JP2002029807A - Refractory material, tunnel, refractory lining worked body for tunnel and method for forming refractory lining worked body for tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refractory material for obtaining a lining-worked structure having sufficient fire resisting performance against tunnel fire. SOLUTION: In the refractory material formed by mixing cement, water and an aggregate, >=50% aggregate fine particles having air pores is contained as the volume ratio of the aggregate in the aggregate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a refractory material used for the inner surface of a tunnel, a tunnel using the refractory material, a tunnel lining body, and a method of forming a tunnel lining body.

[0002]

2. Description of the Related Art When a fire occurs in a road tunnel or the like, there is a possibility that the lining supporting the tunnel may be damaged by high heat. If the lining is damaged, it will not be able to receive the load acting on the tunnel, and not only will groundwater and earth and sand flow out, but the tunnel may collapse. For this reason, it is necessary to provide a lining structure having sufficient fire resistance performance even in a fire in a tunnel.

[0003] As fire countermeasures conventionally proposed in tunnels, there are two countermeasures: (1) secondary lining (see Fig. 12 and (2) fireproof panel (see Fig. 13)). Work (see FIG. 12) This is to cover the inner peripheral surface of the lining body constructed by combining the segment 101 composed of ordinary concrete 102 with the inner peripheral surface shape of the shield tunnel with the secondary lining 103 made of concrete. (2) Fireproof panel (see FIG. 13) This is a fireproof panel on the inner peripheral surface of a lining body constructed by combining the segment 101 composed of ordinary concrete 102 with the inner peripheral surface shape of a shield tunnel. The panel 105 is fixed by dedicated mounting bolts 106. An insert nut 107 is embedded in the concrete 102.

[0004]

However, the above fire countermeasures have the following problems. (1) Problem of secondary lining In the case of secondary lining, the thickness of the secondary lining is required due to the high thermal conductivity of the conventional refractory material, and the excavation cross-sectional area becomes large. In addition, since it is performed after the primary lining, the construction period is long, and the cost is increased. There is a risk of explosion due to a rapid rise in temperature, which is not sufficient as a fire prevention measure. Further, the rigidity in the tunnel axial direction increases, and the seismic resistance decreases.

[0005] In addition to this fire protection,
It has been installed for the purpose of waterproofing, anticorrosion, vibration proofing, meandering correction, smoothing of the inner surface, and interior finishing. However, in recent years, waterproofing and meandering correction have been improved by improving shield excavating technology and segment assembling technology, and the necessity of smoothing the inner surface and finishing the interior has been reduced by the use of boltless segments. For this reason, secondary lining has been omitted in order to reduce costs by reducing the excavated section and shortening the construction period. Similarly, in the case of road tunnels, the number of cases in which secondary lining is omitted has increased, and accordingly, a covering material having a fireproof function in consideration of a fire occurrence is required.

(2) Problem of fireproof panel Fireproof material (ceramics) constituting fireproof panel 105
However, the material cost is high because a water guide material and a mounting member (corrosion resistance and heat resistance) are required. further,
In the case of mounting the fireproof panel 105 or in the case of a large cross section (a road tunnel is generally a large cross section), temporary facilities such as scaffolding are also required, and the construction is troublesome.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a fireproof structure for realizing a lining structure having sufficient fireproof performance against a tunnel fire. It is another object of the present invention to provide a tunnel, a refractory lining for a tunnel, and a method for forming a refractory lining for a tunnel using the refractory material.

[0008]

In order to achieve the above object, according to the present invention, in a refractory material formed by mixing cement, water and aggregate, air holes are formed in the aggregate. It is characterized in that the aggregate fine particles are contained in an aggregate volume ratio of about 50% or more. As the aggregate fine particles, fine hollow glass spheres (silas balloon) or diatomaceous earth obtained by foaming volcanic glass in shirasu by heat treatment are used. As described above, by mixing porous aggregate fine particles having air holes such as "Shirasu balloon" and "diatomaceous earth" into the refractory material, the fire resistance performance against fire is improved as compared with the conventional refractory material, and the fire resistance is improved. The aim is to reduce material costs and improve workability.

A refractory material is provided on an inner surface of the tunnel lining body. Further, a refractory material is provided on the inner surface of each of the plurality of segments constituting the tunnel lining body.

Further, the fire-resistant material and concrete in which a reinforcing member is buried are provided, and the reinforcing member is a fire-resistant lining for a tunnel buried separately from the fire-resistant material. I do. Still further, in the method for forming a fire-resistant lining for a tunnel according to the present invention, a fire-resistant material is poured into a formwork, and a reinforcing member is positioned in a state of being floated from the fire-resistant material. It is characterized in that concrete is cast so as to bury the members to form a refractory lining for a tunnel.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. The fireproofing method for a tunnel using the fireproof material of the present invention includes an integral casting method in which a fireproof material is integrally molded on the inner periphery of the segment when the segment of the lining body is manufactured (Embodiment 1), and a fireproof method after the lining construction. And a spraying method for spraying a material (Embodiment 2).

Embodiment 1 FIG. 1 shows a general cross section of a tunnel using a refractory material according to Embodiment 1 of the present invention. That is, the refractory material 4 of the present invention is provided on the inner surface of the lining body 3 having a circular cross section constructed by combining the segment 1 composed of the ordinary concrete 2 with the inner peripheral surface shape of the shield tunnel. An invert 5 is provided at the bottom of the lining 3. As shown in FIG. 2, the refractory material 4 is provided integrally on the inner surface of each of the plurality of segments 1 constituting the tunnel lining body 3. Further, a one-touch joint 6 that can be connected to an adjacent segment with one touch is provided on the axial end face and the circumferential end face of each segment 1.

The refractory material 4 is formed by mixing cement, water and aggregate, and the aggregate contains aggregate fine particles having air holes in an aggregate volume ratio of about 50% or more. . As the aggregate fine particles, fine hollow glass spheres (shirasu balloon) or diatomaceous earth obtained by subjecting volcanic glass in shirasu to heat treatment and foaming are used. As described above, by mixing porous aggregate fine particles having air holes such as "Shirasu balloon" and "diatomaceous earth" into the refractory material 4, compared with the conventional refractory material,
The purpose is to improve the fire resistance performance against fire, to reduce the cost of refractory materials and to improve workability. Also,
Light-weight aggregates, coarse aggregates having air holes, fiber reinforcing materials, and the like may be mixed in addition to the above-mentioned constituent materials (cement, water, aggregate).

Next, a method for forming a segment of a fire-resistant lining for a tunnel will be described with reference to FIGS. That is, as shown in FIG. 3, the refractory material 4 is cast in the formwork 10 in advance when the segment 1 of the tunnel lining body 3 is manufactured, and is hardened to the extent that it is not deformed when the lining concrete is cast. Pour lining concrete from above,
It is integrated with the inner side of the lining. At this time, a reinforcing bar 17 as a “reinforcing member” embedded in the lining concrete is positioned in a state of being floated from the refractory material 4, and concrete is cast to form the segment 1 of the refractory lining body for tunnel. is there.

Hereinafter, this procedure will be described in detail. First, as shown in FIG. 3, the working frame for manufacturing a segment is assembled. The mold 10 includes an arc-shaped bottom plate 11 for molding the inner peripheral surface of the segment, a side plate 12 for molding the axial end surface of the segment, and a end plate 13 for molding the circumferential end surface of the segment. It has. Next, as shown in FIG. 4, the refractory spacer 14 is buried and the refractory material 4 is cast on the bottom surface of the formwork to level the surface. In order to obtain sufficient adhesion, an adhesive is applied to the surface of the refractory material 4, or the adhesive is mixed with the refractory material 4 or concrete. Alternatively, after the refractory material 4 has been cast, concrete is poured and adhered without time (before hardening). The components of the refractory spacer 14 have the same composition as the refractory material 4 or components having the same refractory performance. The strength of the refractory spacer 14 is such that it does not break even when the reinforcing bar 17 is placed thereon, for example, the refractory material. 4 and the same strength as that of the fireproof spacer 14.
May be a square, a cylinder, a ring, or the like. Next, as shown in FIGS. 5A and 6, the reinforcing bar 17 is positioned in the mold 10 using the fireproof spacer 14. The refractory spacers 14 support the reinforcing bar 17 in a state of being floated from the refractory material 4 by a predetermined distance (a state of being separated by a predetermined distance), thereby ensuring the covering of the reinforcing bar 17. Thereby, the heat transfer from the refractory material 4 to the reinforcing bar 17 having a good heat transfer coefficient can be suppressed, and the heat insulation can be improved. In other words, the distance to be separated is set to a distance that can sufficiently suppress heat transfer.

As shown in FIG. 5A, the refractory spacer 14 to be buried may be a die-shaped spacer, the lower end of which may penetrate the refractory material 4, or the lower end may extend to a halfway position inside the refractory material 4. . When the refractory material 4 is used after its strength has been improved, a post-mounting spacer 15 that abuts on the refractory material 4 as shown in FIG. 5B may be used. As shown in FIG. 5C, a horse-shaped spacer 16 having a U-shaped cross section may be used. A material having heat resistance is used for the spacers 14. Alternatively, the reinforcing bar cage 17 may be fixed to only the peripheral surface of the formwork 10 without using a spacer, and may be held in a state of being floated from the refractory material 4. Next, as shown in FIG. 6, the concrete 2 is cast (when the refractory material 4 is not cured or cured). After curing the concrete 2, the mold 10 is released, and the segment 1 is completed as shown in FIG.

The assembling procedure of the manufactured segment 1 is as follows. The segments 1 are lifted by a vacuum or gripping type erector (segment assembling apparatus), and the segments 1 are sequentially assembled to form a ring.
The segment 1 having no bolt box or holding hardware is standardized. However, if the refractory material 4 has a defective portion such as a bolt box or holding hardware, the refractory material 4 is sprayed on the defective portion after the assembly of the segment 1 is completed. And filling.

[Second Embodiment] FIG. 8 shows a sectional structure of a tunnel using a refractory material according to a second embodiment of the present invention. The second embodiment is a method (such as NATM) of spraying a refractory material from the inner surface side after the lining construction. Refractory material 4
Is sprayed to the minimum required. The spray type includes a case where an adhesive is mixed and a case where a net is used for the spray portion. That is, the refractory material 4 of the present invention is sprayed on the inner surface of the lining body 3 having a circular cross section constructed by combining the segment 1 composed of the ordinary concrete 2 with the inner peripheral surface shape of the shield tunnel. In this example, regarding the segment 1a facing the road, only the surface exposed at the upper part of the road is covered with the refractory material 4.
Needless to say, the refractory material 4 of this embodiment may be mixed with a fiber reinforcing material or the like as in the first embodiment.

[0019]

Next, examples of the refractory material of the present invention will be described. In the present example, a refractory material piece 20 was prepared as a test piece at an arbitrary mixing ratio of high-strength cement, water, river sand, and aggregate fine particles (diatomaceous earth, shirasu, etc.) and subjected to a heating test. The refractory piece 20 for the heating test is composed of a mortar 21
The refractory material 22 of the present invention is laminated via the boundary surface 23, and has a block shape of 200 × 200 × 100 mm. The mortar 21 has a thickness of 60 mm and the refractory material 22 has a thickness of 40 mm (see FIG. 9). This refractory piece 20
Was subjected to a heating experiment at 1350 ° C. for 120 minutes, and the results are shown in FIG. This 1350 ° C.
As shown in the figure, the maximum furnace heating temperature in the Netherlands, which imposes the strictest safety standards in the world, was adopted. According to the Dutch standard, the concrete 2 must satisfy 380 ° C. or less at the surface 2a of the concrete 2 and 250 ° C. or less at the surface 17a of the reinforcing bar in FIG.

As shown in FIG. 11, when both diatomaceous earth and shirasu are mixed in an aggregate volume ratio of 50 to 100%, even if the refractory material piece 20 is heated, no explosion occurs, and
It was confirmed that the temperature could be maintained at 250 ° C. or lower at the position of the boundary surface 23 between the mortar 21 and the refractory material 22 inside the mm inner surface. On the other hand, it was found that when it is less than 50%, a burst phenomenon occurs.

Here, the aggregate volume ratio refers to the volume ratio of aggregate fine particles in the aggregate contained in the refractory material. Aggregate volume ratio = Va / (Vs + Va) × 100 (%) Vs = S / γs Va = F / γa Vs: Volume of fine aggregate (river sand) Va: Volume of aggregate fine particles (silas, diatomaceous earth) S: Fine Weight of aggregate (river sand) F: weight of aggregate fine particles (silas, diatomaceous earth) γs: density of fine aggregate (rivers sand) γa: density of aggregate fine particles (silas, diatomaceous earth) As an example of the composition at this time, 589 kg of cement, 682 kg of river sand (specific gravity: 2.6), 375 kg of water, fine particles of aggregate (Shirasu specific gravity: 0.2), the aggregate volume ratio is 58%
It is. In addition, in the said embodiment etc., although the rebar 17 is applied as a "reinforcement member", it is not limited to this, As a "reinforcement member", a pipe-shaped sheath pipe used for prestressed concrete or a segment may be used. A metal joint or the like to be connected is applied.

[0022]

As described above, according to the present invention,
Since the refractory material is configured so that the aggregate fine particles contain about 50% or more as an aggregate volume ratio, sufficient strength can be obtained as a refractory coating. In particular, by setting the aggregate volume ratio to 50% or more, the occurrence of the explosion phenomenon can be prevented.
In addition, by mixing porous aggregate fine particles having air holes such as "Shirasu balloon" and "diatomaceous earth" into the refractory material, the fire resistance performance against fire is improved as compared with the conventional refractory material, and the refractory material is improved. Cost reduction and workability can be improved.

Further, the refractory material of the present invention can obtain a sufficient strength as a fire-resistant coating for a tunnel, and its uncured state is the same as that of a conventionally used mortar. The material can be sprayed in the same manner as before. In addition, since shirasu and diatomaceous earth can be integrally manufactured, if a fireproof material is integrally provided on the inner surface of the segment of the tunnel lining, there is no need for installation work like a conventional fireproof panel or temporary equipment such as scaffolding. And construction costs are low. Furthermore, by positioning a reinforcing member (for example, a reinforcing bar) away from the refractory material and casting concrete to form a refractory lining body for a tunnel, the refractory material to the reinforcing member having a good heat transfer coefficient can be obtained. Heat transfer can be suppressed, and heat insulation can be improved.

[Brief description of the drawings]

FIG. 1 is a general sectional view (integral molding method) of a tunnel when a refractory material according to Embodiment 1 of the present invention is used.

FIG. 2 is a perspective view (integral molding method) of a segment into which the refractory material of FIG. 1 is integrally cast.

FIG. 3 is a perspective view showing the segment working formwork of FIG. 2;

FIG. 4 is a view showing a situation in which a spacer is embedded in the mold of FIG. 3 and a refractory material is cast on the bottom of the mold.

FIGS. 5A to 5C are cross-sectional views of various spacer installation portions.

FIG. 6 is a partial cross-sectional perspective view showing a state in which a reinforcing bar is fixed to the formwork of FIG. 4 and concrete is cast.

FIG. 7 is a sectional view of the segment of FIG. 2;

FIG. 8 is a general sectional view (spraying method) of a tunnel using a refractory material according to Embodiment 2 of the present invention.

FIG. 9 is a perspective view of a refractory piece as an experimental specimen according to an example of the present invention.

FIG. 10 is a graph showing a heating curve (Netherlands, Germany, ISO standard) applied in a fire safety standard.

FIG. 11 is a graph showing the temperature of each refractory piece at a 40 mm inner surface position after heating at 1350 ° C. for 120 minutes.

FIG. 12 is a general sectional view (secondary lining) of a conventional tunnel.

FIG. 13 is a detailed installation diagram of a conventional fireproof panel.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 segment 2 concrete 3 lining body 4 refractory material, 5 invert 6 one-touch joint 10 formwork 14,15,16 spacer 17 steel cage

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[Procedure amendment]

[Submission date] December 8, 2000 (200.12.
8)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

6. A refractory lining for a tunnel, wherein the refractory material according to any one of claims 1 to 3 is provided on an inner surface of each of a plurality of segments constituting a tunnel lining body. body.

7. A refractory material according to any one of claims 1 to 3, and a concrete reinforcement member is embedded, the reinforcing member is embedded in a state of being separated from the refractory material A fire-resistant lining for a tunnel, characterized in that:

8. A refractory material is cast on a formwork, a reinforcing member is positioned in a state of being floated from the refractory material, and then concrete is cast on the refractory material so as to bury the reinforcing member. A method for forming a refractory lining for a tunnel, comprising forming a refractory lining for a tunnel.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction contents]

A refractory material is provided on an inner surface of the tunnel lining body. Moreover, the refractory material is provided by spraying on the inner surface of the tunnel lining body. Further, a refractory material is provided on the inner surface of each of the plurality of segments constituting the tunnel lining body.

Continued on the front page (72) Inventor Kazuhiko Kanai 1-24-4 Shinkawa, Chuo-ku, Tokyo Inside Daitoyo Construction Co., Ltd. (72) Inventor Haruo 1-24-4 Shinkawa, Chuo-ku, Tokyo Daitoen Construction Shares In-house (72) Inventor Fumino Inada 1-44 Shinkawa, Chuo-ku, Tokyo F-term (reference) 2D055 EB10 KA00 KB05 LA17 4G012 PA04 PA05 PA09 4G058 GA01 GB02 GC01 GC03 GD11 GF06 GF09

Claims (7)

[Claims] 1. A refractory material formed by mixing cement, water and aggregate, wherein the aggregate contains approximately 50% or more of aggregate fine particles having air holes as an aggregate volume ratio. Characterized by refractory materials. 2. The refractory material according to claim 1, wherein the aggregate fine particles are fine hollow glass spheres obtained by subjecting volcanic glass in Shirasu to heat treatment and foaming. 3. The refractory material according to claim 1, wherein the aggregate fine particles are diatomaceous earth. 4. A tunnel, wherein the refractory material according to claim 1 is provided on an inner surface of a tunnel lining body. 5. A refractory lining for a tunnel, wherein the refractory material according to claim 1 is provided on an inner surface of each of a plurality of segments constituting a tunnel lining body. body. 6. The refractory material according to claim 1, and a concrete in which a reinforcing member is buried, wherein the reinforcing member is buried in a state separated from the refractory material. A fire-resistant lining for a tunnel, characterized in that: 7. A refractory material is cast on a formwork, a reinforcing member is positioned in a state of being floated from the refractory material, and then concrete is cast on the refractory material so as to embed the reinforcing member. A method for forming a refractory lining for a tunnel, comprising forming a refractory lining for a tunnel.