JP7067779B2 - Drainer - Google Patents

Description

The present invention relates to a drainage work.

One of the factors that seriously hinders the excavation of mountain tunnels is the spring water of the tunnel. If high-pressure spring water or a large amount of spring water is generated, it may cause the face to collapse or the tunnel to be submerged, resulting in a significant increase in construction cost and delay in construction period.

Construction methods for spring water countermeasures are roughly divided into drainage work and water stop work, but drainage work is basically adopted in mountain tunnels. The drainage work is a method of drilling a long drainage hole from the tunnel face toward the front ground to drain the spring water in the front ground. As for drainage holes, perforated steel pipes are installed to hold the hole walls because the ground with a lot of spring water is often crushed and cracked. When a drain hole is drilled from within the face (excavation cross section) of the tunnel, this perforated steel pipe is left in the ground where the tunnel is excavated, which hinders tunnel excavation.

Japanese Unexamined Patent Publication No. 2011-80244

Therefore, in order to avoid the above problems, the perforated steel pipe may be placed outside the face surface of the tunnel so as not to interfere with excavation. However, in this case, the longer the drainage hole is, the larger the distance from the cross section of the tunnel to be excavated, and it becomes difficult to efficiently drain the spring water accumulating in the ground in front of the face.

The present invention has been made in view of the above-mentioned conventional circumstances, and provides a reliable and efficient drainage work.

In order to solve the above problem, the invention according to claim 1 is
It is a drainage work that installs a long drainage hole in the ground in front of the face of the tunnel to reduce the spring water that has accumulated in the ground in front of the face.
By injecting a water blocking material into the front ground of the face to block the water vein in the front ground of the face and changing the direction of the water flow, the spring water charged in the front ground of the face is made into the drain hole. It is a drainage work to guide.

The invention according to claim 2 is
The drainage work according to claim 1, wherein the water blocking material to be injected into the ground in front of the face is a urethane-based water blocking material that foams and hardens when it comes into contact with the spring water.

The invention according to claim 3 is
The drainage work according to claim 1 or 2, wherein the material for injecting the waterproof material is configured to be cut and removed at the time of excavation of the tunnel.

In the drainage work of the present invention, a long drainage hole is provided in the ground in front of the face of the tunnel to reduce the amount of spring water in the ground in front of the face. At this time, by injecting a water blocking material into the ground in front of the face to block the water vein in the ground in front of the face and changing the direction of the water flow, the spring water in the ground in front of the face is guided to the drain hole. Therefore, it is possible to reliably and efficiently drain the spring water that has accumulated in the ground in front of the face.

According to the drainage work according to claim 2, since the urethane-based water blocking material that foams and cures by contact with the spring water is used, the water vein can be reliably closed and the direction of the water flow can be easily changed.

According to the drainage work according to claim 3, when the tunnel is excavated, the material for injecting the waterproof material is cut and removed, so that the mountain tunnel can be excavated smoothly.

The present invention will be further described in the following detailed description with reference to the plurality of references mentioned with reference to non-limiting examples of typical embodiments according to the invention, although similar reference numerals are in the drawings. Similar parts are shown through several figures.
(A) is an explanatory view of a plan view explaining a process of forming a drainage hole in the ground in front of the face of a tunnel. (B) is a side view showing a state in which the configuration of (A) is viewed from the side. (A) is an explanatory view of a plan view explaining a process of forming an injection hole in the ground in front of the face of a tunnel. (B) is a side view showing a state in which the configuration of (A) is viewed from the side. (A) is a front view showing an injection bolt. (B) is an explanatory diagram illustrating a state in which the packer is inflated. FIGS. (A) to (D) are explanatory views illustrating each step sequentially performed when the water blocking material is injected by the injection bolt. (A) is an explanatory view of a plan view explaining a water-stopping region stopped by a water-stopping material. (B) is a side view showing a state in which the configuration of (A) is viewed from the side. (A) is a step following FIG. 5, and is an explanatory view in a plan view for explaining a step of forming a drain hole again. (B) is a step following (A), and is a plan view explanatory view explaining the water-stopping region which was stopped by the water-stopping material again.

In the drainage work according to the present embodiment, for example, it is preferable to sequentially perform the following steps (1) to (5).
(1) A step of forming a drainage hole toward the outside of the excavated cross section in the ground in front of the face of the tunnel.
(2) A step of forming an injection hole by drilling a position close to the drain hole in the face of the tunnel.
(3) A process of confirming that spring water comes out from the injection hole.
(4) A step of confirming that the amount of spring water discharged from the drain hole before forming the injection hole is reduced.
(5) A step of injecting a urethane-based water blocking material into the ground in front of the face via an injection bolt inserted into the injection hole and closing the water vein around the injection hole by firing and hardening the urethane-based water blocking material.
Further, it is preferable to repeat the steps performed by the above steps (1) to (5) as the tunnel excavation progresses.

Hereinafter, a specific draining process will be described with reference to FIGS. 1 to 6. In the drainage work of the present embodiment, a long drainage hole 20 is drilled in the face front ground 12 of the tunnel, and the spring water accumulating inside the face front ground 12 is surely and efficiently drained. It is a construction method to pull out.

First, as shown in FIG. 1, in the face 10 formed by excavating a tunnel, a drain hole 20 having a predetermined length (for example, 10 m or 20 m) is formed. Specifically, the drain hole 20 is drilled from the face 10 toward the non-excavation range 12B outside the excavation range 12A (excavation cross section) at the face front ground 12. Here, the excavation range 12A is a portion excavated for forming a tunnel, and the non-excavation range 12B is a portion adjacent to the excavation range 12A and not excavated. The drain hole 20 is inclined with respect to the excavation traveling direction so as to move away from the excavation range 12A toward the inner side of the excavation traveling direction. Further, a perforated steel pipe (not shown) is installed in the drain hole 20 to hold the hole wall. The drain hole 20 formed in the ground 12 in front of the face drains the spring water from the water vein connected to the drain hole 20. Although two drain holes 20 are provided in FIG. 1, a number other than the two may be provided at a position different from the position shown in FIG.

Next, as shown in FIG. 2, a position close to the drain hole 20 (for example, a position adjacent to the drain hole 20 near the edge of the face 10) is drilled in the face 10, and a water blocking material described later is formed. An injection hole 30 for injecting 60 is formed. Specifically, the injection hole 30 has a long shape, and is formed, for example, with a length of about half that of the drain hole 20. Here, it is determined that the spring water flows out from the injection hole 30 after the injection hole 30 is formed and the amount of the spring water flowing out from the drain hole 20 before the injection hole 30 is formed is reduced. confirm. When such a state is confirmed, it can be seen that the water vein connected to the injection hole 30 is also connected to the drain hole 20. Although one injection hole 30 is provided in FIG. 2, two or more injection holes 30 may be provided at a position different from the position shown in FIG.

Subsequently, an injection bolt (corresponding to the "material" in the claims) 40 is inserted into the injection hole 30, and a water blocking material 60 that closes the water vein via the injection bolt 40 is provided to the face front ground 12 (specifically, the face front ground 12 (specifically,). Inject into the excavation range 12A). Here, the water blocking material 60 is a urethane-based chemical solution, and when it comes into contact with water, a foam is formed to exert a water blocking effect. As shown in FIG. 4A, before the injection bolt 40 is inserted into the injection hole 30, the spring water W flows out from the injection hole 30 connected to the water vein V. In the state shown in FIG. 4 (A), the injection bolt 40 is inserted into the injection hole 30 as shown in FIG. 4 (B).

Here, the injection bolt 40 will be described with reference to FIG. As shown in FIG. 3, the injection bolt 40 includes a main body portion 41, a main body valve 42, and a packer 50. The injection bolt 40 can withstand high pressure injection. Further, the injection bolt 40 can be removed by cutting at the same time when excavating the tunnel. For example, the injection bolt 40 is made of resin. The main body 41 is formed in a tubular shape so that the water blocking material 60 can flow through the inner space thereof. The main body 41 has a thread formed on its outer peripheral surface. Further, the main body portion 41 has no thread formed, and a flat portion 43 having a diameter smaller than that of the portion where the thread is formed is formed. The flat portion 43 is formed with a communication hole 44 that communicates the inner space and the outer space of the main body portion 41. Four communication holes 44 are formed in a substantially equal arrangement in the circumferential direction. The communication hole 44 is provided with a communication hole valve 45. The communication hole valve 45 is a rubber ring band, and is assembled to the flat portion 43 so as to close each communication hole 44. The communication hole valve 45 is provided so as to open the main body valve 42, which will be described later, at a pressure lower than the opening pressure.

As shown in FIG. 3A, the main body valve 42 is attached to the tip portion 41A of the main body portion 41. Specifically, the main body valve 42 is fitted to the inner circumference of the tip portion 41A of the main body portion 41. The main body valve 42 is provided so as to be opened at a predetermined pressure. That is, the main body valve 42 is opened when the internal pressure of the main body portion 41 reaches a predetermined pressure (for example, 5 MPa) when the water blocking material 60 is circulated in the main body portion 41.

As shown in FIG. 3, the packer 50 is mounted on the outer peripheral surface of the main body 41. The packer 50 is formed in a tubular shape, is made of rubber, and has elasticity. As shown in FIG. 3B, the packer 50 is attached to the main body 41 by crimping the vicinity of both ends thereof with a resin ring band 51.

As shown in FIG. 4B, when the injection bolt 40 is inserted into the injection hole 30, the spring water W flows out from the base end portion 41B through the inner space of the main body portion 41. Subsequently, as shown in FIG. 4C, the water blocking material 60 is injected into the injection bolt 40 from the base end portion 41B. The injected water blocking material 60 stays in the inner space of the main body 41 to increase the internal pressure and open the communication hole valve 45. When the communication hole valve 45 is opened, the packer 50 is filled with the water blocking material 60. When the water blocking material 60 is filled, the packer 50 expands and is pressed against the inner wall of the injection hole 30. As a result, the injection bolt 40 is fixed to the injection hole 30. Since the communication hole valve 45 acts as a check valve, the packer 50 is maintained in an expanded state without contracting even when the internal pressure drops.

In the state shown in FIG. 4C, the water blocking material 60 is further continuously injected into the injection bolt 40 to increase the internal pressure in the inner space of the main body 41. As a result, when the internal pressure of the main body 41 reaches a predetermined pressure (for example, 5 MPa), the main body valve 42 is opened. Then, as shown by the arrow in FIG. 4C, the water blocking material 60 flows out from the tip portion 41A of the main body portion 41. Further, the water blocking material 60 is continuously injected into the injection bolt 40, and the water blocking material 60 is injected into the water vein V. Here, the injection pressure of the water blocking material 60 is set to a size that can withstand the water pressure of the spring water in the water vein V. The water blocking material 60 is foamed and hardened by contact with spring water. The water blocking material 60 cured in the water vein V closes the water vein V in the vicinity of the injection hole 30 as shown in FIG. 4 (D), and forms a water blocking region AR as shown in FIG. In addition, in FIG. 5, the water stop region AR formed in the vicinity of the injection hole 30 is shown so as to simply surround the injection hole 30.

By blocking the water vein V in the vicinity of the injection hole 30 in this way, the direction of the water vein in the face front ground 12 can be changed. Specifically, by blocking the water vein V at the portion located in the excavation range 12A in the ground in front of the face, the water vein can be changed to the water vein toward the non-excavation range 12B. Then, the spring water charged in the excavation range 12A can be guided to the drain hole 20.

Subsequently, the excavation of the face front ground 12 from which the spring water has been drained as described above is performed. Here, when excavating the ground 12 in front of the face, the injection bolt 40 is also cut and removed at the same time. Therefore, it is not necessary to take out and remove the injection bolt 40 each time excavation is performed, and the excavation of the tunnel can proceed smoothly. Then, the steps described with reference to FIGS. 1 to 5 are similarly performed on the newly formed face 10 (for example, the face 10 formed by excavating until the injection hole 30 disappears). Specifically, as shown in FIG. 6 (A), a new injection hole 30 is cut, and then the steps shown in FIGS. 4 (A) to 4 (D) are performed, and the steps shown in FIGS. 6 (B) are performed. As a result, a new waterproof region AR is formed. After that, the steps shown in FIGS. 1 to 5 are repeated as the excavation progresses.

In the drainage work of the present embodiment, a long drainage hole 20 is provided in the face front ground 12 of the tunnel to reduce the amount of spring water in the face front ground 12. At this time, the water blocking material 60 is injected into the face front ground 12 to block the water veins in the face front ground 12, and the direction of the water flow is changed so that the spring is charged in the face front ground 12. Guide water to the drain hole 20. Therefore, it is possible to reliably and efficiently drain the spring water that has accumulated in the ground 12 in front of the face.

According to the drainage work of the present embodiment, since the urethane-based water blocking material 60 that foams and hardens by contact with the spring water is used, the water vein V can be reliably closed and the direction of the water flow can be easily changed.

According to the drainage work of the present embodiment, the mountain tunnel can be smoothly excavated by cutting and removing the injection bolt 40 for injecting the water blocking material 60 at the time of excavating the tunnel.

<Other embodiments>
It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention according to the purpose and use.

In the above embodiment, the configuration in which one injection bolt 40 is used is shown in the injection step of the water blocking material 60 (see FIG. 4), but the amount of spring water charged in the ground 12 in front of the face and the drain hole 20 It may be increased or decreased as appropriate depending on the number.

In the above embodiment, as shown in FIG. 3, the injection bolt 40 is made of resin and includes a main body portion 41, a main body valve 42, and a packer 50. However, the injection bolt 40 may have any other configuration as long as it can inject the waterproof material 60 and can be cut and removed at the same time when excavating the tunnel.

The above examples are for illustration purposes only and are not to be construed as limiting the invention. Although the invention has been described with reference to examples of typical embodiments, the language used in the description and illustration of the invention is understood to be descriptive and exemplary rather than restrictive. As detailed herein, modifications may be made within the scope of the appended claims without departing from the scope or spirit of the invention in its form. Although specific structures, materials and embodiments have been referred to herein in detail of the invention, it is not intended to limit the invention to the disclosures herein, but rather the invention is claimed in the attachment. It shall cover all functionally equivalent structures, methods and uses within the scope.

Widely used as a technique for draining tunnels.

10 ... Face 12 ... Face front ground 20 ... Drain hole 30 ... Injection hole 40 ... Injection bolt (material)
41 ... Main body 41A ... Tip 42A ... Base 43 ... Flat 44 ... Communication hole 45 ... Communication hole valve 50 ... Packer 51 ... Ring band 60 ... Water stop material AR ... Water stop area V ... Water vein W ... Spring

Claims (4)

It is a drainage work that installs a long drainage hole in the ground in front of the face of the tunnel to reduce the spring water that has accumulated in the ground in front of the face.
By injecting a water blocking material into the front ground of the face to block the water vein in the front ground of the face and changing the direction of the water flow, the spring water charged in the front ground of the face is made into the drain hole. Guidance,
The water blocking material to be injected into the ground in front of the face is a urethane-based water blocking material that foams and hardens when it comes into contact with the spring water . The water blocking material is injected from an injection hole formed in the ground in front of the face.
The drainage work according to claim 1 , wherein the length of the injection hole is shorter than the length of the drainage hole . The first step of forming a drainage hole toward the outside of the excavation section in the ground in front of the face of the tunnel,
The second step of drilling a position close to the drain hole in the face of the ground in front of the face to form an injection hole for injecting a water blocking material.
The third step of confirming that spring water comes out from the injection hole, and
The fourth step of confirming that the amount of spring water flowing out from the drainage hole before forming the injection hole is reduced, and
A fifth, in which a urethane-based water blocking material is injected into the ground in front of the face via an injection bolt, which is a material inserted into the injection hole, and the water vein around the injection hole is blocked by the foaming hardening of the urethane-based water blocking material. Process and
Including
A drainage work in which the first step, the second step, the third step, the fourth step, and the fifth step are repeated in order . The drainage work according to any one of claims 1 to 3 , wherein the material for injecting the water blocking material has a structure that can be cut and removed at the time of excavation of the tunnel.

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