JP2788952B2 - Large section tunnel - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-section tunnel, and more particularly, to a large-section tunnel in which a tunnel structure constituting the large-section tunnel is constructed in advance by a plurality of shield tunnels. About.

[Conventional technology]

A variety of tunnel construction methods have already been provided, but in particular, the shield method can be applied to all types of ground except hard rock, and it does not affect ground facilities and can be constructed deep underground. In recent years, in particular, the construction results have increased.

By the way, in recent years, underground use needs have increased, and accordingly, tunnels have also been required to have a large cross section.

Also, the above-mentioned shield tunnel is being constructed with a large diameter in order to respond to the demand for such a large cross section of the tunnel, and a shield machine having an outer diameter of 14 m or more has recently been planned. .

[Problems to be solved by the invention]

By the way, if an attempt is made to increase the cross section of the shield tunnel as described above, the size of the shield machine used for the tunnel will naturally increase.

However, it is generally said that when the excavation diameter of a shield machine becomes large, the weight increases due to the relationship of W = 2.5D ^{2 to} 3.5D ² (where D: outer diameter of the shield machine, W: weight of the shield machine). Such a large-sized shield machine not only becomes extremely heavy, but also requires a lot of manpower and cost in all aspects such as production, temporary assembly, transportation, on-site assembly, and on-site equipment. Become. In addition, especially in such an ultra-large shield machine, it is currently very difficult to even perform a trial run due to factory equipment and the like.

Accordingly, the present applicant has previously invented a large-section tunnel capable of increasing the tunnel cross-section at a high quality and at a low cost by effectively utilizing the advantages of the shield method, and has already filed an application for the same. No. 2-4074, "Large cross section tunnel and construction method thereof").

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has been made in connection with the foregoing invention. The object of the present invention is to make effective use of the advantages of the shield method to achieve high quality and low cost tunnels. An object of the present invention is to provide a large-section tunnel which can realize a large section and which is more robust and excellent in workability.

[Means for solving the problem]

According to the invention described in claim 1 of the present invention, a tunnel structure that forms an internal space against the earth pressure of a ground formed in an arch shape or a cylindrical shape, and is formed inside the tunnel structure. A tunnel having a large cross section including a tunnel space, wherein the tunnel structure is formed with a preceding shield tunnel formed along a longitudinal direction of the tunnel to be constructed and at a predetermined interval in a radial direction, and The shield tunnel is formed by overlapping a part of the lining body of the adjacently formed shield tunnel with each other, and furthermore, the shield tunnel is formed by the above-mentioned shield tunnel. Is characterized in that it is formed thicker in the overlapping portion with the following shield tunnel than in the non-overlapping portion.

According to a second aspect of the present invention, in the large-section tunnel according to the first aspect, at least the lining body of the preceding shield tunnel includes a tubular structure assembled by segments, A back-filled hardening filler material that is post-punched on the back side of the structure, and furthermore, the tubular structure avoids interference with the following shield tunnel at an overlapping portion with the following shield tunnel. It is characterized by being formed in a concave shape.

[Action]

Since the tunnel structure is constituted by the shield tunnel, the preceding construction of the tunnel structure is possible.

In addition, by structurally integrating a large number of shield tunnels, high rigidity and high water shielding of the tunnel structure can be expected. In addition, by forming the lining of the preceding shield tunnel to be thick at the overlapping portion with the following shield tunnel, the overlapping portion between the preceding shield tunnel and the following shield tunnel can be enlarged, and the tunnel structure of the tunnel structure can be enlarged. The rigidity can be further improved.

Further, in the large-section tunnel according to the second aspect, the concave portion of the tubular structure of the preceding shield tunnel acts as a guide when excavating the following shield tunnel.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of a large-section tunnel according to claim 2 of the present invention.

This large-section tunnel (hereinafter abbreviated as “tunnel”) 1 includes a tunnel structure 2 which is formed in a cylindrical shape as a whole and forms an internal space against the earth pressure of the ground G, and a tunnel structure 2 And a tunnel space 3 formed in the inside of the vehicle.

The tunnel structure 2 is formed of a large number of shield tunnels 4 formed adjacent to each other in the longitudinal direction of the tunnel 1 to be constructed. Also, the shield tunnels 4, 4,... Are formed at predetermined intervals as shown in FIG. 2 and the subsequent shield tunnels 4A, 4A,. It consists of a shield tunnel 4B. In the present embodiment, these shield tunnels 4, 4,.
The rear shield tunnel 4B) is arranged in a ring shape in the radial direction, so that the tunnel structure 2 has a cylindrical shape with a circular cross section as a whole.

Further, in this embodiment, both the leading shield tunnel 4A and the trailing shield tunnel 4B constituting the tunnel structure 2 have a tubular structure 6 assembled by a large number of segments 5, 5,. The structure 6 is covered with a backing 20 made of a hardening filler (backfill hardening filler) 7 such as concrete or mortar, which is post-punched on the back side. However, the diameter of the cylindrical structure 6 is smaller than the inner diameter of the excavation hole 8 excavated by the shield machine as a whole as compared with a general shield tunnel.

Also, each shield tunnel 4 is separated from the adjacent shield tunnel 4 by a distance (preceding shield tunnel).
The distance between the shield tunnel 4A and the subsequent shield tunnel 4B) is set to be smaller than the outer diameter of the shield tunnel 4 itself. Has become.
Thus, the hardened filler 7 (the lining 20) of each of the shield tunnels 4, 4,... Is continuously integrated.

Further, in the tubular structure 6 constituting the lining body 20 of the shield tunnel 4, the tubular structure 6 of the succeeding shield tunnel 4B has a circular cross section in the same manner as an ordinary ordinary tubular structure assembled by segments. Although the cylindrical structure 6 (6 ') constituting the preceding shield tunnel 4A is partially formed inside the cylindrical body in a cross section as shown in FIG. It is formed in a curved concave shape. Here, the concave portion 6a of this cylindrical structure 6 '
Is formed on a portion that interferes with the trailing shield tunnel 4B when the tubular structure 6 ′ is formed in a cylindrical shape, whereby the tubular structure 6 ′ and the trailing shield tunnel 4B are connected to each other. The structure avoids interference.

The outer diameter of the tunnel 1 having the above configuration is 20 here.
~ 40m, and the outer diameter of each shield tunnel 4 is about 0.7
~ 4m.

The construction of the tunnel 1 having the above configuration is performed by the following steps.

First, a tunnel structure 2 composed of a large number of shield tunnels 4, 4,. The construction of the tunnel structure 2 is performed by the following steps.

That is, first, of the shield tunnels 4, 4, ..., which are adjacent to each other at the time of completion shown in Fig. 1, every other preceding shield tunnel 4A, 4A, ... is constructed (see Fig. 3).

The construction of these preceding shield tunnels 4A can be performed in almost the same manner as the ordinary shield method. That is, as shown in FIG. 7, the shield machine 10 is propelled while excavating the ground G by the cutter 11 provided on the front surface thereof, and the arc-shaped segment 5 is inserted into the excavation hole 8 behind the shield machine 10. , 5,... Are assembled to form a tubular structure 6 (6 ′).

However, in this case, a shield machine having a tail void significantly larger than that of a normal shield machine is used as the shield machine 10, whereby the cylindrical structure 6 'is formed to have a smaller diameter than the inner diameter of the excavation hole 8. Has become. In addition, the concave portion 6a of the tubular structure 6 'is used to connect the segment 5 of the portion where the concave portion 6a is to be formed with the excavation hole 8
Are formed so as to be convex toward the center side (so that the outer surface side is concave). In the portion where the tubular structure 6 'is formed, the backfill hardening filler 7 is cast in the space on the back side, that is, between the tubular structure 6' and the excavation hole 8. Thereby, the lining body 20 is completed. The arrow in FIG. 7 indicates the state of the backfill hardening filler 7 being placed. As shown in FIG. 4, the lining body 20 of the preceding shield tunnel 4A completed as described above has a portion corresponding to the concave portion 6a of the tubular structure 6 'formed thicker than other portions. It was done.

When the preceding shield tunnels 4A, 4A,... Are formed in the ground G as described above, the succeeding shield tunnels 4B, 4B,.

As shown in FIG. 5, the process of forming the succeeding shield tunnel 4B is almost the same as that of the preceding shield tunnel 4A.
However, since the distance between the leading shield tunnels 4A, 4A,... Is set smaller than the diameter of the shield tunnel 4 itself as described above, the two leading shield tunnels 4A, 4A,.
When forming the succeeding shield tunnel 4B between A and 4A, together with the ground G between the preceding shield tunnels 4A, a part of the hardened filler 7 constituting the preceding shield tunnels 4A and 4A on both sides is simultaneously used. Excavate (cut).

At this time, since the tubular structure 6 'constituting the lining body 20 of the preceding shield tunnel 4A has a portion where the following shield tunnel 4B is formed in the concave portion 6a in advance,
The shield machine 10 excavating the trailing shield tunnel 4B can cut only the hardened filler 7 without interfering with the tubular structure 6 '. In addition, the concave portion 6a functions as a guide for the shield machine 10 when excavating the following shield tunnel 4B. Thereby, the shield machine 10 can excavate along a predetermined line between the preceding shield tunnels 4A. In particular, in the present embodiment, as described above, when excavating the trailing shield tunnel 4B, the backfill hardening filler 7 of the preceding shield tunnel 4A is also cut together with the ground, so that the excavation resistance of the shield machine 10 is small. There is a fear of escaping to the mountain side (being out of the space between the preceding shield tunnels 4A), but the above configuration can prevent such a situation. In addition, the distance between the shield tunnels 4A and 4B can be reduced because the trailing shield tunnel 4B bites into the concave portion 6a, and the integration of the shield tunnels 4A and 4B can be more firmly achieved. .

As described above, the shield machine 10 excavates between the two preceding shield tunnels 4A, 4A, and assembles the cylindrical structure 6 in the excavation hole 8 ', and then backfills the hardened filler material on the back side. If the lining body 20 is formed by casting 7,
As shown in FIG. 6, subsequent shield tunnels 4B, 4B,... Are formed continuously with the preceding shield tunnels 4A, 4A,.

By the way, in this construction method, a part of the hardened filler 7 of the preceding shield tunnel 4A is thus replaced with the following shield tunnel.
Since the backfill hardening filler 7 constituting the preceding shield tunnel 4A has a small initial strength and a strength that increases with time because the backfill hardening filler 7 constituting the preceding shield tunnel 4A is cut by the shield machine 10 together with the ground when forming 4B. It is more desirable to use those having properties. As another means, for example, setting delay concrete is used as the backfill hardening filler 7 of the preceding shield tunnel 4A, and after the subsequent shield tunnel 4B is constructed, high-temperature air (for example, 70 ° C. or more) is introduced into the preceding shield tunnel 4A. It is also possible to adopt a method such as feeding the required strength. At this time, the supply of the high-temperature air is performed by the cylindrical structure 6 '.
You can use the internal space. The backfill hardening filler 7 for the trailing shield tunnel 4B is preferably made of high-strength concrete.

When the tunnel structure 2 is constructed by the shield tunnels 4, 4,... As described above, the portion of the ground G surrounded by the tunnel structure 2 is excavated to form the tunnel space 3. For example, the target tunnel 1 as shown in FIG. 1 is completed. Excavation of the ground inside the tunnel structure 2 is performed by a generally used excavator. However, since the tunnel structure 2 has already been constructed and the ground G is supported by the excavator, no support work or the like is required. No need to provide.

According to the tunnel 1, since the tunnel structure 2 is constituted by a large number of shield tunnels 4, 4,... Having a small diameter, a tunnel space 3 having a large cross section can be reliably formed. Further, the shield tunnels 4 that are continuously provided to form the tunnel structure 2 are connected to the shield tunnels 4.
Since the backfill hardening filler 7 (lining body 20) constituting the above is integrated by overlapping each other, it is possible to make the tunnel structure 2 extremely high in strength and excellent in water shielding. it can. Moreover, since the concave portion 6a is formed in the tubular structure 6 'of the succeeding shield tunnel 4B at the overlapping portion of the leading shield tunnel 4A and the succeeding shield tunnel 4B, the distance between the shield tunnels 4A and 4B is reduced. As a result, a stronger integration of the tunnel structure 2 can be achieved,
When excavating the trailing shield tunnel 4B,
6a can be used as a guide for shield machines.
Further, as described above, since the tunnel structure 2 is configured by the shield tunnel, it can be applied to all grounds to which the shield method can be applied. Moreover, since the shield machine 10 to be used only needs to be very small, the cost of the shield machine can be significantly reduced.
For this reason, efficient construction can be achieved using a plurality of shield machines 10.

In constructing the tunnel 1, the preceding shield tunnels 4A, 4A,... Do not necessarily have to form the following shield tunnel 4B after all of them are formed. , At least two side-by-side leading shield tunnels 4A, 4A
May be sequentially formed between the preceding shield tunnels 4A at the time of formation.

Next, FIG. 8 shows a second embodiment of the large-section tunnel according to claim 2 of the present invention. The same components as those in the previous embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The tunnel 1 ′ according to the present embodiment is different from the tunnel 1 in that a shield tunnel 4 constituting a tunnel structure 2 is provided.
The inside of the cylindrical structures 6, 6 'is filled with a hardened filler 9 such as concrete or mortar. Other configurations are the same as those of the tunnel 1.

According to the tunnel 1 ', the rigidity of the tunnel structure 2 can be further improved as compared with the tunnel 1 in the previous embodiment.

To construct the tunnel 1 ', in the construction process of the tunnel 1 in the previous embodiment, after forming the following shield tunnel 4B following the preceding shield tunnel 4A as described above, each of the shield tunnels 4, 4,. The hardening filler 9 may be cast in the tubular structure (lining body 20). Alternatively, for the preceding shield tunnel 4A, the hardened filler 9 may be filled in the tubular structure 6 (the lining body 20) before the formation of the following shield tunnel 4B.

Next, FIG. 9 shows an embodiment of a large-section tunnel according to claim 1 of the present invention, which shows a part of a tunnel structure 2. In the figure, the same components as those of the above embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

The lining of the shield tunnel 4,4, ... shown in the above embodiment
20 is the cylindrical structure 6 (6 ') and the backfill hardening filler 7
In contrast, in the present embodiment, the lining body 20 of each of the shield tunnels 4, 4,... It has become. That is,
In this case, the lining body 20 is formed by a cast-in-place lining method without using segments. However, the point that the overlapping portion of the lining body 20 of the preceding shield tunnel 4A and the following shield tunnel 4B is formed to be thicker than the non-overlapping portion is the same as in the above embodiment. That is, in the tunnel structure 2 according to the present embodiment, the cast-in-place concrete 14 (the lining body 20) overlaps between the adjacent shield tunnels 4.

Other configurations are the same as those shown in the above embodiment.

In addition, in order to form the tunnel structure 2 in the present embodiment, similarly to the above, the leading shield tunnel 4 is formed.
A, 4A,... Are preliminarily constructed, and between the preceding shield tunnels 4A, the subsequent shield tunnels 4B, 4B, while cutting a part of the cast-in-place concrete 14 (lining body 20) of the preceding shield tunnel 4A. Just build 4B, ...

In the tunnel structure 2 according to the present embodiment, unlike the tunnel structure 2 shown in the above embodiment, the shield tunnel 4
Since the lining body 20 does not have the cylindrical structure 6 ', the guiding action of the shielding machine by the cylindrical structure 6' when excavating the following shield tunnel 4B cannot be expected, but the shield according to the present invention The tunnels 4, 4,... May be formed by the cast-in-place lining method as described above. Of course, it may be formed by another lining method. Also, for example, of the shield tunnels, 4,..., Only the preceding shield tunnel 4A is formed by the segment lining method, and the subsequent shield tunnel 4B is formed.
May be formed by a cast-in-place lining method. As described above, the construction method of the shield tunnel according to the present invention is not limited, and the point is that, of the shield tunnels 4, 4,. Is formed in a portion where the second shield tunnel 4B overlaps the second shield tunnel 4B, and the second shield tunnel 4B is overlapped with the thicker portion to form a strong tunnel structure. Also in the tunnel structure 2 in FIG. 9, it is of course possible to fill the inside of the lining 20 of each shield tunnel 4 with a hardening filler.

In each of the above embodiments, both the tunnels 1 and 1 '(tunnel structure 2) have been described as having a circular cross section. However, the large cross section tunnel according to the present invention is not limited to a circular cross section. Of course, it is also possible to form a horseshoe, a semicircle, or other cross-sectional shapes. In this case, the formation position (overlapping position) of each of the shield tunnels 4, 4,... To be connected may be determined so that the tunnel structure 2 formed by the shield tunnels 4 has a predetermined cross-sectional shape.

Further, in each of the above embodiments, the structure in which the tunnel structure 2 is closed in a cylindrical shape in the longitudinal section has been described. However, the large-section tunnel according to the present invention is, for example, as shown in FIG. Only a part of the tunnel structure 2 (the upper half in the illustrated example) may be constituted by the tunnel structure 2. In that case, the bottom of the tunnel (invert part)
Then, the concrete 12 may be cast, and the concrete 12 may be reinforced with a lock bolt (not shown).

〔The invention's effect〕

As described above, according to the large-section tunnel according to claim 1 of the present invention, the tunnel structure is constituted by a large number of small-diameter shield tunnels, so that a large-section tunnel space can be reliably formed. In addition, the shield tunnels that constitute the tunnel structure and are connected in succession are integrated by overlapping a part of the lining body that constitutes the shield tunnel, thereby making the tunnel structure with extremely high strength. In addition, it is possible to achieve excellent water shielding. Further, at this time, since the lining body of the preceding shield tunnel is formed thick in the overlapping portion, the overlapping dimension between the shield tunnels can be increased, and the rigidity of the tunnel structure can be increased. Also, since the tunnel structure is composed of a shield tunnel,
The shield method can be applied to all grounds to which the shield method can be applied, and furthermore, the shield machine to be used can be extremely small, so that the cost of the shield machine can be greatly reduced. For this reason, efficient construction can be achieved using a plurality of shield machines.

Further, according to the large-section tunnel according to claim 2 of the present invention, a concave portion is formed on the tubular structure constituting the lining body of the following shield tunnel at the overlapping portion of the preceding shield tunnel and the following shield tunnel. Claim 1
In addition to the effects described in the above, this concave part can be used as a guide for the shield machine when excavating the subsequent shield tunnel, thereby preventing the shield machine from coming off the predetermined excavation line and improving the construction efficiency. Various excellent effects such as improvement and securing of tunnel quality can be achieved.

[Brief description of the drawings]

FIG. 1 is a front sectional view showing a first embodiment of a large-section tunnel according to claim 2 of the present invention, FIG. 2 is a partial front sectional view showing a tunnel structure according to the present embodiment, and FIGS. FIG. 6 illustrates a method of constructing a tunnel structure according to the present embodiment, and FIG. 7 is a side view showing an example of a construction state of a shield tunnel constituting the tunnel structure. FIG. 8 is a front cross-sectional view showing a second embodiment of the large-section tunnel according to claim 2 of the present invention, and FIG. 9 is an embodiment of the large-section tunnel according to claim 1 of the present invention. FIG. 10 is a partial front sectional view of a tunnel structure, and FIG. 10 is a front sectional view showing another configuration example of a large-section tunnel. G: Mt. Chiyama, 1,1 ': Large tunnel, 2: Tunnel structure, 3: Tunnel space, 4: Shield tunnel, 4A: Shield tunnel, 4B: Shield tunnel, 5 ... segment, 6,6 '... tubular structure, 6a ... concave part, 7 ... backfill hardening filler, 20 ... lining body.

────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kiharu Miyake 2-16-1 Kyobashi, Chuo-ku, Tokyo Shimizu Construction Co., Ltd. (72) Inventor Atsushi Denda 2-161 Kyobashi, Chuo-ku, Tokyo Shimizu (56) References JP-A-3-293500 (JP, A) JP-A-59-18896 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) E21D 13 / 02 E21D 13/00 E21D 9/04 E02D 29/04

Claims (2)

(57) [Claims] 1. A tunnel having a large cross section comprising a tunnel structure formed in an arched or cylindrical shape and forming an internal space against the earth pressure of the ground, and a tunnel space formed inside the tunnel structure. The tunnel structure comprises: a preceding shield tunnel formed along a longitudinal direction of a tunnel to be constructed and at a predetermined interval in a radial direction; and a following shield tunnel formed between the preceding shield tunnels. And these shield tunnels are integrated by a part of the lining bodies of the adjacently formed shield tunnels overlapping each other, and the lining body of the preceding shield tunnel is A large-section tunnel characterized by being formed thicker at an overlapping portion with a row shield tunnel than at a non-overlapping portion. 2. The large-section tunnel according to claim 1,
At least the lining body of the preceding shield tunnel is composed of a tubular structure assembled by segments, and a backfill hardening material that is post-punched on the back side of the tubular structure. A large-section tunnel, wherein the structure is formed in a concave shape to avoid interference with the following shield tunnel at an overlapping portion with the following shield tunnel.