JP5727306B2 - Curing method for tunnel lining concrete - Google Patents

Description

  The present invention relates to a method for curing tunnel lining concrete for curing tunnel lining concrete placed at a work site of tunnel construction.

It is known that if the cast concrete dries quickly before a sufficient hydration reaction is performed, problems such as a decrease in durability may occur. For this reason, after concrete has been placed at a construction site such as construction work or civil engineering work, the concrete usually dries quickly by watering the concrete placement surface or covering it with a curing sheet. It is preventing.
For example, Patent Document 1 proposes an inexpensive concrete curing sheet having good workability on site and excellent heat retention as such a curing sheet.

Japanese Utility Model Publication No. 6-65558

However, conventional curing sheets such as the concrete curing sheet of Patent Document 1 may be simply laid on the floor surface as it is when curing concrete placed on the floor surface (see Patent Document 1). For concrete placed on the ceiling or wall surface, it must be adhered to the concrete placement surface using a support material (see FIG. 11 of Patent Document 1), improving its workability. There was room for.
In particular, when curing tunnel lining concrete that has been laid at the tunnel construction site, a curing sheet must be laid on the inner peripheral surface of a wide range of downward tunnels, which is very difficult. there were.

Moreover, in order to improve the durability of the cast concrete, it is preferable to maintain the wet state of the concrete as long as possible so that the hydration reaction is sufficiently performed.
However, with the conventional curing sheet, it is not possible to supply additional water to the concrete placement surface after the curing sheet is laid, and the concrete is kept wet only until the water sprayed first dries. I couldn't.

  The present invention has been considered in view of the above circumstances, and is intended to provide a method for curing tunnel lining concrete that is excellent in workability when curing tunnel lining concrete placed at a tunnel construction work site. And

  The tunnel lining concrete curing method according to the present invention is a method of placing the tunnel lining concrete after setting and fixing the centle, and then repeating the procedure of demolding and moving the centle to cover the entire length of the tunnel. When placing concrete, a bubble sheet formed by laminating a back film that encloses air in the protrusions on a cap film formed with a number of protrusions that bulge in a hollow shape is used to cast the concrete after demolding the center. While extending so that the projection side faces the installation surface, it is supported by a pressing member that is arched along the inner peripheral surface of the tunnel, and a negative pressure is applied between the air bubble sheet and the concrete placing surface. This is a method of laying both in close contact.

  According to the present invention, it is possible to easily lay a wide range of downward tunnel inner peripheral surfaces, and thereby, tunnel lining concrete can be cured sufficiently and efficiently.

It is explanatory drawing which shows the outline of embodiment of the curing method of the tunnel lining concrete which concerns on this invention. It is the principal part enlarged view which expands and shows a part of range (alpha) enclosed with the dashed-dotted line in FIG. 1, and its AA sectional drawing. It is explanatory drawing which shows an example of a bubble sheet structural piece. It is a top view which shows the example which connected the bubble sheet structural piece shown in FIG. 3 to the width direction, and was used as the bubble sheet. It is CC sectional drawing of FIG. It is explanatory drawing which shows the outline of the modification of embodiment of the curing method of the tunnel lining concrete which concerns on this invention. It is explanatory drawing of the site | part shown by the DD cross section of FIG. It is a top view which shows the other example of a bubble sheet. It is EE sectional drawing of FIG. It is explanatory drawing which shows typically the example which laid the bubble sheet over the some division in which the tunnel lining concrete was laid. It is explanatory drawing which shows the outline of the other modification of embodiment of the curing method of the tunnel lining concrete which concerns on this invention. It is explanatory drawing which shows the outline of the other modification of embodiment of the curing method of the tunnel lining concrete which concerns on this invention. It is explanatory drawing which shows the example which branches a watering pipe. It is explanatory drawing which shows the example which provides auxiliary piping in the ladder step shape between two sprinkling pipes.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
In addition, FIG. 1 is a conceptual diagram for demonstrating the curing method of the tunnel lining concrete which concerns on this embodiment.

  The tunnel lining concrete curing method according to the present embodiment is used when placing tunnel lining concrete in a tunnel construction work site, and generally after installing and fixing a formwork called a centle. When laying tunnel lining concrete, and then casting the tunnel lining concrete over the entire length of the tunnel by repeating the process of demolding and moving the centle, it is for curing the placed concrete .

In the present embodiment, as shown in FIG. 1, the bubble sheet 1 is laid on the concrete placement surface 10 after the centle demolding, and the placed concrete is cured.
Here, FIG. 1 is an example of curing for each section of the tunnel lining concrete that is placed by repeating the above-described procedure, and outlines only the structures and equipment laid and installed in the tunnel during curing. The illustrated tunnel lining concrete is omitted.
Moreover, while enlarging a part in the range (alpha) enclosed with the dashed-dotted line in FIG. 1, it shows to Fig.2 (a), and the AA cross section of Fig.2 (a) is shown in FIG.2 (b).

As shown in FIG. 2, the bubble sheet 1 is formed by laminating a back film 4 that encloses air in the protrusion 2 on a cap film 3 formed with a large number of protrusions 2 that bulge in a hollow shape. As the resin, for example, a polyolefin resin such as a polypropylene resin and a polyethylene resin can be used alone or in combination of two or more.
The bubble sheet 1 is not limited to the two-layer structure including the cap film 3 and the back film 4. For example, as shown in FIG. The sheet material 5 having the properties may be laminated.

  In order to lay the bubble sheet 1 on the concrete casting surface 10 after the demolding of the center, first, the bubble sheet 1 covers almost the entire inner peripheral surface of the tunnel from one side wall portion to the other side wall portion. The bubble sheet 1 is spread toward the tunnel traveling direction so as to be covered. At this time, the bubble sheet 1 is stretched so that the protrusion 2 side faces the concrete casting surface 10 after demolding the centle, and the bubble sheet 1 thus stretched is stretched in the tunnel traveling direction. However, it is supported by the pressing member 11 that is arched along the inner peripheral surface of the tunnel at regular intervals.

  In this manner, when the bubble sheet 1 is expanded in this manner, although not particularly shown, it is manufactured in an arch shape so as to face the inner peripheral surface of the tunnel from one side wall portion to the other side wall portion through the top end portion. If the air bag is placed so as to be movable in the tunnel traveling direction, and the air bubble sheet 1 is spread while being moved in the tunnel traveling direction by guiding the air bubble sheet 1 in this air bag, the work is facilitated. be able to. Moreover, in the example shown in FIG. 1, although the bubble sheet 1 is supported by the three pressing members 11, the number of the pressing members 11 which support the bubble sheet 1 is not limited to this, It increases as needed. Needless to say, you can.

After the expansion work of the air bubble sheet 1 on the concrete placement surface 10 to be cured is finished, the air is then evacuated from between the air bubble sheet 1 and the concrete placement surface 10 to obtain the air bubble sheet 1 and the concrete placement surface 10. Make negative pressure between. Thereby , the bubble sheet 1 adheres to the concrete placing surface 10 . That is, a portion of the air bubble sheet 1 facing the concrete placement surface of the protrusion 2 is in close contact with the concrete placement surface 10 via the air-permeable sheet material 5 and a void S is formed around the contact protrusion 2. (See FIG. 2B). As a result, the laying operation of the bubble sheet 1 is completed, and thereafter, the placed concrete is cured so that the space S is maintained at a negative pressure.

By the way, in this embodiment, the air-permeable sheet material 5 is laminated on the protrusion 2 side of the bubble sheet 1 because the protrusion 2 directly contacts the concrete placing surface 10. This is because the trace remains on the concrete placing surface 10 and there is a possibility that a defect in appearance may be pointed out in the finish. The sheet material 5 has air permeability, for example, if it does not prevent the air bubble sheet 1 from coming into close contact with the concrete placement surface 10 when a negative pressure is applied between the air bubble sheet 1 and the concrete placement surface 10. Various materials such as non-woven fabric, woven fabric, and knitted fabric can be used.
In addition, when the trace of protrusion does not remain on the concrete placing surface 10 or when it does not cause a problem in appearance even if it remains, the lamination of the sheet material 5 on the bubble sheet 1 may be omitted. Good.

The foam sheet 1 laid on the concrete placement surface 10 to be cured as described above is laid on the concrete placement surface as long as the space S formed around the protrusion 2 is maintained at a negative pressure. No drop off from 10.
Therefore, according to this embodiment, it is possible to easily lay the air bubble sheet 1 even on a wide range of downward inner peripheral surfaces of the tunnel, thereby sufficiently and efficiently curing the tunnel lining concrete. can do,

In the example shown in FIG. 1, the flat portion 6 on which the protrusion 2 is not formed is formed on the bubble sheet 1 with a predetermined width along the direction orthogonal to the tunnel traveling direction at every constant distance along the tunnel traveling direction. Is provided. In order to prepare the bubble sheet 1 provided with such a flat portion 6, for example, the bubble sheet constituting pieces 1 a as shown in FIG. 3 may be connected in the width direction.
FIG. 3 is an explanatory view showing an example of the bubble sheet constituting piece 1a, FIG. 3 (a) is a plan view showing the outline thereof, and FIG. 3 (b) is a sectional view taken along line BB in FIG. 3 (a). It is. FIG. 4 is a plan view showing an example in which the bubble sheet constituting pieces 1a shown in FIG.

The bubble sheet constituting piece 1a shown in FIG. 3 includes a protrusion forming portion 2a and a thin film portion 6a that is heat-sealed with the end edges overlapped on both side edges of the protrusion forming portion 2a.
As shown in FIG. 4, the bubble sheet 1 used in the example shown in FIG. 1 includes four bubble sheet constituting pieces, a thin film portion 6 a provided on one adjacent bubble sheet constituting piece 1 a, and the other bubble sheet. The thin film portion 6a provided on the component piece 1a can be prepared by overlapping and heat-sealing each edge. At this time, the thin fill portion 6 a located between the adjacent bubble sheet constituting pieces 1 a corresponds to the flat portion 6.

  When preparing the bubble sheet 1 in this way, the width of overlapping the edge of the thin film portion 6a on the side edge of the protrusion forming portion 2a, or one of the bubble sheets when connecting the bubble sheet constituting pieces 1a in the width direction. The width of overlapping the thin film portion 6a provided on the component piece 1a and the edges of the thin film portion 6a provided on the other bubble sheet component piece 1a is appropriately set so that a sufficient fusion allowance can be secured. However, it is preferably 10 to 1000 mm.

  Further, the thickness of the thin film portion 6a is such that, when a negative pressure is applied between the air bubble sheet 1 and the concrete placement surface 10, the surface of the concrete placement surface 10 follows the surface shape of the concrete placement surface 10, and the concrete placement surface The thickness of the thin film portion 6a is preferably 5 to 100 μm. Specifically, the thickness of the thin film portion 6a is preferably 5 to 100 μm.

Further, the width W ₀ of the protrusion forming portion 2a is usually about 1000 to 3000 mm, the width W of the thin film portion 6a is usually about 10 to 1000 mm, and the length L of the bubble sheet constituting piece 1a is usually It is about 900-35000 mm.

When the flat part 6 in which the protrusion 2 is not formed is provided on the bubble sheet 1, when the bubble sheet 1 is laid on the concrete placing surface 10 as described above, the flat part 6 is as shown in FIG. In addition, there are a plurality of partitions in which the gap S is formed around the protrusion 2 as a partition between the protrusion 2 and the other area where the protrusion 2 is formed. To define.
5 is a cross-sectional view taken along the line CC in FIG.

In laying the air bubble sheet 1 on the concrete placing surface 10 as described above, any part of the air bubble sheet 1 can be used to extract air from the space between the air bubble sheet 1 and the concrete placing surface 10 to create a negative pressure. The suction port 12 may be provided in order to remove air from the suction port 12. In the example shown in FIG. 1, a suction port 12 is provided for each section defined by the flat portion 6, and the air between the air bubble sheet 1 and the concrete placing surface 10 is sucked from each suction port 12 to generate a negative pressure. I have to.
By doing in this way, when extracting the air between the bubble sheet 1 and the concrete placing surface 10, non-directional air flow is prevented from occurring, and the air flow is limited for each section. Each compartment can be made negative pressure efficiently.

At this time, as shown in FIG. 6, there is only one suction port 12 provided in the bubble sheet 1, and the ventilation member 20 installed so as to straddle a plurality of sections defined by the flat portion 6 from the suction port 12. Even if the air between the air bubble sheet 1 and the concrete placing surface 10 is sucked into a negative pressure via the above, the same effect as described above can be obtained.
As the ventilation member 20, a gap is formed between the flat portion 6 and the concrete placing surface 10 at a portion where the ventilation member 20 is installed, but adhesion of the flat portion 6 to the concrete placing surface 10 is not hindered at other portions. If it is a thing, it will not specifically limit. For example, a long bundle of metal fibers such as steel wool can be used.

  Further, when the bubble sheet 1 is supported by the pressing member 11 installed in an arch shape, the pressing member 11 may crush the gap S formed around the protrusion 2 and block the air flow. In order to prevent such a situation, the pressing member 11 that supports the bubble sheet 1 is preferably constructed along the flat portion 6.

Moreover, in this embodiment, the water spray pipe 13 is arrange | positioned between the bubble sheet 1 and the concrete placement surface 10 along the tunnel advancing direction in the top end part of the inner peripheral surface of the tunnel. As the water spray pipe 13, for example, a hose-like member having a large number of holes formed so that water flows out from the side surface thereof can be used. By disposing such a sprinkling pipe 13, the concrete casting surface on which the bubble sheet 1 is laid with the water flowing out from the side surface of the sprinkling pipe 13 as a water passage through the gap S formed around the protrusion 2. 10, even after the air bubble sheet 1 is laid, water can be additionally supplied to the concrete placing surface 10.
It should be noted that the amount of water that flows out from the sprinkling pipe 13 and is supplied to the concrete placing surface 10 can be appropriately adjusted according to the size and number of holes drilled in the side face of the sprinkling pipe 13, the water pressure in the sprinkling pipe 13, and the like. it can. At this time, in order to easily adjust the amount of water supplied to the concrete placing surface 10, the end of the sprinkling pipe 13 is sealed by closing the opening of the hose-like member by heat fusion or the like. In addition, it is preferable that water flows out only from the hole formed in the side surface.

  In the example shown in FIG. 1, the water that has flowed out of the water sprinkling pipe 13 and has passed through the concrete placing surface 10 through the gap S as a water channel is drained from the suction port 12 by the suction machine 14. Then, the drained water is sent to the water spray pipe 13 by the water absorption pump 15, and the water additionally supplied to the concrete placing surface 10 is circulated so that it flows out of the water spray pipe 13 again. . By doing in this way, the concrete casting surface 10 can always be in a wet state, the hydration reaction of the placed concrete can be made sufficient, and the durability of the concrete can be improved. .

  At this time, in this embodiment, as described above, the flat portion 6 on which the protrusion 2 is not formed defines a plurality of sections in which the gap S is formed around the protrusion 2. As a result, the flow of water can be limited for each section, and the water can be efficiently circulated in the gap S in the same manner as the air flow can be limited for each section.

  Here, in order for the flat part 6 to adhere well to the concrete placing surface 10 and the effects as described above are sufficiently exhibited, the width of the flat part 6 is 10 to 1000 mm. It is preferably 20 to 300 mm.

Further, when the tunnel lining concrete is placed by repeating the above-described procedure, the joint portion 16 is usually formed for each section, but if such a joint portion 16 is left as it is. It is conceivable that troubles may occur when the pressure between the air bubble sheet 1 and the concrete placing surface 10 is made negative due to air leakage.
In order to avoid such a problem, for example, as shown in FIG. 7, the joint 16 is removably filled with a sealing member 17 made of an elastic material, or a part of the bubble sheet 1 ( Preferably, the thin film portion 6 a) is rolled up so that the pressing member 11 is fitted into the joint portion 16.

  7 is an explanatory diagram of a portion shown by a DD cross section of FIG. 1, and FIG. 7A is a DD cross sectional view of FIG. Moreover, FIG.7 (b) is an important part enlarged view which expands and shows the part enclosed with the dashed-dotted line in Fig.7 (a), Comprising: In the joint part 16 formed for every division of tunnel lining concrete An example in which the sealing member 17 made of an elastic material is detachably filled is shown. FIG. 7C shows an example in which the pressing member 11 is inserted by winding the thin film portion 6a of the bubble sheet 1 around the joint portion 16 in correspondence with FIG. 7B.

[Modification]
While the present invention has been described with reference to the preferred embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Needless to say.

For example, in the above-described embodiment, the example using the bubble sheet 1 provided with the flat portion 6 where the protrusions 2 are not formed is shown for every fixed distance along the tunnel traveling direction. However, the bubble sheet used in the present invention is used. 1 is not limited to this. The air bubble sheet 1 having the protrusions 2 formed on the entire surface can be used without providing the flat portion 6.
Moreover, although the bubble sheet 1 prepared in advance in a required size may be brought into the work site, it may be laid after a predetermined size is appropriately connected in the work site to obtain a required size. .

  When the bubble sheet 1 provided with the flat portion 6 is used, as described above, the thin film portion 6a provided in one adjacent bubble sheet constituting piece 1a and the other bubble sheet constituting piece 1a are provided. If the thin film portion 6a is heat-sealed by overlapping the respective edges, thereby preparing a bubble sheet 1 in which a plurality of bubble sheet constituting pieces 1a are connected to have a required size. Although it is good (refer FIG. 4), when using the bubble sheet 1 in which the protrusion 2 was formed in the whole surface where the flat part 6 is not provided, as shown in FIG. 8, for example, one adjacent bubble sheet component piece While abutting the edge of 1b and the edge of the other bubble sheet constituting piece 1b, a necessary size is obtained by applying a belt-like film material 1c from the back film 4 side as needed and thermally fusing them. In You can go to bed thing.

Here, FIG. 8 is a plan view showing an example in which the bubble sheet constituting pieces 1b are connected in the width direction to form the bubble sheet 1, and FIG. 9 is a cross-sectional view taken along line EE of FIG. The bubble sheet constituting piece 1b shown in these drawings corresponds to the bubble sheet constituting piece 1a shown in FIG. 3 in which the thin film portion 6a is omitted.
In addition, when the edge of adjacent bubble sheet | seat component piece 1b is faced | matched and heat-sealed, some protrusions 2 may be crushed, but detailed illustration is abbreviate | omitted about this. Although not particularly illustrated, thin film portions 6a similar to the bubble sheet constituting piece 1a shown in FIG. 3 may be provided at both end edges where the plurality of bubble sheet constituting pieces 1b are connected in the width direction.

  Further, in order to maintain the inside of the gap S formed around the protrusion 2 at a negative pressure, it is required to make the gap S airtight, but in a portion where there is a possibility that a gap causing air leakage is formed, For example, an adhesive tape or the like may be applied directly to close the gap. Furthermore, the gap may be blocked by arranging a film material prepared separately from the bubble sheet 1. At this time, the film material can be attached by appropriate means such as an adhesive tape or an adhesive.

  Further, in order to closely contact the start side and the end side of the bubble sheet 1 in the tunnel traveling direction with the concrete placing surface 10 without any gap, for example, the pressing member 11 that supports the start side and the end side of the bubble sheet 1 in the tunnel direction. A sponge-like or rubber-like elastic body 18 is attached to the periphery, and the bubble sheet 1 can be brought into close contact with the concrete placing surface 10 by utilizing the elastic deformation of the elastic body 18. At this time, a thin film portion 6 a is provided on the beginning and end sides of the bubble sheet 1 in close contact with the concrete placement surface 10 in the tunnel traveling direction, and the thin film portion 6 a is brought into close contact with the concrete placement surface 10. It is preferable to do so.

Here, an example in which the bubble sheet 1 is laid over a plurality of sections into which tunnel lining concrete has been placed is schematically shown in FIG. 10, but as shown in FIG. An elastic body 18 for attaching the air bubble sheet 1 to the concrete placing surface 10 is attached around the pressing member 11a that supports each of the end side. The other pressing members 11b make the pressure between the air bubble sheet 1 and the concrete placing surface 10 negative, and the air bubble sheet 1 does not hang down until the air bubble sheet 1 is brought into close contact with the concrete placing surface 10. The elastic body 18 may not be attached as long as it can be supported to a certain extent.
In FIG. 10, the traveling direction of the tunnel is indicated by an arrow.

  In addition, the end of the air bubble sheet 1P curing the tunnel lining concrete previously placed is overlapped with the beginning of the tunnel advance direction of the air bubble sheet 1L curing the tunnel lining concrete placed later. It is preferable not to become a hindrance when removing the air bubble sheet 1P for curing the tunnel lining concrete previously placed. FIG. 10 (b) is an enlarged view of the portion surrounded by the alternate long and short dash line in FIG. 10 (a). In this example, the end side in the tunnel traveling direction of the bubble sheet 1P for curing the tunnel lining concrete previously placed is shown. Is supported by the pressing member 11 a at a position before the joint portion 16. Then, the beginning end side of the air bubble sheet 1L for curing the tunnel lining concrete placed later is supported by the pressing member 11a through the seal member 17 as necessary while being wound around the joint portion 16. Thus, the end of the bubble sheet 1P in the tunnel traveling direction and the beginning of the bubble sheet 1L in the tunnel traveling direction are prevented from interfering with each other. By doing in this way, the air bubble sheet 1P which cures the tunnel lining concrete cast | placed previously can be removed, without being damaged, and it becomes possible to use the air bubble sheet 1 repeatedly.

  Further, when the water sprinkling pipe 13 is disposed at the top end of the inner peripheral surface of the tunnel along the tunnel traveling direction, the water sprinkling pipe 13 is disposed at the highest position of the top end so that the tunnel It is preferable that the water flowing out from the water sprinkling pipe 13 is equally supplied to both side wall portions located on the left and right sides in the traveling direction, but when actually working, from the highest position of the top end portion. It must also be taken into account that the water sprinkling pipe 13 is displaced. If the sprinkling pipe 13 is not arranged at the highest position of the top end portion but is arranged at a position lower than that, the water flowing out from the sprinkling pipe 13 is biased toward one side wall portion, and the tunnel Since there is a concern that there will be a difference in the finish of the lining concrete, it is possible to more reliably supply water equally to the side wall portion located on the left side and the side wall portion located on the right side in the tunnel traveling direction. However, the following two means are conceivable as specific means for this purpose.

  First, as shown in FIG. 11, as shown in FIG. 11, the sprinkling pipe 13 is branched, and from a plurality of branch pipes 13 b branched from the main pipe 13 a together with the main pipe 13 a extending along the tunnel traveling direction. It is conceivable to allow water to flow out. By doing in this way, even if the main pipe 13a is arranged to be shifted from the highest position of the top end, water is also drawn from the branch pipe 13b extending to the opposite side across the highest position of the top end. As a result, the water can be equally supplied to both side wall portions located on the left and right sides in the tunnel traveling direction.

As a second means, as shown in FIG. 12, it is conceivable to arrange the two water spray pipes 13 along the tunnel traveling direction so as to be arranged on both sides of the highest position of the top end. By doing in this way, the water which mainly flowed out from one sprinkling pipe 13 is supplied to the side wall part located on the left side in the tunnel traveling direction, and the side wall part located on the right side in the tunnel traveling direction. The water can be supplied equally to both side wall portions located on the left and right sides in the tunnel traveling direction more reliably by mainly supplying the water flowing out from the other water spray pipe. Furthermore, in the example shown in FIG. 12, the auxiliary pipe 13 c that connects the two sprinkler pipes 13 is provided in a ladder step shape, and thus, between the two sprinkler pipes 13 arranged side by side. Water is supplied.
In the example shown in FIGS. 11 and 12, the above-described bubble sheet constituting piece 1 b is connected in the width direction and the thin film portions 6 a are provided at both end edges as the bubble sheet 1. Further, the suction port 12 provided in the bubble sheet 1 is sucked through the ventilation member 20 as one as in the example shown in FIG.

As described above, the sprinkling pipe 13 can be a hose-like member having a large number of holes drilled so that water flows out from the side surface thereof. In the first means, for example, As shown in FIG. 13 (a), the sprinkler pipe 13 may be branched by a cross-shaped joint 131, and as shown in FIG. 13 (b), the sprinkler pipe 13 may be branched by a T-shaped joint 132. In any case, in order to easily adjust the amount of water supplied to the concrete placing surface 10, the end of the branch pipe 13b is sealed and drilled on the side surface. It is preferable that water flows out only from the formed holes (FIG. 11 shows an example in which the water spray pipe 13 is branched by a cross-shaped joint 131). In order to seal the end of the branch pipe 13b, for example, the opening of the hose-like member may be closed by heat sealing.
On the other hand, in the second means, for example, as shown in FIG. 14, an auxiliary pipe 13 c that connects the two sprinkling pipes 13 is provided in a ladder step shape by a T-shaped joint 132. be able to.
In forming the water sprinkling pipe 13 as described above, the hose-shaped member and the joints 131 and 132 can be connected using a suitable connecting tool such as a hose band or a hose clamp.

  INDUSTRIAL APPLICABILITY The present invention can be used as a technique for curing cast tunnel lining concrete at a tunnel construction work site.

DESCRIPTION OF SYMBOLS 1 Bubble sheet 2 Protrusion 3 Cap film 4 Back film 5 Sheet material 6 Flat part 10 Concrete placement surface 11 Holding member 12 Suction port 13 Sprinkling pipe 13a Main piping 13b Branch piping 13c Auxiliary piping 16 Joint part 17 Seal member

Claims (10)

After placing and fixing the centle, cast tunnel lining concrete, then repeat the procedure of demolding and moving the centle to place the tunnel lining concrete over the entire length of the tunnel.
A bubble sheet formed by laminating a back film that encloses air in the protrusions on a cap film formed with a number of protrusions that bulge into a hollow shape,
While extending so that the protrusion side faces the concrete placement surface after decentering, it is supported by a pressing member that is arched along the inner peripheral surface of the tunnel,
A negative pressure is applied between the air bubble sheet and the concrete placement surface so that a portion of the protrusion of the air bubble sheet facing the concrete placement surface is in close contact with the concrete placement surface, and a gap is formed around the protrusion. A method for curing tunnel lining concrete, characterized in that A portion where the protrusion is formed at a certain distance along the traveling direction of the tunnel in the bubble sheet with a flat portion having no protrusion formed in a direction perpendicular to the traveling direction of the tunnel. The tunnel lining concrete curing method according to claim 1, wherein the flat portion is formed along a traveling direction of the tunnel, and a plurality of sections having the protrusions of the bubble sheet are defined .   A suction port is provided in the bubble sheet for each section defined by the flat portion, and air between the bubble sheet and the concrete placing surface is sucked from the suction port to obtain a negative pressure. The tunnel lining concrete curing method described.   A ventilation member is installed so as to straddle a plurality of sections defined by the flat portion, and the air between the air bubble sheet and the concrete placing surface is sucked through the ventilation member to make a negative pressure. Item 3. A method for curing tunnel lining concrete according to Item 2.   The method for curing tunnel lining concrete according to any one of claims 2 to 4, wherein the pressing member is installed along the flat portion.   The tunnel lining concrete curing method according to any one of claims 1 to 5, wherein a water spray pipe is disposed between the bubble sheet and the concrete placing surface along a tunnel traveling direction.   The tunnel lining concrete curing method according to claim 6, wherein the water spray pipe has a main pipe extending along a tunnel traveling direction and a plurality of branch pipes branched from the main pipe.   Two sprinkling pipes are arranged along the tunnel traveling direction so as to be arranged on both sides of the highest position of the top end of the inner peripheral surface of the tunnel, and an auxiliary pipe connecting the two sprinkling pipes is provided. The method for curing tunnel lining concrete according to claim 6 provided in a ladder step shape.   The method for curing tunnel lining concrete according to any one of claims 1 to 8, wherein a sheet material having air permeability is laminated on the protruding side of the bubble sheet. In joints formed for each section of tunnel lining concrete to be placed by repeating the above procedure,
The tunnel lining concrete curing method according to any one of claims 1 to 9, wherein the seal member is removably filled or the pressing member is inserted.

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