JP2005090151A - Tunnel waterproofing construction method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tunnel waterproofing construction method capable of excellently and surely exhibiting the function of a water barrier, in the tunnel waterproofing construction method used for, for example, a watertight tunnel. <P>SOLUTION: This tunnel waterproofing construction method places secondary lining concrete inside a waterproof sheet 3, after laying the waterproof sheet 3 with the water barrier 6 having a plurality of strips of projection ribs 6b projecting to the tunnel inner side on an inner surface of the tunnel natural ground 1 or primary lining 2. After laying the waterproof sheet 3 on a tunnel natural ground inner surface or a primary lining inner surface, perforated hoses 11 and 12 are arranged between the adjacent projection ribs 6b and 6b of the water barrier 6, and the secondary lining concrete is placed while forcibly sucking and exhausting air in the vicinity of a tunnel top end part from an end part of the perforated hoses. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a tunnel waterproofing method. More specifically, the present invention relates to a tunnel waterproofing method used for a watertight tunnel or the like.

  In conventional water tight tunnels, for example, as shown in FIGS. 9 and 10, primary water such as spray concrete constructed on the inner surface of the tunnel ground or on the inner surface of the ground to prevent water in the ground 1 around the tunnel from entering the tunnel. A waterproof sheet 3 is laid on the inner surface of the lining 2 and concrete for secondary lining is placed inside the waterproof sheet 3 to form the secondary lining 5. It should be noted that a cushioning material 4 such as a nonwoven fabric may be interposed between the outer side of the waterproof sheet 3, that is, the inner surface of the natural ground or between the primary lining 2 and the waterproof sheet 3, as necessary.

  As the waterproof sheet 3, generally, a waterproof material such as a synthetic resin sheet formed in a predetermined dimension is sequentially laid on the entire inner surface of the natural ground or the inner surface of the primary lining while sequentially adding, and in that case, adjacent to each other. The sheets are joined together by welding or the like, and the joint (joint portion) is constructed with the utmost care so as not to cause water leakage in the sheet while performing a water tightness test. Moreover, the secondary lining 5 to be constructed on the inner surface side of the waterproof sheet 3 is formed by placing concrete every predetermined length (span) in the tunnel longitudinal direction.

  However, in the watertight tunnel as described above, since the groundwater pressure always acts on the back surface (outer surface) side of the waterproof sheet 3 and the secondary lining 5, for example, the tunnel waterproof sheet 3 with an extension of 3000 m is applied. Even if only one hole is opened, there is a possibility that water leakage from the hole may go around the entire tunnel, making it difficult to locate the water leakage point.

  As a countermeasure, as shown in FIG. 10, the waterproof sheet 3 at the joint J of the secondary lining 5 may become a so-called water channel (water supply) when a hole is formed in the waterproof sheet 3. By providing a water barrier (breakwater) 6 between the secondary lining 5 and the secondary lining 5, it is possible to prevent the leakage of water from spreading over a wide area and to detect and repair the leakage location within the range partitioned by the water barrier 6. There has been proposed a method for easily and quickly (see, for example, Patent Documents 1 and 2 previously proposed by the present applicant).

  As shown in FIG. 11, the water barrier 6 as described above is integrally provided with a plurality of convex ribs 6b extending in the longitudinal direction on a strip-like base material (web) 6a made of the same material as the waterproof sheet 3, for example. With the convex rib 6b facing the secondary lining side, the water barrier 6 is attached to the inner surface side of the waterproof sheet 3 by welding or the like at a position corresponding to the joint J of the secondary lining, and thereafter The secondary lining 5 is applied to the inner surfaces of the water barrier 6 and the waterproof sheet 3.

  However, even if the waterproof sheet 3 and the water barrier 6 are installed on the inner surface of the tunnel as described above, if the concrete that forms the secondary lining 5 is insufficiently filled, the waterproof sheet 3 may be covered with the ground surface or the primary cover. It does not adhere to the inner surface of the work, and a large water pressure acts on that part, causing the waterproof sheet to break and cause water leakage. In particular, the vicinity of the tunnel top end is not filled with concrete because there is no escape of air that was present here, and between the secondary lining 5 and the waterproof sheet 3, FIG. And as shown in FIG. 10, the clearance gap S used as a waterway tends to arise. Further, the water barrier near the top end portion is structured so that air between the adjacent convex ribs 6b and 6b is difficult to escape when the secondary lining concrete is placed, and as a result, as shown in FIG. There is a problem that the gap g is generated without being filled with concrete.

  In order to prevent the formation of the gap S and the gap g due to such unfilling of the secondary lining concrete, the contact grouting is injected near the top end of the secondary lining 5 as shown in FIG. A method of filling the grout material from the hole 7 into the gap S through the hole 7 (see, for example, Patent Document 3 below according to the applicant's proposal), or secondary lining as in Patent Document 4 below There has been proposed a method in which raw concrete is poured into a concrete placement space and then pressed by inserting a pusher from the wife side. However, even if it is possible to eliminate the generation of the gap S by these methods, it is extremely difficult to prevent or eliminate the generation of the gap g as described above between the convex ribs 6b and 6b of the water barrier. there were.

  Therefore, in Patent Document 3, a porous hose (exhaust gas injection hose) 10 is installed between the convex ribs 6b and 6b of the water barrier 6 as shown in FIG. When placing, the air remaining between the convex ribs 6b and 6b is naturally discharged to the outside through the porous hose. However, the remaining air may not always be naturally discharged satisfactorily. Further, after the construction of the secondary lining 5, it has also been proposed in Patent Document 3 that the grout material G is filled in the gap g through the porous hose 10, but at that time, the gap between the convex ribs 6b and 6b is proposed. Since there is no place for the remaining air, it is inevitable that an unfilled portion of the grout material G is generated as shown in FIG. For this reason, there is a problem that the function of the water barrier 6 cannot be fully exhibited.

Japanese Examined Patent Publication No. 6-63436 Japanese Patent No. 2545338 JP 2000-337096 A Japanese Patent Laid-Open No. 11-81892

  The present invention has been proposed in view of the above-described problems, and an object of the present invention is to provide a tunnel waterproofing method capable of exhibiting a water barrier function satisfactorily and reliably.

    In order to achieve the above object, the tunnel waterproofing method according to the present invention has the following configuration. That is, after laying a waterproof sheet with a water barrier having a plurality of convex ribs protruding toward the sky inside the tunnel on the inner surface of the tunnel ground or the inner surface of the primary lining, concrete for secondary lining is placed on the inner side of the waterproof sheet. In the tunnel waterproofing construction method, the waterproof sheet is laid on the inner surface of the tunnel ground or the inner surface of the primary lining, and then a porous hose is disposed between the adjacent convex ribs of the water barrier, and the end of the porous hose It is characterized in that concrete for secondary lining is placed while forcibly sucking and exhausting the air near the top of the tunnel from the top.

  After laying the waterproof sheet with a water barrier on the inner surface of the tunnel ground or the inner surface of the primary lining as described above, a porous hose is disposed between the adjacent convex ribs of the water barrier, and from the end of the porous hose to the top of the tunnel By placing concrete for secondary lining while forcibly sucking and exhausting the air in the vicinity of the portion, the air remaining between adjacent convex ribs can be reduced as much as possible. As a result, the water barrier function can be exhibited well and reliably.

  Hereinafter, the present invention will be specifically described based on the embodiments shown in the drawings. 1 is a longitudinal sectional view of a tunnel to which the tunnel waterproofing method according to the present invention is applied, FIG. 2 is a sectional view taken along line AA in FIG. 1, FIG. 3 is an enlarged view of a chain line portion B in FIG. FIG.

  In the tunnel of this example, sprayed concrete is applied as the primary lining 2 to the inner surface of the excavated natural ground 1, and the waterproof sheet 3 is laid on the inner surface via a cushioning material 4 such as a nonwoven fabric. The primary lining 2 and the cushioning material 4 are provided as necessary, and may be omitted in some cases.

  The waterproof sheet 3 is formed by appropriately joining a waterproof material such as a synthetic resin sheet having a predetermined thickness and a predetermined size and laying the entire periphery of the tunnel. In this embodiment, adjacent sheets are sequentially welded together. At the same time, the waterproof sheet 3 is attached to the inner surface of the tunnel by a fixing tool such as an anchor nail together with the cushioning material 4 without opening a through hole.

  On the inner surface side of the waterproof sheet 3, a concrete secondary lining 5 is applied every predetermined length (span) in the tunnel longitudinal direction as in the conventional example. In the vicinity of the top end, a contact grout injection hole 7 is provided at a predetermined interval in the longitudinal direction of the tunnel. The method of forming the injection hole 7 is appropriate, but in the present embodiment, the secondary lining 5 is attached to the tube 7a and the core material in a state where the rod-shaped core material omitted in the drawing is inserted into the contact grout tube 7a. After burying in the hole, the injection hole 7 having the contact grout tube 7a is formed in the hole by pulling out only the core material.

  Further, as shown in FIGS. 3 and 4, a water barrier 6 is integrally provided on the inner surface of the waterproof sheet 3 by welding or the like at a position corresponding to the joint J of the secondary lining 5 as in the conventional example. Yes. The water barrier 6 has a configuration in which a plurality of convex ribs 6b extending in the longitudinal direction are integrally provided on a belt-like base material (web) 6a as in the conventional example. It arrange | positions so that a direction, ie, the direction of the convex rib 6b, may become a tunnel circumferential direction.

  In constructing the tunnel waterproof structure as described above, after laying the waterproof sheet 3 with the water barrier 6 as described above on the inner surface of the tunnel ground mountain 1 or the primary lining 2 in the same manner as before, A secondary hose 5 is applied, and at that time, a porous hose is disposed between the adjacent convex ribs 6 b and 6 b of the water barrier 6. In this embodiment, as shown in FIGS. 3 and 4, two porous hoses 11 and 12 are arranged between adjacent convex ribs 6b and 6b, respectively, and fixed with a hot melt adhesive or the like. .

  In the present embodiment, each of the perforated hoses 11 and 12 is coated with a braided tube made of mesh, cloth or the like on the outer peripheral surface of a perforated tube 13 having a large number of small through holes 13a on the peripheral surface as shown in FIG. However, in the case of the figure, two types of braided pipes 14 and 15 having different knitting methods and braid densities are sequentially coated. The peripheral wall surface of each of the porous hoses 11 and 12 has a structure that allows air to pass but does not allow the concrete groin to pass through when forming the secondary lining 5, and is configured to allow the grout material described later to pass. . In addition to the above, the porous hoses 11 and 12 can have various configurations. For example, plastic fibers knitted to such an extent that air, grout material, and moisture can be used.

  The arrangement positions and arrangement configurations of the porous hoses 11 and 12 in the tunnel circumferential direction are appropriate. Preferably, the porous hoses 11 and 12 are provided between so-called shoulder portions on both sides in the circumferential direction from the tunnel ceiling as shown in FIGS. Good. Specifically, each of the porous hoses 11 and 12 is arranged within a range in which the central angle θ is about 120 degrees when the both sides are combined with each other in the circumferential direction from the tunnel top end to about 60 degrees. Good. Each of the porous hoses 11 and 12 may be bent at the both ends 11a, 11b, 12a and 12b toward the inner side of the tunnel and inserted and held in a mold F for secondary lining forming.

  In the state where the porous hoses 11 and 12 are disposed between the adjacent convex ribs 6b and 6b of the water barrier 6 as described above, a secondary covering is provided between the water barrier 6 and the waterproof sheet 3 and the mold F. Concrete for working is placed to form a secondary lining 5, and at that time, the end 11 a of at least one of the two porous hoses 11, 12 as shown in FIG. For secondary lining while closing with the sealing tool P etc., connecting the vacuum suction pump etc. not shown in the figure to the other end 11b and forcibly sucking and exhausting the air between the adjacent convex ribs 6b and 6b If the concrete is placed, it is possible to reduce as much as possible the occurrence of the gap g as described above due to the air remaining between the adjacent convex ribs 6b and 6b in the vicinity of the tunnel top end. At this time, both ends of the other hose 12 are closed.

  In addition, when water is discharged from the exhaust side end portion 11b of the hose 11 when placing the concrete for secondary lining while sucking and exhausting air with the both porous hoses 11 as described above, the concrete extends to the periphery of the hose. Can be seen. Alternatively, if the pressure at the exhaust-side end portion 11b is monitored with a pressure gauge or the like, it can be seen that the void has disappeared, and it is only necessary to stop the concrete injection with this signal.

  After constructing the secondary lining 5 as described above, if a gap g is generated between the adjacent convex ribs 6b and 6b in the vicinity of the tunnel top end as shown in FIG. If there is a fear, a grout material injection device (not shown) or the like is connected to one end 12a of the other hose 12 of the porous hoses 11 and 12 as shown in FIGS. When a grout material G such as cement or epoxy resin is injected into the inside, and the air in the gap g is forcibly sucked and exhausted by the porous hose 11 in the same manner as described above, as shown in FIG. The gap g can be sealed with the grout material G.

  At that time, the grout material G is sequentially injected from the one end 12a side of the porous hose 12, the gap g is sealed with the grout material G, and then the grout material G overflows from the other end 12b side. Is stopped, the inside of the hose 12 can also be sealed with the grout material G as shown in FIG. Also, if the porous hose 11 used for exhaust is filled with the grout material G and sealed, the gap g between the adjacent convex ribs 6b and 6b including those hoses 11 and 12 is shown in FIG. ) Can be completely sealed. However, if the porous hose 11 is left as it is without being filled with the grout material G, when water leakage or the like occurs later, the porous hose 11 is filled with the grout material G or the like. It can also be repaired.

  In addition, when constructing the secondary lining 5, between the secondary lining 5 and the waterproof sheet 3 between adjacent water barriers 6 and 6 corresponding to the joint J and J, the When the gap S as in the conventional example is generated, a grout material such as cement milk or high fluidity mortar is injected into the gap S from the injection hole 7 and closed. Or you may apply the method of inserting and pressing a pushing tool from the wife side at the time of secondary lining construction like the said patent document 4. FIG.

  In the above embodiment, two porous hoses are arranged between the adjacent convex ribs 6b and 6b of the water barrier 6, and one end side of each of the hoses is sucked with a pump or the like to perform secondary lining. Although forced exhaust at the time of construction was performed, both ends of either one of the above hoses may be sucked, and each of the two hoses may be used for forced exhaust. Furthermore, the number and structure of perforated hoses are appropriate. In particular, when there is little possibility that the gap g is generated due to forced exhaust during secondary lining construction, forced exhaust and injection of grout material with only one perforated hose. May be performed.

As described above, in the tunnel waterproofing method according to the present invention, the porous hose 11 is disposed between the adjacent convex ribs 6 b and 6 b of the water barrier 6, and the air near the top of the tunnel is discharged from the end of the porous hose 11. Since the concrete for the secondary lining is placed while forcibly exhausting air, the air remaining between the adjacent convex ribs can be reduced as much as possible. As a result, it becomes possible to demonstrate the function of the water barrier well and reliably,
The reliability and stability of the waterproof tunnel can be improved.

The longitudinal cross-sectional view of the tunnel to which the tunnel waterproofing construction method by this invention is applied. AA sectional drawing in FIG. The enlarged view of the chain line part B in FIG. Furthermore, the one part enlarged view. Explanatory drawing which shows an example of a structure of a porous hose. Explanatory drawing which shows an example of arrangement | positioning structure of a porous hose. (A)-(c) is a cross-sectional view of the tunnel upper part which shows an example of a construction process. (A)-(c) is an enlarged view of the water barrier part in the said construction process. The cross-sectional view of the conventional tunnel waterproof structure. The longitudinal cross-sectional view of the said tunnel waterproof structure. FIG. 3 is an enlarged vertical sectional view of a part of the tunnel waterproof structure. The enlarged view of the water barrier part of the said tunnel waterproof structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ground mountain 2 Primary lining 3 Waterproof sheet 4 Buffer material 5 Secondary lining 6 Water barrier 6a Base material 6b Convex rib 7 Injection hole 8 Disc washer 10, 11, 12 Porous hose

Claims (3)

  After laying a waterproof sheet with water barriers with multiple protruding ribs projecting toward the sky inside the tunnel on the inner surface of the tunnel ground or the inner surface of the primary lining, concrete for secondary lining is placed inside the above waterproof sheet In the tunnel waterproofing method, the waterproof sheet is laid on the inner surface of the tunnel ground or the inner surface of the primary lining, and then a porous hose is disposed between the adjacent convex ribs of the water barrier, from the end of the porous hose. A tunnel waterproofing method characterized by placing concrete for secondary lining while forcibly sucking and exhausting air near the top of the tunnel.   Two porous hoses are arranged between the adjacent convex ribs, and concrete for secondary lining while forcibly sucking and exhausting air near the top of the tunnel from the end of one of the porous hoses. After forcing the grout material from the other porous hose to the tunnel top end, forcibly sucking and exhausting the air near the tunnel top end from the end of one of the two porous hoses. The tunnel waterproofing method according to claim 1, wherein the tunnel waterproofing method is injected and solidified.   The tunnel waterproofing method according to claim 1, wherein after the injection of the grout material near the tunnel top end portion, the grout material is injected into the other porous hose and solidified.

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