JP4260238B2 - Shield machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a shield machine.
[0002]
[Prior art]
In islands and desert areas where there is little rainfall, seawater desalination plants have been constructed near the coast to secure drinking water. In addition, seawater is, for example, raw processing water for a salt production plant. In this type of seawater treatment facility, it is necessary to introduce seawater into an apparatus for desalinating seawater.
[0003]
Therefore, in such seawater treatment facilities, conventionally, seawater is taken in by a non-woven fabric wrapped around a vinyl chloride pipe penetrating a large number of water intake holes or by a water intake tunnel in which a perforated fume pipe is embedded.
[0004]
However, since the intake tunnel having such a configuration is embedded by the open-cut method or the submerged method, there are many restrictions on the construction due to the exclusive use of the area directly above the embedded position for the burying operation.
[0005]
Therefore, the present inventors have developed a technique for constructing this type of water intake tunnel by a shield method, and proposed in Japanese Patent Application No. 9-218492. As shown in FIGS. 7 and 8, the segments used in this construction method are integrated by attaching a water-permeable member 2 to the outside of the main body plate 1 such as a steel segment or a ductile segment conventionally used in a normal shield method. It is what.
[0006]
The water permeable member 2 is made of porous concrete or the like, and has a structure in which groundwater or the like that has passed through the water permeable member 2 is positively taken into the interior from water intake holes (not shown) provided in the main body plate 1.
[0007]
However, when such a water intake segment 3 is used to construct a water intake tunnel by a shield machine, there are technical problems described below.
[0008]
[Problems to be solved by the invention]
In other words, in the normal shield method, the tail void generated from the difference in the outer diameter of the shield machine main body 4 and the segment is backfilled to suppress the settlement of the ground surface, thereby ensuring the early stability of the segment.
[0009]
However, when backfilling is performed in the construction of the intake tunnel, an impermeable layer 5 is formed around the permeable member 2 on the outer surface of the intake segment 3 as shown in FIG. Since it cannot be taken in, backfilling cannot be performed.
[0010]
If backfill injection cannot be performed, the shield machine and ground subsidence just above the segment will increase, and it will be difficult to ensure the early stability of the segment.
[0011]
In addition, when excavating a curved section, not only when constructing the intake tunnel described above, but also when constructing a general tunnel, the side of the shield machine is dug in advance so that the passing position of the shield machine Is weakened so that there is less competition with natural mountains.
[0012]
However, in the case of a loose sand layer or the like, if the ground improvement is not performed, there is a problem that the excavation part collapses and the competition between the shield machine and the natural ground in the curved part cannot be made sufficiently small.
[0013]
The present invention has been made in view of such problems, and the object of the present invention is to ensure the early stability of the segment while suppressing an increase in the settlement of the ground surface, and in curve construction. The object is to provide a shield machine capable of eliminating ground improvement.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a shield machine having a chamber filled with excavated earth and sand at the front end side of the shield machine main body, wherein the shield machine is provided on the rear side of the shield machine main body. The intake segment is for assembling a water intake tunnel capable of taking water inside, and provided with a plurality of openings through the hood on the tip side of the shield machine , with the incorporation, a portion of the excavated soil from the chamber, through the opening, and to discharge the rear side outside of the shield machine main body.
According to the shield machine constructed in this way, the shield machine is for constructing a water intake tunnel in which a water intake segment is assembled on the rear side of the shield machine and the water can be taken inside. The hood on the front end side of the machine body is provided with a plurality of openings that pass through it, and a part of the excavated earth and sand is taken from the chamber through the opening as the excavated earth and sand are taken in. Since it is discharged outward, the excavated earth and sand discharged from the opening is sequentially pushed backward along the outer surface of the shield machine, due to the difference in outer diameter between the shield machine and the segment. Fill the resulting tail void.
Therefore, without forming an impermeable layer on the outer periphery of the water intake segment, it is possible to suppress an increase in the ground excavation of the shield machine and the segment and to ensure the early stability of the segment.
In addition, during curve construction, the overexcavated part is filled with excavated earth and sand discharged from the opening, so that the collapse of the overexcavated part can be prevented, and the excavated earth and sand can be Since it is excavated, it is weakened and the competition with the natural ground is also reduced.
The opening can be opened and closed by a movable plate that slides along the inner peripheral surface of the shield machine main body, and can be opened and closed by a movable plate that slides along the axial direction of the shield machine body. can do.
According to this configuration, the excavation of excavated earth and sand from the opening can be adjusted by the movable plate. For example, in the construction of the intake tunnel, in the section where backfilling can be performed, the shield method is used as usual. Construction becomes possible.
Moreover, the shield machine of this invention can be used suitably for construction of a water intake tunnel.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. FIG. 1 shows a first embodiment of a shield machine according to the present invention.
[0016]
The shield machine 10 shown in the figure is a case where the shield tunneling machine 10 is applied to the construction of a water intake tunnel, and the water intake tunnel is constructed by assembling the water intake segments 3 shown in FIGS .
[0017]
The water intake segment 3 is formed by attaching the water permeable member 2 to the outside of the main body plate 1 such as a steel segment or a ductile segment used in a normal shield method.
[0018]
The water permeable member 2 is made of porous concrete or the like, and has a structure in which groundwater or the like that has passed through the water permeable member 2 is actively taken into the inside through water intake holes provided in the main body plate 1.
[0019]
The shield machine 10 shown in the figure is of earth pressure type, and a partition wall 16 is provided on the tip side of the shield machine main body 14 formed in a cylindrical shape.
[0020]
The chamber 18 defined by the partition wall 16 and having an open end is filled with excavated mud and used to counter the earth pressure and water pressure of the natural ground. On the central axis of the partition wall 16, a rotating shaft 22 that supports the cross-shaped spoke 20 is rotatably supported in a penetrating state.
[0021]
An unillustrated bit is fixed to the spoke 20, and the rotary shaft 22 is rotationally driven, whereby the earth and sand are excavated by the bit provided in the spoke 20 and taken into the chamber 18.
[0022]
For example, air bubbles can be used as the additive in the excavation mud taken into the chamber 18. When the air bubbles are mixed into the mud, the fluidity of the mud increases, and the soil becomes equivalent to the natural ground due to the disappearance of the air bubbles. Sex is restored.
[0023]
The basic configuration of the earth pressure type shield machine as described above is the same as that of a conventional type of device, but the shield machine 10 of the present embodiment has a significant difference in the points described below. .
[0024]
That is, in the shield machine 10 of the present embodiment, the opening 24 that discharges a part of the drill mud from the chamber 18 to the rear side of the shield machine main body 14 as the drill mud is taken in is provided in the shield machine main body. A plurality of 14 hood portions 27 are provided.
[0025]
Each opening 24 is formed by drilling the front end side of the shield machine main body 14 defining the side surface of the chamber 18 in a square shape, and a plurality of openings 24 are provided along the circumferential direction of the shield machine main body 14. Yes.
[0026]
According to the shield machine 10 configured as described above, when the drilling mud is taken up and the chamber 18 is filled, a part of the drilling mud is provided with the opening 24. Through the opening 24, the excavator main body 14 is discharged outward from the rear side .
[0027]
The excavation mud discharged to the side of the excavator main body 14 is pushed by the excavation mud sequentially discharged along with the excavation of the shield excavator 10, and sequentially pushed backward along the side of the shield excavator main body 14. The tail void resulting from the difference in outer diameter between the shield machine 10 and the segment 3 is filled.
[0028]
Therefore, without forming an impermeable layer on the outer periphery of the water intake segment 3, it is possible to suppress an increase in the ground surface settlement immediately above the shield machine 10 and the segment 3, and to ensure the early stability of the segment 3. .
[0029]
In addition, since the overexcavated portion is filled with the excavated mud discharged from the opening 24 during the curve construction, the overexcavated portion can be prevented from collapsing, and the excavated mud can be used as a shield machine. Since it is excavated by No. 10, it is weakened and the competition with the natural ground is also reduced.
[0030]
2 and 3 show a second embodiment of the shield machine according to the present invention. The same or corresponding parts as those in the above embodiment are designated by the same reference numerals and the description thereof is omitted. Only the feature points will be described.
[0031]
As in the first embodiment, the shield machine 10a shown in the figure has an opening for discharging a part of the drilling mud from the chamber 18 to the rear side of the shield machine main body 14 as the drilling mud is taken in. A portion 24a is provided.
[0032]
The opening 24a of this embodiment is formed by making the tip side of the shield machine main body 14 defining the side surface of the chamber 18 into a square shape, but the opening area is larger than that of the first embodiment. It is getting bigger.
[0033]
In addition, although the opening part 24a shown in FIG. 2 has shown only the one side surface side of the shield machine main body 14, the thing of the same structure is provided also in the back side of this side surface.
[0034]
The opening 24 a can be opened and closed by a movable plate 26 that slides along the circumferential direction of the shield machine main body 14. The movable plate 26 is curved to the same curved surface as the curved surface of the shield machine main body 14, and one end side thereof is disposed so as to enter the partition wall 16.
[0035]
A rack gear 28 is attached to the edge of the movable plate 26 in the partition wall 16. A pinion 30 is toothed on the rack gear 28, and a motor 32 is connected to the pinion 30.
[0036]
In the opening 24a configured as described above, in addition to the effects of the first embodiment, by driving the motor 32, the movable plate 26 can be slid in the circumferential direction to adjust the degree of opening. it can.
[0037]
Therefore, the amount of excavated mud discharged from the opening 24a can be adjusted. For example, in the construction of the intake tunnel, in the section where the backfill injection can be performed, the opening 24a is completely closed by the movable plate 26. The shield method can be applied as usual.
[0038]
4 and 5 show a third embodiment of the shield machine according to the present invention. The same or corresponding parts as those in the above embodiment are designated by the same reference numerals and the description thereof is omitted. Only the feature points will be described.
[0039]
As in the second embodiment, the shield machine 10b shown in the figure has an opening for discharging a part of the drilled mud from the chamber 18 to the rear side of the shield machine 14 as the drilled mud is taken in. A plurality of portions 24b are provided.
[0040]
The opening 24b of this embodiment is formed by drilling the front end side of the shield machine main body 14 that defines the side surface of the chamber 18 into a square shape. The opening 24b shown in FIG. 4 illustrates only one side of the shield machine main body 14, but the same configuration is also provided on the back side of this side.
[0041]
The opening 24 b can be opened and closed by a movable plate 40 that slides along the axial direction of the shield machine main body 14. The movable plate 40 is curved to the same curved surface as the curved surface of the shield machine main body 14, and one end side thereof is disposed so as to enter the partition wall 16.
[0042]
A telescopic plunger of a jack 42 is coupled to an end edge of the movable plate 40 in the partition wall 16.
[0043]
In the opening 24b configured in this way, by driving the jack 42, the movable plate 40 can be slid in the axial direction and the degree of opening can be adjusted. Therefore, the operation equivalent to that of the second embodiment is achieved. An effect is obtained.
[0044]
In the above embodiment, the case where the shield machine of the present invention is applied to the construction of a water tunnel is illustrated, but the implementation of the present invention is not limited to this, and a normal tunnel is constructed by a shield construction method. Can also be used.
[0045]
When the present invention is applied to a normal shield method, in addition to the effects described in the above embodiment, if a part of excavated earth and sand is discharged to the rear side of the shield machine main body, the friction cutting effect during excavation is improved. By supplementing the filling (reducing volume) and improving the transmission effect of the face pressure, the effect of suppressing ground subsidence can be obtained by reducing the release of ground stress at the tail.
[0046]
【The invention's effect】
As described above in detail in the embodiment, according to the shield machine according to the present invention, while suppressing the increase in settlement of the ground surface, the early stability of the segment is ensured, and the ground improvement in the curved construction is achieved. Can be eliminated.
[Brief description of the drawings]
FIG. 1 is an external view showing a first embodiment of a shield machine according to the present invention.
FIG. 2 is an external view showing a second embodiment of the shield machine according to the present invention.
3 is a cross-sectional view of a main part of FIG.
FIG. 4 is an external view showing a third embodiment of the shield machine according to the present invention.
5 is a cross-sectional view of the main part of FIG. 4;
FIG. 6 is an external view when a water intake tunnel is constructed with a conventional shield machine.
7 is a cross-sectional view taken along line AA in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Main body plate 2 Permeable member 3 Intake segment 10 Shield engraving machine 12 Intake tunnel 14 Shield engraving machine main body 16 Bulkhead 18 Chamber 20 Spokes 24, 24a, 24b Openings 26, 40 Movable plate

Claims (3)

In the shield machine with a chamber filled with excavated soil on the tip side of the shield machine body,
The shield machine is for constructing a water intake tunnel capable of assembling a water intake segment on the rear side of the shield machine main body and taking water inside.
The hood on the tip side of the shield machine main body is provided with a plurality of openings penetrating through the hood, and along with the intake of the excavated earth, a part of the excavated earth from the chamber is passed through the opening. A shield machine that discharges to the outside of the rear side of the shield machine main body.   2. The shield machine according to claim 1, wherein the opening is opened and closed by a movable plate that slides along an inner peripheral surface of the shield machine main body.   The shield machine according to claim 1, wherein the opening is opened and closed by a movable plate that slides along the axial direction of the shield machine main body.

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