JPH0759880B2 - How to install the waterproof sheet for shield tunnel - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for attaching a waterproof sheet for a shield tunnel, and more particularly to an improvement in the method for attaching a waterproof sheet attached to a segment.

<< Conventional Technology >> As a kind of tunnel construction method, a shield construction method is known, and various shield construction methods are provided.

In this type of shield construction method, a method of excavating the ground with a shield machine, assembling a segment as a primary lining on the inner surface side, and placing a secondary lining concrete on the inner surface side of this segment is relatively wide. Has been adopted.

By the way, for example, in a shield tunnel constructed under the sea floor, the soil water pressure increases only by the primary and secondary linings, so that it is difficult to secure long-term water shutoff.

In order to secure such waterproofness, it is conceivable to interpose a waterproof sheet between the primary and secondary linings, for example, as used in the construction of mountain tunnels.

However, if the method of attaching the waterproof sheet used in the mountain tunnel is directly adopted in the shield tunnel, there is a problem described below.

<< Problems to be Solved by the Invention >> That is, the method of mounting the waterproof sheet used in the construction of mountain tunnels is as follows. , The waterproof sheet was nailed with nails.

However, in the shield tunnel, as described above, a segment is used as the primary lining, and the strength of this segment is about 500 kg / cm ² , so it was extremely difficult to attach a nail with an air gun.

The present invention has been made in view of such conventional problems, and an object thereof is to provide a method for attaching a waterproof sheet for a shield tunnel, which can be attached relatively easily.

<< Means for Solving the Problem >> In order to achieve the above object, the present invention is to install a segment on the inner surface of the ground excavated by a shield excavator, in the method of attaching a waterproof sheet to the inner surface of the segment,
It is characterized in that a concave groove portion is formed in advance in the segment, and a rib integrally formed on the back surface side of the waterproof sheet is press-fitted into the groove portion.

The groove may be formed in a substantially arc shape in the circumferential direction of the tunnel to be constructed, and may be formed in an inverted V-shaped cross section whose width becomes wider toward the inner surface side.

Further, the waterproof sheet has a water permeable layer provided on the back side and a waterproof layer provided on the front side, and the rib is provided on the water permeable layer, and the cross-sectional shape of the rib is a hollow circle. Can be formed.

<< Advantageous Effects of the Invention >> According to the method of attaching the waterproof sheet having the above-described configuration, the waterproof sheet is divided into segments by pressing the ribs protruding on the back surface side of the waterproof sheet into the concave groove portions formed in the segments. It can be installed easily because it can be attached to the inner surface.

In this case, if the cross-sectional shape of the groove portion is formed in an inverted V shape in which the width becomes wider toward the inner surface side, the rib is reliably prevented from coming off.

Furthermore, if the rib has a hollow circular cross-sectional shape, it can be easily deformed when press-fitting, which simplifies the press-fitting operation.

<Example> Hereinafter, a preferred example of the present invention will be described in detail with reference to the accompanying drawings.

1 and 2 show an embodiment of a method for attaching a shield tunnel waterproof sheet according to the present invention.

In the mounting method shown in the figure, annular segments 12a to 12d are sequentially assembled in an annular shape on the inner surface of the ground 10 excavated by a shield machine to form a primary lining, and concrete is further applied to the inner surface side of the primary lining. The figure shows a case where it is applied to a shield construction method in which the secondary lining 14 is provided.

Each of the segments 12a to 12d is provided with two grooves 16 having a V-shaped cross section on its inner surface at a predetermined interval.
16 is for guiding water leakage to the lower side of the tunnel when the water permeable layer of the waterproof sheet described later is clogged.
It is formed in an arc shape along the circumferential direction of a to d.

In addition, the groove 16 is not always necessary, and instead of the groove 16, irregularities may be provided on the inner surface of the waterproof sheet.

Further, on the inner surface of each segment 12a to 12d, a screw hole 20 into which a hook 18 for locking a reinforcing bar embedded in the secondary lining 14 is screwed is provided at an appropriate position.

On the other hand, on the connecting surface of each of the segments 12a to 12d, a hole portion into which the segment connecting rod 22 is inserted is provided at a position corresponding to a position in the axial direction, and communicates with one end of the hole portion. Recesses 2 that open to the inner surface side of the segments 12a to 12d
4 are provided.

Further, in this embodiment, a pair of adjacent concave grooves 26 are formed in an arc shape on the inner end side of the connecting surface of each segment 12a to 12d.

As shown in detail in FIG. 2, the concave groove 26 has an inverted V-shaped cross section whose width increases toward the inner surface.

The segments 12a to 12d having the above-described configuration are sequentially assembled in an annular shape on the rear side of the segment 12a to 12d along with the excavation of the shield machine.
A seal material 28 is interposed on the connecting surface of the rod 22, and the rod 22 is interposed so as to crotch on the connecting surface, and the mortar 30 is filled in the recess 24 to connect the segments.

When the segments 12a to 12d are connected in this manner, in this embodiment, the concave groove 26 is formed at the inner end of each connecting surface of the segments 12a to 12d along the circumferential direction of the tunnel.

Next, the waterproof sheet 32 is attached to the inner surfaces of the segments 12a to 12d.

The waterproof sheet 32 shown in this embodiment is composed of a non-woven fabric provided on the back side as shown in the partial cross section of FIG. 2, and the water permeable layer 34 that guides leakage to the lower side of the tunnel.
And a waterproof layer 36 made of an impermeable member such as rubber integrated on the surface side of the water permeable layer 34, and a rib 38 integrated with the water permeable layer 34.

The rib 38 is made of an elastically deformable member such as hard rubber, and has a hollow circular cross section in this embodiment.

To attach the waterproof sheet 32, deform the ribs 38 and
It is done by press-fitting inside.

In this case, in this embodiment, since the recessed groove 26 is formed wide on the back surface side, the press-fitted rib 38 elastically recovers in the recessed groove 26 and returns to the original cross-sectional shape, so that the waterproof sheet 32 Detachment is prevented.

Further, the connecting portions of the waterproof sheets 32 are overlapped with each other and heat-sealed together, and in this embodiment, the hooks 18 are positioned so that the hooks 18 are screwed into the screw holes 20 at the overlapping portions. Is set.

When the waterproof sheet 32 is attached to the inner surface of the segments 12a to 12d as described above, the reinforcing bars are locked to the hooks 18, the formwork is installed, and concrete is placed between the formwork and the waterproof sheet 32. Then, the secondary lining 14 is constructed.

Now, in the method of attaching the waterproof sheet 32 having the above-described configuration, the concave grooves 26 formed in the segments 12a to 12d are
Since the waterproof sheet 32 is attached to the inner surfaces of the segments 12a to 12d by press-fitting the ribs 38 protruding from the rear surface side of the waterproof sheet 32, the construction can be performed easily.

In this case, since the cross-sectional shape of the concave groove 26 is formed in an inverted V shape in which the width becomes wider toward the inner surface side, the rib 38 is reliably prevented from coming off.

Further, since the rib 38 has a hollow circular cross-sectional shape, it can be easily deformed when press-fitting, so that the press-fitting work becomes easy.

In the above embodiment, the concave groove 26 is formed in each segment 12a-
Although the one formed on the connecting surface of d is shown as an example, the formation position of the concave groove 26 is not limited to this, and may be another place.

Further, the cross-sectional shape of the concave groove 26 is not limited to the inverted V-shape, and may be a straight shape as long as the rib 38 to be pressed fits closely to prevent the waterproof sheet 32 from coming off.

Further, the cross-sectional shape of the rib 38 is not limited to the hollow circular shape, and may have a solid cross-section as long as it can be press-fitted into the concave groove 26.

[Brief description of drawings]

FIG. 1 is an explanatory view of an implementation state of a method for attaching a waterproof sheet for a shield tunnel according to the present invention, and FIG. 2 is an enlarged view of a main part of FIG. 10 …… Solid ground 12a ～ d …… Segment 26 …… Concave groove 32 …… Waterproof sheet 34 …… Water permeable layer 36 …… Waterproof layer 38 …… Rib

Claims (3)

[Claims] 1. A method of installing a segment on an inner surface of a ground excavated by a shield excavator and mounting a waterproof sheet on the inner surface of the segment, wherein a concave groove portion is formed in advance on the segment, and a rear surface of the waterproof sheet is formed. A method of attaching a waterproof sheet for a shield tunnel, comprising press-fitting a rib integrally provided on the side into the groove. 2. The groove portion is formed in a substantially circular arc shape in the circumferential direction of the tunnel to be constructed, and has an inverted V-shaped cross section whose width becomes wider toward the inner surface side. How to attach the waterproof sheet for the shield tunnel described above. 3. The waterproof sheet has a water permeable layer provided on the back surface side and a water permeable layer provided on the front surface side, the rib is provided on the water permeable layer, and the cross-sectional shape of the rib is The waterproof sheet for a shield tunnel according to claim 2, wherein the waterproof sheet is attached to the shield tunnel.