JPH0240840B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of covering water conduit for leaking water that occurs or occurs in tunnels for railways, waterways, roads, etc., which are provided through mountainsides, underground, etc.

Tunnels are generally constructed with a cement-concrete layer installed inside a bedrock layer, but groundwater present in the bedrock layer can penetrate into minute cracks in the weakened concrete layer, causing water leakage from the concrete layer over time. Water leaks often occur.

Conventionally, in order to guide the water dripping from the upper part of the concrete layer to the side of the tunnel and the side ditch, a metal plate was installed along the curved surface of the concrete layer, and the metal plate was used to guide the water to the side. Leakage water is directed to the side gutters using gutters.

However, in the above conventional method, the durability of the metal plate exposed in the humid tunnel is extremely short.
On the other hand, in the case of a downside, for example, if a metal plate with advanced corrosion hangs down and comes into contact with the overhead wire installed in the tunnel, a high voltage current will flow, or if a metal plate falls and comes into contact with the rail. There was a risk that various problems could occur, such as disrupting electrical signals for train operation.

The present invention has been made for the purpose of providing a construction method that eliminates the drawbacks of the conventional water conveyance method for tunnels, and its gist is to cover the upper part of a cement structure with a waterproof sheet, and to After fixing the metal mesh directly or indirectly to the cement structure using fasteners, the sheet and the mesh are coated with a polymer cement composition except for the lower side edges of the sheet, and the cement structure is The present invention relates to a covering water conduit construction method for a tunnel, characterized in that water seeping out from the upper part of the tunnel is guided to the lower part of the cement structure by the sheet.

As the waterproof sheet in the present invention, thin plates made of metals such as iron or sheets made of synthetic resins, synthetic rubbers, etc. are generally used, and more specifically, ethylene-acetic acid Sheets made of synthetic resins such as vinyl copolymers, polyethylene, polypropylene, flexible polyurethane, and flexible polyvinyl chloride, and synthetic rubbers such as styrene-butadiene rubber, chloroprene rubber, butyl rubber, and acrylonitrile-butadiene rubber have the polymer cement composition described below. Adhesion to objects, durability,
It is preferably used in terms of workability, cost, etc.
However, when using a sheet made of a non-polar resin such as polyethylene or polypropylene, it is preferable to apply an appropriate primer or treat the surface by physical or chemical means to improve adhesion.

Furthermore, when applying the method of the present invention in cold regions,
When an insulating waterproof sheet made of the above-mentioned synthetic resin or synthetic rubber foam, preferably a closed-cell foam, is used as the waterproof sheet, even if water leaks from the cement structure, freezing of the leaked water can be prevented. You can.

The thickness of these sheets is not particularly limited, but
Generally 0.5 for non-foamed resin or rubber sheets.
-3 m/m, preferably 1-2 m/m, and in the case of foam sheets, it is generally about 2-15 m/m, preferably about 4-10 m/m. Further, when the sheet is thin, particularly when it is a metal sheet, a sheet having a corrugated cross section is often used.

In the method of the present invention, the upper part of a cement structure is covered with the above-mentioned sheet, and a metal mesh is fixed to the cement structure from the outside using fastening fittings. Although not specified, it is usually fixed to the cement structure using the fasteners used for fixing the metal mesh after temporary nailing with concrete nails, and then covered. Further, from the viewpoint of waterproofing, it is preferable that the seams of the sheets are not butted but partially overlapped by an appropriate method.

As the metal mesh in the present invention, iron is preferably used, and specifically, so-called metal lath (flat lath is often used among flat lath, rib lath, hump lath, and corrugated lath), wire lath, and mesh. A welded wire mesh, etc., whose intersection points are welded, is used.
In addition, the mesh roughness, material thickness, etc. are appropriately selected depending on the dimensions of the steel band used and the type of fastening fittings, etc., but in general, the thickness is 0.4 to 2 m/cm.
m, width is about 1 to 3 m/m, and in the case of metal lath, one of about 0.8 to 1.5 m/m x 1.2 to 2.0 m/m is preferably used, and the mesh roughness is usually 20 to 100.
m/m, preferably about 20 to 40 m/m.

In the present invention, these metal meshes may be directly fixed to the existing cement structure from the outside of the sheet using fastening fittings, but from the viewpoint of workability,
Thickness 0.5 to 6 m/m, preferably 1 to 3 m/m,
It is preferable to fix it through a flat steel plate having a width of 5 to 40 m/m, preferably 10 to 30 m/m. That is, by stretching the steel band plate on the outside of the metal net and fixing the steel band plate to the existing cement structure with fastening fittings, the sandwiched metal steel can be indirectly fixed together with the sheet. There is no particular limit to the distance between the fasteners to be driven, but it is usually 10 to 50 cm.
It is said that

Further, as the fastening fitting, a drive set anchor, a self-drilling anchor, a wedge, a construction fastener gun, etc., which will be described later, in which a part of the embedded bolt can be screwed into the outer frame and the inside of the outer frame, can be used. Anchor bolts such as pin anchors are preferred, but concrete nails, barbed nails, wood screws, screws, etc. can also be used.

The polymer cement composition in the present invention is:
Conventionally known products containing water, cement, cement polymers, and aggregates if necessary are widely used, and are called polymer cement paste, polymer cement mortar, polymer cement concrete, etc. depending on the presence or absence of aggregate, type, etc. be done. As the cement, Portland cement, alumina cement, mixed cement, etc. are often used, and these are used alone or in an appropriate mixture.

Cement polymers are also called polymer admixtures, and they exist as polymers in cured polymer cement products and are mixed with them for the purpose of improving their impact resistance, adhesion to existing structures, etc. Examples include natural rubber, chloroprene rubber, butadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, synthetic rubber such as methyl methacrylate-butadiene rubber, polyvinyl acetate, ethylene-vinyl acetate copolymer, styrene-
Acrylic copolymer, polyacrylic acid ester,
Examples include polyvinyl chloride, polyvinylidene chloride, polyvinyl propionate, and the like. Most of these, except for natural rubber, are synthesized by emulsion polymerization, and then stabilizers, antifoaming agents, etc. are added as necessary, and they are usually used in the form of emulsion or latex.

Among the above polymers, styrene-butadiene rubber, acrylonitrile-butadiene rubber, ethylene-vinyl acetate copolymer, styrene - Acrylic copolymers are preferred, and styrene-butadiene rubber and ethylene-vinyl acetate copolymers are particularly preferred. These polymers are usually added in solid amounts of 10 to 30 parts by weight per 100 parts by weight of cement.

Among the aggregates used as necessary, silica sand containing silicic anhydride as a main component and having a particle size of 2.5 m/m or less is particularly preferably used as the fine aggregate. Cement 100 is usually used in terms of shrinkage during curing, various strengths after curing, and economic efficiency.
It is used within a range of 400 parts by weight or less.

Polymer cement compositions generally have greater waterproofing (water impermeability) performance than conventional cement compositions, but various waterproofing agents can be added to polymer cement compositions in order to provide even better waterproofing properties. Good too. A preferable example of the waterproofing agent is a molar ratio of aluminum oxide to silicon dioxide of 1:1 to 1:1.
1:10 amorphous aluminum silicate,
Particularly preferred is a synthetic amorphous aluminum silicate in which the molar ratio is approximately 1:9.

The present invention was made based on the fact that polymer cement compositions have excellent adhesion to metals, particularly iron, and are excellent in waterproofing properties.

That is, according to the findings of the present inventors, for example, when styrene-butadiene rubber or ethylene-vinyl acetate copolymer is used as the polymer in a polymer cement composition, the tensile adhesive strength of the polymer cement composition to a steel plate is higher than that of the conventional polymer cement composition. The strength of the cement composition is approximately 4 to 6 times higher, and the waterproof performance of the composition measured in accordance with JISA1404 is approximately 40 to 60 times higher (both adhesive strength and waterproof performance are higher than ordinary Portland cement as cement). (Compared values for compositions whose polymer-cement ratio, water-cement ratio, polymer specifications, etc. are within the normal usage range).

However, when covering the waterproof sheet and metal mesh with the polymer cement composition, the lower end of the sheet (usually It is necessary to leave the side edges (both ends) uncovered.

Next, the construction method of the present invention will be explained with reference to the drawings showing one embodiment thereof.

In Figures 1 to 4, 1 is an aged reinforced concrete layer provided in contact with the rock layer 2 of the tunnel, 3 is an ethylene-vinyl acetate copolymer sheet with a thickness of 1.5 m/m, and 4 is a 1 m/m thick layer. , width 1.5m/m, mesh roughness 30m/m x 30m/m expanded metal lath made of mild steel plate, A and B each have a thickness of 2m/m and a width of 20
They are steel strips of m/m and are arranged so as to cross each other perpendicularly. The drive set type anchor bolt 5 includes an outer cylinder 6 in which a screw is provided from the lower end of the inner side wall to the center in FIG. It consists of a bolt 7, a washer 8 and a nut 9.

In order to guide the leakage water seeping from the upper part of the concrete layer 1 to the lower part, first, the waterproof sheet 3 is
As shown in the figure, it is temporarily fixed with concrete nails (not shown) along the curved surface of the upper part of the concrete layer 1.
Furthermore, the metal lath 4 is brought into contact with the waterproof sheet 3 from the outside (bottom) side as shown in FIG. The metal lath 4 is stretched by tightening the steel strips A and B to the concrete layer 1 using a method. Anchor bolt 5 connects steel strip A,
To fix B, for example, use a drill to drill a hole in the sheet 3 and the concrete layer 1, and then insert the bolt 7 into the outer cylinder 6.
The anchor bolt 5 screwed into the hole is driven into the hole using an appropriate jig, and then the bolt is rotated.
After moving it forward and attaching the steel strips A and B, which have holes made in advance at intervals of about 30 cm, and attaching the washer 8, the nut 8 is tightened.

On the other hand, 100 parts by weight of ordinary Portland cement;
Styrene/butadiene copolymer emulsion (solid content 45%) 30 parts by weight, silica sand with particle size of 1 m/m or less
A mortar-like polymer cement composition is prepared by stirring and mixing a composition consisting of 300 parts by weight, 30 parts by weight of on-site mixed water, and an appropriate amount of glass fiber.

The obtained composition is sprayed using an appropriate gun, except for the left and right lower end side edges 3' and 3' of the sheet 3 in FIG. 5 was completely covered and smoothed with a plastering trowel to a thickness of 11m/
m of polymer cement layers 10 are formed.

In this embodiment, since the concrete layer 1 is covered from the upper part to the side part with a waterproof sheet 3 of sufficient length, water leakage can be prevented even if there is no gutter installed on the side part to catch water and guide it to the side gutter 11. The sheet 3 is guided from the lower end of the sheet 3 along the side wall surface of the concrete layer 1 to the gutter, but if the length of the sheet 3 is short, it is preferable to provide a gutter.

The covered water conduit construction method for tunnels of the present invention is constructed as described above, and a metal mesh is fixed to the cement structure from the outside of the waterproof sheet with fastening fittings, and a steel band plate used as necessary is used as an impermeable material. Since it is coated with a large polymer cement composition, the metal mesh etc. will not corrode and the durability of the coating layer made of the polymer cement composition is extremely high compared to the conventional method in which the metal plate is exposed inside the tunnel. Moreover, even if an unexpected situation occurs in which a part of the coating layer falls, the trouble caused by this is extremely small compared to the conventional method using the metal plate.

[Brief explanation of drawings]

Figures 1 to 4 are explanatory diagrams of the repair method according to the present invention, where Figure 1 is a longitudinal cross-sectional view of the existing tunnel with a waterproof sheet in contact with it, and Figure 2 is the concrete layer of Figure 1. Fig. 3 is a top view of Fig. 2 (however, the reduction magnification is different), and Fig. 4 is a cross-sectional view of Fig. 2 covered with a waterproof sheet and fixed with a metal lath. It is a sectional view of the state. 1... Reinforced concrete layer, 3... Waterproof sheet, 3', 3'... Lower end side edge of sheet, 4... Metal lath, 5... Drive set type anchor bolt, 10... Polymer cement layer.

Claims (1)

[Scope of Claims] 1. After covering the upper part of the cement structure with a waterproof sheet and fixing a metal mesh to the cement structure from the outside of the sheet directly or indirectly using fastening fittings, The sheet and net are coated with a polymer cement composition except for the lower edge of the sheet, and the sheet is used to guide water leakage from the upper part of the cement structure to the lower part of the cement structure. Features of tunnel covering water conduit construction method. 2. The water conveyance method according to item 1, wherein the waterproof sheet is an ethylene-vinyl acetate copolymer sheet. 3. The water conveyance method according to item 1 or 2, wherein the polymer in the polymer cement composition is styrene-butadiene rubber. 4 Item 1 or 2, wherein the polymer in the polymer cement composition is an ethylene-vinyl acetate copolymer.
Water conveyance method described in section.