JP2022067922A - Construction method of underground structure, and hanging jig - Google Patents

Abstract

To provide a construction method and the like of an underground structure capable of improving efficiency of construction work.SOLUTION: When constructing a deep foundation in a vertical shaft 2 of a circular plane formed on the ground, multiple outer steel frames 6 are hanged using a hanging jig 100, the outer steel frames 6 are placed in the vertical shaft 2 at intervals along a circumferential direction of the vertical shaft 2, and concrete is placed in the vertical shaft 2. The hanging jig 100 has a hanging frame 110 that includes: a body 111, which curves along the circumferential curvature of vertical shaft 2; and a connecting member 112 provided between both ends of the main body 111. The multiple outer steel frames 6 are hung from each of a plurality of positions spaced apart from each other in a bending direction of the main body 111 on the underside of the body 111.SELECTED DRAWING: Figure 5

Description

The present invention relates to a method for constructing an underground structure and a hanging jig used for the method.

Conventionally, a deep foundation has been constructed by excavating a circular flat shaft in the ground, assembling a reinforcing bar cage inside the shaft, and placing concrete (see, for example, Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2009-114649 Japanese Patent Application Laid-Open No. 06-306864

However, if a large-scale deep foundation is constructed by the conventional method, many reinforcing bars are required and it takes a lot of time and effort to arrange the reinforcing bars. Therefore, there has been a demand for a method that can save labor in bar arrangement work and improve the efficiency of construction work.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for constructing an underground structure that can improve the efficiency of construction work.

The first invention for achieving the above-mentioned object is a method for constructing an underground structure, in which a plurality of shaped steels are suspended from a shaft formed on a circular plane in the ground by using a hanging jig, and the shape is described. It has a step of arranging steel in the shaft at intervals along the circumferential direction of the shaft and a step of placing concrete in the shaft, and the suspension jig has a step of placing concrete in the shaft in the circumferential direction of the shaft. It is provided with a suspension frame having a main body curved along the curvature of the main body, and the shaped steel is suspended from each of a plurality of positions on the lower surface of the main body spaced apart from each other in the bending direction of the main body. It is a method of constructing an underground structure.

In the present invention, when constructing an underground structure such as a deep foundation, shaped steel is used as a reinforcing material for the underground structure. By using a high-strength shaped steel, it is possible to save labor in the reinforcing bar arrangement work as compared with the case where a large amount of reinforcing bars are arranged. Further, by using the above-mentioned hanging jig, a plurality of shaped steels can be suspended together at intervals along the circumferential direction of the shaft according to the arrangement in the shaft, and the shaped steels can be suspended. It facilitates loading and subsequent installation work.

It is desirable that the suspension frame has a connecting member bridged between both ends of the main body. Further, it is desirable that the connecting member is fixed to the upper surface of the main body and the legs are provided on the lower surface of the connecting member.
By providing the above-mentioned connecting member on the suspended frame, the rigidity of the suspended frame is improved, and the stability of the shaped steel when suspended is improved. Further, by providing the above-mentioned legs, when the suspension frame is placed on the ground or the like, the connecting member is supported by the main body and the legs, and the suspension frame can be stably arranged.

It is desirable that a swivel is provided in the middle of the wire that suspends the shaped steel.
As a result, it is possible to suppress the rotation of the shaped steel when a load is applied to the wire, and the workability at the time of suspending the shaped steel is improved.

The perforated plate is arranged so as to sandwich the shaped steel, the hole of the perforated plate and the hole of the shaped steel communicate with each other, and the hole of the perforated plate and the hole of the shaped steel are used as the bolt. It is desirable that the perforated plate is attached to the shaped steel, and a hanging metal fitting for attaching a wire rod for suspending the shaped steel is attached to the perforated plate by using another hole of the perforated plate.
In this way, by suspending the shaped steel using the holes of the shaped steel used for attaching the splicing plate or the like, the risk of the shaped steel falling is reduced.

The second invention is a suspension jig for suspending a plurality of shaped steels in a circular flat shaft formed on the ground, and is a suspension frame having a main body curved along the circumferential curvature of the shaft. The shaped steel is suspended from each of a plurality of positions on the lower surface of the main body at intervals in the bending direction of the main body.
The second invention is a hanging jig used in the method for constructing an underground structure of the first invention.

According to the present invention, it is possible to provide a method for constructing an underground structure that can improve the efficiency of construction work.

The figure which shows the deep foundation foundation 10. The figure which shows the striped H-section steel. The figure explaining the construction method of the deep foundation foundation 10. The figure explaining the construction method of the deep foundation foundation 10. The figure which shows the hanging jig 100. The figure which shows the suspension frame 110. The figure which shows the hanging metal fitting 120c and the perforated plate 140. The figure explaining the construction method of the deep foundation foundation 10. The figure explaining the construction method of the deep foundation foundation 10.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

(1. Deep foundation foundation 10)
FIG. 1 is a diagram showing a deep foundation foundation 10 which is an underground structure constructed by the construction method according to the embodiment of the present invention.

The deep foundation foundation 10 is a large-diameter deep foundation foundation with a large diameter, and is used as a foundation for bridge piers and the like.

The deep foundation foundation 10 is constructed by placing concrete 9 in a shaft 2 formed in the ground 1. The shaft 2 and the deep foundation 10 have a circular plane. A steel ring (not shown) is provided on the wall surface of the shaft 2 and a spraying material is sprayed. Alternatively, a liner plate may be provided on the wall surface, or a lock bolt may be provided by spraying on the wall surface.

At the outer peripheral portion of the deep foundation foundation 10, an outer reinforcing bar 5, an outer steel frame 6, an inner reinforcing bar 7, an inner steel frame 8, and the like are embedded in concrete 9. The outside means the side close to the wall surface of the shaft 2, and the inside means the side close to the center of the plane of the shaft 2.

The outer reinforcing bar 5 is a reinforcing bar located on the outermost side of the shaft 2 (deep foundation foundation 10) and arranged along the circumferential direction of the shaft 2. The outer rebar 5 is arranged in a circumferential shape on a plane in the shaft 2. The outer reinforcing bars 5 are installed at predetermined intervals in the vertical direction.

The outer steel frame 6 is a vertical shaped steel arranged inside the outer strip reinforcing bar 5, and in this embodiment, a striped H-shaped steel is used. As shown in FIG. 2, the striped H-shaped steel is an H-shaped steel in which ridges a in the flange width direction are provided on the flange surface.

A plurality of outer steel frames 6 are installed with the width direction of the web aligned with the radial direction of the shaft 2 and at predetermined intervals along the circumferential direction of the shaft 2. Further, in the present embodiment, a plurality of outer steel frames 6 are vertically connected and used by bolt joining using a splicing plate 63.

The inner band reinforcing bar 7 is a reinforcing bar located inside the outer steel frame 6 and arranged along the circumferential direction of the shaft 2. The inner band reinforcing bars 7 are arranged concentrically in the inner and outer doubles in a plane in the shaft 2. The inner band reinforcing bars 7 are installed at predetermined intervals in the vertical direction.

The inner steel frame 8 is a vertical shaped steel arranged inside the inner strip reinforcing bar 7, and in this embodiment, a striped H-shaped steel is used. A plurality of inner steel frames 8 are installed with the width direction of the web aligned with the radial direction of the shaft 2 and at predetermined intervals along the circumferential direction of the shaft 2. Further, in the present embodiment, a plurality of inner steel frames 8 are vertically connected and used by bolt joining using a splicing plate 83.

Reference numeral 3 in FIG. 1 is an installation table 3 used for installing the outer steel frame 6 and the inner steel frame 8, and the installation table 3 is also buried in the concrete 9 in the deep foundation foundation 10. Further, reference numeral 4 in FIG. 1 is bottom concrete for fixing the position of the installation table 3, and the concrete 9 is placed on the bottom concrete 4.

(2. How to build the deep foundation 10)
Next, a method of constructing the deep foundation foundation 10 will be described with reference to FIGS. 3 to 9.

In the present embodiment, after excavating the ground 1 to form the shaft 2, the installation table 3 is provided at the bottom of the shaft 2 as shown in FIG. The installation table 3 has an H-shaped steel 30 and a connecting member 31. In FIG. 3, (a) is a view of the shaft 2 as viewed from above, and (b) is a view showing a vertical cross section of the bottom of the shaft 2. This also applies to FIGS. 4 and 8 below.

The H-section steel 30 is arranged along the radial direction of the shaft 2 with the width direction of the web aligned with the vertical direction. A plurality of H-shaped steels 30 are provided radially at intervals along the circumferential direction of the shaft 2. The upper flange of the H-shaped steel 30 is provided with holes (not shown) used for fixing the outer steel frame 6 and the inner steel frame 8 described later.

The connecting member 31 connects a plurality of H-shaped steels 30 arranged in the circumferential direction of the shaft 2 and maintains a distance between the adjacent H-shaped steels 30. For example, an angle member is used as the connecting member 31, and the connecting member 31 is arranged in a concentric circle of inner and outer doubles on a plane in the shaft 2. The connecting material 31 is joined to the upper flange of the H-shaped steel 30 with bolts or the like.

At the bottom of the shaft 2, if necessary, leveling concrete 33 is placed on the outer periphery of the shaft 2 to adjust the non-landing. The H-shaped steel 30 is marked on the leveled concrete 33 and installed at a predetermined position on the leveled concrete 33. The H-shaped steel 30 is fixed to the leveled concrete 33 and the ground 1 below it by the anchor 34.

In the present embodiment, next, the outer rebar 5 and the outer steel frame 6 are installed as shown in FIG. Here, first, the bottom concrete 4 is placed at the bottom of the shaft 2 to fix the position of the installation table 3. The bottom concrete 4 is placed so that the upper portion of the H-shaped steel 30 is exposed in consideration of the fixing work of the outer steel frame 6 and the inner steel frame 8 described later.

After placing the bottom concrete 4, the outer reinforcing bars 5 are arranged along the circumferential direction of the shaft 2. The outer reinforcing bar 5 is fixedly arranged on a mounting material (not shown) installed on the wall surface of the shaft 2.

In the present embodiment, the outer steel frame 6 is then suspended in the shaft 2 and installed inside the outer reinforcing bar 5. As shown in FIG. 5, the outer steel frame 6 is suspended in the shaft 2 by using a dedicated hanging jig 100 capable of suspending the plurality of outer steel frames 6 at once, and the plurality of outer steel frames 6 are suspended in the shaft. Install sequentially with an interval in the circumferential direction of 2.

The hanging jig 100 collectively suspends the plurality of outer steel frames 6 by a wire w2 (wire material) suspended from the suspension frame 110.

The suspension frame 110 is suspended from the crane by attaching the lower end of the wire w1 (wire material) extending from the crane to each of the plurality of suspension fittings 120a provided on the upper portion thereof, and the wire w2 is provided on the lower portion of the suspension frame 110. It is attached to the hanging metal fitting 120b and hung down.

A swivel 130 is provided in the middle of the wire w2. The lower end of the wire w2 is attached to the hanging metal fitting 120c provided at the upper end of the outer steel frame 6.

6 (a) and 6 (b) are perspective views showing the suspension frame 110, which are a top view of the suspension frame 110 and a bottom view of the suspension frame 110, respectively.

The suspension frame 110 has a main body 111, a connecting member 112, legs 113, and the like. H-shaped steel is used for the main body 111, the connecting member 112, and the leg portion 113, but the present invention is not limited to this.

The main body 111 is an arc-shaped member that curves along the curvature in the circumferential direction of the shaft 2.

The connecting member 112 is a linear member that is fixed to the upper surfaces of both ends of the main body 111 with bolts or the like and is bridged between the both ends.

The leg portion 113 is a linear member that is fixed to the lower surface of the central portion of the connecting member 112 with bolts or the like and is arranged so as to extend from the connecting member 112 to the opposite side of the main body 111.

The hanging metal fittings 120a are provided on the upper surface of the central portion of the main body 111 and the upper surfaces of both ends of the connecting member 112.

FIG. 6C is a view showing the hanging metal fitting 120a on the upper surface of the central portion of the main body 111, and sees a cross section orthogonal to the bending direction of the main body 111 (corresponding to the arrow B in FIG. 6A). It is an arrow.

As shown in FIG. 6 (c), in the hanging metal fitting 120a, the tips of both legs of the U-shaped hanging portion 121 are connected to each other by a linear connecting portion 122, and the connecting portion 122 is the main body 111. It is passed through the hole h of the web, and both legs of the suspension portion 121 are passed through the elongated hole s formed in the flange on the upper surface of the main body 111. The elongated hole s is formed along the tangential direction of the curved main body 111, and the hanging metal fitting 120a can rotate within a certain range in the tangential direction with the connecting portion 122 as a rotation axis.

The above is the same for the hanging metal fittings 120a provided on the upper surfaces of both ends of the connecting member 112, and in the connecting member 112, the elongated holes s are formed along the axial direction of the connecting member 112.

On the other hand, the hanging metal fittings 120b are arranged at a plurality of positions (FIG. 6 (b)) spaced apart from each other in the bending direction of the main body 111, as shown in FIG. 6 (b), in accordance with the arrangement of the outer steel frame 6 in the shaft 2. In the example, it is provided on the lower surface of the main body 111 at the central portion and both ends of the main body 111, and a total of five positions between the central portion and both ends). The hanging metal fitting 120b is provided in the same manner as the hanging metal fitting 120a (see FIG. 6C).

The swivel 130 of FIG. 5 is provided to prevent the outer steel frame 6 from rotating when it is suspended. That is, the wire w2 is a twisted steel wire, and when the load of the outer steel frame 6 is applied to the wire w2, the twist of the steel wire may be unwound and the wire w2 may rotate as shown by the arrow A. When the outer steel frame 6 is directly attached to the lower end of the wire w2, the outer steel frame 6 rotates together with the wire w2, so the swivel 130 is attached in the middle of the wire w2.

Since the upper part of the swivel 130 rotates independently of the lower part, even if the wire w2 (and the upper part of the swivel 130) above the swivel 130 attached to the upper part of the swivel 130 rotates as shown by the arrow A, the swivel 130 The wire w2 below the swivel 130 attached to the lower part of the swivel 130 does not rotate, and the rotation of the outer steel frame 6 is prevented.

FIG. 7 is a diagram showing a hanging metal fitting 120c for attaching the wire w2 to the outer steel frame 6. In the present embodiment, a hole 602 used for attaching the splicing plate 63 is formed in the web 601 at the upper end of the outer steel frame 6, and the hanging metal fitting 120c is attached using the hole 602.

That is, in the present embodiment, the perforated plate 140 for attaching the hanging metal fitting 120c is arranged so as to sandwich the web 601 of the outer steel frame 6. A hole 141 is provided in the lower portion of the perforated plate 140, and the perforated plate 140 is arranged so that the hole 141 communicates with the hole 602 of the web 601. By passing the shaft portion of the headed bolt 143 through these holes 141 and 602 from the one perforated plate 140 side and tightening the nut 144 to the tip of the shaft portion protruding from the other perforated plate 140, the perforated plate 140 is attached to the web 601.

At this time, the upper portion of the double-perforated plate 140 protrudes above the web 601 and another hole 142 is provided at a corresponding position on the upper portion of the double-perforated plate 140. The hanging metal fitting 120c is attached to the perforated plate 140 using the hole 142.

Similar to the above-mentioned hanging metal fitting 120a, the hanging metal fitting 120c is formed by connecting the tips of both legs of the U-shaped hanging portion 121 with a linear connecting portion 122, and the connecting portion 122 is a double-hole perforated plate 140. It is passed through the hole 142 of.

When suspending the outer steel frame 6 into the shaft 2, as shown in FIG. 5, the heights of the lower ends of the five outer steel frames 6 are changed, and the outer steel frames 6 are installed in order from the bottom. In the present embodiment, the lower end of the outer steel frame 6 in the central portion is at a high position, the lower ends of the outer steel frames 6 at both ends are at a low position, and the lower end of the outer steel frame 6 at the intermediate portion is at an intermediate height.

In this way, if the installation work is performed in order from the outer steel frame 6 having the lowest lower end position, the construction becomes more efficient, and when the outer steel frame 6 is installed, the lower end of the adjacent outer steel frame 6 is at a higher position, so that a large work space is secured. You can also do it. For the installation of the outer steel frame 6, for example, in consideration of the length of the outer steel frame 6, an aerial work platform (not shown) capable of removing the ball of the outer steel frame 6 is arranged in the shaft 2 and used for the work.

As shown in FIG. 4B, an end plate 61 is provided at the lower end of the outer steel frame 6, and when the outer steel frame 6 is installed, a hole (not shown) of the end plate 61 is formed in the upper flange of the H-shaped steel 30. The shaft portion of the headed bolt 64 is inserted into these holes from below, and the nut 65 is tightened to the tip of the shaft portion protruding from the end plate 61. As a result, the outer steel frame 6 is fixed to the upper flange of the H-shaped steel 30.

In this way, a plurality of outer steel frames 6 are arranged in the circumferential direction of the shaft 2. The upper ends of these outer steel frames 6 are connected to each other by a connecting member 62 arranged along the circumferential direction of the shaft 2.

The connecting member 62 is, for example, an angle member, and is arranged in a concentric circle of inner and outer doubles. The inner and outer connecting members 62 are joined to the inner flanges and outer flanges of the plurality of outer steel frames 6 arranged in the circumferential direction of the shaft 2 with bolts or the like, whereby the upper ends of the plurality of outer steel frames 6 are joined by the connecting member 62. Be concatenated. The connecting material 62 maintains the distance between the adjacent outer steel frames 6, and the installation accuracy of the outer steel frames 6 is improved.

Next, as shown in FIG. 8, the inner band reinforcing bar 7 is installed inside the outer steel frame 6 at a predetermined distance from the outer steel frame 6. The inner band reinforcing bar 7 can be fixed to a frame (not shown) provided on the outer steel frame 6.

After that, the inner steel frame 8 is suspended in the shaft 2 and installed inside the inner band reinforcing bar 7. The inner steel frame 8 can be suspended by using the suspension jig 100 in the same manner as before. An end plate 81 is provided at the lower end of the inner steel frame 8, and the end plate 81 is fixed to the upper flange of the H-shaped steel 30 by using a head bolt 84 and a nut 85 as before.

A plurality of inner steel frames 8 are arranged in the circumferential direction of the shaft 2. The upper ends of these inner steel frames 8 are connected to each other in the same manner as the outer steel frame 6 by using the same connecting material 82 as the connecting material 62 described above.

In this way, as shown in FIG. 9A, the outer band reinforcing bar 5, the outer steel frame 6, the inner band reinforcing bar 7, and the inner steel frame 8 are installed in the shaft 2. After that, as shown in FIG. 9B, a part of the deep foundation foundation 10 is constructed by placing concrete 9 in the shaft 2. The concrete 9 is placed so that the upper ends of the outer steel frame 6 and the inner steel frame 8 are exposed, and the connecting members 62 and 82 are removed after the concrete 9 is placed and reused in a later step.

After that, as shown in FIG. 9 (c), new outer band reinforcing bars 5, outer steel frames 6, and inner band reinforcing bars are placed above the outer band reinforcing bars 5, outer steel frames 6, inner band reinforcing bars 7, and inner steel frames 8 installed earlier. 7. Install the inner steel frame 8 in the same way as before. However, the lower ends of the outer steel frame 6 and the inner steel frame 8 are not fixed to the installation table 3, but are bolted to the upper ends of the outer steel frame 6 and the inner steel frame 8 below the outer steel frames 6 and the inner steel frames 8 using splicing plates 63 and 83. ..

Then, as shown in FIG. 9D, a new concrete 9 is placed above the concrete 9 that has been placed earlier. By repeating the steps of FIGS. 9 (c) and 9 (d), the deep foundation 10 shown in FIG. 1 is constructed.

As described above, according to the present embodiment, when constructing the deep foundation foundation 10, shaped steel (outer steel frame 6 and inner steel frame 8) is used as a reinforcing material for the deep foundation foundation 10. By using a high-strength shaped steel, it is possible to save labor in the reinforcing bar arrangement work as compared with the case where a large amount of reinforcing bars are arranged. Further, by using the above-mentioned hanging jig 100, a plurality of shaped steels can be hung together at intervals along the circumferential direction of the shaft 2 according to the arrangement in the shaft 2. It facilitates the lifting of steel and subsequent installation work.

Further, by providing the connecting member 112 on the suspension frame 110, the rigidity of the suspension frame 110 is improved, and the stability when the shaped steel is suspended is improved. Further, by providing the leg portion 113 on the lower surface of the connecting member 112 of the hanging frame 110, the connecting member 112 is supported by the main body 111 and the leg portion 113 when the hanging frame 110 is placed on the ground or the like at the time of temporary placement or the like. The suspension frame 110 can be stably arranged.

Further, by providing the swivel 130 in the middle of the wire w2 for suspending the shaped steel, it is possible to suppress the rotation of the shaped steel when a load is applied to the wire w2, and the workability at the time of suspending the shaped steel can be suppressed. Is improved.

Further, the shaped steel is generally hung by using a tightening jig such as a hanging clamp, but there is a risk that the shaped steel may fall. However, in the present embodiment, the shaped steel hole 602 used for attaching the splicing plate or the like is used, and as described above, the shaped steel is hung by using the perforated plate 140 and the hanging metal fitting 120c, so that the shaped steel falls or the like. It is possible to reduce the risk of steel and increase the safety during construction.

However, the present invention is not limited to the above embodiments. For example, the reinforcement arrangement in the deep foundation foundation 10 is not limited to the above, and the inner steel frame 8 may be omitted. Further, as the outer steel frame 6 and the inner steel frame 8, it is also possible to use a shaped steel other than the striped H-shaped steel. Further, the number of stages of the outer rebar 5 and the inner rebar 7 can be changed.

Further, in the present embodiment, an example of constructing the deep foundation foundation 10 as an underground structure has been described, but the construction method of the present embodiment can also be applied to the case of constructing other underground structures.

Further, the configuration of the suspension jig 100 is not limited to the above, and there may be a suspension frame 110 having a main body 111 that curves along the curvature in the circumferential direction of the shaft 2. It is also possible to use a wire other than the wire w2, such as a chain, for suspending the shaped steel.

Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to such an example. It is clear that a person skilled in the art can come up with various modified examples or modified examples within the scope of the technical idea disclosed in the present application, and these also naturally belong to the technical scope of the present invention. Understood.

1: Ground 2: Vertical shaft 3: Installation stand 5: Outer wire bar 6: Outer steel frame 7: Inner steel frame 8: Inner steel frame 9: Concrete 10: Deep foundation 100: Suspension jig 110: Suspension frame 111: Main body 112: Connecting member 113: Legs 120a, 120b, 120c: Hanging metal fitting 130: Swivel 140: Perforated plate w1, w2: Wire

Claims (6)

It ’s a method of constructing underground structures.
A process of suspending a plurality of shaped steels into a circular flat shaft formed on the ground using a hanging jig and arranging the shaped steels in the shaft at intervals along the circumferential direction of the shaft.
The process of placing concrete in the shaft and
Have,
The suspension jig comprises a suspension frame having a body that curves along the circumferential curvature of the shaft.
A method for constructing an underground structure, characterized in that the shaped steel is suspended from each of a plurality of positions on the lower surface of the main body at intervals in the bending direction of the main body. The method for constructing an underground structure according to claim 1, wherein the suspension frame has a connecting member bridged between both ends of the main body. The connecting member is fixed to the upper surface of the main body and
The method for constructing an underground structure according to claim 2, wherein the legs are provided on the lower surface of the connecting member. The method for constructing an underground structure according to any one of claims 1 to 3, wherein a swivel is provided in the middle of the wire for suspending the shaped steel. The perforated plate is arranged so as to sandwich the shaped steel.
The hole in the perforated plate and the hole in the shaped steel communicate with each other.
The perforated plate was attached to the shaped steel using bolts passed through the holes of the perforated plate and the holes of the shaped steel.
According to any one of claims 1 to 4, a hanging metal fitting for attaching a wire rod for suspending the shaped steel by using another hole of the perforated plate is attached to the perforated plate. The method of constructing the described underground structure. A hanging jig for suspending multiple shaped steels in a circular flat shaft formed on the ground.
A suspension frame having a body that curves along the circumferential curvature of the shaft.
A hanging jig characterized in that the shaped steel is suspended from each of a plurality of positions on the lower surface of the main body at intervals in the bending direction of the main body.

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