JP2003321999A - Reinforcing method of tunnel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reinforcing method of a tunnel wherein work is easily carried out and a clearance to an existing lining is small, and which can provide an excellent strength and durability. <P>SOLUTION: A lining ring 15 connecting a plurality of covering plates 20 made from a cementitious hardening body as a hardening body of a mixture containing cement, fine aggregate, pozzolanic reaction particle, metal fiber, quartz powder, fibrous or flaky reinforcing particle, a water reducing agent and water is placed in a gap to an existing lining 11 of an existing tunnel 10 to be reinforced and the reinforcing tunnel, and a filler 16 such as a mortar or the like is grouted between the existing lining 11 and the lining ring 15 to reinforce the existing lining 11. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel reinforcing method for preventing peeling and peeling of lining concrete in an existing tunnel and improving load resistance and durability of the lining.

[0002]

2. Description of the Related Art Conventionally, as one of the methods for reinforcing an existing tunnel, as shown in FIG. 6 (a), carbon in a one-way or two-way arrangement on the surface of concrete (existing lining) 11 on the inner surface of the existing tunnel. A method of attaching the fiber sheet 50 using an adhesive such as a room temperature curing epoxy resin is used. With this method, the reinforcing member can be arbitrarily shaped on-site, so there are no restrictions such as obstacles and construction is easy, and
It has the advantage of not corroding and having excellent durability,
There was a problem with fire resistance. On the other hand, in order to improve the strength of reinforcement, as shown in FIG. 6 (b), a steel support bar 60 is constructed on the surface of the existing lining 11, and this support bar 60 contains an acrylic resin and contains short fibers. Concrete plate reinforced with (PI
C foam) or a cement mixed with a reinforcing material such as fine silica, and a lining member 61 such as an HMC plate in which a thermosetting resin is mixed is attached, and the lining member 61 and the existing lining 11 surface A method of backfilling the gap with a filler 62 such as air mortar or lightweight mortar, or using a steel plate 70 on the surface of the existing lining 11 using anchor bolts 71 and an adhesive resin 72 as shown in FIG. 6C. Methods such as bonding are used.

[0003]

However, the above-mentioned H
In the method of attaching MC plate, etc., not only the work for constructing the supporting work is required, but also the strength of the reinforcing portion is maintained,
In order to carry out backfilling of about 200 mm, the separation distance from the existing lining surface was large, and at the time of work, it was necessary to install wiring and piping such as electric and communication cables in the tunnel. On the other hand, the method of adhering the steel plate to the lining surface can reduce the separation distance from the existing lining surface, but since each steel plate is fixed to the lining surface with anchor bolts, work efficiency is improved. There was a problem that it was bad.
Further, the above steel sheet is heavy in weight per unit volume, so that it is difficult to perform the construction, and since the steel sheet is easily corroded, it is necessary to perform regular coating.

The present invention has been made in view of the conventional problems and is not only easy to construct, but also has excellent strength and durability, and can reduce the distance from the existing lining. The purpose is to provide a method for reinforcing a tunnel.

[0005]

Means for Solving the Problems As a result of intensive studies on the above problems, the present inventors have made a covering made of a cementitious hardened material having a compressive strength of 5 times or more and a bending strength of 10 times or more of ordinary concrete. It was concluded that the above problems can be solved by joining the work plates together to assemble the lining ring and disposing it on the lining surface of the existing tunnel. That is, the method for reinforcing a tunnel according to claim 1 of the present invention is to install a ring-shaped support member made of grooved steel on the lining surface of an existing tunnel, and between the support members, cement and a maximum particle size of 2 mm or less. Fine aggregates, pozzolanic reactive particles having an average particle size of 1 μm or less, metal fibers, quartz powder having an average particle size of 3 to 20 μm, fibrous or flaky reinforcing particles having an average particle size of 1 mm or less, a water reducing agent and water. After temporarily fixing a plurality of lining plates made of cementitious hardened body that is a cured product of the mixture, fix the lining plate by injecting a filler into the gap between the lining plate and the existing lining surface, It is characterized in that it is configured to reinforce the existing lining, the lining plate, high strength, and
By constructing a cemented hardened body that does not require reinforcement and prestressing, the lining plate can be made thinner and lighter in weight, so that manual construction can be facilitated and work efficiency can be significantly improved. It will be possible. In addition, since the lining plate of the present invention has high strength and can be thinned, the distance between the lining plate and the existing lining can be reduced, so that it is possible to reinforce the existing tunnel without violating the construction limit of the existing tunnel. Moreover, since the lining plate is extremely dense due to the inclusion of fine particles, neutralization and deterioration are suppressed,
Since the resistance to salt damage is also improved, it becomes possible to perform reinforcement having excellent strength and durability.

A method for reinforcing a tunnel according to claim 2 is
By selecting the addition amount of the pozzolanic reactive particles, metal fibers, quartz powder, reinforcing particles and the like, the length of the metal fibers, etc., the compressive strength of the cement hardened product is 180 MPa or more and the four-point bending strength is 30 MPa or more. It is characterized by doing
This makes it possible to make the lining plate thinner.

The tunnel reinforcing method according to claim 3 is characterized in that mortar or cement milk having a small shrinkage ratio is used as the filling material, whereby the lining ring and the existing lining ring are used. The lining surface can be integrated and the reinforcing effect of the existing lining can be further enhanced.

Further, the tunnel reinforcing method according to claim 4 is characterized in that the thickness of the central portion of the lining plate is made thinner than that of the peripheral portion thereof to further reduce the weight of the lining plate. .

The method for reinforcing a tunnel according to claim 5 is
It is characterized in that a packing for water stop is provided on the side surface side of the lining plate in order to cope with irregularity of shape due to construction error and to improve water stop. The tunnel reinforcing method according to claim 6 is characterized in that the surface of the lining plate is coated in order to prevent corrosion of the metal fibers exposed on the surface of the lining plate.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. FIG. 1 is a schematic diagram showing a method of reinforcing a tunnel according to an embodiment of the present invention. In this example, an existing lining 11 of an existing tunnel 10 to be reinforced and a subway 12 provided in the tunnel 10 are provided. A ring-shaped support member 14 made of channel steel is installed on the surface between the track base 13 and a plurality of lining plates 20 made of cement mortar mixed with metal fibers are joined to the support member 14. After constructing the lining ring 15 with the above, the filling material 16 such as mortar is injected between the surface of the existing lining 11 and the lining ring 15 to integrate the lining ring 15 and the existing lining 11 with each other. Then, the existing lining 11 is reinforced, and both ends (lowermost part) of the lining ring 15 are fixed to the existing lining 11 with anchors or the like, and the line base 13
Consolidate with concrete 17 etc.

2 (a) to 2 (c) are views showing an example of the construction of the lining plate 20. FIG. 2 (a) is a plan view, and FIGS. 2 (b) and 2 (c).
The drawings are a side view and a cross-sectional view taken along the line AA of FIG. The lining plate 20 is a rectangular plate having a concave cross section in which the wall thickness of the central portion 20a is made thinner than that of the peripheral portion 20b, and the side surfaces 20c to 20f thereof have a water blocking property for improving water blocking capability. A packing 21 is provided. Further, in this example, as shown in FIG.
20, the side surfaces 20c, 20d in the circumferential direction of the existing lining 11 are shaped such that one is convex and the other is concave, and the adjacent lining plates 20, with the packing 21 interposed therebetween,
20 are joined together. This makes it possible to cope with irregularities in the cross-sectional shape and prevent the corners of the lining plate 20 from being chipped during assembly. Reference numeral 22 is an insertion hole for a temporary fixing bolt, which will be described later, provided at the four corners of the peripheral portion 20b, and 23 is a grout hole for injecting the filler 16. The lining plate 20 having the grout holes 23 is prepared at a ratio of about one in five.

The lining plate 20 of the present invention comprises cement, fine aggregate having a maximum particle size of 2 mm or less, pozzolanic reactive particles having an average particle size of 1 μm or less, metal fibers, quartz powder having an average particle size of 3 to 20 μm, and average particles. It was made from a cementitious hardened body which is a hardened body of a mixture containing fibrous or flaky reinforcing particles having a diameter of 1 mm or less, a water reducing agent and water. In this example, the pozzolanic reactive particles, metal fibers and quartz powder were used. The amount of reinforcing particles added, the length of metal fibers, etc. are appropriately selected, and the compressive strength of the hardened cementitious material is 180 MPa or more and the four-point bending strength is 30 MPa.
It was set to MPa or more. With respect to the cement and the fine aggregate, in the hardened cementitious body, general types can be used without specifying their types.
At this time, as the fine aggregate, if the maximum particle size exceeds 2 mm, the strength development is deteriorated, so the maximum particle size is 2 mm.
It is desirable to keep below. Further, the amount of the fine aggregate added is preferably 50 to 250 parts by weight with respect to 100 parts by weight of cement in consideration of the strength to be obtained.

Examples of the pozzolanic reactive particles include silica fume, silica dust, fly ash, blast furnace slag, volcanic ash, silica gel, precipitated silica and the like.
Among these, silica fume and silica dust are
The average particle size is 1 μm or less, and crushing or the like is not required, which is advantageous in cost. The amount of the pozzolanic reactive particles added is preferably 5 to 50 parts by weight with respect to 100 parts by weight of cement in consideration of fluidity and strength development of the mixture.

Examples of the above-mentioned metal fibers include steel fibers and amorphous fibers, but it is desirable to use steel fibers because they are excellent in strength, easy to obtain, and advantageous in cost. The size of the metal fiber is preferably 2 mm or more, and more preferably 10 to 30 mm. The length / diameter ratio is preferably 20-200. This is because when the diameter is small, the strength of the fiber itself is insufficient, and it becomes easy to break when subjected to tension, and when the diameter is large, the number of fibers with the same compounding amount decreases, so the effect of improving bending strength decreases. To do. Also, as the length increases,
Fiber balls tend to form during kneading, and the length is 2
This is because if it is less than mm, the effect of improving the bending strength is reduced. The addition amount of this metal fiber is 0.
The amount is preferably 1 to 4%, preferably 0.5 to 3.5%. This is because if the content of the metal fibers is low, the bending strength is reduced, and if the content of the metal fibers is too large, the unit water content must be increased in order to ensure workability during kneading, resulting in a decrease in strength. Is.

Examples of the above-mentioned quartz powder include quartz, amorphous quartz, opalaceous and cristobalite silica-containing powders. The average particle size of the quartz powder is 3 to 20 μm, preferably 4 to 10 μm. If the average particle size of the quartz powder is outside the above range, the fluidity and strength development of the mixture will deteriorate. The blending amount of the quartz powder is preferably 5 to 50 parts by weight with respect to 100 parts by weight of cement in view of fluidity and strength development of the blend. The fibrous reinforcing particles include wollastonite fibers, bauxite fibers, mullite fibers, calcium titanate fibers, silicon carbide fibers, carbon fibers and the like, and the flaky reinforcing particles include mica flakes and talc. Flakes, vermiculite flakes,
There are alumina flakes and the like. The average particle size (length in the case of fiber) of these fibrous or flaky reinforcing particles is 1 m.
If it exceeds m, it becomes difficult to secure desired strength and toughness, so it is set to 1 mm or less. Further, the addition amount of these fibrous or flaky reinforcing particles is 5 to 3 with respect to 100 parts by weight of cement in order to secure desired strength and toughness.
Amounts of 5 parts by weight are suitable.

Examples of the water reducing agent (dispersing agent) include AE water reducing agents, high-performance water reducing agents, and high-performance AE water reducing agents, as well as lignin-based, naphthalenesulfonic acid-based, melamine-based, and polycarboxylic acid-based water reducing agents. Although it can be used, it is desirable to use a high-performance water reducing agent or a high-performance AE water reducing agent having a particularly large water reducing effect. If the amount of the water reducing agent added is too small, kneading becomes difficult, and if it is too large, the strength is reduced. Therefore, the amount of the water reducing agent is 0.5 to 2.5 parts by weight in terms of solid content based on 100 parts by weight of cement. It is desirable to do. The cementitious hardened product contains the water reducing agent in the above range, and thus has high fluidity in the uncured state (“JIS R
5201 (Method of testing physical properties of cement) 11. In the method described in “Flow test”, the flow value measured without performing 15 drop motions is 230 mm or more). The amount of water is 10 to 30 parts by weight, preferably 15 to 25 parts by weight, based on 100 parts by weight of cement. When the amount of water is less than 10 parts by weight, kneading becomes difficult and the fluidity of the mixture is lowered to deteriorate moldability. On the other hand, when the amount of water exceeds 30 parts by weight, strength is lowered.

According to the present invention, since the lining plate is made of the cementitious hardened material having a compressive strength of 5 times or more and bending strength of 10 times or more of that of ordinary concrete, the lining board 2 is used.
Since 0 can be made non-reinforcing and thin, and the lining plate 20 can be made lighter, manual construction becomes easier. Furthermore, the lining plate 2
Since 0 can be thinned, the distance between the lining plate 20 and the existing lining 11 can be reduced, and the existing tunnel 10
It is possible to reinforce without violating the building limits of In this example, as described above, the central portion 2 of the lining plate 20.
Since the rectangular concave portion is formed in 0a and the thickness of the central portion 20a is thinner than the thickness of the peripheral portion 20b, the weight of the lining plate 20 can be further reduced (see FIG. 2). Moreover, since the lining plate 20 is remarkably dense due to the inclusion of fine particles, neutralization and deterioration are suppressed, and resistance to salt damage is also improved. Therefore, reinforcement having excellent strength and durability is performed. be able to.

Next, a method of reinforcing a tunnel according to the present invention will be described. First, as shown in FIG. 3 (a), the channel steel 14 a is positioned in the circumferential direction of the existing lining 11 for positioning.
The ring-shaped support member 14 is assembled by connecting a plurality of joint sockets 14b with each other. In this example, since the lining plate 20 is arranged in the traveling direction of the tunnel, as shown in FIGS. 3B and 3C, the flange portions 14F of the two C-shaped steels 14C face in opposite directions. In addition, the positions are shifted from each other, the joints are joined by the anchor bolts 14p, and they are fixed to the existing lining 11 by the driven anchor bolts 14q. Note that one H-shaped steel may be used as the channel steel 14a. Next, as shown in FIGS. 4 (a) and 4 (b),
The lining ring 15 is constructed by mounting a plurality of lining plates 20 while assembling them in the circumferential direction of the support member 14. Specifically, the temporary fixing bolts 25 are inserted into the insertion holes 22 provided at the four corners of the lining plate 20 via the temporary fixing metal fittings 24, and the lining plate 20 is fixed to the flange portion of the channel steel 14a. Temporarily stop at 14F. At this time, since the upper surface of the lining plate 20 is attached so as to be located on the lower surface of the flange portion 14F, the lining plate 2
If it is attached while rotating 0, the lining plate 20
Can be easily installed while being assembled in the circumferential direction.

Then, as shown in FIG. 5 (a), after assembling a predetermined number of the lining rings 15, the back of the lining plate 20 into which the filling material 16 such as mortar is injected through the grout holes 23. Performing the filling work and the consolidation work, existing lining 1
By filling the gap with the surface 1 and integrating the plurality of lining rings 15 with the existing lining 11, the temporary fittings 24 (not shown) and the temporary fixing bolts 25 are removed.
As shown in FIG. 5B, the reinforcement of the existing lining 11 having the predetermined length is completed. The filling material 16 can be properly injected by providing the grout overflow hole 26 in the lining plate 20 at the top end of the lining plate 20. Here, as the filler 16, a mortar or cement milk having good injectability, low shrinkage rate, high fluidity, high early development strength, and strength equal to or higher than that of existing lining concrete. Is preferred. Thereby, the lining ring 15 and the existing lining 11 can be integrated, and the reinforcing effect of the existing lining 11 can be enhanced. In addition, in this example, the distance between the surface of the existing lining 11 and the lining plate 20 is the above C-type steel 14C.
Is regulated by the thickness of the backing layer, so that a uniform backing layer can be formed. That is, since the total thickness of the lining plate 20 and the back-filled filling material 16 can be set to about 50 mm to 100 mm, there are few places where wiring or piping such as the electric / communication cable 18 in the tunnel 10 needs to be refilled. Become. Finally, both ends (lowermost part) of the lining ring 15 are fixed to the existing lining 11 surface with anchors or the like,
The track base 13 is fixed with concrete 17 or the like.
Further, in order to prevent corrosion of the metal fibers exposed on the surface of the lining plate 20, it is desirable to apply coating to the surface of the lining plate 20. The coating may be applied in advance to at least the surface of the lining plate 20 on the inner side of the tunnel 10.

As described above, according to the present embodiment, the ring-shaped support member 14 made of the channel steel 14a is installed on the surface of the existing lining 11 of the existing tunnel 10 to be reinforced,
A plurality of lining plates 20 made of cement mortar mixed with existing metal fibers are temporarily fixed between the support members 14 to construct a lining ring 15, and then the existing lining 11 and the lining ring 15 are formed. Since the filling material 16 is injected between the lining ring 15 and the lining ring 15 so as to be integrated with each other to reinforce the existing lining 11, work efficiency can be improved and the existing lining 11 and Since the separation distance can be reduced, reinforcement can be performed without violating the construction limit of the existing tunnel. In addition, since the cement mortar has high compressive strength and bending tensile strength, the lining plate 20 can be made thin and lightweight. Therefore, it is possible to perform manual work, and it is possible to perform reinforcement having excellent strength and durability. Further, in this example, since the thickness of the lining plate 20 and the backfill layer is thin, there is an advantage that the places where the wiring and piping of the electric / communication cable 18 and the like in the tunnel 10 have to be relocated are reduced.

In this embodiment, the subway 12
In order to reinforce the tunnel 10 provided with the track base 13 and the like, a lining ring 15 having an open end was constructed, but it seems that the inner surface of the existing lining 11 is circular like a headrace tunnel. In that case, a closed lining ring may be constructed. Further, in the above example, the lining plate 20 having a rectangular plate shape with a concave sectional shape in which the wall thickness of the central portion 20a is thinner than that of the peripheral portion 20b is used. The shape and the like of the work plate is not limited to this, and may be appropriately determined depending on the shape and the like of the tunnel 10.

[0022]

As described above, according to the present invention, a ring-shaped support member made of channel steel is installed on the lining surface of an existing tunnel, and between the support members, five times that of ordinary concrete is provided. After temporarily fixing a plurality of lining plates made of a cementitious hardened body having the above-mentioned compressive strength and 10 times or more bending strength, a filler is injected into the gap between the lining plate and the existing lining surface. Since the lining plate is fixed to reinforce the existing lining, the concrete of the existing lining can be surely prevented from peeling off and the work efficiency can be improved. In addition, the lining plate can be made thinner and lighter, which not only facilitates manual work, but also makes it possible to reduce the separation distance from the existing lining by making it thinner, so the existing tunnel construction Reinforcement can be done without violating the limits.

[Brief description of drawings]

FIG. 1 is a diagram showing a method of reinforcing a tunnel according to the present embodiment.

FIG. 2 is a diagram showing a configuration of a lining plate according to the present embodiment.

FIG. 3 is a diagram showing a configuration of channel steel according to the present embodiment.

FIG. 4 is a diagram showing a method of attaching a lining plate.

FIG. 5 is a view showing a mounted state of a lining plate.

FIG. 6 is a diagram showing a conventional tunnel reinforcing method.

[Explanation of symbols]

10 Existing Tunnel, 11 Existing Lining, 12 Subway, 13 Track Base, 14 Supporting Member, 14a Channel Steel, 14b Joint Socket, 14C C Steel, 15 Lining Ring, 16 Filling Material, 17 Concrete Consolidation, 18 Cable, 20 lining plate, 20a Central part of lining plate, 20b Peripheral part of lining plate, 21 Water blocking packing, 22 Temporary fixing bolt insertion hole, 23 Grout hole, 24
Temporary fittings, 25 temporary fixing bolts, 26 grout overflow holes.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C04B 24:24 C04B 14:38 Z 14:38 22:06 A 22:06 14:06 Z 14:06) (72) Inventor Shinji Tsuchida 218-3 Kitajuku, Isayama, Shimodate-shi, Ibaraki Japan Concrete Industry Co., Ltd. (72) Inventor Makoto Katagiri 2-4-2 Daisaku, Sakura City, Chiba Central Research Institute, Pacific Cement Co., Ltd. (72) Inventor Tatsuro Hirayama 3-8-1 Nishikanda, Chiyoda-ku, Tokyo F-term in Taiheiyo Cement Co., Ltd. (reference) 2D055 BA00 BB01 BB02 CA00 GB01 GC01 JA00 KA01 KA02 KB07 LA16 4G012 PA04 PA15 PA19 PB26 PC03 PC12

Claims (6)

[Claims] 1. A ring-shaped support member made of channel steel is installed on the lining surface of an existing tunnel, and cement, fine aggregate with a maximum particle size of 2 mm or less, and pozzolan with an average particle size of 1 μm or less are provided between the support members. -Based reactive particles, metal fibers, average particle size 3 to 20
After temporarily fixing a plurality of lining plates made of cement powder, which is a hardened product of a mixture containing quartz powder of μm, fibrous or flaky reinforcing particles having an average particle size of 1 mm or less, a water reducing agent and water, A method for reinforcing a tunnel, characterized in that a filler is injected into a gap between a lining plate and an existing lining surface to fix the lining plate to reinforce the existing lining. 2. The hardened cementitious material is 180 MPa.
The method for reinforcing a tunnel according to claim 1, which has the above-mentioned compressive strength and a four-point bending strength of 30 MPa or more. 3. The tunnel reinforcing method according to claim 1, wherein the filler is mortar or cement milk having a small shrinkage. 4. The tunnel reinforcing method according to claim 1, wherein the thickness of the central portion of the lining plate is smaller than that of the peripheral portion. 5. The tunnel reinforcing method according to claim 1, wherein a packing for water blocking is provided on a side surface side of the lining plate. 6. The method of reinforcing a tunnel according to claim 1, wherein the surface of the lining plate is coated.