JPH1136352A - Waterproof work of underground structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waterproof work of an underground structure, in which a waterproof layer which does not bring inconveniences such as cracks or chips can be formed between an earth-retaining wall and the underground structure, even when the inside of the earth-retaining wall constructed in the underground is excavated and concrete is placed in the wall face of the earth- retaining wall or the inside of the excavating bottom face to construct a concrete underground structure. SOLUTION: A waterproof sheet 12 is arranged on the wall face 4 of an earth-retaining wall 2 to form a waterpoof layer 8 and a cut-off layer 10 is formed on the waterproof layer 8. The waterproof sheet 12 is constituted of a woven cloth made of organic fiber or the like as the base material and a rubber asphalt material thereon so as to be extensible. Even if the wall face 4 or the excavating bottom face 6 is uneven and coarse when concrete is placed, concrete can be stretched and closely stuck on these faces and favorably interposed. The cut-off layer 10 is made of polymer cement or the like and it absorbs water penetrated from breakages of the waterproof layer 8 by the hydration and prevents the penetration of water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete underground by excavating the inside of an earth retaining wall constructed underground and placing concrete on the wall surface of the earth retaining wall exposed by the excavation or inside the excavated bottom. Waterproofing which is preferably applied to a method of constructing a structure, which prevents the structure from being soiled by water such as groundwater penetrating through cracks or poorly filled portions of the concrete skeleton of the underground structure or a decrease in durability. It concerns the construction method.

[0002]

2. Description of the Related Art Conventionally, water such as groundwater has penetrated into an underground structure through a crack or a poorly filled portion generated in a concrete skeleton, and the structure has been soiled or deteriorated in durability. Various waterproofing measures have been taken in order to prevent such problems as described above. As one of the waterproofing measures, there is known a waterproofing method of forming a waterproof layer on an outer wall of an underground structure to block water from entering. In this waterproofing method, when forming a waterproof layer, a method such as asphalt waterproofing, sheet waterproofing, and coating film waterproofing has been performed.

[0003]

However, as described above, in the waterproofing method of forming a waterproof layer on the outer wall of an underground structure, the underground structure is constructed by open excavation, or when the underground structure is constructed outside the underground structure. It was suitable when a sufficient working space could be secured, but was excavated inside the earth retaining wall constructed underground, and concrete was poured into the wall of the earth retaining wall and the inside of the excavated bottom. It is a method of constructing an underground structure, and is not suitable for forming a waterproof layer on the wall of a retaining wall or the bottom of an excavation. In other words, when the construction of the underground structure is performed by open excavation, or when a sufficient working space can be secured outside the underground structure, the underground structure that is smoothly formed by the formwork etc. Since the waterproofing layer can be formed directly on the outer wall surface of the above, there was no major problem even if the waterproofing method such as the above-mentioned conventional asphalt waterproofing, sheet waterproofing, and coating film waterproofing was applied. On the other hand, in the construction method of excavating the inside of the earth retaining wall and casting concrete on the wall surface of the earth retaining wall and the inside of the excavation bottom, the waterproof layer is formed directly on the outer wall of the underground structure Therefore, a waterproof layer had to be formed on the wall surface of the retaining wall or the bottom of the excavation, which is generally rough and not very smooth due to the inclusion of earth and sand. If conventional waterproofing methods such as asphalt waterproofing, sheet waterproofing, and coating film waterproofing are applied to the retaining wall and the bottom of the excavation, defects such as breakage and cracks will occur in the waterproof layer,
It was not possible to sufficiently prevent the structure from being soiled, reduced in durability, and malfunctioning of equipment and the like.

The present invention has been made in view of the above circumstances, and an object of the present invention is to excavate an inside of a retaining wall constructed in the ground, and to form a concrete on the wall surface of the retaining wall and the inside of the excavated bottom surface. Even if a concrete underground structure is constructed by casting a waterproof layer, a waterproof layer can be formed between the retaining wall and the underground structure so that failure such as breakage or cracking does not occur. An object of the present invention is to provide a waterproofing method for an underground structure.

[0005]

In order to achieve the above object, in a method for waterproofing an underground structure according to the present invention, the inside of a retaining wall constructed underground is excavated and the excavation is exposed. In the method of constructing a concrete underground structure by placing concrete inside the wall surface of the retaining wall or the inside of the excavation bottom, after excavation, at the time of placing the concrete, the fiber is attached to the wall surface of the retaining wall or the excavation bottom surface. A waterproofing sheet having extensibility formed by using a waterproofing material based on a reinforcing cloth material made of a material is provided to form a waterproofing layer, and the waterproofing layer is formed from a cement-based hydration-reactive composition. Forming a waterproof layer.

In such a waterproofing method for an underground structure, an extensible waterproofing sheet formed on a reinforcing cloth material made of a fiber material is provided as a waterproofing layer on a wall surface of a retaining wall or an excavated bottom surface. Therefore, a tough and durable waterproof layer can be formed, and even if the wall surface and excavation surface of the retaining wall are rough and rough, the waterproof layer is extended to adhere to the wall surface of the retaining wall and the excavation bottom surface. Therefore, it is possible to satisfactorily intervene between the wall surface of the retaining wall or the excavated bottom surface and the underground structure without causing a problem such as cracking or cutting. In addition, since a waterproof layer made of a cement-based hydratable composition is formed on the waterproof layer, it is possible to prevent the intrusion by absorbing water, such as groundwater, which tries to enter the underground structure by hydration reaction. it can. Further, if the water blocking layer is formed outside the waterproof layer, it is possible to protect the waterproof layer from welding sparks such as gas welding and arc welding during construction, and prevent problems such as flying sparks.

Further, when the waterproof sheet is provided, if the waterproof layer is integrally formed in advance on the surface of the waterproof sheet, the waterproof layer and the waterproof layer can be formed collectively. , Labor can be saved.

If the waterproof sheet is formed using a rubber asphalt-based material as the waterproof material,
A waterproof layer excellent in waterproofness can be formed.

Further, if the water-stopping layer is formed using polymer cement in the cement-based hydration-reactive composition, it is possible to form a water-stopping layer having excellent water-stopping properties.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for waterproofing an underground structure according to the present invention will be described below with reference to the accompanying drawings.

In the method for waterproofing an underground structure according to the present invention, the inside of a retaining wall constructed underground is excavated, and concrete is cast using the excavated wall or excavated surface as a formwork surface. This is a method of constructing a concrete underground structure inside the retaining wall, especially after excavating the inside of the retaining wall,
Before placing concrete, place a waterproof sheet on the concrete wall of the retaining wall or excavation surface to form a waterproof layer, and form a waterproof layer on the concrete placing side of this waterproof layer. It is.

FIG. 1 shows an embodiment of a waterproofing method for an underground structure according to the present invention, in which a wall surface 4 exposed by excavation of a retaining wall 2 constructed in the ground and an excavation surface also exposed. FIG. 3 shows a state in which a waterproof layer 8 and a waterproof layer 10 are formed on the bottom surface 6. The waterproof layer 8 is disposed so as to face the wall surface 4 of the retaining wall 2 or the excavated bottom surface 6, and is provided by attaching a waterproof sheet 12 having waterproof property with a fastening material such as an adhesive or a fixing screw. It was formed. The retaining wall 2 on which the waterproof layer 8 is formed includes, for example, a soil column wall, a parent pile / horizontal sheet wall, a concrete underground continuous wall, and the like. On the other hand, the water stop layer 10 is formed on the wall surface 4 side of the retaining wall 2 of the waterproof layer 8 or on the side opposite to the excavation bottom surface 6 side.

Here, the waterproof sheet 12 is formed by using a waterproof material.
It is formed using an extensible rubber-based material such as a rubber asphalt-based material, an acrylic rubber-based material, a chloroprene rubber-based material, a urethane rubber-based material, or a butyl rubber-based material. In particular, if a rubber asphalt-based material is used, a waterproof sheet 1 that is inexpensive and has excellent waterproof properties can be obtained.
2 can be formed.

Further, in the waterproof sheet 12,
It is formed using a waterproof material based on a reinforcing cloth material made of a fiber material. Here, as the reinforcing cloth material, for example, polypropylene-based fiber, vinylon-based fiber, polyvinyl alcohol (PVA) -based fiber, ester-based fiber,
An extensible cloth material such as a woven or nonwoven fabric made of an organic fiber material such as polyamide fiber, acrylonitrile fiber or rayon, or an inorganic fiber material such as carbon fiber or glass fiber is used. In particular, if an impregnating cloth material such as a thick nonwoven fabric or a three-dimensionally woven cloth is used as the reinforcing cloth material, the waterproofing material is impregnated into the reinforcing cloth material as an emulsion to form an integral piece. It is possible to form a strong waterproof sheet 12 having excellent properties and excellent toughness.

On the other hand, the water-stopping layer 10 is made of a cement-based hydration-reactive composition, undergoes a hydration reaction with water, swells while absorbing water, and stops water. Here, as the cement-based hydration-reactive composition, for example, a polymer cement in which ethylene vinyl acetate (EVA) or the like is mixed as a polymer is used. The water blocking layer 10 is preferably formed in a layered form by applying the cement-based hydration-reactive composition on the surface of the waterproof sheet 12. Bentonite may be used for the cement-based hydration-reactive composition of the water blocking layer 10.

If the waterproof layer 10 is provided integrally with the waterproof sheet 12 in advance and a waterproof sheet with a waterproof layer is formed, the waterproof sheet 10 can be formed together with the waterproof layer 8 so as to save labor. Is preferable.

Further, as shown in FIG. 2, the waterproof sheet 12 with a waterproof layer is made of a cloth material 14 having an impregnating property as a reinforcing cloth material. To form a waterproof material layer 16 integrally, and impregnate the lower surface side of the cloth material 14 with a cement-based hydration-reactive composition by coating or the like to form a cement-based hydration-reactive composition layer 18. When integrally formed, the waterproof sheet 12 with a waterproof layer having excellent integrity can be formed, and the waterproof sheet 12 with a waterproof layer with high toughness can be obtained.

As described above, the wall surface 4 of the retaining wall 2 and the excavated bottom surface 6
In addition, the waterproof sheet 12 as described above is provided to provide the waterproof layer 8.
After the formation of the waterproof layer 10 and the formation of the waterproof layer 10, as shown in FIG. 3, concrete is cast inside the underwater layer 10 to construct an underground structure 20 made of concrete.

FIGS. 4 (a) and 4 (b) show a waterproof sheet 12 with a waterproof layer on the wall surface 4 of the retaining wall 2 and before and after the concrete is poured. The state after the installation is shown. Here, the waterproof sheet 12 with a waterproof layer is fixed and fixed to the core member 22 such as I-shaped steel or the like embedded in the retaining wall 2 by, for example, slipping with fixing screws 24. Things. At the fixing position of the fixing screw 24 of the waterproof sheet 12 with the water blocking layer, a reinforcing material is applied or reinforced by a waterproof material 26, and the head of the fixing screw 24 is covered and protected.

As shown in FIG. 4 (a), before the concrete 30 is cast, there is a gap between the wall surface 4 of the retaining wall 2 having a rough and uneven surface and the waterproof sheet 12 with a waterproof layer. A void 28 is formed at a plurality of locations. Here, as shown in FIG. 4B, when the concrete 30 is cast inside the retaining wall 2, the waterproof sheet 12 with a waterproof layer is formed.
Is pressed from the poured concrete 30 and extruded into the gap 28. Here, the waterproof sheet 12 with the waterproof layer is formed based on the reinforcing cloth material 14 as described above and is formed to have excellent toughness and extensibility. It is stretched appropriately without causing cracks, breakage, etc., and adheres well to the wall surface 4 of the retaining wall 2 so that the retaining wall 2 and the concrete 3
0 can be smoothly interposed.

Even when the excavated bottom surface 6 is rugged and rough, similarly to the wall surface 4 of the retaining wall 2, when the concrete 30 is cast, the waterproof sheet 12 with a waterproof layer is provided.
Satisfactorily adheres to the excavated bottom surface 6 and can be smoothly interposed between the excavated bottom surface 6 and the cast concrete 30 without causing cracks, breakage, and the like. The excavated bottom 6
5, when the concrete 30 is cast, as shown in FIG. 5, a protective mortar is applied on the waterproof sheet 12 with a waterproof layer by coating or the like to form a protective mortar layer 32, and the surface is adjusted and smoothed. If it does, concrete 30 can be cast well.

From the above, in the waterproofing method, a waterproof layer 8 is formed on the wall surface 4 of the retaining wall 2 and the excavated bottom surface 6.
Since the waterproof sheet 12 with a water-blocking layer having extensibility is formed based on a reinforcing cloth material made of a fiber material, the waterproof layer 8 having excellent toughness and durable can be formed. When the construction is performed, even if the properties of the wall surface 4 of the retaining wall 2 and the excavated bottom surface 6 are uneven and rough, the waterproof sheet 1
2 can be extended and brought into close contact with the wall surface 4 or the excavated bottom surface 6 of the retaining wall 2, so that a failure such as a break or a crack occurs between the wall surface 4 or the excavated bottom surface 6 of the retaining wall 2 and the underground structure 20. The waterproof layer 8 that is unlikely to be generated can be favorably provided.

Further, since the waterproof layer 8 is formed with the waterproof layer 10 made of a cement-based hydratable composition,
Even when a failure such as a break or a crack occurs in the waterproof sheet 12 with a waterproofing layer, there is a joint failure portion on the side of the waterproof material layer 16 of the waterproof sheet 12 with a waterproof layer. Water can be absorbed by the hydration reaction to prevent its intrusion. Further, since the waterproof layer 10 is formed outside the waterproof layer 8, it is possible to protect the waterproof layer 8 from welding sparks such as gas welding and arc welding during construction, and to prevent the occurrence of a fire due to a jump fire or the like. it can.

Accordingly, it is possible to prevent as much as possible the intrusion of water such as groundwater into the underground structure 20 to cause the structure to be stained or deteriorated in durability, to cause troubles in equipment, and the like. The underground structure 20 excellent in waterproofness can be constructed.

Further, the waterproof sheet 12 without or with the water blocking layer is provided with the wall surface 4 of the retaining wall 2 or the excavated bottom surface 6.
As shown in FIG. 6, it is preferable to wind up in a roll shape and dispose it sequentially while dispensing it as shown in FIG. And the waterproof sheet 12
On both side edges of the joint protection tape 3 along the longitudinal direction
4 and when the waterproof sheets 12 are joined together, from above the protective tape 34 applied to the waterproof sheet 12,
It is preferable to apply a joint tape 36 made of the same material as the waterproof material of the waterproof sheet 12, such as a rubber asphalt material or a butyl rubber material. In addition, the joining of the waterproof sheets 12 may be performed with an adhesive,
Further, the heat welding may be performed by heating with a pressure cylinder.

When the underground structure 20 is to be constructed by the reverse driving method, as shown in FIG.
Waterproof sheet 1 wound in a roll according to the construction procedure of
2 are arranged while being sequentially fed out according to the construction procedure from the upper floor side to the lower floor side. On the other hand, the underground structure 20
In the case of constructing the underground structure 20 by the continuous striking method, as shown in FIG. 8, according to the construction procedure of the underground structure 20, the waterproof sheet 12 wound into a roll is attached to the excavated bottom surface 6 of the lower floor.
They are arranged in order from the side to the upper floor side. By arranging the waterproof sheet in this manner, the waterproof sheet can be easily installed without requiring much storage space.

By the way, in the above embodiment, the waterproof layer 1
Although 0 is formed on one side of the waterproof sheet 12, the present invention is not limited to this, and the waterproof layer 10 may be formed on both sides of the waterproof sheet 12 or embedded in the waterproof sheet 12. It may be formed, or may be provided on the wall surface 4 side of the retaining wall 2 or the excavation bottom surface 6 side of the waterproof layer 8. The waterproof layer 10 may be provided on the waterproof sheet and installed together with the waterproof sheet as the waterproof sheet 12 with the waterproof layer. In the present invention, the waterproof layer 10 is not necessarily provided on the waterproof sheet 12 in advance. However, after the waterproof sheet 12 is installed, the waterproof sheet 12 may be provided later.

[0028]

According to the waterproofing method for an underground structure according to the present invention, as described in the embodiments of the present invention, a reinforcing cloth material made of a fiber material is used as a waterproof layer on the wall surface of the retaining wall or the bottom surface of the excavation. The stretchable waterproof sheet formed on the base is installed, so even if the properties of the retaining wall surface and the excavated surface are rough and rough, the waterproof layer is extended and adhered to the retaining wall surface and the excavated bottom surface Thus, a tough and durable waterproof layer can be interposed between the retaining wall surface or the excavated bottom surface and the underground structure. In addition, since a waterproof layer made of a cement-based hydratable composition is formed on the waterproof layer, it is possible to prevent water such as groundwater from entering the underground structure by a hydration reaction, thereby preventing the intrusion. it can. Further, if the water blocking layer is formed outside the waterproof layer, it is possible to protect the waterproof layer from welding sparks such as gas welding and arc welding during construction, and to prevent troubles such as fires caused by flying sparks. From these facts, it is possible to prevent as much as possible the intrusion of water such as groundwater into the underground structure, thereby causing the structure to be soiled or deteriorated in durability, and to prevent the occurrence of malfunctions of equipment and the like. An underground structure with excellent properties can be constructed.

Further, when the waterproof sheet is provided, if the waterproof layer is integrally formed on the surface of the waterproof sheet in advance, the waterproof layer and the waterproof layer can be formed collectively, thereby saving labor. , It is possible to reduce the cost and the construction period.

If the waterproof sheet is formed by using a rubber asphalt material as the waterproof material, a waterproof layer having excellent waterproof properties can be formed.

Further, if the water-stopping layer is formed using a cement-based hydration-reactive composition using polymer cement, a water-stopping layer having excellent water-stopping properties can be formed.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment in which a waterproof layer and a waterproof layer are formed on a wall surface of an earth retaining wall and an excavated bottom surface by a waterproofing method for an underground structure according to the present invention. It is.

FIG. 2 is a sectional perspective view showing an embodiment of the waterproof sheet according to the present invention.

FIG. 3 shows an example of a concrete underground structure constructed by placing concrete on the inside of a wall surface of an earth retaining wall and an excavation bottom surface by the waterproofing method of an underground structure according to the present invention. It is a longitudinal section showing an embodiment.

FIGS. 4A and 4B are cross-sectional views showing states before and after concrete is cast on the inside of the wall surface of the retaining wall on which the waterproof sheet is provided, respectively. is there.

FIG. 5 is a longitudinal sectional view showing one embodiment when concrete is cast on the excavated bottom surface on which the waterproof sheet according to the present invention is provided.

FIG. 6 is a perspective view showing an embodiment of a method for arranging a waterproof sheet according to the present invention.

FIG. 7 is a longitudinal sectional view showing an embodiment in which the waterproofing method for an underground structure according to the present invention is applied to a reverse driving method.

FIG. 8 is a longitudinal sectional view showing an embodiment in a case where a waterproofing method for an underground structure according to the present invention is applied to a progressive driving method.

[Explanation of symbols]

 2 Retaining wall 4 Wall surface 6 Excavation bottom surface 8 Waterproof layer 10 Waterproof layer 12 Waterproof sheet 14 Reinforcement cloth material 20 Underground structure 30 Concrete

Claims (4)

[Claims] 1. Excavating the inside of the earth retaining wall constructed underground,
In a method of constructing a concrete underground structure by placing concrete inside the excavated bottom wall surface or the excavated bottom surface, the excavation may include the following steps: On the bottom surface of the excavation, a waterproof sheet having an extensibility formed by using a waterproof material based on a reinforcing cloth material made of a fiber material is disposed to form a waterproof layer, and a cement-based hydration layer is formed on the waterproof layer. A method for waterproofing an underground structure, comprising forming a water blocking layer made of a reactive composition. 2. The waterproofing method for an underground structure according to claim 1, wherein, when the waterproof sheet is provided, the waterproof layer is integrally formed on a surface of the waterproof sheet in advance. 3. The method for waterproofing an underground structure according to claim 1, wherein the waterproof sheet is formed using a rubber asphalt-based material as the waterproof material. 4. The method for waterproofing an underground structure according to claim 1, wherein the water blocking layer is formed by using polymer cement for the cement-based hydration-reactive composition.