JP2000257392A - Waterproof formwork and tunnel construction method using the same - Google Patents

Abstract

(57) [Summary] An object of the present invention is to provide a water-stopping formwork capable of increasing the water-stopping property and a tunnel construction method using the same. SOLUTION: A water stopping mold 11 is arranged on the outer peripheral side of an inner mold 3, and a joint between the water stopping molds 11 is formed by a water stopping plate portion 12 and an engagement step portion 13. It is configured to engage. And, in the meshing step 13,
A water blocking agent injection hole was formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water stopping mold suitable for constructing a tunnel employing a self-hardening filler such as concrete or mortar, and a method of constructing a tunnel using the same. .

[0002]

2. Description of the Related Art As is well known, for example, when a tunnel is constructed by a shield method for a soft ground having a high groundwater level, a segment is generally used for the primary lining. In recent years, instead of using segments, assembling a formwork behind a shield excavator and casting concrete as self-hardening material directly between the formwork and ground to fill the lining wall Form,
The so-called ECL method (Extruded Concrete Lining Metho
Development of d) is also underway.

In the ECL method, after the poured concrete is hardened and the lining wall is formed, it is natural that the concrete can sufficiently withstand the ground pressure (earth pressure and groundwater pressure). It must be able to withstand the ground pressure even with uncured concrete immediately after casting. In particular, when the ECL method is applied to a ground with a high groundwater pressure, a measure for securing sufficient waterproofness by uncured concrete is indispensable. For this reason, the present applicant has previously described a tunnel lining method in the ECL method in which the casting pressure of concrete is always maintained at a level higher than the ground pressure, so that the water stopping property is ensured even with uncured concrete. (For example, JP-A-4-161599).

[0004]

However, the above-mentioned conventional techniques have the following problems.
In such an ECL method, at the time of casting concrete in a normal state, the casting pressure is maintained at a predetermined pressure equal to or slightly higher than the pressure of the concrete that has been previously cast, and this is pre-cast. By casting before the set concrete is hardened, the two types of cast concrete are integrated. As a result, the lining wall is formed as a continuous body having no seams, thereby securing the water stopping property.

[0005] However, for example, on the days when construction is closed, the concrete poured first hardens completely.
It will not be integrated with the concrete to be cast in the first process after the holidays, and a seam will be formed here, and there is a risk of water leakage from this part. Had been requested.

[0006] In addition, the lining wall continuously formed by continuously casting concrete is shrunk as the hardening heat of the concrete is gradually reduced, and as a result, the lining wall is formed on the lining wall. Cracks may occur. In particular, when the surrounding ground is solid, the outer peripheral surface side of the lining wall is constrained by the surrounding ground, and cracks are likely to occur due to shrinkage. Since it is difficult to specify the location of such a crack, it is also difficult to deal with water leakage from this location.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has as its object to provide a water-stopping formwork capable of further improving the water-stopping property and a tunnel construction method using the same. I do.

[0008]

The invention according to claim 1 is
Between the peripheral wall of the pit excavated on the ground by the shield excavator and the inner formwork assembled at intervals on the inner peripheral side of the peripheral wall,
A water stopping mold used for a tunnel in which the inner surface of the peripheral wall is lining by being filled with a self-hardening filler, wherein the water stopping mold is arranged on an outer peripheral side of the inner mold. And a protruding plate portion protruding forward or rearward is formed at one of the ends at the front end and the rear end in the tunnel axis direction, and the other end is formed. And a meshing portion meshing with the protruding plate portion is formed.

By arranging the water-stopping formwork on the outer peripheral side of the inner formwork, water leakage from the lining wall formed by hardening of the poured concrete is prevented. In addition, in the joint portion between the water stopping molds, a projecting plate portion formed at one end of the water stopping mold and a meshing portion formed at the end of the other water stopping mold. By engaging
Water leakage from this part can also be prevented.

According to a second aspect of the present invention, there is provided the water stopping mold according to the first aspect, wherein a pin is formed on one of the front end and the rear end, and the pin is formed on the other end. A pin hole into which the hole is inserted.

Accordingly, when the water stopping molds are joined together, the pins can be engaged with the pin holes to perform the positioning.

The invention according to claim 3 is the invention according to claim 1 or 2
The water stopping mold according to the above, wherein the meshing portion includes a water stopping agent between the projecting plate portion of the other water stopping mold when connecting another water stopping mold. It is characterized in that a water blocking agent injection hole for injection is formed.

[0013] By injecting the water-stopping agent into the joint between the water-stopping molds through the water-stopping agent injection hole, the projecting plate portion of one of the water-stopping molds and the other water-stopping formwork mesh with each other. The gap with the part can be closed.

The invention according to claim 4 is the water stopping mold according to any one of claims 1 to 3, wherein the water stopping mold is joined to the outer peripheral surface of the inner mold. Therefore, a concave portion corresponding to the convex portion provided on the outer peripheral surface of the inner mold frame is formed.

The water stopping mold can be set by engaging the recess formed in the water stopping mold with the projection provided on the outer peripheral surface of the inner mold.

According to a fifth aspect of the present invention, while excavating the ground with a shield excavator, the peripheral wall of the excavated ground is covered with an inner form at a predetermined interval, and the front or rear of the tunnel is covered. A water stopping mold having a protruding plate portion formed to protrude on one of the side ends and a meshing portion formed to mesh with the protruding plate portion on the other side, Set along the outer peripheral surface, the projecting plate portion or the meshing portion of the water stopping mold, the meshing portion of the other water stopping mold installed ahead of the excavation direction rear side or Engaging with the protruding plate portion, and thereafter, filling the self-hardening filler between the water stopping mold and the peripheral wall, and removing the inner mold after the self-hardening filler is cured. Features.

As a result, the water-stopping formwork is present on the inner peripheral surface side of the lining wall formed by curing the self-hardening filler, thereby preventing water leakage from the lining wall. it can. Further, by fitting the protruding plate portion and the engagement portion together, it is possible to ensure the water stopping at the joint between the water stopping molds.

According to a sixth aspect of the present invention, there is provided the tunnel construction method according to the fifth aspect, wherein a water-stopping agent injection hole is formed in advance at a meshing portion of the water-stopping formwork, and After the water mold is engaged with the water-stopping mold on the rear side, a water-stopping agent is injected between the engagement portion and the protruding plate portion from the water-stopping-agent injection hole.

Thus, it is possible to close the gap between the projecting plate portion of one of the water stopping molds and the meshing portion of the other water stopping mold.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of a waterproofing form according to the present invention and a method for constructing a tunnel using the form. FIG.

In FIG. 1, reference numeral 1 denotes a shield excavator for excavating a tunnel T in a ground G, and 2 denotes a cylindrical skin plate forming an outer shell of the shield excavator 1, for example.
1a is a cutter provided at the tip of the skin plate 2 for excavating the ground G, and 3 is a cutter assembled at a predetermined interval inside the peripheral wall Tw of the pit excavated by the shield excavator 1. Reference numeral 4 denotes a mold, and reference numeral 4 denotes a self-hardening filler such as concrete or mortar which is cast and filled between the inner mold 3 and the peripheral wall Tw of the pit. Further, reference numeral 5 is
It is a propulsion jack that takes a reaction force from the inner formwork 3 and plays a role in advancing the shield excavator 1.

In the annular space between the skin plate 2 and the inner mold 3 assembled inside the skin plate 2, a shield mold 8 made of a ring-shaped plate material is provided over the entire periphery thereof. The excavator 1 is housed so as to be movable back and forth in the axial direction. The end form 8 is driven forward and backward in the space by a pressing jack 9 fixed to the skin plate 2 in front of the space.

A skin plate 2 is provided on the outer periphery of the wife form 8.
A seal member (not shown) is provided at a portion in contact with the side and the inner mold frame 3. Further, the self-hardening filler 4 is provided on the tip end surface of the wife form 8, that is, the surface that directly presses the self-hardening filler 4.
In order to detect the pressure, a pressure sensor (not shown) such as a strain gauge type earth pressure gauge is attached, and this pressure sensor is connected to control means (not shown) for controlling the driving of the pressing jack 9. The pressure of the self-hardening filler 4 pressed by the wand mold 8 is detected every moment and inputted to a control means (not shown).

Here, the water stopping mold 11 used for lining the tunnel T will be described. As shown in FIG. 2, the water stopping mold 11 is arranged along the outer peripheral surface of the inner mold 3, has the same shape as the inner mold 3, and has an inner peripheral surface having the inner surface. It is formed along the outer peripheral surface of the mold 3. The water stopping mold 11 is precast with an inorganic material having high strength and high toughness, such as mortar mixed with fibers such as steel fiber vinylon and polypropylene.

As shown in FIGS. 2 and 3, the water-stopping formwork 11 has an end portion which is set on the outer peripheral surface side of the inner formwork 3 and which is located on the forward side in the excavation direction of the shield excavator 1. 11a
A water blocking plate portion (projecting plate portion) 12 protruding forward is formed, and a meshing step portion (meshing portion) 13 is formed at an end 11b on the rear side.

As shown in FIG. 3, the water stopping plate portion 12
Is formed to protrude forward by a predetermined size continuously on the outer peripheral surface of the water stopping mold 11 and is formed continuously in the circumferential direction of the water stopping mold 11. On the other hand, the engaging step 13 is provided with the water stopping mold 11.
Is formed by forming a step 13a having a size corresponding to the thickness of the water blocking plate portion 12 with a length corresponding to the protrusion size of the water blocking plate portion 12 with respect to the outer peripheral surface of the water blocking plate portion 12. I have.

With such a configuration, when the two water-blocking molds 11 are joined to each other in the excavation direction, the water-blocking plate portion 12 of one of the water-blocking molds 11 is connected to the other water-blocking mold. The frame 11 overlaps with the meshing step 13 so as to mesh with each other.

The meshing step 13 is formed with a water blocking agent injection hole 15 which communicates the inner peripheral surface side and the outer peripheral surface side.
The water-stopping agent injection hole 15 is formed by, for example, injecting a water-stopping agent such as a water-swellable polymer from the inner peripheral surface side of the inner mold 3.
The water-stopping agent is filled in the gap between the meshing step 13 and the water-stopping plate 12 overlapping therewith.

Further, on the inner peripheral surface of the water stopping mold 11, a plurality of concave portions 16 are formed at predetermined positions. On the outer peripheral surface of the inner mold 3, a projection (not shown) is integrally provided at a position corresponding to the recess 16.

Next, a method of constructing the tunnel T using the water stopping mold 11 will be described. As shown in FIG. 1, to excavate the tunnel T, first, the shield excavator 1
The inner mold 3 is assembled into a predetermined shape behind the skin plate 2 while excavating the ground G with the cutter 1a provided at the front of the skin plate 2 to form a pit.

As shown in FIG. 2, when assembling the inner mold 3, the inner mold 3 is previously inserted into the concave portion 16 of the water-stopping mold 11 in a convex portion (not shown) on the outer peripheral surface side of the inner mold 3. The assembling work is performed in a state where these are integrally set. And when assembling the inner formwork 3 and the water stopping mold 11, it is joined to the inner formwork 3 and the water stopping form 11 which are assembled earlier in the excavation direction.
The water stopping mold 11 to be newly assembled has its engaging step 13 engaged with the water stopping plate part 12 of the water stopping mold 11 previously assembled.

In this manner, the inner mold 3 and the water stopping mold 11
Are assembled into a predetermined shape, and then, in the space between the assembled water-stopping formwork 11, the peripheral wall Tw of the outer peripheral side thereof, and the wife formwork 8, for example, the figure formed on the wife formwork 8 The self-hardening filler 4 is filled with the concrete pumping pipe 17 from the filling port not to be filled. At this time, the pressing jack 9 is driven to press the poured self-hardening filler material 4 with the end mold 8, and the pressure is always higher than the pressure of the surrounding ground, and the self-dried filling material 4 is previously driven. The pressure is maintained so that the predetermined pressure is equal to or slightly higher than the pressure of the hard filler 4. At this time, the operation of the pressing jack 9 is controlled by a control means (not shown) based on the pressure of the self-hardening filler material 4 detected by a pressure sensor (not shown) provided on the end form 8. The pressure of the self-hardening filler 4 is automatically maintained at a value within a predetermined range exceeding the pressure of the surrounding ground.

In this manner, the self-hardening filler material 4 that has been cast is integrated with the self-hardening filler material 4 that has been previously placed, and at that time, groundwater is prevented from entering from surrounding ground. You. In addition, by performing the setting of the self-hardening filler 4 before the self-hardening filler 4 of the rear ring that has been previously set is hardened, the seam is not normally formed in both the self-hardening fillers 4. Thus, the lining wall W is formed as a continuous body. In addition, due to the pressure of the self-hardening filler material 4 that has been cast, the protruding plate portion 12 and the engaging step portion 13 of the engaging portion of the water stopping molds 11 come into close contact with each other.

Next, while holding the pressure of the self-hardening filler material 4 that has been cast by the pressing jack 9, a reaction force is obtained by the inner formwork 3 assembled by the propulsion jack 5, and the shield excavator 1 is excavated forward. In the next ring, a new inner mold 3 and a new waterproof mold 11 are assembled. Then, while the pressing jack 9 is contracted and the wife form 8 is moved forward, the self-hardening filler 4 is filled, and the self-hardening filler 4 is pressed by the wife form 8, and after that, the above operation is sequentially performed. The tunnel T is constructed repeatedly.

After the self-hardening filler 4 is cured, the inner mold 3 is released. Thereby, the inner peripheral surface of the water stopping mold 11 forms the surface of the lining wall W of the tunnel T.

In such a water stopping mold 11 and the method of constructing the tunnel T using the same, the entire inside surface of the lining wall W is covered with the water stopping mold 11, so that, for example, it is closed. Water leakage from the lining wall W can be prevented even at places where a seam exists on the lining wall W before and after the day. In addition, water leakage due to a crack or the like that may occur at an unspecified location is reliably prevented. In addition, since the water-stopping plate portion 12 and the meshing step portion 13 overlap at the joint between the water-stopping molds 11, the water-stopping at this portion can be enhanced. As described above, by using the water stopping mold 11, it is possible to greatly improve the water stopping performance even in a tunnel T or the like constructed particularly below the groundwater level.

In addition, the inner peripheral surface of the lining wall W of the tunnel T is formed by the water stopping mold 11, which is formed by precasting as described above. Therefore, the inner peripheral surface of the lining wall W becomes a very smooth surface, and it is possible to omit the secondary lining which has been conventionally performed for the purpose of finishing, thereby shortening the construction period and obtaining cost reduction effects. Can also.

Since the water-stopping mold 11 has a plurality of recesses 16 on the inner peripheral surface thereof, the inner mold 3
By inserting a convex portion (not shown) provided on the outer peripheral surface of the watertight mold 11 into the concave portion 16, the water stopping mold 11 can be set integrally with the inner mold 3. Therefore, the water stopping mold 11
Is set in the inner mold 3 in advance, so that the inner mold 3
The setting of the water stopping mold 11 can be performed simultaneously with the assembling. As a result, it is possible to suppress an increase in cost and a prolonged construction period without particularly troublesome construction in obtaining the high water-stopping property as described above. In addition, it is possible to prevent the water stopping mold 11 from shifting when the self-hardening filler 4 is cast.

Further, since the water-stopping agent injection hole 15 is formed in the engagement step portion 13 of the water-stopping form 11, the water-stopping form 11 is removed after the inner form 3 is removed from the mold. In the case where water leakage is observed at the joint or the like, the water stopping process can be performed on this portion by injecting a water stopping agent or the like from the water stopping agent injection hole 15.

In the above embodiment, the water stopping mold 11 is used.
Has been described, but other configurations may be appropriately adopted without departing from the gist of the present invention. FIG.
As shown in (a), one end 11a and the other end 1
1b, a pin 20 and a pin hole 21 may be formed. Thereby, when joining the water stopping molds 11, the pins 20 are inserted into the pin holes 21, whereby the positioning of the water stopping mold 11 and the joining of both are ensured. Also, as shown in this figure, if the pin hole 21 and the water-stopping agent injection hole 15 are also used, it is possible to save the trouble of manufacturing and to inject the water-stopping agent into the joint portion between the pin 20 and the pin hole 21. It is possible to do. FIG. 4 (b)
As shown in (1), a pin 22 and a pin hole 23 extending in the front-rear direction may be formed at one end 11a and the other end 11b of the water stopping mold 11. Of course, the material and the like of the water stopping mold 11 are not limited to those described above, and other materials can be appropriately used. In addition, for the water stopping mold 11, for example,
The surface may be roughened in order to increase the adhesion to the self-hardening filler 4.

In the above embodiment, the inner mold 3 and the water stopping mold 11 are set to be aligned in the front-rear direction. It is also conceivable to shift the construction. In such a case, it is conceivable to adopt a configuration in which the water stop plate portion 12 and the engagement step portion 13 are omitted.

Further, the construction is such that the injection of the water-stopping agent into the water-stopping agent injection hole 15 is performed as necessary when water leakage is observed, but it is needless to say that the water-stopping agent injection hole 15 may be necessarily injected.

The structure of the shield excavator 1 used in the present construction method is not limited at all, and any configuration of the shield excavator 1 may be applied as long as the ECL method can be implemented.

In addition, in the above embodiment, the case of constructing the tunnel T having a circular cross section is taken as an example. However, there is no intention to limit the configuration of the tunnel itself to be constructed. It is also possible to apply the technology of the present invention to tunnels having other shapes.

Other than this, any configuration may be adopted as long as it does not depart from the gist of the present invention, and it is needless to say that the above-described configurations may be appropriately combined selectively. No.

[0046]

As described above, according to the water stopping mold according to the first aspect, the concrete is hardened and formed by disposing the water stopping mold on the outer peripheral side of the inner mold. Water is prevented from leaking from the lining wall, and at the joint between the water stopping molds, the projecting plate portion of one of the water stopping molds and the engagement portion of the other water stopping form are engaged. Thereby, water leakage from this portion can also be prevented. In this way, even in a tunnel or the like constructed below the groundwater level, if there is a seam of concrete, or if a crack occurs in the lining wall, it is possible to secure water stoppage, Water stoppage can be greatly improved. In addition, by forming the water stopping mold in advance, it is not necessary to finish the inner peripheral surface of the tunnel.

According to the water stopping mold according to the second aspect, when the water stopping molds are joined together, the pins and the pin holes are engaged with each other, whereby the positioning and the joining of both can be reliably performed. it can.

According to the water-stopping mold of the third aspect, the water-stopping agent is injected into the joint between the water-stopping molds through the water-stopping agent injection hole, so that the projecting plate portion and the meshing portion are connected to each other. The gap can be closed, the waterproofness of this portion can be increased, and the above effect can be further remarkable.

According to the water stopping mold according to the fourth aspect, the concave portion formed on the water stopping mold is engaged with the convex portion provided on the outer peripheral surface of the inner mold, whereby the water stopping mold is formed. The frame can be easily set, and the water stopping mold can be prevented from shifting when the self-hardening filler is poured.

According to the method for constructing a tunnel according to the fifth aspect, even in the case of a tunnel or the like constructed below the groundwater level, when a concrete joint is present or when a crack occurs in a lining wall. In addition, it is possible to greatly improve the water stoppage. In addition, finishing the inner peripheral surface of the tunnel becomes unnecessary by molding the water stopping mold in advance.

According to the tunnel construction method of the sixth aspect, the gap between the projecting plate portion and the meshing portion is formed by injecting the waterproofing agent into the joint portion between the waterproofing molds from the waterproofing agent injection hole. Can be prevented, and the water stopping property of this portion can be increased.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an example of an embodiment of a water stopping mold and a tunnel construction method using the same according to the present invention.

FIG. 2 is a side sectional view showing an installation state of the water stopping mold.

FIG. 3 is a side sectional view showing an example of the water stopping mold.

FIG. 4 is a side sectional view showing another example of the water stopping mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shield excavator 3 Inner form 4 Self-hardening filler material 11 Water stopping form 11a, 11b End part 12 Water stopping plate part (projecting plate part) 13 Meshing step part (meshing part) 15 Water stopping agent injection hole 16 Concave part 20,22 pin 21,23 pin hole G Chiyama T Tunnel Tw Surrounding wall

Claims (6)

[Claims] 1. A self-hardening filler is filled between a peripheral wall of a pit excavated in the ground by a shield excavator and an inner formwork spaced apart from the inner peripheral side of the peripheral wall. A water stopping mold used for a tunnel in which the inner surface of the peripheral wall is lining, wherein the water stopping mold is arranged on an outer peripheral side of the inner form, and the tunnel A projecting plate portion projecting forward or rearward is formed at one of the ends at the front and rear ends in the axial direction,
A water-stopping formwork, wherein a meshing portion meshing with the protruding plate portion is formed at the other end. 2. The water stopping mold according to claim 1, wherein a pin is formed at one of the front and rear ends and a pin hole is inserted at the other. A water-stopping formwork characterized by having a shape formed thereon. 3. The water-stopping formwork according to claim 1, wherein when the other water-stopping formwork is connected to the engagement portion, the other water-stopping formwork protrudes. A water-stopping form, wherein a water-stopping agent injection hole for injecting a water-stopping agent is formed between the plate portion and the plate portion. 4. The water stopping mold according to claim 1, wherein the water stopping mold is joined to an outer peripheral surface of the inner forming form. Wherein a concave portion corresponding to the convex portion provided on the outer peripheral surface of the mold is formed. 5. Excavating the ground with a shield excavator, covering the peripheral wall of the ground excavated with an inner form at a predetermined interval, and forming a front end or a rear end of the tunnel. A water stopping mold having a protruding plate portion formed to protrude on one side and a meshing portion formed to mesh with the protruding plate portion on the other side is set along the outer peripheral surface of the inner mold. Then, the protruding plate portion or the engaging portion of the water stopping mold is engaged with the engaging portion or the protruding plate portion of the other water stopping mold which is provided in advance in the excavation direction rear side. Thereafter, a self-hardening filler is filled between the water stopping mold and the peripheral wall, and the inner mold is removed from the mold after the self-hardening filler is cured. Method. 6. The method for constructing a tunnel according to claim 5, wherein a water-stopping agent injection hole is formed in advance at a meshing portion of the water-stopping formwork, and the water-stopping formwork is moved backward. A water-stopping agent is injected between the engagement portion and the protruding plate portion from the water-stopping agent injection hole after being engaged with the water-stopping formwork on the side of the tunnel.