JP2016084629A - Form for invert - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a form for an invert, which enables a placing joint part between lining concrete and invert concrete to be constructed with high quality.SOLUTION: A form 1 for an invert includes a curved form 2 for molding an inner empty face of the invert, and a reinforcing material 3 that is provided on the back face of the curved form 2. An inclined form 5 for molding an upper end face of the invert is provided. The inclined form 5 is detachably attached to a beam material 4 horizontally laid along a tunnel axis direction on the reinforcing material 3.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an invert form used for constructing an invert.

For example, in the NATM tunnel, the standard support pattern changes according to the ground grade.
As shown in FIG. 6, the cross-sectional shape of the tunnel (leg shape of lining concrete) differs between the section with invert and the section without invert, depending on the support pattern.

  In the section where invert is present, it is common that the joint portion (corner portion) between the lining concrete C1 and the invert concrete C2 is formed in a cross-sectional curve shape as in the tunnel T2 shown in FIG. 6B. .

In general, such a corner portion (upper end portion of invert) having a curved cross section is constructed by using an invert form having a curved surface (surface on the concrete side).
For example, Patent Document 1 discloses an invert form that includes a skin plate having a curved molding surface and a reinforcing member fixed to the back surface of the skin plate.

JP 2012-229546 A

The top surface of the invert concrete (joint surface with the lining concrete leg) is inclined so that the ground side is lower than the inside sky side so that the axial force can be smoothly transmitted between the lining concrete and the invert. It is molded into the state.
Such finishing work of the upper end surface of the invert is generally performed by scraping concrete.

  By the way, the upper end of the invert is designed with a sharply curved surface (joint circle) compared to the shape of the lining concrete and the shape of the bottom board, and the shape is easy to concentrate stress. It is desirable to install.

  From such a viewpoint, an object of the present invention is to provide an invert form that enables high-quality construction of a joint portion between lining concrete and invert concrete.

  In order to solve the above-mentioned problems, the present invention provides a tunnel invert form comprising: a curved form for forming an inner surface of an invert; and a reinforcing material provided on the back surface (upper face) of the curved form. Further, it is characterized in that an inclined mold for forming the upper end surface of the invert is further provided.

  According to such an invert form, since the connecting surface (upper end face of invert) with the lining concrete is formed by the inclined form, the concrete can be densely constructed.

  If the inclined mold is detachably attached to the reinforcing material, the inclined mold can be easily removed. If the inclined form is removed immediately after the concrete is compacted, the lentance treatment can be performed on the day of placing.

It is desirable that a beam material along the tunnel axis direction is provided on the reinforcing material, an arm member is provided on the inclined mold frame, and an end portion of the arm member in the tunnel in the tunnel is detachably fixed to the beam material.
According to such an invert form, since the inclined form is supported by the beam material, it is possible to prevent the inclined form from being lifted. Further, the beam material functions as a weight for preventing the curved mold from being lifted, and prevents the curved mold from bending.

  Further, if an increaser for placing concrete between the inverting reinforcing bar and the curved mold is locked to the beam material, the concrete is applied to the lower surface of the inclined mold. Installation can be performed easily.

  The reinforcing material extends from the upper end of the curved mold in the direction toward the inner side of the tunnel, and the vertical reinforcing material that connects the lower end of the curved mold and the tip of the horizontal reinforcing material Further, if a work scaffold supported by the horizontal reinforcing material and the vertical reinforcing material is formed above the curved formwork, workability at the time of placing the concrete is further improved.

  According to the invert form of the present invention, it is possible to construct the joint portion between the lining concrete and the invert concrete with high quality.

It is sectional drawing which shows the tunnel which concerns on embodiment of this invention. (A) The perspective view which shows the mold for inversion of this embodiment, (b) is an expanded sectional view which shows a part of (a). It is a perspective view which shows the use condition of the same mold for invert. (A) is a side view which shows an incrementer, (b) is the perspective view. (A) And (b) is a perspective view which shows the construction procedure of invert concrete placement using the invert formwork. It is a standard sectional view of a tunnel, (a) is a sectional view when there is no invert, (b) is a sectional view when there is invert.

In the embodiment of the present invention, a case where the tunnel lining T shown in FIG. 1 is constructed is illustrated. The tunnel lining T includes lining concrete C1, invert concrete C2, and shotcrete C6.
The tunnel invert form 1 (see FIG. 2) according to the present embodiment is used when constructing both end portions C3 and C3 (joint portions of the lining concrete C1 and the invert concrete C2) of the invert concrete C2. is there.

  An inclined surface C4 and a horizontal surface C5 are formed on the upper surface of the end portion C3 of the invert concrete C2 (joint surface between the lining concrete C1 and the shotcrete C6). The inclined surface C4 is a plane whose normal is the inner peripheral surface of the joint portion between the lining concrete C1 and the inverted concrete C2. The horizontal plane C5 forms a joint surface between the shotcrete C6 and the invert concrete C2.

As shown in FIG. 2, the invert form 1 of the present embodiment includes a curved form 2, a reinforcing material 3, a beam 4, an inclined form 5, an incrementer 6, and a work scaffold 7. It has.
The length (in the tunnel axis direction) of the invert form 1 of this embodiment is 11 m in accordance with a general invert construction extension (= 10.5 m), but the length of the invert form 1 Is not limited.

  The curved surface form 2 is made of a plate material formed into a curved surface shape according to the inner surface shape of the end portion C3 of the invert concrete C2 (the shape of the joining circle between the lining concrete C1 and the invert concrete C2). Mold the empty surface.

The curved mold 2 of the present embodiment is formed of a steel plate, but the material constituting the curved mold 2 is not limited, and may be a wooden board, for example.
The curved mold 2 is reinforced by the reinforcing material 3 provided on the back surface (upper surface), and thus has a rigidity that is not deformed by the pressure of the cast concrete.

The reinforcing material 3 is a frame-shaped member formed by combining steel materials, and is disposed on the surface (back surface or top surface) of the curved mold 2 on the inner side of the tunnel, as shown in FIG. .
In the present embodiment, the plurality of reinforcing members 3 are arranged at predetermined intervals in the tunnel axis direction. The number of reinforcing members 3 and the arrangement pitch are not limited. Further, the reinforcing material 3 may be a hook-shaped member formed integrally.

  The reinforcing member 3 is formed in a fan shape when viewed from the side by a lateral reinforcing member 31, a vertical reinforcing member 32, and a curved reinforcing member 33. Each reinforcing material 31, 32, 33 is formed by processing L-shaped steel (angle material). In addition, the material which comprises the reinforcing material 3 is not limited, For example, a flat steel and a channel steel may be sufficient.

  The lateral reinforcing material 31 extends from the upper end portion of the curved mold 2 toward the inner side of the tunnel. In the present embodiment, the horizontal reinforcing member 31 is substantially horizontal in a state where the invert form 1 is installed, but the angle of the horizontal reinforcing member 31 is not limited.

  The vertical reinforcing member 32 is erected on the upper surface of the curved mold 2 and supports the tip of the lateral reinforcing member 31. That is, the vertical reinforcing member 32 is disposed so as to connect the lower end portion of the curved mold 2 and the distal end portion (end portion on the tunnel center side) of the horizontal reinforcing member 31. In the present embodiment, the vertical reinforcing member 32 is formed so as to be substantially vertical in a state where the invert form 1 is installed, but the angle of the vertical reinforcing member 32 is not limited.

  The curved surface reinforcing member 33 is disposed so as to connect the base end portion (end portion on the natural mountain side) of the horizontal reinforcing member 31 and the leg portions (the vertical reinforcing member 32, the curved mold 2 and the joint portion) of the vertical reinforcing member 32. ing. The curved surface reinforcing member 33 is made of a member bent into a curved shape along the inner surface (joint circle shape) of the curved mold 2 and is in contact with the inner side surface of the curved mold 2.

A beam member 4 is provided on the upper surface of the lateral reinforcement member 3 (lateral reinforcement member 31).
As shown in FIG. 2, the beam member 4 is an H-shaped steel provided along the tunnel axis direction, and is laid on a plurality of reinforcing members 3, 3. In addition, the material which comprises the beam material 4 is not limited, For example, L-shaped steel and groove type steel may be sufficient.

Although the beam member 4 of the present embodiment is welded to the lateral reinforcing member 31, the fixing method of the beam member 4 is not limited, and may be fixed through a jig such as a vise, for example. .
Although the attachment position of the beam member 4 is not limited, it is set to the natural ground side (for example, a position about 2/3 of the length of the lateral reinforcement member 31) from the central portion of the lateral reinforcement member 31. In the present embodiment, the beam member 4 is arranged so that the straight line connecting the inner space side lower edge of the upper flange of the beam member 4 and the upper end of the curved mold 2 is the angle of the inclined surface C4 (the inclined mold 5). It is arranged. In addition, it is desirable to arrange the beam member 4 on the natural ground side with respect to the central portion of the lateral reinforcing member 31 for the purpose of preventing the curved formwork 2 from being lifted.

As shown in FIG. 2B, the beam member 4 is formed with an attachment portion 41 for attaching the arm member 52 of the inclined mold frame 5.
The attachment part 41 of this embodiment consists of a through-hole (opening) formed in the web of the beam material 4. An arm member 52 is inserted through the attachment portion 41. A plurality of attachment portions 41 are provided at predetermined intervals with respect to the axial direction of the tunnel.

  The attachment portion 41 is formed in a rectangular shape that is larger than the outer shape of the arm member 52. When the arm member 52 is inserted into the attachment portion 41, a gap is formed between the arm member 52 and the opening edge of the attachment portion 41. In addition, the shape of the attachment part 41 is not limited, A circle etc. may be sufficient. Further, the attachment portion 41 is not necessarily a through hole. For example, a bracket or a cylindrical body protruding from the web of the beam member 4 or a configuration capable of gripping the arm member 52 may be used.

  As shown in FIG. 2, the inclined mold 5 is a mold that forms an inclined surface C4 of an end C3 of the invert concrete C2 (joint portion between the lining concrete C1 and the invert concrete C2). In a state where it abuts on the upper end (edge on the natural ground side), it is detachably attached to the curved frame 2 and the beam member 4 of the reinforcing member 3.

As shown in FIG. 3, the inclined mold 5 according to the present embodiment includes a mold body 51, an arm member 52, a clamp 53, and a fixing metal 54.
In the present embodiment, a plurality of formwork bodies 51 are arranged along the tunnel axis direction.

The mold body 51 is formed in a box shape by a bottom plate 55 for forming the upper surface of the invert concrete C2 and a rectangular frame member 56 provided on the upper surface of the bottom plate 55.
As shown in FIG. 2A, the tip of the mold body 51 is located at the boundary between the inclined surface C4 and the horizontal surface C5 of the inverted concrete C2.

There is a gap between the base end of the mold body 51 (the end on the sky side in the tunnel) and the upper end of the curved mold 2 so that concrete can be poured.
It should be noted that there is no need to form a gap between the mold body 51 and the curved mold 2 if the concrete can be placed under the mold body 51. For example, a gap between the mold body 51 and the curved mold 2 may be omitted, and an injection hole for placing concrete may be provided in the bottom plate 55.

  As shown in FIG. 3, the arm member 52 is interposed between the mold body 51 and fixed to the mold body 51 by a clamp 53.

  The arm member 52 is made of wood having a rectangular cross section. The lower surface of the arm member 52 is flush with the bottom surface of the mold body 51 (the side surface of the inverted concrete C2 of the bottom plate 55). As shown in FIG. 2A, the tip of the arm member 52 is located at the boundary between the inclined surface C4 and the horizontal surface C5 of the inverted concrete C2. The tip position of the arm member 52 is not necessarily located at the boundary between the inclined surface C4 and the horizontal plane C5. Moreover, the material which comprises the arm member 52 is not limited.

As shown in FIG. 2B, the base end portion of the arm member 52 (the end portion on the sky side in the tunnel) is inserted through the attachment portion 41 of the beam member 4.
The arm member 52 is fixed to the attachment portion 41 by pushing the camber 57 between the opening edge portion of the attachment portion 41 and the arm member 52.

  At this time, the upper end portion of the arm member 52 is in contact with the inner edge of the upper flange of the beam member 4, and the middle portion of the arm member 52 is in contact with the upper end (tip of the natural ground side) of the curved mold 2. Yes. In this embodiment, the arm member 52 is in contact with two points of the inner flange side edge of the upper flange of the beam member 4 and the upper end of the curved mold 2, so that the arm member 52 (inclined mold 5). The inclination angle is determined. In the present embodiment, the inclination angle of the arm member 52 is set to about 30 ° with respect to the horizontal plane, but the inclination angle may be appropriately set according to the inclination angle of the inclined surface C4. For example, what is necessary is just to set in the range of 20 degrees-40 degrees with respect to a horizontal surface.

The clamp 53 is a gate-shaped jig, and sandwiches the frame members 56, 56 of the adjacent mold body 51, 51 and the arm member 52, thereby holding the mold body 51, 51 and the arm member 52. It is fixed. By fixing the mold body 51 to the arm member 52, the mold body 51 is disposed at a predetermined angle.
The method for fixing the mold body 51 and the arm member 52 is not limited. For example, the mold body 51 and the arm member 52 may be fastened with bolts and nuts.

Moreover, the fixture 54 is a gate-shaped jig as shown in FIG. 2B and FIG. The lower end of the fixing metal 54 is fixed to the curved mold 2 or the reinforcing material 3.
The fixture 54 is erected from the upper end of the curved mold 2 in accordance with the position of the arm member 52. The arm member 52 is inserted through the fixing bracket 54.
The arm member 52 is fixed to the fixing bracket 54 by pushing a camber 57 between the arm member 52 and the fixing bracket 54.

  The arm member 52 is fixed at two points of the fixing bracket 54 and the attachment portion 41 of the beam member 4. Thereby, rattling of the arm member 52 is prevented. Buoyancy generated in the curved mold 2 and the inclined mold 5 is transmitted to the beam member 4 via the arm member 52.

In addition, the fixing method of the arm member 52 (inclined formwork 5) is not limited. For example, the beam member 4 and the fixing bracket 54 may be fastened with bolts and nuts.
Further, the arm member 52 may be provided so as to hold the formwork body 51 from the upper surface of the formwork body 51, and the joining method of the formwork body 51 and the arm member 52 is not limited.

  The increaser 6 is a device for placing concrete on the lower side of the inclined mold 5, and as shown in FIG. 4A, via an engaging member 61 formed on the side surface, Locked to the beam member 4.

As shown in FIG. 4B, the increaser 6 is a box-shaped (tubular) member having an upper surface and a lower surface that are opened. By discharging the concrete introduced from the opening (input port 62) on the upper surface of the increaser 6 from the opening (discharge port 63) on the lower surface, the concrete is placed at a predetermined position.
The increaser 6 is installed so that the discharge port 63 (lower end) of the increaser 6 is at the same height as the upper end of the curved mold 2.

  As shown in FIG. 4A, the increaser 6 is formed so that the width of the lower surface is smaller than the width of the upper surface in a side view, and the reinforcing bar R and curved surface type for the invert concrete C2. It has a shape that can be disposed between the frame 2 (concrete covering portion).

The length of the incrementer 6 (the width in the tunnel axis direction) is set equal to the installation interval of the arm members 52 (the gap between the arm members 52).
Furthermore, the width of the discharge port 63 of the increaser 6 (the width in the tunnel width direction) is smaller than the gap between the curved mold 2 and the mold body 51 of the slope mold 5.

That is, the incrementer 6 has a shape that allows concrete to be poured into a space surrounded by the curved mold 2, the mold body 51, the arm member 52, and the invert bar R.
On the left and right sides of the increaser 6 (front and rear in the tunnel axis direction), handles 64 and 64 when the increaser 6 is moved are formed. The shape and arrangement of the handle 64 are not limited. Further, instead of the handle 64, a locking member or the like may be formed.

As shown in FIG. 2, the work scaffold 7 is disposed above the curved mold 2 and is supported by a lateral reinforcing material 31 and a vertical reinforcing material 32. The working scaffold 7 is a so-called expanded metal reinforcing material. It is formed by fixing on 3. In addition, the material which comprises the working scaffold 7 is not limited to an expanded metal, For example, you may form with what is called a scaffold board | plate, another board | plate material, etc.

Next, the construction method of the tunnel lining T using the invert form 1 of this embodiment will be described.
First, as shown in FIG. 5A, the rebar R is assembled and the invert form 1 is installed. Thereafter, concrete for invert concrete C2 is placed up to the level of the horizontal plane C5.

Next, as shown in FIG. 5B, the incrementer 6 is locked to the beam member 4.
The inclined mold 5 may be installed in advance, or may be installed immediately before the increaser 6 is installed.

  Subsequently, the inclined surface C4 is formed by placing concrete using the increaser 6. The concrete of the inclined surface C4 is placed on the lower side of the mold body 51 by being introduced from the gap between the slope mold 5 (the mold body 51) and the curved mold 2.

As the concrete is put in, a vibrator (not shown) is inserted from the outlet 63 of the incrementer 6 to compact the cast concrete.
When the concrete placement is completed and a predetermined strength is developed in the cast concrete, the invert form 1 is removed. After removing the invert form 1, a trowel finish (secondary concrete finish) of the surface of the cast concrete may be performed as necessary.

When removing the invert form 1, first, the inclined form 5 is removed.
When removing the inclined mold 5, the clamp 53 is removed, the mold body 51 is removed, the cambers 57 and 57 are loosened using a hammer or the like, and then the arm member 52 is attached to the mounting portion 41 and the fixing bracket. What is necessary is just to extract from 54. The arm member 52 does not necessarily need to be extracted.
When the inclined mold 5 is removed, the curved mold 2 (including the reinforcing material 3, the beam material 4, and the work scaffold 7) is removed.

  As described above, according to the invert mold 1 of the present embodiment, the inclined mold 5 forms the joining surface with the lining concrete C1 (the upper end surface of the invert concrete C2), so that the raised portion is higher than the horizontal plane C5. (Inclined surface C4) can be constructed with high quality.

  Moreover, since force is transmitted between the curved mold 2 and the inclined mold 5 via the arm member 52, the inclined mold 5 can be prevented from being lifted. By preventing the inclined mold 5 from being lifted up, it is possible to suppress casting concrete that tends to flow in a lower direction from the upper surface, and to achieve concrete solidification.

Further, since the arm member 52 is in contact with the upper end of the curved mold 2, the curved mold 2 can be prevented from being lifted by suppressing the curved mold 2 from above.
In addition, the curved mold 2 can be prevented from being lifted by the weight of the beam member 4. Furthermore, since the beam members 4 are arranged along the tunnel axis direction, the bending of the curved mold 2 can be eliminated.
And the stress transmission performance improves by improving the quality of the junction part of the lining concrete C1 and the invert concrete C2, and the improvement of durability of the tunnel T can be aimed at.

In addition, since the inclined mold 5 is detachable, if the inclined mold 5 is removed immediately after compaction of the cast concrete, the lentance treatment can be performed on the day of placing.
Further, since the curved mold 2 is light and easy to handle, it is easy to remove the mold. Therefore, early quality confirmation is possible and concrete secondary finishing is also possible.

  Moreover, by using the incrementer 6 locked to the beam member 4, it becomes easy to place concrete on the lower surface of the inclined mold frame 5, and at the same time, compacting with a vibrator allows the concrete to be put into place. It can be constructed with high density.

  Since the lower end of the increaser 6 is located at the same height as the upper end of the curved mold 2, the concrete may be overlaid to a position higher than the top of the curved mold 2 in the increaser 6. it can. Therefore, the compacting operation can be performed without worrying about the concrete spilling from the formwork.

Since the pitch of the arm member 52 and the length of the incrementer 6 are set to be equal to each other, the construction can be performed without requiring the concrete to flow, and the workability is excellent.
Since the increaser 6 can be easily attached and detached, it is easy to change the concrete placement location.

Since the work scaffold is formed, the work at the time of placing concrete, the attaching / detaching work of the inclined mold 5 and the increaser 6 and the like are facilitated, and the workability is further improved.
Moreover, by using the increaser 6, it is possible to prevent material separation of the concrete.

Since the inclination angle of the inclined mold 5 is determined by bringing the arm member 52 into contact with the curved mold 2 and the upper flange of the beam member 4, workability is excellent.
Further, since the inclined mold 5 is disposed in contact with the upper end of the curved mold 2, the inclined surface C4 can be easily formed from the upper end of the curved mold 2.

The present invention is not limited to the above-described embodiment, and the above-described constituent elements can be appropriately changed without departing from the spirit of the present invention.
For example, the beam member 4 may be installed as necessary, and may be omitted when the slope formwork 5 is directly fixed to the reinforcing member 3.

Further, the increaser 6 may be used as necessary, and concrete may be directly placed in the mold using a transport pipe extending from the pump.
Moreover, what is necessary is just to form a work scaffold as needed.

  Further, the inclined mold 5 does not necessarily need to be detachably attached. For example, it may be provided so as to be rotatable in the vertical direction via a hinge, or may be provided so as to be slidable in the vertical direction or the horizontal direction. Further, the inclined mold 5 may be integrally fixed to the curved mold 2.

DESCRIPTION OF SYMBOLS 1 Form for inversion 2 Curved form 3 Reinforcement material 31 Lateral reinforcement material 32 Vertical reinforcement material 4 Beam material 41 Mounting part 5 Inclined formwork 51 Formwork body 52 Arm member 6 Increser 7 Working scaffold C1 Clay concrete C2 Invert Concrete C3 Invert concrete edge C4 Inclined surface C5 Horizontal surface T Tunnel lining

Claims (5)

A curved formwork for forming the inner surface of Invert;
A tunnel inversion formwork comprising a reinforcing material provided on the back surface of the curved formwork,
An invert mold, comprising an inclined mold for molding the upper end surface of the invert.   The invert formwork according to claim 1, wherein the inclined formwork is detachably attached to the reinforcing material. On the reinforcing material, a beam material is laid along the tunnel axis direction,
The inclined mold has an arm member,
3. The invert form according to claim 1, wherein an end of the arm member on the air side in the tunnel is attached to the beam member. 4.   The invert mold according to claim 3, wherein an increase for placing concrete between the invert reinforcing bar and the curved formwork is locked to the beam material. frame. The reinforcing material is a lateral reinforcing material that extends from the upper end of the curved mold in the direction toward the inside of the tunnel, and a vertical reinforcing material that connects the lower end of the curved mold and the tip of the horizontal reinforcing material. , And
The invert according to any one of claims 1 to 4, wherein a working scaffold supported by the lateral reinforcing member and the vertical reinforcing member is formed above the curved formwork. Formwork for.

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