JP2002089186A - Seismically isolated structure for structure and segment for tunnel lining - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a segment for tunnel lining, contributing to an improvement in the aseismic base isolation of a structure installed in the ground, and a seismically isolated mechanism for the structure supported on the foundation installed in the ground or the water. SOLUTION: A seismically isolated structure (12) comprises a coating (18) of water permeable paint containing impalpable powder (24), which covers the surface of the structure (10), and a water screen (20) formed of moisture (22) around the structure (10), which passes through the coating (18), and the impalpable powder (24) exuding from the coating (18) between the coating (18) and the surface of the structure (10). Additionally, the structure (12) can comprise a waterproofing coating (29) substantially specifying the surface of the structure (10).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation structure for a structure, particularly a seismic isolation structure for a tunnel which is an underground structure, and a lining segment thereof.

[0002]

2. Description of the Related Art Conventionally, as a seismic isolation structure for a tunnel, there has been proposed a structure in which an outer peripheral surface of a tunnel body or a lining thereof is covered with a sheet having a small coefficient of friction or a sliding material such as bentonite.

[0003] When a local strain is generated in the surrounding ground due to an earthquake, the tunnel receives an axial force on its outer peripheral surface. This causes a low friction state between the tunnel and the surrounding ground due to the presence of the sheet or the sliding material. , A relative slippage occurs between the surrounding ground and the tunnel, and the destruction of the tunnel frame or its lining is avoided.

However, when the sheet is used, even if the surface of the frame or lining and the sheet are smooth, there is a limit in reducing friction between the sheet and the sheet. Further, when using the sliding material, it is difficult to select a sliding material that maintains stable physical properties for a long time in the ground and does not penetrate into the ground or move on the outer periphery of the frame or lining. It is. Therefore, there is still room for improvement in seismic isolation measures.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to improve seismic isolation of a structure installed underground, and to provide a tunnel lining segment contributing to such improvement. Is to do. Another object of the present invention is to
It is to provide a seismic isolation mechanism for a structure supported on a foundation installed underground or underwater. Still another object of the present invention is to form a sliding material between two smooth surfaces that are in contact with each other to realize low friction and long-term stability of the sliding material.

[0006]

SUMMARY OF THE INVENTION The present invention provides a seismic isolation structure for a structure such as a tunnel installed underground. This seismic isolation structure is formed by a water-permeable paint film containing fine powder, which covers the surface of the structure, and water around the structure that has passed through the film and fine powder oozing out of the film. A water film formed between the film and the surface of the structure.

The present invention also provides a seismic isolation structure for a structure such as a bridge supported on a foundation installed underground or underwater. The seismic isolation structure includes a film of the water-permeable paint that covers a top surface of the foundation, and the water film existing between the film and the top surface of the foundation.

In the seismic isolation structure, the substantial surface and top surface can be defined by a waterproof coating applied to the surface of the structure and the top surface of the foundation, respectively. The water-permeable paint is made of, for example, an aqueous emulsion type silicone paint, and the fine powder is made of, for example, fine powder of titanium oxide.

The present invention also provides a tunnel lining segment having an outer peripheral surface covered with a coating of the paint. The segment may include a waterproof coating applied to the outer peripheral surface that substantially defines the outer peripheral surface.

[0010]

According to the seismic isolation structure of the present invention, the surface of the underground structure and the paint film covering the underground structure can be separated from each other by the water film present between them. . In addition, the coating of the paint, which receives the soil pressure from the surrounding ground of the structure, is substantially integrated with the surrounding ground.

From this, the structure can move relative to the film integral with the surrounding ground along the water film via the water film, and the relative movement is caused by the water film. It involves rolling motion of the fine powder inside. For this reason, the frictional resistance of the structure relative to the surrounding ground during relative movement is relatively small, and an effective seismic isolation effect can be obtained regardless of the magnitude of the earthquake. Here, the surface of the structure and the coating provide two smooth surfaces, and the water film therebetween forms a lubricant, whereby the lubricant (water film) has a long-term stability. And a reduction in friction between the structure and the surrounding ground.

The underground structure to which the present invention is applied is typically a tunnel, and a coating of the paint is formed on an outer peripheral surface of a lining that defines a tunnel space and includes, for example, a plurality of segments.

In a seismic isolation structure for a structure such as a bridge supported on a foundation installed in the ground or underwater, the coating of the paint covering the top surface of the foundation may be a weight of the structure. And integrated with the structure. From this, the structure is capable of relative movement with low friction along the top surface of the foundation via the water film and the fine powder present between the coating and the foundation. With this, it exerts an effective seismic isolation function for large and small earthquakes. The surface of the structure,
The waterproof coating substantially defining the outer peripheral surface of the segment and the top surface of the foundation is installed in a soft viscous soil including groundwater with a high salt concentration, for example, due to its waterproofing action. In this case, the contact of the groundwater with the surface of the structure or the like and the deterioration and corrosion of the surface itself due to the contact are prevented. Thereby, the lubricant (water film) necessary for exhibiting the seismic isolation effect can be maintained on the surface of the structure or the like for a long period of time.

As the paint and the fine powder, an aqueous emulsion type silicone paint and a fine powder of titanium oxide are preferably used.

[0015]

1 and 2, a seismic isolation structure 12 according to the present invention is applied to a tunnel 10, which is a typical structure installed underground.

The tunnel 10 having a circular cross section shown in FIG. 1 includes a plurality of segments 14 made of steel, concrete, or the like. These segments 14 are assembled in a cylindrical shape along a wall excavated by a shield machine (not shown) propelled underground.

A tunnel 10 having a rectangular cross section shown in FIG.
Consists of a tunnel body 16 formed in the excavated ground by cast-in-place concrete.

The seismic isolation structure 12 according to the present invention, as shown in detail in FIG. 3, includes a coating 18 of a water-permeable paint containing fine powder, which covers the surface of the tunnel 10, which is the aforementioned structure. And a water film formed between the surface of the tunnel and the tunnel. The water film 20 is composed of water 22 around the tunnel 10 that has passed through the film 18 and the fine powder 24 oozing out of the film 18.

The surface of the tunnel 10 shown in FIG. 1 is the outer peripheral surface of all the segments 14, and the surface of the tunnel 10 shown in FIG. 2 is the outer peripheral surface of the tunnel frame 16. .

In order to form a film 18 covering the surface of the tunnel 10, the water permeable paint is previously applied to the outer peripheral surface of the segment 14 before the installation to form a film. The segment 14 can be handled in the same manner as the segment to which the paint is not applied, and the seismic isolation structure of the present invention can be easily formed only by installing the segment 14 on the excavation wall surface and through a process described later. be able to.

The water-permeable paint is applied to the outer peripheral surface of the tunnel body 16 after molding and before backfilling with earth and sand.

The thickness of the coating is preferably 1 mm or less, more preferably 0.5 mm or less.

As the water-permeable paint, for example, an aqueous emulsion type silicone paint can be used. This paint has the advantage that no harmful organic solvent is used because it is water-based, and that it is easy to handle. The paint may be a urethane-based paint or an acrylic-based paint as long as the paint has water permeability, and more specifically, can paint water to form the water film 20.

The fine powder 24 in the paint is added as a filler, so that the strength of the paint film can be ensured so that the characteristic of relative movement (sliding) does not change due to plastic deformation even under high pressure. Such a high-strength substance, for example, a fine powder of titanium oxide, another metal powder, or the like. It is desirable that the fine powder 24 has good rolling properties and is rounded as a whole.

Since the water-permeable paint has a property of allowing water to pass through, moisture around the tunnel 10 installed in the ground penetrates into the coating film over time, and the permeated water flows to the surface of the tunnel 10. Up to. During this time, the fine powder 24 in the coating film is carried to the surface of the tunnel 10 by the moisture.

As a result, a thin water film 20 containing fine powder 24 and moisture 22 is formed between the coating film and the surface of the tunnel 10, and the coating film can be separated from the surface of the tunnel 10 with a small frictional force. In this state, a film 18 covering the surface is formed.

In the example shown in FIG. 1, the moisture around the tunnel 10 is the moisture in the backfill material 28 such as mortar filled between the segment 14 and the surrounding ground 26 or the surrounding ground 26. This is the moisture in the surrounding ground 26 in the example shown in FIG.

The coating 18 covering the surface of the tunnel 10 is pressed against the surface of the tunnel 10 under the soil pressure of the surrounding ground 26. Therefore, the coating 18 is in contact with the back filling material 28 or the surrounding ground 26 on the outer peripheral surface thereof, and forms an integral part thereof. In addition, the inner peripheral surface of the coating 18 facing the surface of the tunnel 10 is relatively smooth because the inner peripheral surface of the coating 18 is applied to the surface of the tunnel.
Further, it is in contact with the surface of the tunnel 10 via the water film 20.

From this, it is clear that the tunnel 10 has, with respect to its axial direction, the coating 18 (and thus the backfill implant 28).
Alternatively, relative movement (sliding) with low friction using the water film 20 as a sliding material with respect to the surrounding ground 26) is possible.

This relative movement involves the rolling of the fine powder 24 in the water film in contact with the surface of the tunnel 10 and the inner peripheral surface of the film 18. For this reason, the magnitude of the frictional force generated between the tunnel 10 and the film 18 generated during the relative movement is set to be extremely small.

The relative movement of the tunnel 10 with respect to the coating 18 causes a distortion in the surrounding ground 26 due to the earthquake, which significantly reduces the external axial force transmitted from the surrounding ground 26 to the tunnel 10 (seismic isolation effect). ). Due to this seismic isolation effect, breakage or damage of the tunnel 10 can be avoided.

The structure to which the seismic isolation structure of the present invention is applied is as follows:
In addition to the tunnel, another underground structure that defines an underground space such as a basement may be used.

Further, the seismic isolation structure of the present invention may include a bridge (not shown) supported on a foundation such as a footing (not shown) installed underground or underwater, in addition to the underground structure.
And the like.

In the seismic isolation structure of the bridge, when the bridge is constructed, the paint is applied to the top surface of the footing,
The seismic isolation structure can be formed by placing a pier (not shown) of the bridge on the paint film of the paint.

Since the footing is in water or in the ground, moisture penetrates into the coating from the periphery of the coating to form the coating. The coating of the bridge pier and its superstructure, which receives gravity, is integral with the bridge, and the water film containing the moisture and the fine powder is formed between the coating and the surface of the footing. .

Therefore, as in the case of the underground structure, a relative motion with small friction can be generated between the footing and the pier in the event of an earthquake, whereby a seismic isolation effect is obtained, and the bridge is damaged. , Destruction, etc. can be avoided.

The particle size, amount and the like of the fine powder added as a filler in the paint can be appropriately determined according to the type and weight of the structure to which the seismic isolation structure is applied. For example, in the application to the tunnel shown in FIG. 1, the weight ratio of silicone to titanium oxide in the silicone paint is about 1: 2.
5 By the way, tunnel 10, segment 14,
The footing (hereinafter referred to as “structure or the like”) may be installed in a soft clay soil containing groundwater with a high salt concentration. In an environment containing salt, the surface (the surface, the outer peripheral surface, and the top surface) of the structure or the like is degraded or corroded through the water film 20. Therefore, the water film is formed on the surface of the structure or the like. 20
May be difficult to hold. In order to avoid this, as shown in FIG. 4, it is desirable to provide a waterproof coating 29 that substantially defines the surface of the structure or the like. The waterproofing film 29 has a waterproofing action of the film, thereby cutting off the water containing the salt with respect to the surface of the structure or the like itself, preventing the surface from deteriorating, corroding, and the like, and preventing the water film 20 from disappearing. The seismic isolation effect can be maintained for a long time. The waterproof coating 29 is preferably made of an epoxy paint or a hard silicone paint. These paints are
It is suitable for forming a smooth and hard waterproof coating on the surface of the structure or the like. The waterproof coating 29 is applied to the surface of the structure, that is, the surface of the tunnel 10, the
The outer peripheral surface of No. 4 and the top surface of the footing are applied so as to cover them and are cured. Therefore, the coating 18 is formed on the waterproof coating 29 that substantially defines the surface of the structure or the like so as to cover the waterproof coating 29. Waterproof coating 29
Can be set to, for example, 0.1 to 0.5 mm.

To confirm the effect of the seismic isolation structure shown in FIG.
An experiment as shown in FIG. 5 was performed, and an experiment result as shown in FIG. 6 was obtained.

Referring to FIG. 5, blocks 32 and 34 made of two identical cubes (each side is 10 cm) are placed on a carriage 30.
Are stacked. The lower block 32 is made of a concrete block simulating the segment for tunnel lining, and the upper block 34 is made of the backfill material block 34.

In the experiment, the upper and lower blocks 3 were used for comparison.
2 and 34, the seismic isolation structure of the present invention comprising the film and the water film is disposed,
The test was performed on the lower block 32 of the base plates 2 and 34 coated with a fluororesin.

In the seismic isolation structure according to the present invention, the aqueous emulsion type silicone paint is applied to the upper surface of the preformed concrete block 32 to a thickness of about 0.5 mm using a brush, and then the paint is applied. The block 32 is placed in a rectangular parallelepiped formwork with the application side facing up, and a backfill material is cast on the block 32 in the formwork to form the block 34, and then this is put in water for one month. It was formed by curing.

The experiment was conducted while applying a vertical stress A (approximately 0.2 N / mm ² ) to the upper one of the upper and lower blocks 32, 34 mounted on the carriage 30.
When a horizontal shearing force B was applied to No. 4, the shear stress generated in both blocks 32 and 34 and the relative shear displacement of both blocks were measured. The measurement results are as shown in FIG.

According to the measurement results shown in FIG. 6, for both blocks 32 and 34 to which the seismic isolation structure of the present invention is applied,
Under the application of the shear force, almost constant shear stress was generated, and the relative displacement between the two blocks increased.

On the other hand, for both blocks 32 and 34 including the block 32 coated with the fluororesin,
Under the application of the shearing force, the shear stress and the relative displacement increase almost linearly, and the shear stress and the shear displacement are each about 0.
At 27 N / mm ² and 4.6 mm, the shear stress of the upper block 34 exceeded the shear strength, causing the block 34 to shear fracture.

Thus, the effectiveness of the present invention was confirmed.

After the experiment, when the two blocks 32 and 34 to which the seismic isolation structure of the present invention was applied were separated, the coating was integrated with the block 34 simulating the backfilling material.
On the upper surface of the block 32 imitating the segment, a film of slightly turbid water containing the fine powder of titanium oxide was formed. Further, the exposed surface of the coating was smooth, and when this was rubbed with a finger, the fine powder of titanium oxide emerged and turned white.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a tunnel which is an underground structure to which the present invention is applied.

FIG. 2 is a cross-sectional view of another tunnel which is an underground structure to which the present invention is applied.

FIG. 3 is a sectional view showing details of the seismic isolation structure of the present invention.

FIG. 4 is a sectional view of a seismic isolation structure similar to that shown in FIG. 3 according to another example of the present invention.

FIG. 5 is a schematic diagram showing equipment of an experiment conducted to test the effect of the present invention.

FIG. 6 is a graph showing the results of an experiment performed using the equipment shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Structure 12 Seismic isolation structure 14 Segment 16 Tunnel body 18 Coating 20 Water film 22, 24 Water and fine powder in water film 26 Surrounding ground 28 Backfilling injection material 29 Waterproof coating

Continued on the front page (72) Inventor Tota Katsukawa 2-1 Tsukudo-cho, Shinjuku-ku, Tokyo F-term (reference) 2D055 BB01 JA00 KB04 LA19 3J048 AC03 BE12 EA38

Claims (10)

[Claims] 1. A seismic isolation structure for a structure installed underground, comprising: a film of a water-permeable paint containing fine powder, which covers a surface of the structure; A seismic isolation structure for a structure, comprising: a water film formed between the film and the surface of the structure by ambient moisture and fine powder oozing from the film. 2. The method according to claim 1, further comprising a waterproof coating applied to said surface, substantially defining the surface of said structure.
Seismic isolation structure of the structure described in. 3. The seismic isolation structure of a structure according to claim 1, wherein the structure comprises a tunnel. 4. A seismic isolation structure for a structure supported on a foundation installed in the ground or underwater, comprising a coating of a water-permeable paint containing fine powder, covering a top surface of the foundation. A seismic isolation structure for a structure, comprising: a water film formed between the coating and a top surface of the base by moisture around the base that has passed through the coating and fine powder oozing from the coating. 5. The seismic isolation structure of a structure according to claim 4, further comprising a waterproof coating applied to the top surface, substantially defining a top surface of the foundation. 6. The seismic isolation structure for a structure according to claim 4, wherein the structure comprises a bridge. 7. The water-permeable coating material comprises an aqueous emulsion type silicone coating material, and the fine powder comprises a fine powder of titanium oxide.
Seismic isolation structure of the structure described in the paragraph. 8. A tunnel lining segment having an outer peripheral surface covered with a film of a water-permeable paint containing fine powder. 9. The tunnel lining segment according to claim 8, further comprising a waterproof coating applied to the outer peripheral surface, substantially defining the outer peripheral surface. 10. The tunnel lining segment according to claim 8, wherein the water-permeable coating is made of an aqueous emulsion type silicone coating, and the fine powder is made of titanium oxide fine powder.