JPH08312284A - Device for fixing vertical-shaft earth-retaining wall and method for drilling vertical shaft - Google Patents

Abstract

PURPOSE: To firmly hold and fix an earth-retaining wall in place even through manual operations, when drilling a vertical shaft while extending the earth- retaining wall by joining of a liner plate to a drilled part as drilling proceeds. CONSTITUTION: After natural ground 10 is leveled, a linear plate 11 is circumferentially placed and joined on the surface of the ground at a vertical shaft drilling position so as to temporarily install the above-ground part of an earth-retaining wall. A grounding plate 2 is attached to a lower flange of the liner plate 11, and a top plate 3 is attached to an upper flange of the liner plate 11. The grounding plate 2 is connected to the top plate 3 by a leg 4. Three or more fixing devices are mounted to hold and fix the earth retaining wall in place. As subsequent drilling proceeds, the linear plate 11 is joined so as to extend the earth retaining wall into the vertical shaft to drill the vertical shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fixing device for a shaft retaining wall and a method for excavating a shaft.

[0002]

[Prior Art] Roads, Mountains, Farmlands, Railways, Bridges, Foundations,
Vertical shafts are excavated in various fields such as dams, sewage, electric power, and gas. When excavating a vertical shaft, it is generally assumed that a retaining wall is constructed to prevent the collapse of sediment, and a liner plate with flanges on the four sides of a corrugated steel plate is often used for the retaining wall. .

FIG. 4 is a perspective view of the liner plate (a).
And a corrugated steel plate 12 as shown in the widthwise sectional view (b).
Flanges 13, 1 having connecting holes 16, 17 on the four sides of
4 and 15 are provided, and a cylindrical earth retaining wall can be configured by abutting them in the vertical and horizontal directions and bolting them through the connecting holes 16 and 17.

FIG. 5 concretely shows how the liner plate 11 is assembled to construct the earth retaining wall 22 while excavating a vertical shaft. First, as shown in FIG.
A circular hole 2 with a depth equivalent to the width of one liner plate
1 is dug into the circular hole 21 as shown in FIG.
By arranging the liner plate 11 vertically and joining it in the circumferential direction, the uppermost one step of the earth retaining wall 22 is constituted. Backfill the soil in the gap between the retaining wall 22 and the ground 10,
Keep it compact. After that, as shown in FIG. 7C, the liner plate 11 is further dug by the width of the liner plate 11, and the liner plate 11 is vertically arranged below the uppermost earth retaining wall and joined in the circumferential direction. The earth retaining wall of the step is constructed. When the liner plate 11 is connected to the excavated portion and the earth retaining wall 22 is extended by repeating this operation, a vertical shaft having a predetermined depth can be excavated as shown in FIG.

[0005]

The method of connecting the liner plate to the excavated portion and extending the soil retaining wall in this way is called root joint. In the root joint, the weight of the soil retaining wall is supported by the excavated portion. Therefore, it is necessary to support the weight of the retaining wall at the top of the retaining wall. However, as shown in FIG. 5, only by backfilling the soil around the uppermost part of the retaining wall and compacting the soil, the soil in the refilling portion may be loosened during the lower excavation, and the retaining wall should be sufficiently retained. It cannot be fixed. If the retaining wall is not held and fixed properly and the verticality is lost, the excavation direction cannot be maintained accurately.

In order to solve this problem, conventionally, for example, as shown in FIG. 6, a method of assembling a support beam 23 on a retaining wall 22 to form a cross beam and suspending and retaining the entire retaining wall 22 with the support beam 23 has been proposed. there were. In addition, as shown in FIG. 7, the retaining wall 22
There was also a method of filling concrete 24 around the uppermost part of and hardening it. However, as the vertical section increases,
The work of handing over the support beams 23 becomes impossible by manpower, and a crane is required, and more concrete 24 is required for holding and fixing. Vertical shafts are often excavated in places where it is difficult to bring in large machinery and materials, such as in the mountains, and these methods were not sufficient measures.

In Japanese Patent Publication No. 62-11157, as shown in FIG. 8, fixing metal fittings 25 shown in FIG. 9 are attached to a plurality of places around the upper end 22a of the uppermost retaining wall 22 for fixing. A method is described in which the metal fitting 25 is extended to the outside of the digging pit to hold the uppermost retaining wall 22. According to this method, a heavy object such as a crane is not required at the time of assembling, and it can be assembled only by human power, and the entire material is lightened.

However, in the fixing metal fitting 25 shown in the publication, the portion protruding from the fixing portion 25a to the outside is the holding rod 25b, which does not have a large ground contact area and has a cantilever structure. Not enough to fix. When the earth retaining wall is heavy, it is said that it is effective to attach the auxiliary support 25c as shown in FIG. 9 (b). However, because of the attachment of the auxiliary support 25c, the surrounding natural ground is extra. It has to be dug, and the work efficiency is insufficient.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a vertical shaft earth retaining wall fixing device and a vertical shaft excavating method which can be carried by human power, have high efficiency in installation work, and can securely hold and fix an earth retaining wall.

[0010]

The fixing device for a shaft retaining wall according to the present invention is attached to a lower flange of a liner plate constituting a ground portion of the retaining wall, a ground plate contacting the surface of the earth, and an upper flange of the liner plate. It is a fixing device for a vertical shaft earth retaining wall, characterized in that a top plate attached to is connected by legs. A slip stopper is preferably provided below the outer periphery of the ground plate.

Further, the shaft excavating method of the present invention is a shaft excavating method in which a soil retaining wall is extended by joining a liner plate to the excavated portion as the shaft excavating progresses. By arranging and joining liner plates circumferentially on the surface of the shaft excavation position, the above-ground part of the earth retaining wall is temporarily installed, and the fixing device of the shaft earth retaining wall of the present invention is fixed through the upper and lower flanges of the liner plate.
This is a method for excavating a vertical shaft, in which at least one retaining wall is attached and fixed, and then a liner plate is joined to the excavated portion as the excavation proceeds to extend the retaining wall into the vertical shaft.

[0012]

Actions and Examples The actions will be described with reference to the examples of the present invention.

As shown in FIG. 1, the vertical shaft retaining wall fixing device of the present invention is constructed by connecting the ground plate 2 and the top plate 3 by the leg portions 4.

The ground plate 2 is for contacting with the surface of the earth and for holding the weight of the earth retaining wall which extends downward as the excavation of the shaft progresses and for fixing the earth retaining wall. For this purpose, in the case of a holding method of a cantilever structure with a small ground contact area such as the holding rod described in Japanese Patent Publication No. 62-11157, the load is concentrated on the connecting portion between the earth retaining wall and the fixing metal fitting. It is not effective because it causes deformation.

The top plate 3 and the legs 4 of the fixing device of the present invention.
Is for strengthening the connection between the fixing device and the liner plate. That is, the grounding area is widened and the connecting portion with the liner plate is the grounding plate 2 and the top plate 3, and the grounding plate 2 and the top plate 3 are connected by the leg portions 4 to form an integrated structure. Since the load of the retaining wall is transmitted to the entire surface of the grounding plate 2, it can be stably fixed to the ground.

The reason why the top plate 3 and the leg portions 4 are reinforced in this way is to avoid the need to newly dig the ground for reinforcement. If the reinforcing member is provided above the ground plate 2, it is not necessary to dig the ground. However, since a place to connect the top plate 3 to the upper side is required, when excavating using the fixing device of the present invention, the earth retaining wall for one stage of the liner plate is temporarily installed on the ground surface. This temporary earth retaining wall functions to protect the excavation work area, specifically to prevent the topsoil from falling off and to prevent work tools from falling off, thus ensuring the safety of the drilling operator. On the liner plate side of the ground plate 2 and the top plate 3, connection holes 5 and 6 corresponding to the connection holes of the flange of the liner plate are provided. As shown in FIG. 2, the ground plate 2 is the ground portion of the earth retaining wall. Liner plate 1
It is attached to the lower flange 13 of No. 1 by bolt connection and brought into contact with the ground surface, and the top plate 3 is attached to the upper flange 14 of the liner plate 11 by bolt connection so that the weight of the whole earth retaining wall is transmitted by both plates.

The lower side of the ground plate 2 may be flat, but it is preferable to provide a slip stopper 7 as shown in FIGS. 1 and 2 because it is effective in preventing horizontal movement of the earth retaining wall.
The slip stopper 7 may be a member continuous in the circumferential direction,
It may be provided intermittently.

The shape of the ground plate 2 and the top plate 3 on the side of the liner plate is a straight line in the example of FIGS. 1 and 2, but as shown in FIG. 3, it is curved according to the shape of the liner plate 11. I don't mind.

Although the leg 4 is a plate in the illustrated example, it may be a shaped steel, a rod, a pipe or the like. Further, welding or bolting can be used to connect the leg 4 to the top plate 3 and the ground plate 2.

Regarding the size of the fixing device for the shaft earth retaining wall of the present invention, the ground plate 2 is attached to the lower flange of the liner plate, and the top plate 3 is attached to the upper flange of the liner plate. It is necessary to have the same dimension as the width of one sheet, for example, 500 mm, but there is a degree of freedom for the other portions, and the width w and the length L can be set as appropriate in consideration of the strength of the natural ground. is there.

The fixing device of the shaft earth retaining wall of the present invention is not particularly large as compared with the liner plate, and even if it is excavated in a place such as a mountain area where the working conditions and working conditions are poor, the manpower is sufficient for carrying and installing. It is possible with. In particular, when the legs are connected to the top plate and the ground plate by bolts, it is advantageous that they can be disassembled compactly, transported, and assembled on site.

A steel plate may be used as the material of the fixing device for the shaft retaining wall of the present invention similarly to the liner plate, and for example, a steel plate having a thickness of 9 mm may be used.

The method for excavating a shaft according to the present invention is a method for excavating a shaft while holding and fixing the earth retaining wall, using the fixing device for the earth retaining wall of the shaft according to the present invention. First, as shown in FIG. 3, after the ground 10 is leveled to secure a horizontal portion, the liner plate 1 is circumferentially formed on the surface of the shaft excavation position.
By arranging and joining 1 above, the aboveground part of the retaining wall is temporarily installed. Then, three or more fixing devices 1 for a shaft earth retaining wall of the present invention are attached through upper and lower flanges of the liner plate 11 to hold and fix the earth retaining wall. In addition, in FIG.
The state where three pieces are attached to the left and right and the other side while four pieces are being attached is shown. After holding and fixing the retaining wall, full-scale excavation is started, and the liner plate 1 is attached to the excavated portion as the excavation progresses, as in (c) and (d) of the conventional example shown in FIG.
It is sufficient to excavate the soil retaining wall by joining 1 while excavating to a predetermined depth. The above-ground part of the earth retaining wall is
It can be temporarily installed after the leveling of the natural ground 10 and before the start of excavation.
It is also possible to tentatively install after preliminarily digging up to a depth of 2 steps, for example, 500 to 1000 mm.

The number of fixing devices is set to three or more because at least three pieces are required because one plane is determined by three points in order to hold and fix the retaining wall. For three or more, the weight of the earth retaining wall varies depending on the diameter and depth of the shaft, and the number of fixing devices may be increased as necessary in consideration of the strength of the ground.

As described above, in the shaft excavation method of the present invention, the earth retaining wall can be stably fixed to the leveled ground by the fixing device, so that the verticality of the earth retaining wall hardly occurs. Further, even if the verticality is out of order, the vertical portion of the retaining wall remains on the ground even during the excavation, so the verticality can be easily adjusted. That is, even if the uppermost part of the retaining wall is held vertically at the beginning of excavation, if the top of the retaining wall is buried in the ground as in the conventional case, if the top of the retaining wall is misaligned as the excavation progresses, the vertical It's hard to notice the madness, and even if you notice it, it's difficult to adjust. On the other hand, if the uppermost part of the retaining wall is on the ground as in the present invention, the vertical deviation is easily noticed and the adjustment is easy.

[0026]

According to the present invention, even when excavating a vertical shaft in a place where transportation and working conditions are poor, it is possible to securely hold and fix the earth retaining wall of the vertical shaft by manual transportation and installation. Also, since the uppermost part of the retaining wall is above the ground even during excavation, it is easy to adjust the verticality of the retaining wall.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a fixing device for a shaft retaining wall of the present invention.

FIG. 2 is a side view (a), a front view (view taken along arrow aa) (b), and a plan view (b) illustrating a fixing device for a shaft retaining wall of the present invention.
-B arrow view) (c).

FIG. 3 is a diagram illustrating a shaft excavation method of the present invention.

FIG. 4 is a perspective view (a) and a width direction sectional view (b) showing a liner plate.

FIG. 5 is a view showing a conventional example of constructing a retaining wall by assembling a liner plate while excavating a vertical shaft.

FIG. 6 is a diagram showing a conventional example of holding and fixing the uppermost portion of the retaining wall.

FIG. 7 is a diagram showing a conventional example of holding and fixing the uppermost part of the retaining wall.

FIG. 8 is a diagram showing a conventional example of holding and fixing the uppermost portion of the retaining wall.

FIG. 9 is a diagram showing an example of a conventional fixing fitting for holding and fixing the uppermost portion of the retaining wall.

[Explanation of symbols]

 1 Fixing Device 2 Grounding Plate 3 Top Plate 4 Leg 5 Mounting Hole 6 Mounting Hole 7 Slip Prevention 10 Ground Slip 11 Liner Plate 12 Corrugated Steel Plate 13 Lower Flange 14 Upper Flange 15 Flange 16 Connection Hole 17 Connection Hole 18 Bolt 20 Ground Surface 21 Circular hole 22 Earth retaining wall 23 Support beam 24 Concrete 25 Fixing metal fittings

Claims (3)

[Claims] 1. A ground plate that is attached to a lower flange of a liner plate that constitutes the above-ground portion of the retaining wall and contacts the ground surface, and a top plate that is attached to an upper flange of the liner plate are connected by legs. Fixing device for vertical shaft retaining wall. 2. The shaft earth retaining wall fixing device according to claim 1, wherein a slip stopper is provided below the outer periphery of the ground plate. 3. A shaft excavating method of extending a retaining wall by joining a liner plate to an excavated portion as the shaft excavation progresses, in a method of excavating a rock, after leveling of the ground,
Liner plates are arranged circumferentially on the surface of the shaft excavation position,
The ground portion of the retaining wall is temporarily installed by joining, and the upper and lower flanges of the liner plate are interposed therebetween.
It is characterized in that three or more fixing devices for the shaft retaining wall are attached to hold and fix the retaining wall, and then the liner plate is joined to the excavated portion as the excavation proceeds to extend the retaining wall into the shaft. How to excavate a vertical shaft.