Propulsion box and method for manufacturing the same

Abstract

The present invention provides a propulsion box and a method for manufacturing the same, which, when a launching platform is formed in a launching tunnel and concrete is poured on the launching platform to manufacture a propulsion box, prevents the propulsion box and the launching platform from becoming one and preventing propulsion from becoming impossible, or prevents the box from being damaged when thrust is applied, thereby enabling efficient propulsion. [Solution] The front and rear surfaces are open, and the concrete jacking box is a horizontally oriented cylindrical structure consisting of an upper floor plate 9a, a lower floor plate 9b, and left and right wall plates 9c, 9d. A shaped edge-cutting material 14 is placed on the bottom surface of the concrete jacking box 9.

Description

Technical Field

[0001] The present invention relates to a propulsion casing used in a propulsion method and a method for manufacturing the same.

Background Art

[0002] In a propulsion method in which a large underground structure made of reinforced concrete is dug horizontally as a propulsion casing under railways, roads, etc., the content thereof is also shown in the following patent documents.

Patent Document 1

[0003] As shown in FIG. 9, sheet pile walls 2 are driven beside the upper traffic 1 such as railways, and a launching pit 3 and a receiving pit 4 are constructed. A press-fitting machine (not shown) is installed in the launching pit 3, and a roof steel pipe 5 having a box-shaped cross-section is press-fitted toward the receiving pit 4. The press-fitting machine has an extrusion mechanism using a jack or the like for the roof steel pipe 5 and an internal excavation mechanism for the roof steel pipe 5 using an auger or the like.

[0004] The roof steel pipe 5 is a box-shaped cylindrical body having a substantially square cross-section, and a friction cutter plate 6 made of a flat steel plate is placed on the upper surface. Such roof steel pipes 5 are press-fitted one by one.

[0005] A launching platform 7 is formed in the launching pit 3, a reaction wall 8 and a concrete casing 9 as a propulsion casing as an underground structure are set, a strut 17 and a primary propulsion jack 10 are provided between the reaction wall 8 and the concrete casing 9, and a cutting edge 11 is provided at the tip of the concrete casing 9.

[0006] A small jack 12 for pushing out the roof steel pipe 5 is disposed between the tip of the concrete casing 9 and the rear end of the roof steel pipe 5. Also, the rear end of the friction cutter plate 6 is fixed to the launching pit 一侧 by a stopper member 13, and a temporary support is provided on the receiving pit 4 side.

[0007] The friction cutter plate 6 is released from its locking mechanism with respect to the front end of the roof steel pipe 5. The propulsion jack 10 is extended to take reaction force from the reaction wall 8 and excavate the concrete box structure 9. At the same time, the small jack 12 is used to push the roof steel pipe 5 ahead of the concrete box structure 9. The friction cutter plate 6 is left in the ground at this time.

[0008] By advancing the roof steel pipes 5 and concrete box bodies 9 while leaving the friction cutter plates 6 in place, these roof steel pipes 5 and concrete box bodies 9 move while disconnected from the ground, thus avoiding frictional resistance due to soil pressure.

[0009] Furthermore, in order to excavate the concrete box structure 9, the front of the cutting edge 11 is excavated, but this work is protected by the roof steel pipe 5, so it can be carried out safely without the risk of soil collapse. The tip of the roof steel pipe 5 that comes out into the receiving shaft 4 is supported by a temporary support stand, and the fastenings with bolts and nuts are released and removed one piece at a time.

[0010] Regarding the method of propelling the concrete box structure 9, a reaction force receiving member and a center-hole type towing jack can be installed on the receiving tunnel 4 side, and the underground structure 9 can be pulled in from the receiving tunnel 4 side by pulling a towing member made of PC steel wire, one end of which is fixed to the underground structure with an anchoring device, with this towing jack. Alternatively, the front end of the concrete box structure 9 can be used to directly push the roof steel pipe 5 without installing the small jack 12. [Overview of the project] [Problems that the invention aims to solve]

[0011] The concrete box body 9, which serves as the jacking box, is assembled on the launching platform 7 inside the launching shaft 3. A strut 17 and a push jack 10 are placed between the reaction wall 8 and the concrete box body 9. A cutting edge 11 is provided at the tip of the concrete box body 9, and the push jack 10 is extended to advance the jacking.

[0012] The launch platform 7 is constructed with a foundation of crushed stone and concrete laid on top of it. Although it is separated from the concrete box 9, the frictional resistance when pushing out the concrete box 9 is high, and there is a risk that the concrete box 9 may be damaged.

[0013] As a countermeasure, when constructing a concrete box 9 by pouring concrete onto the launching platform 7, it is conceivable to install some kind of barrier between the bottom of the box and the launching platform in order to propel it after construction. However, even if steel plates are used as the barrier, for example, there is no established technology for how to install them on the launching platform.

[0014] Even if steel plates are laid on the launching platform as a barrier, the method of fixing them is problematic, and there is a risk that they may move and shift along with the launching concrete box 9.

[0015] The object of the present invention is to overcome the disadvantages of the conventional example and to provide a propulsion box and a method for manufacturing the same that, when a launching platform is formed in a launching shaft and concrete is poured on the launching platform to manufacture a propulsion box, there is no risk of the propulsion box and the launching platform becoming integrated and preventing propulsion after manufacturing, or the box being damaged when thrust is applied, thereby enabling efficient propulsion. [Means for solving the problem]

[0016] To achieve the above objective, the present invention as described in claim 1 is a propulsion box having open front and rear surfaces, and is a horizontally oriented cylindrical concrete propulsion box consisting of an upper floor plate, a lower floor plate, and left and right wall plates, with a similarly shaped edge-cutting material placed on the bottom surface of the propulsion box. To achieve this, the edge-cutting material is welded to the inside with a shear connector, which is then integrated with the bottom surface of the concrete jacking box. This is the gist of it.

[0017] According to the present invention as described in claim 1, since a demarcation material of the same shape is placed on the bottom surface of the propulsion box, this demarcation material can separate the bottom surface of the box from the launching platform, allowing the propulsion box to be smoothly pushed out without frictional resistance. Moreover, since the bottom surface of the box is covered with the demarcation material, damage can also be prevented.

[0018] Also, a shear connector is welded to the inside of the edge cutting material, and by integrating it with the bottom surface portion of the concrete propulsion casing through this, the edge cutting material moves integrally during the extrusion of the propulsion casing, enabling smooth extrusion.

[0019] The present invention according to claim 2 has a gist that the shear connector is a framework made of stirrups, and this framework is welded inside the edge cutting material.

[0020] According to the present invention described in claim 2, when the shear connector is made of stirrups, making it a framework saves the labor of welding each one by one. Also, by making it a framework, the stirrups are grouped together and formed into a single structure, and can be placed within a concentrated range, so it can be installed efficiently.

[0021] The present invention according to claim 3 has a gist that before placing concrete, an edge cutting material having the same shape as the bottom surface portion of the propulsion casing is installed on the starting platform, and reinforcement bars are arranged and concrete is placed thereon to fabricate the propulsion casing.

[0022] According to the present invention described in claim 3, to arrange an edge cutting material having the same shape on the bottom surface portion of the propulsion casing, reinforcement bars are arranged and concrete is placed on the edge cutting material to fabricate the propulsion casing, so the arrangement of the edge cutting material can be easily performed.

[0023] The present invention according to claim 4 has a gist that the edge cutting material is used as a part of the formwork for concrete placement.

[0024] According to the present invention described in claim 4, by using the edge cutting material as a part of the formwork for concrete placement, a part of the formwork set for fabricating the propulsion casing can be omitted, and the labor for fabrication can be saved.

Advantages of the Invention

[0025] As described above, in the propulsion casing of the present invention and its manufacturing method, when a launching pad is formed in the launching pit and concrete is placed on the launching pad to manufacture the propulsion casing, after the manufacturing, when propelling the propulsion casing, there is no risk that the propulsion casing and the launching pad are integrated and propulsion becomes impossible, or that the casing is damaged when a thrust is applied. As a result, efficient propulsion can be achieved.

Brief Description of the Drawings

[0026] [Figure 1] It is a perspective view showing one embodiment of the propulsion casing of the present invention. [Figure 2] It is a front view showing one embodiment of the propulsion casing of the present invention. [Figure 3] It is a perspective view showing a first example of the edge cutting material used in the propulsion casing of the present invention. [Figure 4] It is a perspective view showing a second example of the edge cutting material used in the propulsion casing of the present invention. [Figure 5] It is a perspective view showing a third example of the edge cutting material used in the propulsion casing of the present invention. [Figure 6] It is a perspective view showing a first example of the Dibel bars used in the propulsion casing of the present invention. [Figure 7] It is a perspective view showing a second example of the Dibel bars used in the propulsion casing of the present invention. [Figure 8] It is a perspective view showing a third example of the Dibel bars used in the propulsion casing of the present invention. [Figure 9] It is a perspective view showing an example of the propulsion method.

Embodiments for Carrying Out the Invention

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing one embodiment of the propulsion casing of the present invention, FIG. 2 is a front view thereof, and in the figure, 9 indicates a concrete casing as the propulsion casing.

[0028] The concrete box structure 9 is a horizontally oriented cylindrical concrete jacking box structure with open front and rear surfaces, consisting of an upper floor plate 9a, a lower floor plate 9b, and left and right wall plates 9c and 9d.

[0029] In this invention, a demarcation material 14 of the same shape is placed on the bottom surface below the lower floor plate 9b of the concrete box body 9, which is the propulsion box body.

[0030] The edge-cutting material 14 is made of steel plate and has a channel shape with side walls 14a on both sides that are raised on the left and right.

[0031] Furthermore, the edge-cutting material 14 has a shear connector, a dowel bar 15, welded to its inside, and is integrated with the bottom surface of the concrete box body 9 via this dowel bar 15.

[0032] As shown in Figure 6, the dowel reinforcement bars 15 are rod-shaped members with horizontal legs 15a on the left and right sides, and a trapezoidal bend in the middle to form a convex portion 15b. As shown in Figure 3, these legs 15a are used as welding points and are arranged side by side with spacing between them.

[0033] Furthermore, it is preferable that the orientation of the dowel reinforcement bars 15 be directed in the direction in which the concrete box structure 9 is being propelled.

[0034] As another embodiment of the dowel reinforcement 15, as shown in Figure 7, single dowel reinforcement 15s as shown in Figure 6 may be arranged opposite each other with a gap between them, and connecting reinforcement 16 may be placed between them to form a ladder-like frame. Such a frame is prepared in advance and welded to the edge-cutting material 14.

[0035] Figure 8 shows another example of a frame assembly using the dowel bars 15, where three dowel bars 15 are placed side by side and connecting bars 16 are placed across them to form a ladder-like structure.

[0036] Figures 4 and 5 show the edge-cutting material 14 with dowel bars 15 installed.

[0037] Next, a method for manufacturing the concrete box body 9, in which the edge-cutting material 14 is placed on the bottom surface, will be described.

[0038] The concrete box structure 9 was fabricated by pouring formwork concrete in the launching shaft 3. Prior to this fabrication, a demarcation material 14, identical in shape to the bottom surface of the concrete box structure 9, was placed on the launching platform 7 of the launching shaft 3. Reinforcement bars and concrete were then poured on top of this to fabricate the concrete box structure 9.

[0039] In this case, the edge-cutting material 14 is used as part of the formwork for concrete pouring, and the edge-cutting material 14 is incorporated into the formwork.

[0040] A demarcation material 14 is placed at the bottom of the concrete box structure 9, and when it is propelled by the jacking jack 10 to excavate, this demarcation material 14 is also propelled at the same time. [Explanation of Symbols]

[0041] 1…Upper traffic 2…Steel sheet pile earth retention 3...Starting pit 4...Arrival pit 5... Steel pipe for roofing 6... Friction cutter plate 7... Launching platform 8... Reaction wall 9...Concrete box structure 9a...Upper floor slab 9b…Bottom floor board 9c,9d…Left and right wall boards 10…Propulsion jack 11…Blade opening 12...Small jack 13...Stopping member 14... Edge separation material 14a... Side wall 15...Gibber's muscle 15a...Leg 15b...Convex part 16...Connecting muscle 17... Strut

Claims

1. This propulsion box is a horizontally oriented cylindrical concrete jacking box with open front and rear surfaces, consisting of an upper floor plate, a lower floor plate, and left and right wall plates. A shear connector of the same shape is placed at the bottom surface of the propulsion box, and the shear connector is welded to the inside of the shear connector, thereby integrating it with the bottom surface of the concrete propulsion box.

2. The shear connector is a frame made of dowel bars, and the propulsion box according to claim 1, wherein this frame is welded to the inside of the edge-cutting material.

3. A method for manufacturing a concrete box for a tunneling method, characterized in that, before concrete pouring, a demarcation material having the same shape as the bottom surface of the tunneling box is placed on a launching platform, and then reinforcement and concrete are poured on top of this to manufacture the tunneling box.

4. A method for manufacturing a concrete box for a pipe jacking method according to claim 3, wherein the edge-cutting material is used as part of the formwork for concrete pouring.

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