JP3494253B2 - Concrete box for underground structure construction - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a concrete box used for constructing an underground structure such as an underground passage for laying water and sewage systems, common ditches, telegraphs and telephones in urban areas.

[0002]

2. Description of the Related Art There are various construction methods for constructing such an underground structure using a concrete box, but a so-called open-cut method (open-cut method in which the concrete box is sequentially hung and hung down) Construction method) and the construction of a starting shaft, and the propulsion method that pushes the concrete box in order from here to the ground, and the open shield method that makes the best use of the open cutting method and the shield method.

FIG. 5 shows the outline of the open shield construction method. In the figure, 11 is an open shield machine, which is composed of left and right side wall plates 11a and 11b and a bottom plate 11c which connects the side wall plates 11a and 11b, and the front and rear end faces and the upper face are opened. It is a shield machine. In the open shield machine 11, the propulsion jacks 12 are arranged side by side in the vertical direction facing backward. In the figure, 13 indicates a partition wall provided inside the shield machine 11.

By installing this shield machine 11 in the starting pit,
The earth and sand in front of the start pit is excavated from the front surface or the upper surface opening of the shield machine 11, and the earth is discharged. Then, the propulsion jack 12 of the shield machine 11 is extended, a reaction force is applied to the reaction force wall in the starting pit to advance the shield machine 11, and the concrete box 1
The second one is suspended from above and set behind the propulsion jack 12 which is contracted in the tail portion 11d of the shield machine 11.

Then, similarly, the excavating means 14 such as a shovel, an auger, and a bucket is used to excavate the earth and sand from the front surface or the upper surface of the shield machine 11 and discharge the soil to move the shield machine 11 forward, and the first concrete box body. The second concrete box 1 is hung in front of 1. After that, the same excavation and setting process of the concrete box 1 is repeated to sequentially bury the concrete boxes 1 in the column in the ground and backfill the back of the concrete box 1 with the open shield machine 11. When it reaches the reaching pit, remove it and complete the construction.

In any of the construction methods including the open shield construction method, the concrete box 1 used is composed of an upper floor slab 2, a left side wall slab 3, a right side wall slab 4, and a lower floor slab 5 as shown in FIG. In principle, the internal penetrating portion that opens at is rectangular in cross section, but the corners are often chamfered to form a haunch 6.

Although not shown in the drawing, such concrete boxes 1 are arranged in a column, and a small through hole penetrating in the front-rear length direction is provided at a corner portion where the haunch 6 is located. Insert the tension material such as PC steel wire to fix the tension.

By the way, the size of the concrete box 1 is somewhat different, but the height is about 1 to 2 m and the width is 1 to 3 m.
The length is about 1 to 3 m, which is quite large. Therefore, it is different in size and application from the circular concrete fume pipe.

[0009]

In such a concrete box 1, the left side wall slab 3 and the right side wall slab 4 are compressed when the force from the propulsion jack 12 for advancing the shield machine 11 is applied. Then, a bending moment is applied to the upper floor slab 2 and the lower floor slab 5, and cracks 10 may be formed on the end faces thereof.

An object of the present invention is to solve the disadvantages of the above-mentioned conventional example and prevent concrete from being cracked in the end faces of the upper floor slab and the lower floor slab when receiving a propulsive force from a jack. It is to provide a box.

[0011]

In order to achieve the above object, the present invention comprises left and right side wall plates and a bottom plate connecting the side wall plates.
Open the front and rear end faces and the top face, and push the propulsion jack backward.
Using an open shield machine that is placed side by side vertically
As the one used for the open shield construction method ,
The left and right side wall slabs, the lower floor slab, and the rectangular cross-section penetrating part that opens in the front and back are the corners of the concrete box that is chamfered to form the end face of the upper and lower floor slabs. In between the left side wall slab and the right side wall slab, a recess that forms a gap when joining the concrete boxes is formed so that the end faces of the upper floor slab and the lower floor slab are thinly cut out, and, The recesses should be formed on either one of the front and rear end faces of each concrete box, or the recesses should be formed on every other front and back end faces of the continuous concrete box. The main point is to dispose a sealing material.

[0012]

According to the present invention as set forth in claim 1, the concrete boxes are joined together by a recess provided between the left side wall slab and the right side wall slab at the end faces of the upper and lower slabs of the concrete boxes. At this time, a gap is formed between the end faces of the upper floor slab and between the end faces of the lower floor slab. As a result, the end faces of the upper floor slab and the lower floor slab do not come into surface contact with each other and cannot be pressed, so when the force of the propulsion jack for advancing the shield machine is applied, the left wall slab, the right side slab Even when the wall slab is in a compressed state, there is no fear that a bending moment is applied to the upper floor slab and the lower floor slab, and as a result, no crack is generated.

According to the second aspect of the present invention, the recesses are formed on one of the front and rear end surfaces of each concrete box so that all the concrete boxes can be manufactured to the same standard. You can

According to the third aspect of the present invention, the recesses are formed on every other front and rear end surfaces of the continuous concrete box, so that the recesses can be combined with a conventional product in which the recesses are not formed. Become.

According to the fourth aspect of the present invention, by disposing the sealing material in the recess, it is possible to prevent water leakage and water leakage.

[0016]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a perspective view showing a first embodiment of a concrete box for constructing an underground structure of the present invention, and FIG. 2 is a plan view of the same.

The concrete box 1 of the present invention is also composed of an upper floor slab 2, a left side wall slab 3, a right side wall slab 4, and a lower floor slab 5, as in the above-mentioned conventional example. Although it has a rectangular cross section, corners are chamfered to form a haunch 6.

In the present invention, a recess 7 is formed between the left side wall plate 3 and the right side wall plate 4 at the end faces of the upper floor plate 2 and the lower floor plate 5. The recess 7 may have a thickness of several millimeters or a dozen millimeters, and is like a thin cutout of the end faces of the upper floor slab 2 and the lower floor slab 5.

As shown in FIG. 2, the recess 7 is formed on one of the front and rear end faces of each concrete box 1.

As described above, the concrete boxes 1 are arranged in a column, and a small through hole penetrating in the longitudinal direction is provided at the corner where the haunch 6 is located. Although a tension member such as the above is inserted and fixed by tension, a gap is formed between the end faces of the upper floor slab 2 and between the end faces of the lower floor slab 5 by the recess 7.

Because of this clearance, the end surfaces of the upper floor slab 2 and the lower floor slab 5 do not come into surface contact with each other and cannot be pressed. Therefore, for example, in the open shield construction method, the shield machine 11 is advanced as shown in FIG. Even if the left side wall slab 3 and the right side wall slab 4 are compressed when a force is applied by the propulsion jack 12 for the purpose, there is no possibility that a bending moment is applied to the upper floor slab 2 and the lower floor slab 5. As a result, no crack is generated.

As shown in FIG. 4, the recess 7 is provided with a water-swellable rubber sealant mainly composed of a water-swellable composition or a sealant 8 made of a rubber seal such as butyl rubber.
The sealing material 8 serves as a water stop measure against water leakage and water intrusion through the recess 7.

As the sealing material 8, it is possible to combine both a water-swelling rubber sealing material and a normal rubber sealing material, and in consideration of the balance with the sealing material 9 arranged on the joint surface between the concrete boxes 1. decide.

FIG. 3 is a plan view showing a second embodiment of the present invention, in which the recesses 7 are formed on the front and rear end surfaces of every other concrete box 1 among the continuous concrete boxes 1. .

In this case, it can be used in combination with a conventional type concrete box in which the recess 7 is not formed.

[0026]

As described above, the concrete box for constructing an underground structure of the present invention can prevent the end faces of the upper floor slab and the lower floor slab from being cracked when receiving a propulsive force from a jack. It is a thing.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a concrete box for constructing an underground structure of the present invention.

FIG. 2 is a plan view showing a first embodiment of the concrete box for constructing an underground structure of the present invention.

FIG. 3 is a plan view showing a second embodiment of the concrete box for constructing an underground structure of the present invention.

FIG. 4 is a cross-sectional plan view showing the first embodiment of the concrete box for constructing an underground structure of the present invention.

FIG. 5 is an explanatory diagram showing an outline of an open shield construction method.

FIG. 6 is a perspective view showing a conventional example.

[Explanation of symbols]

1… Concrete box 2… Upper deck 3 ... Left side wall version 4 ... Right side wall version 5 ... Lower floor version 6 ... Haunch 7 ... Recess 8 ... Sealing material 9 ... Sealant 10 ... Crack 11 ... Open shield machine 11a, 11b ... Side wall plate 11c ... Bottom plate 11d ... Tail part 12 ... Propulsion jack 13 ... Bulkhead 14 ... Excavation means 15 ... Backfill

   ─────────────────────────────────────────────────── ─── Continued front page       (56) References JP-A-63-75229 (JP, A)                 57-174584 (JP, U)                 Actual Kohei 5-45660 (JP, Y2)

Claims (4)

(57) [Claims] 1. A left and right side wall plate and a bottom plate connecting between the side wall plates
The front and rear end faces and the top face are opened, and the propulsion jack is
Use an open shield machine that is arranged vertically side by side
As used in the open shield construction method, it consisted of an upper floor slab, a left side wall slab, a right side wall slab, and a lower floor slab. In the box, between the left side wall slab and the right side wall slab at the end faces of the upper floor slab and the lower floor slab, a recess is formed between the upper floor slab and the lower floor slab to form a gap when joining the concrete boxes. A concrete box for constructing an underground structure, characterized in that the end face is formed as a thin notch. 2. The concrete box for constructing an underground structure according to claim 1, wherein the recess is formed on one of the front and rear end surfaces of each concrete box. 3. The concrete box for constructing an underground structure according to claim 1, wherein the recesses are formed on every other front and rear end surfaces of the continuous concrete box. 4. The sealing material is provided in the recess.
A concrete box for constructing an underground structure according to claim 3.