soil and an internal space not exposed to the soil, the internal space being disposed rearward of the chamber in the tunneling direction, the partition wall having a first through hole located below the rotation axis and a second through hole located above the first through hole; a conveyor for transporting the excavated soil taken into the interior space from the chamber through the first through hole in a rearward direction in the excavation direction; a valve for opening and closing the second through hole; Equipped with When the soil improvement material is injected from the first injection nozzle, the valve is opened to discharge mud from the chamber to the interior space through the second through hole. digging machine.

2. The tunneling machine according to claim 1, The mud-adding material can be supplied into the chamber from the second through hole before the ground improvement material is injected from the first injection nozzle. digging machine.

3. A ground improvement method for carrying out ground improvement using a tunneling machine disposed underground, comprising the steps of: A step of disposing a cutter head portion, which is disposed rotatably about a rotation axis with respect to the tunneling machine body, at a predetermined rotation angle position on the front side of the tunneling machine body in the tunneling direction; moving an injection nozzle provided in the cutter head portion radially outward from an outer edge portion of the cutter head portion in the radial direction; A step of high-pressure spraying a ground improvement material from the spray nozzle located radially outward from the outer edge portion toward the front side of the excavation direction in a direction angled radially outward with respect to the rotation axis; A ground improvement method comprising:

4. A ground improvement method for carrying out ground improvement using a tunneling machine disposed underground, comprising the steps of: The tunneling machine body, A cutter head portion is disposed on the front side of the excavation machine body in the excavation direction and configured to be rotatable about a rotation axis with respect to the excavation machine body; a partition wall dividing the inner space of the tunneling machine body into a chamber exposed to the soil and an internal space not exposed to the soil, the internal space being disposed rearward of the chamber in the tunneling direction, the partition wall having a first through hole located below the rotation axis and a second through hole located above the first through hole; a conveyor for transporting the excavated soil taken into the interior space from the chamber through the first through hole in a rearward direction in the excavation direction; a valve for opening and closing the second through hole; Providing the tunneling machine comprising: placing the cutter head at a predetermined rotation angle position; moving an injection nozzle provided in the cutter head portion radially outward from an outer edge portion of the cutter head portion in the radial direction; a step of injecting a soil improvement material at high pressure from the injection nozzle located radially outward from the outer edge portion toward the front side in the excavation direction, and opening the valve to discharge mud from the chamber to the interior space through the second through hole; A ground improvement method comprising:

5. A ground improvement method for carrying out ground improvement using a tunneling machine disposed underground, comprising the steps of: A first step of disposing a cutter head portion rotatably disposed with respect to the tunneling machine body at a predetermined rotation angle position on the front side of the tunneling machine body in the tunneling direction; a second step of moving a first injection nozzle provided in the cutter head portion radially outward from an outer edge portion of the cutter head portion in the radial direction; a third step of high-pressure-injecting a ground improvement material from the first injection nozzle located radially outward from the outer edge portion toward a front side in the excavation direction; a fourth step of injecting a fluid at high pressure from a second injection nozzle provided in the cutter head toward an outer side in the radial direction in the moving direction of the first injection nozzle, simultaneously with the second step or prior to the second step; A ground improvement method comprising:

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