JPH0452312Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a waterproof sheet for tunnel construction.

[Prior art and its problems]

As shown in Figure 1, the NATM construction method, which is becoming approximately standardized as a tunnel excavation method, protects the tunnel excavation wall surface with primary shotcrete 1 and lock bolts 2, and extends from the wall surface deep into the ground. This is a tunnel construction method in which the earth's soul exerts stress on each other as it moves little by little from its original position, and the initial earth pressure balances out as a whole, keeping the excavated room safe. .

Dripping water from springs in tunnels can cause cars to slip and deteriorate due to electrolytic corrosion, and in cold regions it can cause traffic problems due to icicles and ice formation. A waterproof sheet is placed between the next volume of shotcrete 1 and the spring water is drained into the drainage pipe 7 under the road surface.
It is designed to induce drainage.

In the early days, flat plastic sheets were used as waterproof sheets, but later they were made with non-woven fabric attached to improve drainage.

However, the nonwoven fabric may be compressed by the pressure of the concrete placed in the secondary roll, reducing its drainage function, and since the nonwoven fabric always contains water, there is a risk of freezing in cold regions. 60−
A device with numerous unevenness was devised as shown in Japanese Patent No. 162199.

The present invention aims to provide a waterproof sheet for tunnel construction that can maintain the drainage properties due to the unevenness of the uneven waterproof sheet and can solve the following problems.

In other words, the secondary roll concrete 3 of the NATM construction method
After the formwork is removed, the arch top sinks due to hardening and shrinkage as time passes, and a gap is created between the primary roll concrete 1 and the afterload acting on the primary concrete roll 2 at the arch top. Since stress is not transmitted to the next concrete roll, there is a problem in that the tunnel strength is reduced.

Furthermore, when a conventional waterproof sheet for tunnel construction is stretched over the primary concrete roll, there is a problem that generally there are recesses between the nailed parts, so they do not adhere tightly and leave large gaps, which prevents stress from being transmitted.

The former problem cannot be solved to some extent by pouring mortar into the gap formed, and the latter problem cannot be solved.

Therefore, the present invention aims to provide a waterproof sheet for tunnel construction that is useful for solving these problems.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a tunnel in which an appropriate number of annular protrusions that bulge out to the opposite side when pressure is applied to one side are dotted and protruded toward the other side. Examples of construction waterproof sheets are explained below.

〔Example〕

FIG. 2 is a plan view of an embodiment of the present invention, and FIG. 3 is a sectional view taken along the line A-A in FIG. The structure is the same as the conventional product, but the structure of the protrusion is significantly different from the conventional product.

That is, in the present invention, the protrusion is an annular protrusion 14 that expands to the opposite side when pressure is applied to one side.

In the embodiment, a case in which a double annular protrusion was formed protrudingly formed on one side was exemplified, but a single annular protrusion or three or more annular protrusions may be used.

The size, height, and number of layers of the annular protrusion are selected depending on the place of use.

The structure for joining adjacent sheets may be a conventional structure using male and female engaging parts, but in this embodiment, hook parts 12a and 13a are provided at the edges,
In addition, a dot-like protrusion 12b and a groove 13b that fit into each other are provided, and a waterproof expansion rubber 15 is provided on either one (the male engagement portion side in the embodiment).

Next, its usage, action, and effects will be explained.

Figure 4 shows a sample using the waterproof sheet according to the present invention.
This figure shows the top of the arch of a tunnel constructed using the NATM construction method, illustrating the state in which the secondary concrete roll 3 has hardened and shrunk to form a void _X1 .

In the figure, 16 is a peg using a waterproof seat 17, 1
8 is an embedded injection pipe with a check valve, and 19 is a concrete mortar injection hose.

As shown in Fig. 4, when a void X ₁ occurs,
As described above, the afterload acting on the primary concrete roll 1 is not transmitted to the secondary concrete roll 3, resulting in a decrease in tunnel strength.

In order to correct this, secondary roll concrete 3
An injection pipe is buried in advance during concrete pouring, and the voids are filled after the secondary concrete roll 3 hardens and shrinks.
A method of pouring concrete mortar 20 in X ₁ was devised.

However, with conventional tarpaulin, the air gap x ₁
is filled with the filled concrete mortar 20, but since the surface of the primary concrete roll 1 is generally highly uneven, a gap _X2 still remains between the primary concrete roll 1 and the waterproof sheet 11.

This gap _X2 is useful as a drainage channel, but on the other hand, it is problematic if it is too large.

However, when the waterproof sheet 11 according to the present invention is used, when the filled concrete mortar 20 is press-fitted, the annular protrusion 14 expands and comes into contact with the primary concrete roll 1, as shown in FIG.
It becomes like a pillar that supports the next roll of concrete, and the afterload is transmitted to the second roll of concrete 3 via the annular protrusion 14 and the filled concrete mortar 20.

This effect can be seen even in the case of placing ordinary secondary rolled concrete, and by using _the waterproof sheet according to the present invention, even when the gap There is an effect that a tunnel structure can be obtained in which the afterload acting on the primary concrete volume 1 is reliably transmitted to the secondary volume concrete 3 while reliably holding the volume.

[Effect of idea]

By using the proposed waterproof sheet when implementing the NATM construction method, it is possible to construct a tunnel structure that secures drainage channels and reliably transmits the afterload acting on the primary concrete roll 1 to the secondary concrete roll 3. .

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the NATM construction method, Figure 2 is a plan view of an embodiment of the present invention, Figure 3 is a sectional view taken along line A-A in Figure 2, and Figure 4 is a diagram showing the use of the waterproof sheet of the present invention.
Figure 5 is a detailed view of the top of the arch when constructed using the NATM construction method, showing the state after the correction filler concrete is poured. 11...Main body, 12...Male engaging portion, 13...
Female type engaging portion, 14... annular projection.

Claims (1)

[Scope of utility model registration request] A waterproof sheet for tunnel construction, characterized by having an appropriate number of annular protrusions dotted on one side that expand toward the opposite side when pressure is applied to one side.