JPH0913404A - Construction method for underground structure - Google Patents

Abstract

PURPOSE: To provide a construction method for an underground structure, by which a water resistant layer can be easily constructed. CONSTITUTION: The ground inside of a continuous underground wall 3 constructed with a suitable width is excavated to form an open-cut groove, and a polyurethane resin liquid agent is sprayed with high pressure to the inside surface of the continuous underground wall 3 to form a water resistant layer 2. After resin mortar primer is applied to the surface of the layer, cast-in-place concrete is placed in a formwork taking the water resistant layer 2 as the outer formwork to construct an underground structure 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for constructing an underground structure.

[0002]

2. Description of the Related Art Normally, an underground structure by an excavation method, for example, a common ditch is constructed by cast-in-place concrete,
A rubber / asphalt sheet waterproof material is used for this.

As shown in FIG. 11, this rubber / asphalt sheet waterproofing material is used as a rubber / asphalt sheet 3 waterproof material.
Before the 0 is attached to the outer wall of the underground structure 40, it is attached to the direct concrete 50 of the continuous underground wall, which is applied after applying the primer.

[0004]

[Problems to be Solved by the Invention] However, since this primer flows down from the continuous underground wall without impregnating the surface of the concrete directly hit with groundwater, the rubber / asphalt sheet waterproof material is directly hit. It wasn't easy to stick to concrete. Therefore, it was difficult to construct the waterproof layer in the underground structure.

The present invention has been made in view of these problems, and an object thereof is to provide a method for constructing an underground structure in which a waterproof layer can be easily constructed.

[0006]

[Means for Solving the Problems] The construction method for an underground structure according to the present invention for achieving the above-mentioned object is a construction method for constructing an underground structure by an excavation method, and is a continuous underground structure constructed with an appropriate width. After excavating the ground inside the wall, on the inner surface of the continuous underground wall, a rapid-curing polyurethane resin liquid agent is injected at high pressure through a drain material to form a waterproof layer, and on the surface of the waterproof layer. A resin mortar-based primer is applied, and in-situ concrete is placed in a formwork having the continuous underground wall on which the waterproof layer is formed as an outer formwork to construct an underground structure. In addition, the resin mortar-based primer includes 20 to 35 weight parts of an aqueous emulsion adhesive agent, 35 to 45 weight parts of silica sand, 35 to 45 weight parts of cement, and 0 parts of water.
The drain material is a non-woven fabric, and the drain material is a non-woven fabric.

[0007]

[Operation] After excavating the ground inside the continuous underground wall constructed with an appropriate width, a quick-setting polyurethane resin liquid agent is injected at high pressure onto the inner surface of the continuous underground wall through a drain material to form a waterproof layer. And a resin mortar-based primer is applied to the surface of the waterproof layer, and a cast-in-place concrete is placed in the formwork with the continuous underground wall on which the waterproof layer is formed as the outer formwork to construct an underground structure. By constructing an object, a waterproof layer is formed on the entire outer surface simultaneously with the construction of the underground structure, which facilitates construction.

Further, when a rapid-curing polyurethane resin liquid agent is injected at high pressure onto the inner surface of the continuous underground wall through a drain material, even if the surface of the continuous underground wall or the drain material is wet, Since the polyurethane resin liquid agent is instantly cured while blowing away such water, a waterproof layer can be easily formed on the wet surface.

Further, by forming the waterproof layer with a quick-curing polyurethane resin liquid agent, a seamless waterproof layer can be formed in a short time.

Further, the drain material interposed between the continuous underground wall and the waterproof layer guides the groundwater springing from the continuous underground wall to the drainage ditch or the like.

Further, since the continuous underground wall formed by directly spraying the waterproof layer is used as the outer formwork, the excavation cross section is reduced, and the backfilling work after the construction of the new outer formwork or the underground structure is performed. Since it is unnecessary, it is possible to achieve work efficiency, shorten the construction period, and reduce the construction cost.

The waterproof layer can be easily attached to the outer surface of the underground structure by applying a resin mortar-based primer on the surface of the waterproof layer and pouring in-place concrete.

The resin mortar primer is 20 to 35 parts by weight of an aqueous emulsion adhesive and 35 to 4 of silica sand.
By mixing 5 parts by weight, 35 parts by weight of cement and 45 parts by weight of water and 0 parts by weight to 10 parts by weight, the adhesive strength with the waterproof membrane and the adhesive strength with cast-in-place concrete are sufficiently developed.

This aqueous emulsion adhesive is an aqueous emulsion containing one or more resins selected from styrene-butadiene rubber, nitrile rubber, acrylic, ethylene-vinyl acetate, epoxy and urethane.

As this water-based emulsion adhesive,
For example, when 27 weights of synthetic rubber-based Mitsui Toatsu Chemical Co., Ltd. Structopon 2031, 40 weights of No. 7 silica sand, 40 weights of ordinary Portland cement, and 5 weights of water are mixed, the strongest adhesive force is developed. .

However, the water-based emulsion adhesive is 20
If the amount is less than the weight, the adhesive strength with the waterproof membrane is reduced, and if the amount exceeds 35%, the separation phenomenon of the aqueous emulsion adhesive occurs at the time of mixing.

Further, if the silica sand is less than 35 weight, the adhesive strength to the cast-in-place concrete is lowered and the compressive strength is lowered, and if it exceeds 45 weight, sedimentation of the silica sand occurs at the time of mixing and it becomes hard, so that it is applied. It will be difficult.

If the amount of cement is less than 35% by weight, the adhesive strength to the cast-in-place concrete will be reduced and curing will be poor, and if it exceeds 45% by weight, it will be hard and difficult to apply.

Further, even if the amount of water is 0, it can be sufficiently mixed with the water in the aqueous emulsion adhesive, but 10
If the weight is exceeded, it becomes soft and easy to flow, making the coating operation difficult.

Since the drain material is a non-woven fabric, it can be easily attached to the continuous underground wall.

[0021]

EXAMPLE An example of the method for constructing an underground structure according to the present invention will be described below based on the method for constructing a common groove. FIG. 1 is a sectional view of an underground structure constructed by the construction method of the present invention, and FIGS. 2 to 10 are sectional views showing a construction method of an underground structure of the present invention.

FIG. 1 shows an underground structure 1 constructed by the construction method of the present invention, the entire outer periphery of which is approximately 1.5 mm to 5. mm.
It is covered with a waterproof layer 2 having a thickness of 0 mm, and both walls are constructed so as to be in contact with the continuous underground wall 3 with the waterproof layer 2 interposed therebetween. The waterproof layer 2 is attached to the continuous underground wall 3 via a drain material 4 such as a non-woven fabric, and the drain material 4 guides the groundwater spouted from the continuous underground wall 3 to the drain.

The waterproof layer 2 is formed of a two-liquid mixing type super rapid curing type polyurethane spraying agent, and for example, a rim spray F-1000 manufactured by Mitsui Toatsu Chemicals, Inc. is used. This is a mixture of a urethane polyprepolymer as a main component and a special mixed resin as a curing agent in which organic pigments are mixed. The pot life is several seconds, the touch-drying time is 8 to 20 seconds, and the curing time is 30 seconds.
In addition, it has a physical property of elongation of 380%.

The construction method for this underground structure will be described below. First, as shown in FIG. 2, a continuous underground wall 3 is constructed along the boundary line of the ground to be excavated, and the ground surrounded by this is sequentially excavated by the excavator 5 and the bulldozer 6 while the cutting beam 7 is formed. To form the cut groove 8. This continuous underground wall 3
Is well known in the art and is not particularly limited, but in this embodiment, a column-type underground wall called a so-called SMW is constructed.

Next, as shown in FIG. 4, when the digging groove 8 is formed, waste concrete is cast on the bottom of the groove 8 to form a leveling layer 9, and a bottom waterproof layer 12 is formed on this surface. At the same time, a part of the side waterproof layer 14 is formed on the lower surface of the continuous underground wall.

As shown in FIG. 5, the bottom waterproof layer 12 contains 80 to 12 of a fast-curing polyurethane resin liquid agent (rim spray F-1000) 11 via a primer 10.
It is formed by spraying at a high pressure of 0 Kgf / cm 2.

A resin mortar-based primer 13 is applied to the surfaces of the bottom waterproof layer 12 and the side waterproof layer 14 described above, which is a synthetic rubber-based struct made by Mitsui Toatsu Kagaku Co. as an aqueous emulsion adhesive. Pound 2031
No. 27 weight, No. 7 silica sand 40 weight, ordinary Portland cement 40 weight, and water 5 weight%. Adhesion to poured concrete is possible and the strongest adhesive force is exhibited.

Next, as shown in FIG. 6, a drain material 4 such as a non-woven fabric is attached to the continuous underground wall 3 with the stable 15, and the polyurethane resin liquid agent 11 is applied to the drain material 4 at 80 to 120 kgf.
When it is sprayed at a high pressure of / cm @ 2, even if the surface of the continuous underground wall and the drain material are wet, the polyurethane resin liquid agent 11 is instantly hardened and the side waterproof layer 14 is formed while blowing away the water. Then, the resin mortar-based primer 13 is applied to the surface of the side waterproof layer.

When the injection pressure of the polyurethane resin liquid agent 11 is less than 80 gf / cm 2, moisture is less likely to scatter, resulting in poor adhesiveness. Become.

Next, as shown in FIG. 7, the bottom waterproof layer 12
Concrete is placed on the bottom of the underground structure 1
, The resin mortar-based primer 1
Part of the bottom waterproof layer 12 and the side waterproof layer 14 is adhered by 3.

Then, as shown in FIG.
The side waterproof layer 14 is formed on the upper continuous underground wall surface 3 by the same method as described above, and the resin mortar primer 13 is applied to the surface thereof.

Then, a form 18 is formed by using the continuous underground wall 3 having the side waterproof layer 14 as an outer form, and concrete is placed therein to construct the underground structure 1. The side waterproof layer 14 is adhered to the side wall 19 by the mortar primer 13.

Next, as shown in FIG. 9, the primer 10 is sprayed on the outer surface of the top 20 of the underground structure 1 and then the polyurethane resin liquid agent 11 is applied at 80 to 120 Kgf / cm.
Spraying at a high pressure of 2 forms the upper waterproof layer 21.

When this upper waterproof layer 21 is formed, the waterproof layer 2 having a thickness of 1.5 mm to 5 mm is formed on the entire outer circumference of the underground structure 1.
Is formed. Then, as shown in FIG. 10, the backfill material is backfilled to complete the construction of the underground structure 1. The waterproof layer 2 is not limited to a thickness of 1.5 mm to 5 mm, and can be changed as needed.

The following table shows the results of experiments showing the performance of the waterproof layer 2 of the present invention, and the following effects could be confirmed. In addition, "Tufnel E in the table below
“X” is a non-woven fabric manufactured by Mitsui Kasansan Co., Ltd.

[Table 1]

[0036]

EFFECTS OF THE INVENTION After excavating the ground inside the continuous underground wall constructed with an appropriate width, a rapid-curing polyurethane resin liquid agent is injected at high pressure onto the inner surface of the continuous underground wall through a drain material. A waterproof layer is formed, a resin mortar-based primer is applied to the surface of the waterproof layer, and a cast-in-place concrete is cast in the formwork with the continuous underground wall on which the waterproof layer is formed as an outer formwork. By constructing the underground structure, a waterproof layer is formed on the entire outer surface simultaneously with the construction of the underground structure.

When a rapid-curing polyurethane resin liquid agent is injected at high pressure onto the inner surface of the continuous underground wall through a drain material, even if the surface of the continuous underground wall or the drain material is wet, Since the polyurethane resin liquid agent is instantly cured while blowing off the attached water, the waterproof layer can be easily formed on the wet surface.

A seamless waterproof layer can be formed in a short time by forming the waterproof layer with a liquid polyurethane resin liquid of a fast curing type.

By the drain material interposed between the continuous underground wall and the waterproof layer, the groundwater springed from the continuous underground wall can be guided to the drainage ditch or the like.

Since the continuous underground wall formed by directly spraying the waterproof layer is used as the outer form, the excavation cross section is reduced, and a new outer form and backfilling work after the construction of the underground structure are unnecessary. Therefore, the work efficiency, the work period can be shortened, and the work cost can be reduced.

The waterproof layer can be easily adhered to the outer surface of the underground structure by applying a resin mortar-based primer on the surface of the waterproof layer and pouring in-situ concrete.

By forming the resin mortar-based primer by mixing the water-based emulsion adhesive in an amount of 20 to 35 weight, silica sand in an amount of 35 to 45 weight, cement in an amount of 35 to 45 weight, and water in an amount of 0 to 10 weight. , Develops the strongest adhesion between waterproof membrane and cast-in-place concrete.

Since the drain material is a non-woven fabric, it can be easily attached to a continuous underground wall.

[Brief description of the drawings]

FIG. 1 is a sectional view of an underground structure, and FIG. 1B is an enlarged sectional view of a main part.

FIG. 2 is a cross-sectional view showing a construction state of open cut grooves.

FIG. 3 (1) is a horizontal cross-sectional view of a continuous underground wall spanned by beam beams, and FIG. 3 (2) is a vertical cross-sectional view thereof.

FIG. 4 is a cross-sectional view showing a formation state of a part of a bottom waterproof layer and a side waterproof layer.

5 (1), (2), and (3) are cross-sectional views showing a process of forming a bottom waterproof layer.

6 (1), (2), and (3) are cross-sectional views showing a step of forming a side waterproof layer.

FIG. 7 is a cross-sectional view showing a formation state of a side waterproof layer on the upper side of the leveling layer.

FIG. 8 is a cross-sectional view in which concrete is placed in a formwork having a continuous underground wall as an outer formwork.

FIG. 9 is a cross-sectional view of an underground structure showing a formation state of an upper waterproof layer.

FIG. 10 is a cross-sectional view of an underground structure constructed by the construction method of the present invention.

FIG. 11 is a cross-sectional view of a conventional underground structure.

[Explanation of symbols]

 1 Underground structure 2 Waterproof layer 3 Continuous underground wall 4 Drain material 7 Girder 8 Cutting groove 9 Leveling layer 10 Primer 11 Polyurethane resin liquid agent 13 Mortar resin primer 18 Form

(72) Inventor Hirohide Sakaguchi 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Hiroyuki Katayama 1190, Kasama-cho, Sakae-ku, Yokohama, Kanagawa Mitsui Toatsu Chemical Co., Ltd.

Claims (3)

[Claims] 1. A construction method for constructing an underground structure by an excavation method, which comprises excavating a ground inside a continuous underground wall having an appropriate width, and then forming a drain material on an inner surface of the continuous underground wall. A rapid-curing polyurethane resin liquid agent is sprayed at high pressure to form a waterproof layer, and a resin mortar-based primer is applied to the surface of the waterproof layer to form a continuous underground wall on which the waterproof layer is formed as an outer mold. A construction method for an underground structure, in which in-situ concrete is poured into the formwork to construct an underground structure. 2. The resin mortar-based primer comprises 20 to 35 parts by weight of an aqueous emulsion adhesive and 35 to 4 of silica sand.
The method for constructing an underground structure according to claim 1, wherein the cement is formed by mixing 5 weights, 35 to 45 weights of cement, and 0 to 10 weights of water. 3. The method for constructing an underground structure according to claim 1, wherein the drain material is a non-woven fabric.