JPH07103797B2 - Concrete lining construction method for tunnels - Google Patents

Description

TECHNICAL FIELD The present invention relates to a concrete lining construction method for a tunnel, particularly to a segment applied as a primary lining on an excavated surface of a tunnel,
Alternatively, the ECL (Extruded Concrete Lining) method (also called direct-cast concrete lining method or cast-in-place concrete lining method) is used to project the primary lining concrete on the excavated surface of the tunnel to the primary lining side. TECHNICAL FIELD The present invention relates to a concrete lining construction method for a tunnel in which concrete is laid under the interposition of plastic sheets which are formed with a large number of hollow convex portions.

When laying concrete on the lining surface of the primary lining of the tunnel under the interposition of such a large number of hollow convex plastic sheets (hereinafter, this type of concrete lining method is referred to as hollow convex sheet lining type concrete This is an advantage because the concrete lining of the tunnel can be performed with the drainage space reliably formed on the back.

However, on the other hand, since the convex part of the sheet is hollow, that is, a cup-shaped cross-section, which is rigid in shape, unless the primary lining surface of the tunnel is the same surface with no step at the lining joint, it is stretched over the primary lining surface. The hollow convex portion of the stepped portion of the sheet is floated from the primary lining surface. When the hollow sheet convex portion floats from the primary lining surface, the concrete filled by pumping by a concrete pump into the inner space of the primary lining surface is not crimped by the hollow convex portion on the primary lining surface. Sufficient strength and watertightness required as work cannot be secured. Moreover, the primary lining of the tunnel is
As is well known to those skilled in the art, it is extremely difficult to arrange the same on the same plane without steps.

2. Description of the Related Art Conventionally, in a hollow lining sheet lining type concrete lining method, concrete is attached to each hollow bulge of a sheet under the placing by a concrete pump so that the hollow lining can be crimped to the primary lining surface under the interposition thereof. No measures have been developed to fill the inner space of the convex portion, and the usefulness of this type of construction method has not been fully utilized.

Incidentally, the method of the invention of Japanese Patent Publication No. 61-54919 has already been proposed as a hollow lining sheet lining type concrete lining method, but by overcoming the shape rigidity of the sheet hollow bulge, each hollow bulge of the sheet There is no mention of modifying the part so that it touches the step on the primary lining surface in a good fit. That is, in the conventional proposal, concrete is filled into the inner space of the convex portion of each sheet so that the concrete is pressed against the primary lining surface of the hollow convex portion of the sheet under the driving of the concrete pump. There is no guarantee that

Problems to be Solved by the Invention Problems to be solved are the above-mentioned problems of the prior art.

That is, the object of the present invention is to place concrete with respect to each hollow convex portion of the sheet by placing with a concrete pump so that the usefulness of the hollow convex portion sheet lining type concrete lining method can be fully utilized. It is intended to fill the inner space of the convex portion even in the lower and the primary lining surface having a step in a manner that is well suited.

Means for Solving the Problems In order to achieve the above object, the present invention is a target for constructing a hollow convex sheet lining type concrete lining, a segment as a primary lining applied to a tunnel excavation surface,
Or, it was specified as the primary lining concrete that was applied by the ECL method, and a large number of plastic sheets with hollow convex parts that were scattered on the predetermined side, and the rising parts of the hollow convex parts were more than the non-convex parts. It is characterized in that it is thin, and the convex top plate is thicker than the convex rising portion and thinner than the non-convex portion in combination with the specific one.

By adopting this configuration, when the plastic sheet with hollow convex portions is stretched on the primary lining surface of the tunnel and concrete is cast, the non-convex portions of the sheet and the convex rising portions thinner than the convex top plate are made of concrete. It acts like a spring under the load of driving, and the convex top plate, which is thinner than the non-convex part and thicker than the rising part of the convex part, fits nicely to the step of the primary lining surface and to the tunnel crossing shape, that is, the radius. , Press on this.

Thus, by placing with a concrete pump, for each hollow convex portion of the sheet, concrete under the interposition of the hollow convex portion,
It is possible to fill the hollow of the convex portion in a manner that is well adapted to the stepped primary lining surface. Therefore, in the hollow convex sheet-lining concrete lining method, the adhesion of the secondary lining concrete to the primary lining surface is improved, and the watertightness is improved.

Since the method of the present invention achieves the above results, it is particularly suitable for performing concrete lining on tunnels requiring a higher degree of watertightness than mountain tunnels, for example, deep-sea tunnels such as undersea tunnels and high-pressure tunnels.

EXAMPLES Next, with reference to the accompanying drawings showing example embodiments of the present invention,
The present invention will be described.

In the figure, reference numeral (1) is a plastic sheet used in the present invention, and the plastic sheet (1) has a large number of hollow convex portions (2) projecting to one side, and the hollow convex portions are formed. In (2), the rising part (21) has a non-convex part (11)
The thickness of the convex top plate (22) is thinner than that of the convex rising portion (21) and smaller than that of the non-convex portion (11).

The plastic sheet (1) with the hollow convex portion (2) is applied to the excavated surface of the tunnel, for example, the segment assembled in the invert portion, or the primary lining concrete (3) constructed by the ECL method to the hollow convex portion. The part (2) is stretched on the side of the primary lining (3), and the concrete (4) is poured into the primary lining (3) by a concrete pump with the sheet (1) interposed.

Then, the sheet (1) is loaded by the load of concrete pouring.
The rising part (21) and the non-convex part (11) of each hollow convex part (2) of
Also, under the correlative thickness difference of the convex top plate (22), the convex rising part (21) functions like a spring, and the convex top plate (22) is on the side of the tunnel ground, that is, the primary lining (3). The face side is pressed. Therefore, the top plate (22) of each hollow convex portion (2) of the sheet (1) fits nicely to the step (30) on the surface of the primary lining (3) and also to the round cross-section shape of the tunnel. , The primary lining (3) surface is crimped.

In this way, concrete is placed by the concrete pump on each hollow convex portion (2) of the sheet (1), with the presence of the hollow convex portion (2) even on the primary lining surface having steps.
The hollow convex portion top plate closely fits the primary lining surface and can be filled in the convex portion inner space (2a) in a stable manner.

In addition, although the embodiment described above is a concrete lining for the invert portion of the tunnel, the method of the present invention is not limited to this, and also includes concrete lining construction of the arch portion and the side portion. Of course, in the case of concrete lining on the arch and side,
It goes without saying that the same results as above can be obtained.

EFFECTS OF THE INVENTION According to the present invention as described above, even if there is a step on the primary lining surface, concrete is placed by the concrete pump for each hollow convex portion of the sheet and the primary cover is provided under the presence of the hollow convex portion. The hollow convex portion top plate closely adheres to the primary lining surface while conforming well to the work surface, so that the inner space of the convex portion can be filled in a stable manner. Therefore, in the hollow convex sheet-lining concrete lining method, the adhesion of the secondary lining concrete to the primary lining surface is improved, and the watertightness is improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a plastic sheet used in the method of the present invention, FIG. 2 is an enlarged sectional view of a hollow convex portion in the sheet of FIG. 1, and FIG. 3 is a cross section showing an example of the method of the present invention. FIG. 4 and FIG. 4 are cross-sectional views showing the step portion of the primary lining surface. (1) …… Plastic sheet (2) …… Hollow convex part (2a) …… Inside convex part (3) …… Primary lining (4) …… Concrete (11) …… Non-convex part (21)… … Convex rising part (22) …… Convex top plate

Claims (2)

[Claims] 1. A concrete lining is provided on a segment provided as a primary lining on an excavated surface of a tunnel, with a plurality of hollow convex portions projecting toward the segment and interspersed with plastic sheets formed in a scattered manner. In the construction method, the rising portion of the hollow convex portion in the plastic sheet is thinner than the non-convex portion, and the convex top plate is thicker than the convex rising portion and thinner than the non-convex portion. Concrete lining construction method for tunnels. 2. The ECL method is used to cover the concrete under the interposition of plastic sheets that are formed on the primary lining concrete that is provided on the excavated surface of the tunnel and have a number of hollow protrusions protruding toward the concrete side. It is a construction method,
As the plastic sheet, the hollow convex portion in which the rising portion is thinner than the non-convex portion, and the convex top plate is thicker than the convex rising portion and thinner than the non-convex portion is applied to the concrete cover of the tunnel. Construction method.