JP2014020124A - Construction method of water collection tunnel and water collection tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a construction method of a water collection tunnel in which a cut-off property during tunnel construction can be ensured and water can be surely collected during service, and the water collection tunnel.SOLUTION: A construction method of a water collection tunnel includes: a tunnel construction step for forming a tunnel in which grout holes 14 are closed; and an opening step for opening the grout holes 14 to form a water collection hole 12 in the tunnel. A water collection tunnel 1 comprises a tunnel body 11 and a plurality of grout holes 14 penetrating the tunnel body 11, and is formed to guide underground water W around the tunnel into the tunnel by communicating an inner space of the tunnel and a rock mass G via the grout holes 14.

Description

  The present invention relates to a method for constructing a water collection tunnel and a water collection tunnel.

There are cases where groundwater is collected by installing a water collection pipe in the ground. As a method for forming such a water collecting pipe, there is a case where a water collecting tunnel provided with a water intake is formed in the ground.
It is necessary to prevent the water collection tunnel from being submerged by water taken from the water intake by shielding the water intake during construction.

As a construction method of the water collection tunnel, for example, Patent Document 1 discloses a construction method in which the water intake is closed by a pressure difference inside and outside the tunnel.
This construction method is to remove the cap after increasing the pressure in the tunnel after constructing the tunnel with the water inlet connected to the water permeable part formed on the outer surface side of the tunnel closed with the inner lid and cap. Thus, the water intake is closed by the inner lid. Thereafter, the worker is evacuated from the tunnel and the pressure in the tunnel is lowered to drop the inner lid and open the water intake.

  Patent Document 2 discloses a tunnel in which a water permeable portion formed on the outer surface side of the tunnel and a water intake port connected to the water permeable portion are formed, and is made of a biodegradable resin so as to cover the outer peripheral surface of the water permeable portion. Disclosed is a water collection tunnel that has water-impervious sheets installed, water-proofing is ensured during tunnel construction, and the water-impervious sheet melts after a predetermined time so that water can be collected from the water intake. ing.

  Furthermore, in Patent Document 3, a tunnel is constructed using a pipe material having a water-stopping layer and a water-permeable layer made of expanded polystyrene, and water can be collected by reducing the water-stopping layer with a solvent after tunnel construction. A method for forming a tunnel is disclosed.

JP-A-11-303155 JP 2003-268814 A JP 2009-235883 A

  Since the construction method of the water collection tunnel of patent document 1 requires a large-scale tunnel pressure air installation, it takes time to arrange, drive, and remove the equipment. Moreover, there is a possibility that the inner lid does not fall only by the pressure difference inside and outside the tunnel.

  Moreover, the water collecting tunnel of patent document 2 may not biodegrade an impermeable sheet | seat depending on the microorganisms which exist in the ground. In this case, since water permeability cannot be ensured, construction sites are limited.

  Moreover, in the water collection tunnel of patent document 3, a water intake (water flow part) may be plugged up with the residue after melt | dissolution. Moreover, although the expanded polystyrene which forms a water-stopping layer is fixed with an adhesive, there is a concern about water leakage from the bonded portion.

  Furthermore, since the conventional water collection tunnel generally has a special function in the segment itself, such as forming a water permeable portion (permeable layer) partially made of porous concrete or the like, the manufacturing cost of the segment is low. It will be high.

  The present invention solves the above-mentioned problems, and proposes a method for constructing a water collection tunnel and a water collection tunnel that can ensure water-stopping during tunnel construction and that can reliably collect water during operation. This is the issue.

  In order to solve the above-described problems, a method for constructing a water collection tunnel according to the present invention includes a tunnel construction process for forming a tunnel in which a grout hole is closed, and a water intake is formed in the tunnel by opening the grout hole. And an opening step.

According to the construction method of such a water collection tunnel, water can be reliably collected using a grout hall.
By using the grout hole of the segment, it is not necessary to give the segment a special function, and the material cost (segment manufacturing cost, etc.) does not increase.

In the opening step, the piston is used in a state where a grout hole opening machine including a cylinder portion and a piston portion including a perforated rod inserted in the cylinder portion is used, and the cylinder portion is attached to the grout hole. The piston portion may be inserted into the natural ground by pushing the portion toward the natural ground. If it does in this way, a water intake can be formed reliably.
In addition, the amount of water intake can be adjusted by changing the length and the porosity of the perforated rod.

  In addition, a cutting mechanism is provided at the tip of the grout hole cap, and in the opening step, the grout hole cap is rotated forward to penetrate the backfill layer, and then the grout hole cap is rotated backward to rotate the grout hole cap. If it is removed from the grout hole, it is possible to reliably secure a water intake even in a tunnel having a backfill layer.

  Further, the water collection tunnel of the present invention is a water collection tunnel comprising a tunnel main body and a plurality of grout holes penetrating the tunnel main body, and the inner sky of the tunnel communicates with a natural ground by the grout hole. The groundwater around the tunnel is formed so that it can be led into the tunnel.

  Since such a water collection tunnel uses a grout hall as a water outlet, it can be easily constructed without requiring special equipment.

  According to the water collection tunnel construction method and the water collection tunnel of the present invention, it is possible to secure water-stopping performance during tunnel construction and reliably collect water during operation.

It is a longitudinal cross-sectional view which shows the outline | summary of the water collection tunnel which concerns on embodiment of this invention. It is sectional drawing which shows the water collection tunnel shown in FIG. It is sectional drawing which shows the water intake of 1st Embodiment. It is a figure which shows the construction condition of the water intake of FIG. 3, Comprising: (a) is sectional drawing of grout hole before grout hole plugging machine installation, (b) is sectional drawing of grout hole after grout hole plugging machine installation It is. (A)-(c) is sectional drawing which shows each construction step of the water intake of 2nd Embodiment. (A)-(c) is sectional drawing which shows the other form of a grout hole cap.

  In the first embodiment, a case will be described in which the water collection tunnel 1 is formed so as to pass below the ground facility 2 in order to collect contaminated groundwater that has permeated the ground from the ground facility 2.

  As shown in FIG. 1, the water collecting tunnel 1 constitutes a part of a tunnel T formed from the shaft 3 toward the lower side of the ground facility 2. Although FIG. 1 shows the case where the water collection tunnel 1 has a downward slope, the water collection tunnel 1 may have an upward slope. The slope (inclination direction and angle) of the water collecting tunnel may be appropriately set according to the pump of the shaft 3, topography, and the like.

The tunnel T includes a water collection tunnel section T1 and a normal tunnel section T2.
As shown in FIG. 1, the water collection tunnel section T1 is a section below the ground facility 2, and the normal tunnel section T2 is a section other than the water collection tunnel section T1.

In the tunnel T, the water collection tunnel section T1 is formed by a water collection tunnel 1 capable of taking in groundwater, and the normal tunnel section T2 is formed by a normal shield tunnel 1a.
In the present embodiment, the case where the tunnel T is formed by a shield tunnel will be described. However, the tunnel type of the tunnel T is not limited, and may be a propulsion tunnel or a TBM, for example. Further, it may be a tunnel T formed by a box culvert or the like laid by excavation work.

  As shown in FIG. 2, the water collecting tunnel 1 includes a tunnel main body 11 and a plurality of water intakes 12, 12,.

  The tunnel body 11 is formed in a circular cross section by combining a plurality of segments 13, 13,. Note that the cross-sectional shape of the tunnel body 11 is not limited to a circular shape.

  A grout hole 14 is formed at the center of each segment 13. An internal thread is formed on the inner peripheral wall of the grout hole 14. The arrangement and number of the grout holes 14 are not limited and may be set as appropriate.

  The grout hole 14 is used as a backfill injection hole at the time of tunnel construction, and is formed so as to penetrate the tunnel main body 11 and to communicate the interior sky of the water collecting tunnel 1 and the natural ground G. The water collecting tunnel 1 is formed so that the ground water can be led from the surrounding natural ground G to the inner space with the grout hole 14 as the water inlet 12.

  In the gap between the outer surface of the water collecting tunnel 1 and the natural ground G, a backfilling material (grout) is injected, and a backfilling layer 4 is formed. The water intake 12 formed using the grout hole 14 penetrates the backfill layer 4 and faces the natural ground G. The material constituting the backfilling material is not limited to grout.

The construction of the water collecting tunnel 1 includes a tunnel construction process and an opening process.
As shown in FIG. 1, the tunnel construction process is a process of constructing a tunnel T from the shaft 3 toward the lower side of the ground facility 2.

In the tunnel construction process, the tunnel T in a state where the grout hole 14 is closed by the grout hole cap 15 is constructed by a shield method (see FIG. 4A).
The construction of the tunnel T is performed by connecting the segment ring in the ground along the axial direction along with the underground excavation by the excavator M.

  The segment ring is formed by combining a plurality of segments 13,... Behind the excavator M, and is connected to an existing segment ring to form a tunnel lining (tunnel body 11).

  When the segment ring assembled in the excavator M comes out of the tail of the excavator M, grout (backfill material) is injected from the grout hole 14 to the outer periphery of the segment ring (tunnel). In the present embodiment, a grout hole cap 15 (see FIG. 4A), which is a check valve made of resin, is mounted in advance in the grout hole 14 to prevent inflow of groundwater W or earth and sand during tunnel construction. At the same time, the grout can be injected. In addition, the grout hole cap 15 does not necessarily need to be a check valve. For example, when backfill injection is not required, a resin lid may be used. Moreover, the grout hole cap 15 screwed to the grout hole 14 after grout injection may be used.

  The opening process is a process of opening the grout hole 14 and forming the water intake 12 in the tunnel T in the water collecting section T1 after the tunnel T is constructed.

  In the present embodiment, as illustrated in FIG. 3, the grout hole 14 is opened using the grout hole opening machine 5.

  The grout hole opening machine 5 includes a cylinder part 51 and a piston part 52 which is a perforated rod built in the cylinder part 51. The cylinder part 51 and the piston part 52 are constituted by cylindrical members, and the piston part 52 is slidably held in the cylinder part 51.

  As shown in FIG. 3 and FIG. 4B, the cylinder portion 51 includes a fluid inlet 53 formed on the rear end side and a fluid outlet 54 formed on the front end side. The fluid inlet 53 is connected to the inner cylinder chamber 51 a in the cylinder 51, and the fluid outlet 54 is connected to the natural mountain cylinder chamber 51 b in the cylinder 51.

  When fluid (air, water, oil, etc.) in the natural mountain side cylinder chamber 51b is discharged from the fluid discharge port 54 and fluid (air, water, oil, etc.) is injected from the fluid inlet 53 into the inner cylinder chamber 51a. The piston part 52 extends.

The piping connected to the fluid inlet 53 is connected to an injection device (not shown) through the tunnel mine and the shaft.
In this embodiment, the fluid discharged from the fluid discharge port 54 is discharged as it is into the tunnel without being collected.

  Screw processing (male thread) is applied to the outer peripheral surface of the front end side (natural ground side) of the cylinder portion 51 and is screwed into the grout hole 14. The fixing method of the grout hole opening machine 5 is not limited. For example, the grout hole opening machine 5 may be fixed by using an insert hardware attached to the segment 13 at the time of manufacturing the segment.

The piston portion 52 is formed with an enlarged diameter portion 55 that slides in the cylinder portion 51. The enlarged diameter portion 55 divides the inside of the cylinder portion 51 into an inner cylinder chamber 51a and a natural mountain cylinder chamber 51b. A sealing material such as an O-ring is fitted on the enlarged diameter portion 55.
When the diameter-expanded portion 55 receives the pressure of the fluid press-fitted into the inner-side cylinder chamber 51a, a force that pushes the piston portion 52 acts.

  A cutting mechanism 56 such as a bit or a tip is provided at the tip of the piston 52 (the end on the natural ground side). A plurality of through holes 57 are formed on the side surface (the rear portion of the cutting mechanism 56) of the tip portion of the piston portion 52. Further, the rear end of the piston portion 52 is open. In addition, the structure of the front-end | tip (cutting mechanism 56) of the piston part 52 is not limited. For example, by making the cutting mechanism 56 a spoke type, the tip of the piston portion 52 may be opened and the through hole 57 may be omitted.

In the opening process, first, the grout hole opening machine 5 is fixed to the grout hole 14 as shown in FIG. After fixing the grout hole opening machine 5 to the grout hole 14, the worker retreats outside the tunnel T.
Thereafter, the injection device (not shown) on the ground is operated to press the fluid through the fluid inflow port 53, thereby increasing the pressure (hydraulic pressure, air pressure or water pressure) in the cylinder portion 51, and the piston portion 52 is moved to the ground. Extrude to G side.

As shown in FIG. 3, the piston portion 52 pushed to the natural ground G side penetrates the grout hole cap 15 and penetrates into the natural ground G.
By arranging the tip of the piston portion 52 in the natural ground G, the interior sky of the water collecting tunnel 1 and the natural ground G are in communication with each other, and the water collecting tunnel 1 is formed.

  According to the water collecting tunnel 1 of the present embodiment, the groundwater W is taken from the through holes 57, 57,... The groundwater W taken from the through hole 57 is taken into the inner space of the tunnel T through the piston portion 52 (water intake 12).

  In the water collecting tunnel 1, the water intake 12 is shielded and the groundwater W is not taken into the tunnel until the opening process is performed, so that leakage during construction does not occur. Therefore, even if the purpose is to collect contaminated groundwater, the tunnel T can be constructed safely.

Since the water intake 12 is formed by using the grout hole 14, the water collecting tunnel 1 can be reliably constructed without requiring a special segment.
For this reason, no setup change is required when the tunnel T is constructed, and the construction is excellent.

  Moreover, the proof strength of the tunnel main body 11 is excellent compared with the conventional water collection tunnel provided with the water-permeable layer etc., and lining of a lining is also possible.

  Moreover, since the water intake 12 can be formed using the grout hole 14 where necessary, the setting of the water collection tunnel section T1 can be freely performed according to the situation of the site. .

  Even if the plug opening process is not performed immediately after the tunnel construction process, there is no deterioration or deformation due to secular change, etc., and even if the standby period is several years, Risk is small.

  In addition, it is good also as a structure which forms the helical unevenness | corrugation (square screw) in the internal peripheral surface of the cylinder part 51, and the outer peripheral surface of the piston part 52, respectively, and provides a rotational force to the piston part 52 with a pressure. By doing so, the backfill layer 5 and the natural ground G can be cut while the piston portion 52 rotates.

Here, if air is used as the fluid, there is no need to consider the return of the fluid (hydraulic oil or water). That is, the fluid discharge port 54 only needs to be opened in the tunnel mine, so that the piping work is facilitated.
The grout hole cap 15 may be pierced by a hydraulic drifter or an air drifter.

The inside of the piston part 52 is configured so that gravel is filled in the tip part as the clogging preventing means 52a and the water collecting performance is not deteriorated. Here, the code | symbol 52b is a water-permeable cover material for preventing the outflow of gravel from the piston part 52. FIG.
The clogging prevention means 52a is not limited to gravel, and may be a mesh member, a strainer, or the like. Further, the lid member 52b may be disposed as necessary.
A screen or the like may be provided at the rear end portion of the piston portion 52.

  2nd Embodiment demonstrates the case where the water intake 12 is formed by removing the grout hole cap 15 screwed by the grout hole 13. FIG.

The construction of the water collecting tunnel 1 includes a tunnel construction process and an opening process.
As shown in FIG. 1, the tunnel construction step is a step of constructing a tunnel T from the vertical shaft 3 toward the lower side of the ground facility 2.

  In the tunnel construction process, after placing the segment ring in the ground, grout (backfill material) is injected from the grout hole 14 to the outer periphery of the segment ring (tunnel). When the injection of the backfill material is completed, the grout hole cap 15 is screwed into the grout hole 14 (see FIG. 5A).

As shown in FIG. 5 (a), the grout hole cap 15 is a columnar member provided with a screw processing corresponding to a square screw formed on the inner surface of the grout hole 14, and has a bit or a chip at the tip. A cutting mechanism 16 is provided.
The grout hole cap 15 may be provided with a nipple so that grease can be filled.

The material of the grout hole cap 15 is not limited. However, it is preferable that the grout hole cap 15 is made of stainless steel, titanium, FRP or the like because it does not easily rust.
The cutting mechanism 16 may be formed as necessary, and is not necessarily formed.

  Since the contents of the other tunnel construction process are the same as the contents shown in the first embodiment, detailed description thereof is omitted.

  In the plug-opening process, a recovery device (not shown) is installed, and after the worker is evacuated from the tunnel T, the grout hole cap 15 is removed from the grout hole by remotely operating the recovery device. The hole 14 is opened (see FIG. 5).

What is necessary is just to fix a collection | recovery apparatus to the insert metal fitting attached to the segment 13 at the time of segment manufacture. In addition, the fixing method of a collection | recovery apparatus is not limited.
Further, the recovery device may be electric or hydraulic, and its drive type is not limited.

  First, as shown in FIGS. 5A and 5B, the grout hole cap 15 is rotated forward using the recovery device, and the grout hole cap 15 is advanced to the natural ground G side. If it carries out like this, the back filling layer 4 and the natural ground G will be cut by the cutting mechanism 16, and the front-end | tip of the grout hole cap 15 will be inserted in a natural ground.

Next, as shown in FIG. 5C, the grout hole cap 15 is reversely rotated using the recovery device, and the grout hole cap 15 is removed from the grout hole 14.
If it carries out like this, the inside of the water collection tunnel 1 and the natural ground G will be in the communication state by the grout hole 14, and the water collection tunnel 1 will be formed. The forward / reverse rotation of the grout hole cap 15 may be performed manually.

  According to the water collection tunnel 1 of the present embodiment, as shown in FIG. 5C, the groundwater W of the natural ground G around the water collection tunnel 1 passes through the grout hole 14 (water intake 12). It is taken into the inner space of T. Therefore, the same effect as the water collecting tunnel 1 of the first embodiment can be obtained.

  In addition, the structure of the grout hole cap 15 is not limited to what is shown in FIG. 5, What is necessary is just to comprise suitably. For example, as shown in FIG. 6 (a), as the cutting mechanism 16, a spoke-type bit (for example, a cross bit type having a cross shape in front view) is used to take in the earth and sand cut into the inner surface of the cutting mechanism 16. May be configured to be possible. Moreover, the groove | channel 15a, 15a for taking in earth and sand may be formed in the front end side surface of the grout hole cap 15. If it does in this way, when pushing the grout hole cap 15 into the natural ground G, the escape place of earth and sand can be ensured, and it can prevent becoming impossible to push.

  Further, as shown in FIG. 6C, if the grout hole 14 and the grout hole cap 15 have a taper that increases in diameter toward the inner side of the pit, the grout hole cap 15 is easily removed.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above-described embodiment, and the above-described components can be appropriately changed without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the tunnel formed by the segments has been described, but the lining structure of the tunnel is not limited, and for example, a tunnel formed by a fume tube or a box culvert may be used.

  The water collection tunnel 1 may be formed over the entire length of the tunnel T, or may be formed in a part of the tunnel T.

DESCRIPTION OF SYMBOLS 1 Catchment tunnel 11 Tunnel main body 12 Water intake 14 Grout hole 15 Grout hole cap 16 Cutting mechanism 41 Cylinder part 42 Piston part G Ground mountain T Tunnel W Groundwater

Claims (4)

A tunnel construction process for forming a tunnel with a closed grout hole;
And a step of opening the grout hole to form a water intake in the tunnel.   In the opening step, the piston is used in a state where a grout hole opening machine including a cylinder portion and a piston portion including a perforated rod inserted in the cylinder portion is used, and the cylinder portion is attached to the grout hole. The method for constructing a water collection tunnel according to claim 1, wherein the piston portion is inserted into a natural ground by pushing the portion toward the natural ground. A cutting mechanism is provided at the tip of the grout hole cap,
2. The opening step according to claim 1, wherein after the grout hole cap is rotated forward to penetrate the backfill layer, the grout hole cap is reversely rotated and removed from the grout hole. To build a water collection tunnel. The tunnel body,
A water collecting tunnel comprising a plurality of grout holes penetrating the tunnel body,
The water collection tunnel characterized in that the inside of the tunnel communicates with the natural ground by the grout hole, and is formed so that the groundwater around the tunnel can be led into the tunnel.

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