JPH09310591A - Structure of form - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the term of works, and to reduce construction cost by installing a plurality of open-close type side planks with waterstop holding sections to a side plank mounted at the end section of forms and setting up detachable type side planks among the mutual open-close type side planks. SOLUTION: A part in the peripheral direction of forms 21 can be folded up to the inside, and the diameter of the other sections can be reduced while the forms 21 can be conveyed forward in the execution direction through the inside of an underground structure. A side plank for forming the placing joint surface of the underground structure is installed at an end section in the front of the execution direction of the forms 21. A rockable open-close type side plank 35A with waterstop holding sections 38c, 39c is mounted on the side plank. A plurality of the open-close type side planks 35A are disposed in the peripheral direction of the form unit 21 at regular intervals, and detachable type side planks to the form unit 21 are arranged among the mutually adjacent open-close type side planks 35A. Accordingly, operation at a time when the forms 21 are moved forward can be conducted easily and quickly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a formwork structure suitable for use in constructing an underground structure such as an underground conduit or a tunnel.

[0002]

2. Description of the Related Art Among underground structures such as underground conduits and tunnels, the underground structure is provided at a relatively shallow position below the ground surface. The so-called open-cut construction method of filling the ground after forming the structure on the bottom is most commonly used. In this method, in order to form an underground structure at the bottom of a groove, a formwork for forming the inner peripheral surface of the underground structure is assembled over a certain length in the continuous direction of the structure, and concrete is formed. After casting, the mold is dismantled after it has hardened. After this, the formwork is rearranged forward in the construction direction of the underground structure, and assembling and disassembling the formwork is repeated in the same manner as above to form the underground structure over a predetermined length. There is. However, in such a construction method, the assembling and disassembling work of the formwork are both performed manually at the site, so the workability is poor, which hinders reduction of the construction period and reduction of the construction cost.

As one of means for solving such a problem, there is a construction method using a needle beam type steel frame. This method is used in the formwork device 1 as shown in FIG.
Is used. This formwork apparatus 1 is roughly composed of a cylindrical formwork body 2 and a beam 3 arranged parallel to the axis of the formwork body 2. As shown in FIG. 8, the mold body 2 is divided into a plurality of units in the circumferential direction, and the bottom mold 2A and
It is composed of side molds 2B and 2B and an upper mold 2C. Of these, the upper mold 2C is further divided into two,
It is configured such that both ends thereof can be folded inward. Then, this formwork main body 2 includes an upper formwork 2C.
Is folded, and the bottom mold 2A and the side molds 2B, 2B are drawn inward in the cross-sectional direction so that the diameter can be reduced as a whole. Also, the beam 3 shown in FIG.
Is provided with a moving mechanism (not shown) that moves the mold body 2 forward and backward along the direction in which the beam 3 continues.

In order to form the underground structure 4 by using such a formwork device 1, first, the reinforcing bars constituting the underground structure 4 are first assembled on the front side in the construction direction of the formwork device 1. .
Next, the form body 2 is reduced in diameter, and the beam 3 is
Then, the mold main body 2 is expanded in diameter after being moved inward along the pre-assembled rebar. Then, concrete C is cast on the outer peripheral side of the mold 2 and is hardened, whereby the underground structure 4 in this section is formed. After this,
In the same manner as described above, by repeating the assembling of the reinforcing bars, the diameter reduction / advancement / expansion of the form body 2, and the placing and curing of concrete C, the underground structure 4 is extended and constructed. ing.

[0005]

However, the conventional formwork structure as described above has the following problems. In the above-mentioned formwork device 1, when forming the underground structure 4, the end plate 5 of the formwork body 2 is provided with the end plate 5 for forming the striking surface 4a. When the mold body 2 is moved forward, the end plate 5 moves forward in the section where the reinforcing bars are assembled first. Therefore, in order to avoid interference with the previously assembled reinforcing bars, the end plate 5 is moved forward. It is necessary to remove the end plate 5 over the entire circumference and attach it again to the mold body 2 after completion of the advancement. To remove and attach this gable plate 5,
Needless to say, it took time and labor, and this point hindered the further reduction of the construction period of the underground structure 4 and the reduction of the construction cost. Further, as shown in FIG. 9, in order to prevent the ingress of groundwater from the splicing surface 4a of the underground structure 4 from the splicing portion of the previously formed portion and the subsequently formed portion. It is necessary to provide an annular water stop plate 7 that is continuous in the circumferential direction. Therefore, the end plate 5 needs to have a structure for holding the water stop plate 7, and at present, a structure for bolting the water stop plate 7 to the end plate 5 using the bracket 8 is used. The work of removing and installing the gable plate 5 was troublesome. The present invention has been made in view of the above points, and an object of the present invention is to provide a formwork structure capable of shortening the construction period and the construction cost.

[0006]

The invention according to claim 1 is
Formwork for forming the inner wall of reinforced concrete underground structure continuous in one direction, part of its circumferential direction can be folded inward, and the other part can be reduced in diameter In addition, it is configured to include a transporting means for transporting the formwork forward through the inside of the underground structure in the construction direction, and the underground structure is provided at an end portion on the front side in the construction direction of the formwork. A gable plate for forming the splicing surface is swingably provided, and an intermediate portion of the gable plate is foldable so that a water blocking plate to be embedded in the splicing surface can be sandwiched and held therein. It is characterized in that it is provided with a retractable gable plate.

According to a second aspect of the present invention, in the formwork structure according to the first aspect, a plurality of the openable and closable end plates are arranged at intervals defined in the circumferential direction of the formwork and are adjacent to each other. It is characterized in that a detachable gable plate which is detachable from the mold is arranged between the openable gable plates.

According to a third aspect of the invention, in the formwork structure according to the second aspect, as the detachable end plate is separated from the formwork toward the front in the construction direction, the width direction thereof becomes gradually larger. It is characterized by having a tapered shape.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An example of an embodiment of a formwork structure according to the present invention will be described below with reference to FIGS. Here, the formwork structure according to the present invention will be described using an example of a case where the formwork structure is used for constructing a tunnel, for example.

As shown in FIG. 1, the formwork apparatus 20 comprises a tubular formwork unit 21 corresponding to the cross-sectional shape of the inner surface of a tunnel (underground structure) T to be formed, that is, a circle, and a formwork unit. 21 and a form supporting beam 22 extending along the axial direction.

The mold frame unit 21 is composed of a plurality of ring molds 21a, for example, seven ring-shaped molds 21a, which are separably connected in the axial direction. As shown in FIG. 2, the mold unit 21 is also divided into four in the circumferential direction into a bottom (invert) mold 23, side molds 24 and 25, and an upper mold 26. The frame unit 21 has a substantially square-shaped frame 27 at its center.
The bottom mold 23, the side molds 24 and 25, and the upper mold 26 are supported on the frame 27 in the following manner.

As shown in FIG. 3, the bottom frame 23 is divided into two in the circumferential direction, and can be folded inward by hinges provided at both ends. The two bottom molds 23 are opened and closed by the bottom hydraulic cylinders 28, 28.

The side molds 24 and 25 and the upper mold 26 are drawn inward by the side hydraulic cylinders 29 and 29 in a substantially horseshoe-shaped state, and their outer diameters in the cross-sectional direction are reduced. It can be reduced.

The formwork support beam 22 has a three-dimensional truss structure having a rectangular cross section, and is arranged on the central axis of the formwork unit 21. As shown in FIG. 1, the form supporting beam 22 includes a leg 3 that is extendable forward and backward.
It has 0 and 31, and these legs 30 and 31 stand on the construction bottom surface or the bottom form 23 (see FIG. 2). Further, as shown in FIG. 2, the frame support beam 22 supports the frame 27 slidably above and below the frame 27 along the axial direction of the frame unit 21. As a result, the mold frame unit 21 and the mold frame support beam 22 are movable back and forth in the axial direction. The formwork support beam 22 is provided with a drive mechanism (conveying means; not shown) for moving the formwork support beam 22 back and forth with respect to the formwork unit 21.

As shown in FIG. 1, in the formwork unit 21 of the formwork device 20 having such a structure, concrete injection ports 33, 33, ... A concrete injection pipe 34 is connected to the inlet 33. As a result, concrete is injected from the concrete injection pipe 34 to the outer peripheral side of the form unit 21 through the concrete injection port 33.

Further, at the peripheral edge of the front end of the mold unit 21, there is provided a gable plate 35 which closes the gap between the mold unit 21 and the surrounding ground over the entire circumference. As shown in FIG. 4, the end plate 35 is an openable / closable end plate 35A that can be opened and closed.
And a detachable end plate 35B that can be attached and detached, and the open-close end plate 35A and the detachable end plate 35B are alternately arranged in the circumferential direction.

As shown in FIGS. 4 (a) and 5, the opening / closing end plate 35A includes a support bracket 36 fixed to the front end peripheral portion of the form unit 21, and the support bracket 36.
And a gable plate main body 37 hinged to. Furthermore, the end plate main body 37 is
The base 38 on the support bracket 36 side and the tip 3 on the outer peripheral side
It is divided into two parts.

As shown in FIG. 5, the base portion 38 of the end plate body 37 has a mold surface 38a, connecting plates 38b and 38b formed on both sides of the mold surface 38a in the circumferential direction, and the mold surfaces 3a and 3b.
8a and a water stop plate holding portion 38c formed on the outer peripheral side of the connecting plate 38b. And this base 3
Reference numeral 8 is rotatably connected to the support bracket 36 via pins 40 at the inner peripheral side ends of the connecting plates 38b, 38b. On the other hand, the tip portion 39 is formed of a form frame surface 39a, a sheet pile holding bracket 39b for holding the sheet pile 41, and a water stop plate holding portion 39c formed on the inner peripheral side of the form frame surface 39a. . A shaft 42 is provided at an end portion on the inner peripheral side of the tip 39, and is rotatably connected to the connecting plates 38b, 38b of the base 38 via the shaft 42.

As a result, as shown in FIG. 6, the base portion 38 and the tip portion 39, which constitute the end plate body 37, can be folded in two steps by the pin 40 and the shaft 42. Then, as shown in FIG. 5, the gap between the mold frame unit 21 and the surrounding ground in the extended state of the end plate body 37, that is, the mold surface 38a of the base 38 and the mold surface 39a of the tip 39. When the water blocking plate is closed, the water blocking plate holding portion 38c of the base portion 38 and the water blocking plate holding portion 39c of the distal end portion 39 are separated from each other by a predetermined gap so that the water blocking plate 45 can be held by being sandwiched there. Are facing each other. Water stop plate 4
Reference numeral 5 denotes a cylindrical member having a constant length in the axial direction of the formwork unit 21 and continuous in the circumferential direction, and by embedding it in the casting joint surface of the concrete C to be cast on the front end side of the construction, Concrete to be newly placed (not shown)
It is intended to stop the water at the splicing part with.

Also, as shown in FIG. 4, the detachable end plate 3
The width dimension of 5B is set to a dimension such that the openable and closable end plates 35A adjacent to each other do not interfere with each other when the openable and closable end plate 35A is folded and opened. FIG.
As shown in (a), each detachable end plate 35B has a tapered shape in which the dimension in the circumferential direction gradually decreases as it is separated from the mold unit 21, when viewed in cross section. The openable and closable end plate 35A has both end surfaces formed by inclined surfaces corresponding to the detachable end plate 35B. The removable gable plates 35B are detachable between the adjacent openable gable plates 35A when they are closed, and when they are attached, the gap between the form unit 21 and the surrounding ground is closed. be able to.

Next, as shown in FIG. 1, in order to form the tunnel T by using such a formwork device 20, basically, a tunnel excavated by a shield excavator or the like is used in the same manner as the conventional one. In H, assembling the reinforcing bar, advancing the formwork support beam 22 to the section where the reinforcing bar is assembled, advancing the formwork unit 21 in a reduced diameter state, expanding the formwork unit 21 concrete injection pipe 34, concrete pouring From the inlet 33, filling the space between the mine H and the form unit 21 with concrete C, after the concrete C develops a predetermined strength,
After the diameter of the mold unit 21 is reduced, the tunnel T having a predetermined length is formed by repeating the above steps.

Here, in the above case, as shown in FIGS. 5 and 6, the reinforcing bars S are arranged so as not to interfere with the opening / closing operation of the opening / closing end plate 35A.

Prior to the filling of the concrete C, as shown in FIG. 5, a water blocking plate 45 is attached to the base portion 38 and the tip end portion 39 of the opening / closing gable plate 35A of the gable plate 35 of the form unit 21. It is set by being sandwiched between the plate holding portions 38c and 39c. If concrete C is filled in this state, the water stop plate 45 is buried in the splicing surface on the front end side in the construction direction.

When the diameter of the form unit 21 is reduced (see FIG. 3), the end plate 35 provided at the front end portion thereof is used.
Open as shown below. First, the detachable end plates 35B, 35B, ... Are pulled out over the entire circumference of the end plate 35 prior to the diameter reducing operation of the form unit 21. Then, each opening-and-closing type gable board 35A is opened. At this time, as shown in FIG. 6, the opening-and-closing type end plate 35A is configured to open in two stages by the base portion 38 and the tip end portion 39, so that the water blocking plate 45 held by the concrete C is hardened. It can be easily removed by leaving it inside. In this way, by opening the end plate 35 over the entire circumference, the end plate 35 does not interfere with the rebars (not shown) previously assembled when the mold unit 21 is moved forward.

In the structure of the formwork apparatus 20 described above, the end plate 35 is provided at one end of the formwork unit 21.
5 has a structure in which an openable / closable end plate 35A having a water blocking plate holding portion 38c, 39c is swingable. Further, a plurality of openable and closable end plates 35A are arranged at intervals defined in the circumferential direction of the mold unit 21, and the openable and closable end plates 35A are attached to and removed from the form unit 21 between adjacent adjoining openable end plates 35A. The detachable end plate 35B is arranged. Thus, when the formwork unit 21 is moved forward, it is sufficient to open and close the releasable end plate 35A after removing only the detachable end plate 35B without attaching and detaching the end plate over the entire circumference as in the conventional case. Further, since the water blocking plate 45 can be held by being sandwiched between the water blocking plate holding portions 38c and 39c of the opening / closing type end plate 35A, the water blocking plate 45 can be easily held without using any bracket or the like. As a result, it is possible to reduce the construction period and the construction cost.

By the way, in the formwork apparatus 20 described above,
A removable gable plate 35B is arranged between the openable gable plates 35A adjacent to each other. In contrast to such a configuration, for example, it is conceivable to provide a plurality of opening / closing gable plates 35A adjacent to each other over the entire circumference without using the detachable gable plate 35B. In this case, the gable plate main body 37 of each opening / closing gable plate 35A is provided. Due to the difference in circumferential length between the inner and outer circumferences,
When the openable / closable end plate 35A is opened, it overlaps with another adjacent open / closed end plate 35A. Therefore, especially the retractable end plate 3
When closing 5A, it is necessary to sequentially close the openable and closable end plate 35A over the entire circumference, which is inconvenient in work and inconvenient. On the other hand, as described above, by applying the configuration in which the removable gable plates 35B are arranged between the adjacent gable plates 35A which are adjacent to each other, only the removable gable plates 35B are removed and then the openable gable plates 35A are removed. By opening, the opening / closing work of the end plate 35 can be performed from any position without interfering with the adjacent open / close type end plates 35A, and can be performed in parallel at a plurality of positions. As a result, also in this respect, the effect of shortening the construction period and the construction cost can be made more remarkable.

Moreover, as the detachable end plate 35B is separated from the form unit 21 toward the front in the construction direction,
Since the taper shape whose width direction gradually increases, the detachable end plate 35B can be easily attached and detached,
Further, at the time of mounting, since the openable and closable end plates 35A and 35A on both sides of the detachable end plate 35B are pressed in the circumferential direction (sideways), the end plate 35 can be reliably closed.

It should be noted that, in the above-described embodiment, the configuration of the formwork device 20 other than the end plate 35 is not limited to the above-mentioned one, and other structures may be applied. Also,
An example of forming the tunnel T having a circular cross-section with the formwork device 20 has been described, but the present invention can be similarly applied to other underground structures such as a water conduit other than the tunnel. Furthermore, the same configuration as that of the formwork device 20 can be applied to other shapes, such as a rectangle, instead of the circular shape in cross section. In the case of forming an underground structure having a rectangular cross section, the detachable end plate 35B is abolished and the openable bracket 3 is provided over the entire circumference.
It is also possible to arrange the 5A adjacent to each other, and in this case also, the water blocking plate 45 is attached to the water blocking plate holding portions 38c, 39.
It can be held at c. Further, the method of constructing the tunnel T is not limited in any way, and other construction methods such as an open cut construction method can be applied in addition to the shield construction method. Further, the reinforcing bars S may be arranged by a predetermined length as the formwork apparatus 20 advances, or may be arranged in advance over the entire length of the tunnel T.

[0029]

As described above, according to the formwork structure of the first aspect of the present invention, the end plate of the formwork is provided with the end plate, and the end plate is swingably attached to the formwork. The gable plate is provided, and the openable gable plate is foldable at an intermediate portion thereof so that the water blocking plate can be sandwiched and held therein. As a result, when the formwork is moved forward, it is possible to simply open and close the releasable type end plate without removing and attaching the end plate over the entire circumference as in the conventional case. Further, since the water blocking plate can be sandwiched and held in the folding portion of the intermediate portion of the openable gable plate, the water blocking plate can be easily held without using any bracket or the like. As a result, it is possible to reduce the construction period and the construction cost.

According to the formwork structure of the second aspect, a plurality of the openable and closable end plates are arranged at a predetermined interval in the circumferential direction of the formwork, and the molds are provided between the adjacent openable and closable end plates. The frame is provided with a detachable gable plate which is detachable. As a result, even when the underground structure has a curved shape such as a circular shape in cross section, opening / closing the removable gable plate after removing the removable gable plate may cause adjacent openable gable plates to interfere with each other. Since it is not necessary, the work of opening and closing the end plate can be performed from any position, and can be performed in parallel at a plurality of positions. As a result, the work period can be shortened and the work cost can be further reduced.

According to the formwork structure of the third aspect, as the detachable gable plate is separated from the formwork toward the front in the construction direction, the width direction thereof becomes a tapered shape. ing. This makes it possible to easily attach and detach the detachable gable plate, and at the time of attachment, the openable gable plates on both sides of the detachable gable plate are pressed in the circumferential direction.
It is possible to reliably perform the blockage by the gable plate.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an example of a formwork apparatus according to the present invention.

FIG. 2 is a front view of the formwork apparatus.

FIG. 3 is a front sectional view showing a state where the diameter of the formwork apparatus is reduced.

4A and 4B are a plan view and a front view showing a gable frame provided in the formwork apparatus.

FIG. 5 is a side view showing the end frame.

FIG. 6 is a side view showing an open state of the gabled frame.

FIG. 7 is a side view showing an example of a conventional formwork apparatus.

FIG. 8 is a front view of the formwork apparatus.

FIG. 9 is a side sectional view showing a gable frame provided in the formwork apparatus.

[Explanation of symbols]

 21 Formwork Unit (Formwork) 35 Gable Plate 35A Openable Gable Plate 35B Detachable Gable Plate 45 Water Stop Plate T Tunnel (Underground Structure)

Claims (3)

[Claims] 1. A formwork for forming an inner wall of a reinforced concrete underground structure continuous in one direction, part of which in the circumferential direction can be folded inward, and the other part has a reduced diameter. With a possible configuration, it is configured to include a conveying means for conveying the formwork forward through the inside of the underground structure in the construction direction, at the end portion on the construction direction front side of the formwork, A gable plate for forming a splicing surface of the underground structure is swingably provided, and an intermediate portion of the gable plate is foldable so that a water stop plate to be embedded in the splicing surface is provided. A formwork structure characterized in that it is provided with an opening-and-closing type gable plate configured to be able to sandwich and hold. 2. The formwork structure according to claim 1, wherein a plurality of the openable and closable gable plates are arranged at intervals defined in the circumferential direction of the formwork, and between the openable and closable gable plates adjacent to each other. The formwork structure is characterized in that a detachable gable plate which is detachable from the formwork is provided in the. 3. The formwork structure according to claim 2, wherein the detachable end plate has a taper shape in which a width direction thereof gradually becomes larger as the detachable end plate is separated from the formwork toward a front side in a construction direction. Formwork structure characterized by that.