JP3250647B2 - Construction method of arched tunnel - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tunnel construction method suitable for use in constructing an arched tunnel mainly by a digging method or the like.

[0002]

2. Description of the Related Art Conventionally, in order to construct a tunnel by an open-cutting method or the like, a method of assembling a concrete formwork on the ground and casting concrete in the formwork on site to form a tunnel wall has been generally used. Was. However, on-site casting requires facilities and materials associated with casting, such as installing scaffolding to form the formwork, and installing shoring to support the scaffolding or casting concrete. Invite. In order to improve this point, a method of constructing a tunnel wall by sequentially installing and connecting precast concrete blocks manufactured in a factory in advance has been frequently used.

[0003]

However, in the method of connecting precast concrete blocks, when a large-scale large-section tunnel is to be constructed, the blocks become extremely thick accordingly.
To construct all of the tunnel walls with such blocks requires a great deal of labor in transport and installation. Also,
Emergency evacuation zones, emergency telephone equipment, fire extinguishing equipment, etc. are usually provided at regular intervals on the side wall of the tunnel, so blocks with complicated shapes corresponding to these are manufactured, and the installation sequence is managed accordingly. It also takes time and effort.

[0004] The present invention has been made in view of the above circumstances, and achieves both the simplicity of installation of an emergency evacuation zone on the side wall, an emergency telephone facility, a fire extinguishing facility, and the like, and the advantage of forming a tunnel wall by precast concrete. It aims to provide a construction method of an arched tunnel.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and has left and right side walls formed from the bottom of a tunnel to a substantially intermediate portion of a tunnel height by casting concrete in place. After forming and hardening the concrete, a pair of left and right parts are divided at the top, between the upper parts of the side walls.
Bridge a pair of precast concrete arc plates
Forming an installation top wall, and combining the side wall and the arc plate with each other,
The position of the pin provided on one of these
At least the pin head or pin
Rubber or other cushion on one of the positioning hole bottoms
Interposed between the side wall and the arc plate
At a slight gap between the side wall and the arc plate.
Fill the gap with mortar and cure, then
The tops of both the arc plates divided at the section are perpendicular to the division plane
Prestress is introduced by tensioning the penetrated PC steel
And the side wall and the arc plate are fastened and fixed.
It is characterized in that.

[0006]

[0007]

According to the present invention, the side wall up to about half the height of the tunnel is formed of cast-in-place concrete, and the top wall above this is formed of precast concrete. Therefore, the construction of a scaffold for casting on site is simplified, and the danger of casting concrete to the top can be avoided. Compared with the case where the entire wall of the tunnel is constructed of precast concrete, the labor required for transporting and installing the precast concrete is reduced. The installation space for emergency telephone equipment and fire hydrant equipment can be efficiently and easily formed by casting in place. Also, construct a highly rigid tunnel.
The earth pressure on the top wall composed of the arc plate
When an additional bending moment is generated,
Is made of prestressed PC steel
The axial force generated on the top wall is received by the concrete itself.
The joints against shear forces.
Counter with a pin inserted in the positioning hole
Is possible. In other words, the high rigidity of the entire arched tunnel
To resist various kinds of stress as described above
It is considered to be a tunnel that can be used. Also, at least
On either the head or the bottom of the pin positioning hole.
Insert a cushion such as rubber between the side wall and the arc plate.
Since it is installed with a slight gap, when installing the arc plate
Or, when prestress is introduced, the arc plate may
The rack is less likely to be damaged.

[0008]

FIG. 1 is a front view of a multi-way arched tunnel T constructed according to an embodiment of the present invention.
The procedure for constructing is described below.

First, a foundation 1 is laid on the ground G that has been cut and leveled by means of discarded concrete or the like. Next, on the foundation 1, a bottom portion 2, left and right end side walls 3, and a central side wall 4 for partitioning the left and right tunnel inner spaces T1, T2 are integrally formed by casting concrete in place. The height of the side walls 3 and 4 is set to be slightly higher than the middle of the tunnel height. The inner surfaces of the side walls 3 and 4 and the outer surface of the end side wall 3 are curved so as to form an arch shape. The upper surface of each of the side walls 3 and 4 is a surface on which an arc plate 5 described later is placed, and this upper surface is formed in a horizontal plane. The end side walls 3, 4 are arranged at regular intervals, as shown in FIG.
3 and a fire hydrant installation space 7 shown in FIG. 3, and an emergency evacuation space (not shown) is provided.

When the concrete at the bottom portion 2, the end side walls 3, 4 and the center side wall 5 is hardened, a pair of left and right precast concrete arc plates 5 are bridged from both the end side walls 3 and 4 to the upper surface of the center side wall 5. . The arc plate 5 is a set of a pair of right and left parts divided at the top, and forms the top walls 8 of the left and right tunnel inner spaces T1, T2, and is arranged in a large number in the tunnel length direction.

The arc plate 5 is a rectangular plate curved at a predetermined curvature and is manufactured in advance at a factory. At one end in the length direction (circumferential direction) of the arc plate 5, a joint portion 10 that fits and fits on the upper surface of the side walls 3, 4 is formed, and at the other end portion is a portion where the arc plates 5 abut each other. A top 11 is formed. As shown in FIGS. 4 to 6, a plurality of anchor bolt insertion holes 11 and positioning holes 12 are alternately formed at equal intervals in the joint portion 10. As shown in FIG. 6, the anchor bolt insertion hole 11 extends vertically in a state where the arc plate 5 is installed, and penetrates therethrough, and a counterbore 11a is formed at an upper portion. The positioning hole 12 is shown in FIG.
As shown in the figure, a predetermined depth is formed on the bottom surface side of the joint portion 10.

An anchor bolt 13 inserted into the anchor bolt insertion hole 11 and a pin 14 inserted into the positioning hole 12 are previously buried in the upper surface of each of the side walls 3 and 4 at the stage of forming the side walls 3 and 4. The pin 14 is made of steel, and its head is provided with a cushion 15 made of rubber or the like. Then, the anchor bolt 13 is inserted into the anchor bolt insertion hole 11.
Then, the arc plate 5 is placed on the side walls 3 and 4 by fitting the pins 14 into the positioning holes 12. The pin 14 has a clearance between the arc plate 5 and the side walls 3 and 4, and the mortar M is filled into the clearance and hardened to set the level.

A joint plate 30 is provided on the end face 5a of the top 20 of the arc plate 5 and the arc end face 5b along the length direction. As shown in FIG. The nuts 32 are connected to connect the left and right arc plates 5 and the arc plates 5 adjacent to each other in the tunnel length direction. At this stage, the bolts 31 and the nuts 32 are temporarily tightened to introduce prestress later, and are not tightly tightened to the end.

As shown in FIG. 7, PC steel rod insertion holes 21 are formed in the top portions 20 of the left and right arc plates 5 so as to be continuous with each other at right angles to the end surface 5a of the top portion 20 which is a dividing surface. And the continuous PC steel rod insertion holes 21
Then, a PC steel rod (PC steel material) 22 is passed through, and a tension is applied by nuts 23 screwed into both ends of the steel plate. The reaction force for tension is configured to be received by the bearing surface 24 a of the convex portion 24 bulging out from the arc plate 5. In addition to this, as shown in FIG.
a may be provided.

After the prestress is introduced into the tops 20 of the left and right arc plates 5 as described above, the joint plates 30 are completely fastened by the bolts 31 and the nuts 32. In addition, a nut 16 is screwed into the upper end protruding portion of the anchor bolt 13 passed through the anchor bolt insertion hole 11 in the joint portion 10, and the arc plate 5 is finally fixed to the side walls 3, 4.

When the installation and fixation of a large number of arc plates 5 on the side walls 3 and 4 are completed over the entire length of the tunnel as described above, the earth and sand are backfilled to form an underground tunnel.

In the method of constructing a tunnel according to the above method, the side walls 3 and 4, which are approximately half of the lower side of the tunnel wall, are formed by casting concrete in place, and the top wall 8 above this is precast concrete. It is formed by mounting an arc plate 5 made of steel. According to this method, since only the lower part is constructed by casting concrete in place, it is possible to simplify the scaffolding and to avoid the danger of casting concrete to the top. Further, as compared with the case where the entire wall of the tunnel is constructed of precast concrete, the side walls 3 and 4 are constructed by casting in place, so that the labor required for transporting and installing the arc plate 5 is reduced. This is particularly noticeable in the case of large-scale large-section tunnels. In addition, there is no need to manufacture a block having a complicated shape in order to provide a space for installing an emergency telephone and a fire hydrant, and to manage the installation order accordingly. These spaces can be formed more efficiently and easily by casting in place.

When a bending moment due to earth pressure or the like is generated in the top wall 8 constituted by the arc plate 5, the bending moment is received by a PC steel bar into which prestress has been introduced. The concrete itself receives the axial force (stress along the circumferential direction) generated on the top wall 8 and the side walls 3 and 4. Further, the structure in which the pin 14 is fitted into the positioning hole 12 at the joint 10 is opposed to the shearing force. In this way, since the structure has a structure against each stress, a tunnel wall having a sufficient strength is obtained.

The pin 14 of the joint 10 is positioned in the positioning hole 12.
Since the cushion 15 is attached to the head of the pin 14 when the arc plate 5 is installed or when the prestress is introduced as described above,
The arcuate plate 5 is less susceptible to damage such as scratches and cracks. Also,
The anchor bolts 13 and the pins 14 are buried in the mortar M and are isolated from the outside, so that they are prevented from rusting and deterioration due to rust is prevented.

[0020]

As described above, according to the arch type tunnel construction method of the present invention, the left and right side walls, which are formed from the bottom of the tunnel to the substantially middle portion of the tunnel height, are formed by casting concrete in place. After the concrete is hardened, an arc-shaped slab made of precast concrete is bridged between the upper portions of the side walls to form an installation top wall. Therefore, the construction of a scaffold for on-site casting is simplified, and concrete is cast to the top. The danger of installation of the precast concrete can be avoided.Compared to the case where the entire wall of the tunnel is constructed of precast concrete, the labor required for transporting and installing the precast concrete is reduced. Such an installation space has an effect that it can be efficiently and easily formed by casting in place. Ma
In addition, since a highly rigid tunnel can be constructed,
Earth pressure is applied to the top wall composed of the arc plate, and the bending moment is increased.
When this occurs, this bending moment is
Can be received with PC steel materials with
The axial force generated on the top wall must be received by the concrete itself.
And the joint is resistant to shear forces.
Counter with a pin inserted in the positioning hole
Can be. In other words, increasing the overall rigidity of the arched tunnel
To withstand the various types of stress described above.
The tunnel can be structured as follows. Also, at least
Is either the pin head or the bottom of the pin positioning hole
Then, a cushion such as rubber is interposed between the side wall and the arc plate.
An arc plate is installed because there is a slight gap between them
Or when pre-stress is introduced,
Damage such as cracks can be reduced.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a tunnel constructed by a method according to an embodiment of the present invention.

FIG. 2 is a front sectional view of a portion of the tunnel where a fire hydrant is installed.

FIG. 3 is a front sectional view of a portion of the tunnel where an emergency telephone installation space is provided.

FIG. 4 is a plan view of a joining portion of the arc plate to a side wall.

FIG. 5 is a sectional view taken along line PP of FIG. 4;

FIG. 6 is a sectional view taken along line QQ of FIG. 4;

FIG. 7 is a cross-sectional view showing a joint structure between tops of an arc plate by introducing prestress.

FIG. 8 is a cross-sectional view showing a joint structure between arc plates by a joint plate.

FIG. 9 is a cross-sectional view showing another example of the joining structure between the tops of the arc plate by introducing prestress.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Foundation, 2 ... Bottom part, 3 ... End side wall, 4 ... Central side wall, 5
... Arc plate, 6 ... Emergency telephone installation space, 7 ... Fire hydrant installation space, 8 ... Top wall, 10 ... Junction, 14 ... Pin, 15
... Cushion, 20 ... Top, 22 ... PC steel rod (PC steel), 30 ... Coupling plate, G ... Ground, T ... Tunnel.

──────────────────────────────────────────────────続 き Continuing from the front page (73) Patent holder 000150110 Takenaka Civil Engineering Co., Ltd. 8-21-1, Ginza, Chuo-ku, Tokyo (73) Patent holder 591041727 Aisawa Industry Co., Ltd. 1-5 Omoecho, Okayama-shi, Okayama Pref. No. 1 (73) Patent holder 000198307 Ishikawajima Building Materials Industry Co., Ltd. 1-212-1, Yurakucho, Chiyoda-ku, Tokyo (72) Inventor Mitsuo Saito 2-6-121 Yaesu, Chuo-ku, Tokyo Inside Ishikawajima Building Materials Industry Co., Ltd. (56) reference Patent flat 7-139295 (JP, a) JP Akira 59-145846 (JP, a) JP flat 2-91398 (JP, a) (58 ) investigated the field (Int.Cl. ⁷ , DB name) E21D 11/04

Claims (1)

(57) [Claims] 1. Left and right side walls formed from the bottom of a tunnel to a substantially middle part of the height of the tunnel are formed by casting concrete in place, and after the concrete is hardened , the left and right sides are divided at the top portion between the upper portions of the side walls. One-on-one precast
Overlay a concrete arc plate to form the installation top wall
The side wall and the arc plate are provided on one of them.
Pin into the pin positioning hole provided on the other side,
At least either the pin head or the bottom of the pin positioning hole
On the other hand, by interposing a cushion such as rubber,
Installed with a slight gap between the side wall and the arc plate
And, hard to fill the mortar into the gap between the arc plate and the side wall
And then the tops of both of the arc plates divided at the top
The PC steel material penetrated perpendicular to the dividing plane
Introduce the restless connection and connect with the side wall and circle
A method for constructing an arched tunnel, comprising fastening and fixing an arc plate .