JP6941537B2 - Construction method of curing formwork structure and tunnel lining body - Google Patents

Description

The present invention relates to a curing formwork structure and a method of constructing a tunnel lining body.

It is known that underwater curing enhances the strength, denseness, crack resistance, and durability of concrete. Therefore, when curing concrete, it is preferable to adopt a curing method that can prevent drying and create an environment close to underwater curing.
As such a curing method, for example, there is a method of sprinkling water on the surface of concrete after demolding. However, although sprinkling curing can create an environment similar to underwater curing on a horizontal surface such as the upper surface of concrete, it takes time and effort to evenly and evenly retain water on the side surfaces (vertical surface, slope, etc.). It takes.
Therefore, Patent Document 1 discloses a curing method using a curing mold including a mold body and a water-retaining portion that covers the inner surface of the mold body. In this curing method, concrete is placed in a curing form, and after a predetermined strength is developed in the concrete, water is supplied to the water retention part, and the concrete is cured in an environment close to underwater curing.
Further, Patent Document 2 describes a curing method in which after a predetermined strength is developed in concrete, a support member of a formwork is once loosened, a water retention mat is sandwiched between the concrete and a weir, and water is supplied to the water retention mat. Is disclosed. In the curing method of Patent Document 2, the formwork (weir plate) is fixed by a jig embedded in concrete.

Japanese Unexamined Patent Publication No. 2010-163785 Japanese Unexamined Patent Publication No. 2014-181524

In the conventional curing method, it is necessary to perform curing with the support member used at the time of placing concrete left behind. Therefore, when concrete is continuously placed by moving the formwork (slide center, etc.) in sequence like tunnel lining, the formwork (supporting member) should be moved until the curing is completed. This was an obstacle to shortening the construction period. Further, the jig of Patent Document 2 has a problem that it cannot be used for the construction of a tunnel lining body.
From this point of view, the present invention proposes a method of constructing a curing formwork structure and a tunnel lining body capable of starting concrete placing work in another construction area without waiting for the elapse of the curing period. Is the subject.

In order to solve the above problems, the curing formwork structure of the present invention includes a water-permeable formwork attached to the surface of concrete, a formwork support material for fixing the water-permeable formwork, and curing water on the water-permeable formwork. The formwork support material is characterized in that the formwork supporting material is pressed against the surface of the concrete by taking a reaction force against the curing water supply means. ..
When the curing water supply means includes a water storage tank for storing the curing water and a water tank pedestal on which the water storage tank is mounted, between the water permeable form and the water tank pedestal. The formwork support material may be provided.
Further, it is desirable that the water-permeable formwork includes a weir plate and a water-retaining layer laminated on the concrete side of the weir plate.
According to such a curing formwork, since the water-permeable formwork is fixed by the weight of the curing water supply means (water storage tank), it is not necessary to use the support structure used at the time of concrete placing during the curing period. Therefore, by diverting the support structure, it is possible to start the construction of other construction areas during the curing period, and by extension, the construction period can be shortened.

Further, the method of constructing the tunnel lining body of the present invention is a formwork assembling step in which a water-permeable formwork supported by a slide center is installed in the drilling hole, and between the inner wall surface of the drilling hole and the water-permeable formwork. It includes a casting step of placing concrete and a support material installation step of removing the slide center and installing a formwork support material for supporting the water-permeable formwork. It is characterized in that a curing water supply means for supplying curing water to the water-permeable formwork is provided, and the mold support material is interposed between the water-permeable mold and the curing water supply means.
According to the construction method of the tunnel lining body, the slide center can be moved to the next construction zone with the water permeable formwork left. That is, according to the present invention, it is possible to carry out the construction of the tunnel lining body in the trailing construction zone while performing curing while supplying curing water to the concrete surface in the preceding construction zone. As a result, the construction period of tunnel construction can be shortened.

According to the curing formwork structure and the construction method of the tunnel lining body of the present invention, it is possible to start the concrete placing work in another construction area without waiting for the elapse of the curing period by the water-permeable formwork.

It is a front view which shows the formwork for lining concrete which concerns on embodiment of this invention. It is a front view which shows the installation state of the water-permeable formwork. It is an enlarged cross-sectional view which shows the water-permeable formwork. It is a front view which shows the curing formwork structure.

In the present embodiment, when constructing a tunnel lining body that is continuous in the tunnel axial direction using a slide center, a method of constructing the tunnel lining body that makes it possible to shorten the construction period as compared with the conventional method and a method of constructing the tunnel lining body. The curing formwork structure used for this will be described. The construction method of the tunnel lining body and the curing formwork structure of the present embodiment can shorten the construction period by starting the concrete placing work in the adjacent trailing construction zone in parallel with the concrete curing in the preceding construction zone. It is said.

The construction method of the tunnel lining body of the present embodiment includes a formwork assembly process, a casting process, a support material installation process, and a curing process.
In the formwork assembly process, as shown in FIG. 1, the slide center 1 is installed in the excavation hole 2. The slide center 1 is movable along the axial direction of the tunnel, allowing the lining concrete of the tunnel to be continuously cast. In this embodiment, the sprayed concrete 21 is sprayed on the hole wall (inner surface) of the excavation hole 2. The slide center 1 is installed in a state where a predetermined distance (thickness required for the tunnel lining body) is secured from the surface of the hole wall (sprayed concrete 21 in this embodiment) of the excavation hole 2. The sprayed concrete 21 may be omitted depending on the ground conditions.
The slide center 1 of the present embodiment includes an upper foam 11, a side wall foam 12, and a lower foam 13. The upper foam 11 is arranged at the top of the tunnel. The side wall foam 12 is arranged on the side wall portion of the tunnel. The upper end of the side wall foam 12 is connected to the end of the upper foam 11. The lower foam 13 is connected to the lower end of the side wall foam 12 and is disposed on the legs of the tunnel side wall.
A support member 14 is arranged on the inner air side (center side of the tunnel) of the upper foam 11, the side wall foam 12, and the lower foam 13. The support member 14 is a member that supports the upper foam 11, the side wall foam 12, and the lower foam 13, and is a framework structure formed in a portal shape by appropriately combining shaped steel and the like. The support member 14 has wheels 15 at the lower ends and travels on rails laid along the tunnel axial direction. That is, the slide center 1 can be moved to a predetermined position. The traveling means of the support member 14 is not limited.
The support member 14 rotatably supports the upper foam 11, the side wall foam 12, and the lower foam 13 around a rotation axis parallel to the tunnel axis or forward and backward in the tunnel radial direction. That is, the slide center 1 can be reduced in diameter at the time of demolding (moving). Further, the support member 14 includes a work scaffold 16. The work scaffold 16 functions as a scaffold for workers at the time of placing concrete and a temporary storage place for materials and equipment. The arrangement of the work scaffold 16 is not limited.

As shown in FIG. 2, the outer surface (the surface on the hole wall side) of the lower foam 13 of the present embodiment is located closer to the center of the tunnel than the outer surface of the side wall foam 12. That is, a step is formed between the side wall foam 12 and the lower foam 13. In the present embodiment, the water permeable form 3 is provided at the stepped portion between the side wall foam 12 and the lower foam 13. That is, the water-permeable formwork 3 is provided so as to be attached to the surface of the concrete C in a state of being supported by the slide center 1. The outer surface of the water permeable formwork 3 is flush with the outer surface of the side wall foam 12.

The water-permeable formwork 3 includes a weir plate 4, a water-retaining layer 5 laminated on the concrete C side of the weir plate 4, and a water-permeable sheet 6 laminated on the concrete C side of the water-retaining layer 5. The configuration of the water-permeable formwork 3 is not limited.
The weir plate 4 is made of a wooden plate material. The weir plate 4 disperses the force when supporting the water-permeable formwork 3. The material constituting the weir 4 is not limited to wood. Further, the weir plate 4 may be provided as needed, and may be omitted if the water retention layer 5 has sufficient proof stress.

The water retention layer 5 is formed of a plate material configured to retain water. As shown in FIG. 3, the water-retaining layer 5 of the present embodiment includes a core material 51 and face materials 52 and 52 laminated on both sides of the core material 51, respectively. The material constituting the water retention layer 5 is not limited as long as it is a plate-shaped member capable of retaining water.
The core material 51 is formed by heat-sealing two thermoplastic resin sheets 54, 54 on which a plurality of hollow convex portions 53, 53, ... Are formed, in a state where the hollow convex portions 53 are butted against each other. There is.
The hollow convex portions 53, 53, ... Of the thermoplastic resin sheets 54, 54 have a truncated cone shape and have the same dimensions. The plurality of hollow convex portions 53, 53, ... Are arranged on one surface of the thermoplastic resin sheet 54 at regular and staggered intervals, and a continuous internal space 55 is provided inside the core material 51. It is formed. The shape of the hollow convex portion 53 is not limited to a truncated cone shape, and may be, for example, a prismatic trapezoidal shape or a columnar shape. Further, the size and arrangement of the hollow convex portion 53 are not limited. The material constituting the thermoplastic resin sheet 54 is not limited, but polypropylene-based resins such as homopolypropylene, random polypropylene, and block polypropylene are available in terms of productivity, cost, physical properties, low temperature resistance, and heat resistance. It is preferable from the viewpoint of the balance with the characteristics such as.

The face materials 52 and 52 laminated on both sides of the core material 51 are made of a plate material or a sheet (thermoplastic resin sheet) made of a thermoplastic resin. The material of the face material 52 is not limited, but it is compatible with the core material 51 and can be heat-sealed, and has a balance with characteristics such as cost, physical properties, low temperature resistance, and heat resistance. From the viewpoint of excellent properties, for example, polypropylene-based resins such as homopolypropylene, random polypropylene, and block polypropylene are preferable.

A plurality of through holes (leaching means) 56, 56, ... Are formed on the surface (outer surface) of the water retention layer 5 on the water supply layer side so that water (curing water, breathing water, etc.) can flow in and out. Has been done. The through holes 56 are formed in the face material 52 and the core material 51, and some of the through holes 56 reach the internal space 55. Therefore, when water is passed through the internal space 55 of the water retention layer 5, the water flows out from the through hole 56 and is supplied to the surface of the concrete C via the water permeable sheet 6. The size of the through hole 56 is not limited, but it is preferably 1 mm or more in diameter so as not to be clogged by mortar or fine aggregate. Further, the arrangement of the through holes 56 is not limited, but in the present embodiment, the distance between the through holes 56 (the distance between the adjacent through holes 56, 56) is 10 mm or more.

As shown in FIG. 2, the water permeable sheet 6 is arranged on the contact surface with the concrete C, absorbs excess water (including breathing water) generated after the concrete C is placed, and is formed of the concrete C. Moisture (curing water) is supplied to the surface of concrete C during curing.
The water permeable sheet 6 of this embodiment is a non-woven fabric. The material constituting the water-permeable sheet 6 is not limited as long as it is a sheet material having water permeability, and may be, for example, a woven fabric or a vinyl sheet having a large number of holes formed therein. You may.

In the placing step, as shown in FIG. 1, concrete C is placed between the inner wall surface of the excavation hole 2 (sprayed concrete 21) and the slide center 1 (water permeable formwork 3).
Excess water including breathing water generated after placing the concrete C flows out from the through holes 56, 56, ... To the internal space 55 of the water permeable formwork 3 through the water permeable sheet 6. The surplus water that has flowed out into the internal space 55 may be drained as appropriate, or may be stored in the internal space 55. The surplus water may be drained from, for example, a drainage port (not shown) formed in advance in the permeable mold 3. When the concrete C develops a predetermined strength, the slide center 1 is demolded and moved. At this time, the water-permeable formwork 3 is left on the surface of the concrete C.

In the support material installation step, the slide center 1 is removed (that is, the slide center 1 is moved), and as shown in FIG. 4, the form support material 8 that supports the water-permeable form 3 is installed to cure the mold. The frame structure 7 is formed. The curing formwork structure 7 includes a water-permeable formwork 3 attached to the surface of concrete C, a formwork support material 8 for fixing the water-permeable formwork 3, and a curing water supply means for supplying curing water to the water-permeable formwork 3. It has a 9.
After removing the slide center 1, the curing water supply means 9 is arranged, and the mold support material 8 is interposed between the water permeable mold 3 and the curing water supply means 9. The curing water supply means 9 of the present embodiment includes a water storage tank 91 for storing the curing water and a water tank stand 92 on which the water storage tank 91 is mounted. The water tank stand 92 is erected on the roadbed, and the water tank 91 is installed on the water tank stand 92. In the present embodiment, the formwork support material 8 is interposed between the water-permeable formwork 3 and the aquarium stand 92. When the water tank stand 92 is not provided (that is, when the water tank 91 is directly installed on the roadbed), the formwork support material 8 is interposed between the water-permeable form 3 and the water tank 91. Just do it.
The formwork support material 8 of the present embodiment is configured to be expandable by combining a so-called single pipe and a jack. The material constituting the formwork supporting material 8 is not limited as long as it can support the water-permeable formwork 3 at the time of curing.
Further, the aquarium stand 92 of the present embodiment is formed by a framework scaffold. The configuration of the water tank stand 92 is not limited as long as it can support the water tank 91, and may be formed by, for example, combining single pipes.

In the curing process, the concrete C is cured using the curing formwork structure 7. In the present embodiment, curing water is supplied to the water-retaining layer 5 (internal space 55) of the water-permeable formwork 3 and cured in an environment close to underwater curing until the concrete C develops a predetermined strength. The curing water is supplied from the curing water supply means 9 (water storage tank 91) to the water retention layer 5 via the water supply pipe 93. The water storage tank 91 is arranged at a position higher than the water retention layer 5, and the curing water is supplied to the water retention layer 5 by allowing it to flow down naturally. The method of supplying the curing water is not limited, and for example, it may be pumped by a pump or the like. Further, the formwork supporting material 8 takes a reaction force against the curing water supply means 9 and presses the water-permeable formwork 3 against the surface of the concrete C. The curing water supplied to the water-permeable formwork 3 (water-retaining layer 5) permeates the water-permeable sheet 6 through the through holes 56 and is supplied to the surface of the concrete C. Therefore, concrete C is cured in an environment close to underwater curing (water retention curing). When surplus water is stored in the water retention layer 5, the surplus water is also supplied to the surface of the concrete C.
When the curing of the concrete C is completed, the curing formwork structure 7 (water permeable formwork 3) is removed from the surface of the concrete C, and the curing water supply means is removed or moved.

According to the method of constructing the curing formwork structure 7 and the tunnel lining body of the present embodiment, the water-permeable formwork 3 is fixed by the weight of the curing water supply means 9 (water storage tank 91), and is therefore used when placing concrete. It is not necessary to use the provided support structure (slide center 1) during the curing period. Therefore, the slide center 1 can be cured while being moved to the next construction zone. As a result, it becomes possible to start construction (concrete placement) of another construction zone during the curing period, and by extension, the construction period can be shortened.
Since the water-permeable formwork 3 is used continuously from the time of placing concrete, it is not necessary to newly form the curing formwork structure 7 at the time of curing, and the workability is excellent.
Since the curing formwork structure 7 is mainly composed of a water storage tank 91 for storing the curing water supplied at the time of curing, it is not necessary to separately construct a support structure. Due to the weight of the water storage tank 91, the water permeable form 3 can be reliably pressed down. Further, since the curing formwork structure 7 uses commonly distributed materials such as a frame scaffold and a single pipe, it is economical and easy to handle.
Breathing water generated after the concrete C is placed and air bubbles generated on the surface of the concrete C (contact surface between the concrete C and the formwork) can be discharged through the water-permeable formwork 3, so that the construction is performed with high quality. be able to.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and each of the above-mentioned components can be appropriately modified without departing from the spirit of the present invention.
In the above-described embodiment, the construction of the tunnel has been described, but the construction that can be adopted by the curing formwork structure 7 is not limited to the tunnel construction, and can be adopted by the construction of any concrete structure.
In the above embodiment, the case where the curing formwork structure 7 is formed with the water-permeable formwork 3 used at the time of placing concrete left behind has been described, but the curing formwork structure 7 uses the formwork used at the time of placing concrete. It may be formed again after being demolded.

1 Slide center 2 Drilling hole 3 Water permeable formwork 4 Weir plate 5 Water permeable layer 6 Water permeable sheet 7 Curing formwork structure 8 Formwork support material 9 Curing water supply means 91 Water storage tank 92 Water tank stand

Claims (4)

A permeable formwork attached to the surface of concrete,
The formwork support material for fixing the water-permeable formwork and
A curing form structure including a curing water supply means for supplying curing water to the water-permeable form.
The formwork support material has a curing formwork structure, characterized in that the water-permeable formwork is pressed against the surface of the concrete by taking a reaction force against the curing water supply means. The curing water supply means includes a water storage tank for storing the curing water and a water tank stand on which the water storage tank is mounted.
The curing formwork structure according to claim 1, wherein the formwork support material is interposed between the water-permeable formwork and the aquarium stand. The curing formwork structure according to claim 1 or 2, wherein the water-permeable formwork includes a weir and a water-retaining layer laminated on the concrete side of the weir. The formwork assembly process, in which the permeable formwork supported by the slide center is installed in the excavation hole,
A casting process of placing concrete between the inner wall surface of the excavation hole and the permeable formwork,
It is a construction method of a tunnel lining body including a support material installation step of removing the slide center and installing a formwork support material for supporting the water-permeable formwork.
In the support material installation step, a curing water supply means for supplying curing water to the water-permeable formwork is arranged, and the mold support material is interposed between the water-permeable mold and the curing water supply means. A method of constructing a tunnel lining body, which is characterized by being installed.

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