JPH0932486A - How to build an arched tunnel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate installation of an emergency telephone facility, a fire extinguishing facility, etc., on side walls and to provide the advantages of forming tunnel walls from precast concrete. SOLUTION: Side walls 3, 4 are formed by in-situ concrete placing, and a top wall is formed by circular plates 5 installed across the side walls 3, 4. Spaces for installing emergency telephones and fire hydrants can be formed efficiently in the in-situ placed portions, and the work of transporting and installing the circular plates 5 is simplified.

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 constructing an arched tunnel mainly by an excavation method or the like.

[0002]

2. Description of the Related Art Conventionally, in order to construct a tunnel by an excavation method or the like, a method of assembling a concrete formwork on the ground and placing concrete in the formwork on site to form a tunnel wall has been generally used. It was However, on-site pouring requires equipment and materials associated with pouring, such as setting up scaffolding to form a formwork, and supporting structures to support scaffolding or pouring concrete. It also invites As a method for improving this point, a method of constructing a tunnel wall by sequentially installing and connecting precast concrete blocks manufactured in advance in a factory has been widely used.

[0003]

However, in the method of connecting precast concrete blocks, when constructing a large-scale large-section tunnel, the blocks become extremely thick accordingly,
To construct all of the tunnel walls with such blocks requires a great deal of labor for transportation and installation work. Also,
Since the evacuation zone, emergency telephone equipment, fire extinguishing equipment, etc. are usually installed at regular intervals on the side wall of the tunnel, blocks with complicated shapes are manufactured according to these, and the installation sequence is also managed accordingly. It takes time and effort to do it.

The present invention has been made in view of the above circumstances, and makes it easy to install an emergency evacuation zone on a side wall, emergency telephone equipment, fire extinguishing equipment, and the like, and achieve the advantages of forming a tunnel wall by precast concrete. The purpose is to provide a method for constructing an arched tunnel.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above object, and the left and right side walls formed from the bottom of the tunnel to the middle of the height of the tunnel can be cast by concrete on site. After forming and hardening the concrete, an arc top plate made of precast concrete is laid across the upper portions of the side walls to form an installation top wall.

[0006] In addition, a precast concrete circular arc plate forming the top wall is divided into a pair of left and right ones divided at the top.
Composed in pairs. Further, in the above method, the joint between the side wall and the arcuate plate has a structure in which a pin provided on one of these is fitted into a pin positioning hole provided on the other, and at least either the pin head or the pin positioning hole bottom is formed. On the other hand, a cushion such as rubber is interposed, or the tops of both arc plates divided at the top are connected by tensioning the PC steel material that penetrates perpendicular to the dividing surface to introduce prestress. To do.

[0007]

According to the present invention, the side wall up to about half the height of the tunnel is made of cast-in-place concrete, and the top wall above it is made of precast concrete. Therefore, scaffolding for on-site pouring can be simplified, and the risk of pouring concrete up to the top can be avoided. Compared to the case where the entire wall of the tunnel is constructed with precast concrete, the labor required for transporting and installing precast concrete is reduced. In addition, the installation space for emergency telephone equipment and fire hydrant equipment can be efficiently and easily formed by on-site casting.

[0008]

FIG. 1 is a front view of a multi-way arched tunnel T constructed by the method of one embodiment.
The procedure for constructing is described below.

First, the foundation 1 is laid on the ground G, which has been ground by excavation, by means such as discarded concrete. Next, a bottom 2, left and right end side walls 3, and a central side wall 4 for partitioning the left and right tunnel inner cavities T1 and T2 are integrally formed on the foundation 1 by in-situ casting of concrete. The height of the side walls 3 and 4 is set to be slightly higher than the middle portion of the height of the tunnel. 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 to be described later is placed, and the upper surface is formed to be a horizontal surface. As shown in FIG.
The emergency telephone installation space 6 shown in FIG. 3 and the fire hydrant installation space 7 shown in FIG. 3 are provided, and an emergency evacuation space not shown is provided.

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

The arc plate 5 is a rectangular plate body that is curved with a predetermined curvature, and is manufactured in advance in a factory. At one end of the arc plate 5 in the length direction (circumferential direction), there is formed a joint 10 that fits on the upper surfaces of the side walls 3 and 4, and at the other end of the arc plate 5 where the arc plates 5 are butted. The 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 in the joint portion 10 at equal intervals. As shown in FIG. 6, the anchor bolt insertion hole 11 extends in the vertical direction and penetrates in a state where the arc plate 5 is installed, and a counterbore 11a is formed in the upper portion. The positioning hole 12 is shown in FIG.
As shown in, a predetermined depth is formed on the bottom surface side of the joint 10.

An anchor bolt 13 that is inserted through the anchor bolt insertion hole 11 and a pin 14 that is inserted into the positioning hole 12 when the side walls 3 and 4 are formed are embedded in the upper surfaces of the side walls 3 and 4, respectively. The pin 14 is made of steel, and a cushion 15 made of rubber or the like is attached to its head. Then, the anchor bolt 13 is inserted into the anchor bolt insertion hole 11.
Then, the circular plate 5 is placed on the side walls 3 and 4 by inserting the pin 14 into the positioning hole 12 through. The pin 14 has a height such that there is a gap between the arc plate 5 and the side walls 3 and 4, and the mortar M is filled into the gap and cured to set the level.

A joint plate 30 is provided on the end surface 5a of the top portion 20 of the arc plate 5 and the arc end surface 5b along the lengthwise direction. As shown in FIG. The nuts 32 are coupled 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 in order to introduce prestress later, and are not tightened until the end.

As shown in FIG. 7, PC steel rod insertion holes 21 are formed in the tops 20 of the left and right circular arc plates 5 and are continuous with each other at a right angle to the end face 5a of the top 20 which is a dividing surface. Then, the PC steel rod insertion holes 21, 21 that are continuous
A PC steel rod (PC steel material) 22 is passed through and is tightened by nuts 23 screwed into both ends, thereby introducing a pre-stress in the left-right direction to the tops 20 of the left and right arc plates 5. The reaction force due to the tension is received by the seat surface 24a of the convex portion 24 that is bulged on the arc plate 5. In addition to this, as shown in FIG.
a may be provided.

After the prestress is introduced into the top portions 20 of the left and right arc plates 5 as described above, the joint plates 30 are completely fastened with the bolts 31 and the nuts 32. Further, the nut 16 is screwed into the upper end projecting portion of the anchor bolt 13 which is passed through the anchor bolt insertion hole 11 at the joint portion 10, and finally the arc plate 5 is fixed to the side walls 3 and 4.

After the installation and fixing of the large number of arc plates 5 on the side walls 3 and 4 is 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 the lower half of the tunnel wall, are formed by in-situ casting of concrete, and the top wall 8 of the upper side is precast concrete. It is formed by installing the arc-shaped plate 5 made of aluminum. According to this method, since only the lower part is constructed by concrete pouring at the site, scaffolding for that purpose can be simplified and the risk of pouring concrete up to the top can be avoided. 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 the field, so that the labor required for the transportation and installation work of the arc plate 5 is reduced. This is especially remarkable in the case of large-scale large-section tunnels. Further, it is not necessary to manufacture a block having a complicated shape in order to provide an emergency telephone installation space or a fire hydrant installation space, and to manage the installation sequence accordingly. These spaces can be formed more efficiently and easily when cast on site.

When a bending moment due to earth pressure or the like is generated in the top wall 8 constituted by the arcuate slab 5, the bending moment is received by the prestressed PC steel rod. Further, 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. Furthermore, the structure in which the pin 14 is fitted into the positioning hole 12 at the joint portion 10 opposes the shearing force. In this way, since the structure resists each stress, the tunnel wall has sufficient strength.

The pin 14 of the joint portion 10 has a positioning hole 12
In the structure fitted in, since the cushion 15 is attached to the head of the pin 14, when the arc plate 5 is installed or when prestress is introduced as described above,
The arc plate 5 is less susceptible to damage such as scratches and cracks. Also,
Since the anchor bolt 13 and the pin 14 are filled with the mortar M and are shielded from the outside, they are rust-proof and are prevented from being deteriorated due to rust.

[0020]

As described above, according to the method for constructing an arch-type tunnel of the present invention, the left and right side walls that are formed from the bottom of the tunnel to the substantially middle portion of the tunnel height are formed by concrete pouring on site. After the concrete is hardened, a circular plate made of precast concrete is laid across the upper part of the side wall to form a top wall for installation, which simplifies the construction of scaffolding for on-site pouring and drives concrete up to the top. You can avoid the danger of installing it, and reduce the labor required for transporting and installing this precast concrete as compared to constructing the entire wall of the tunnel with precast concrete. Such an installation space has an effect that it can be efficiently and easily formed by on-site casting.

[Brief description of 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 having a fire hydrant installation space.

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

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

5 is a cross-sectional view taken along the line PP of FIG.

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

FIG. 7 is a cross-sectional view showing a joint structure between tops of arc-shaped plates 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 a joining structure between the tops of arc-shaped plates by introducing prestress.

[Explanation of symbols]

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

 ─────────────────────────────────────────────────── ─── Continuation of the front page (71) Applicant 000150110 Takenaka Civil Engineering Co., Ltd. 8-21-1 Ginza, Chuo-ku, Tokyo (71) Applicant 591041727 Aisawa Industry Co., Ltd. 1-5-1 Omotemachi, Okayama City, Okayama Prefecture (71) Applicant 000198307 Ishikawajima Building Materials Co., Ltd. 1-12-1 Yurakucho, Chiyoda-ku, Tokyo (72) Inventor Mitsuo Saito 2-6-21 Yaesu, Chuo-ku, Tokyo Ishikawajima Building Materials Co., Ltd.

Claims (4)

[Claims] 1. The left and right side walls that are formed from the bottom of the tunnel to the middle of the height of the tunnel are formed by in-situ casting of concrete, and after the concrete is hardened, an arc plate made of precast concrete is hung between the upper parts of the side walls. A method for constructing an arched tunnel, which comprises passing and forming an installation top wall. 2. The construction of an arch-shaped tunnel according to claim 1, wherein the precast concrete circular arc plates forming the top wall are a pair of left and right divided at the top. Method. 3. The joint between the side wall and the arc plate has a structure in which a pin provided on one of the side walls is fitted into a pin positioning hole provided on the other side, and at least a pin head portion or a pin positioning hole bottom portion is formed. A method of constructing an arch-shaped tunnel according to any one of claims 1 and 2, characterized in that a cushion of rubber or the like is interposed in either one of them. 4. The top parts of both of the arc plates divided at the top part are connected by tensioning a PC steel material penetrating perpendicularly to the dividing surface to introduce prestress. Item 2. The method for constructing an arched tunnel according to item 2.