JPS6156398B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a waterproof layer with a built-in drainage channel for draining water leakage from a primary lining surface in order to prevent water leakage from a tunnel structure.

One method of constructing a tunnel is to excavate the ground, spray the tunnel, then drive lock bolts, and then pour concrete lining to construct the tunnel.

In this type of tunnel construction method, in order to prevent cracks in the inner concrete lining (secondary lining concrete) and water leakage from construction joints, a method was adopted in which a waterproof layer was formed on the shotcrete wall in advance. , a method of attaching a sheet of polyvinyl chloride, polyethylene, or the like with nails or the like has been used. However, this method not only has problems with the waterproofing of the nails and the joining method between the sheets, but also the unavoidable sagging of the sheets between the nails after nailing. This tends to cause the sheet to be pulled downward and the nail portions torn or folded over and broken when secondary lining concrete is poured.

In addition, if there is water leakage from the shotcrete wall during waterproofing construction, it will take time to clean up the water leakage from nails and joints, which will impair work efficiency. This would have hindered the pouring of the next lining concrete, and could have led to serious defects such as not being able to secure a sufficient thickness of concrete.

Currently, as a waterproofing method for concrete structures, in addition to sheet waterproofing, spray waterproofing using a rubber asphalt emulsion, which is also the base material of the present invention, is also implemented. In this method, a rubber asphalt emulsion and a decomposer aqueous solution are simultaneously sprayed and mixed from separate routes, and a rubber asphalt film is rapidly formed on the wall surface. It has the excellent characteristics that it follows the unevenness of the base well, and since it does not require organic solvents or fire, it does not harm the environment or hygiene, and there is no risk of fire. However, if there is moisture on the wall,
There is also the problem that if adhesiveness deteriorates and water leaks, a film will not be formed in that area.

On the other hand, no matter what kind of waterproofing work is used, when forming a waterproof layer, if the number of leakage points is extremely small or limited, water should be collected downward by hanging a gutter or attaching a hose to the leakage point. Although the method of primary treatment by draining water is practical,
When there are many water leakage points, the work is complicated, and complete collection and treatment of wastewater cannot be expected.

Therefore, the waterproof layer tends to be incomplete, and conventionally it has been considered very difficult to completely waterproof this type of tunnel structure.

In view of this situation, the present invention was developed as a method for forming a complete waterproof layer in cases where water leaks from many places on a shotcrete wall surface. death,
In addition, the present invention provides a method that makes it possible to form a waterproof layer that is substantially in close contact with the tunnel shape.

That is, as shown in the drawing, (a) a primary rubber asphalt waterproofing layer 3 is formed by spraying on a wall made of shotcrete 1, and (b) a lower layer is then applied to leakage points 8 scattered on this waterproofing layer. A water collection pipe 4 or water collection zone material is arranged up to the drainage groove 7, and the top thereof is covered with a flexible waterproof sheet 10 to form a drainage path, (c)
Furthermore, a second rubber asphalt waterproof layer 5 is placed on top of that.
It is formed by spraying to form a waterproof layer that closely adheres to the exact shape of a tunnel with a built-in leakage drainage channel. By placing the lining concrete 6 on the waterproof layer thus formed, a strong tunnel without water leakage can be constructed.

The construction method of the present invention will be explained in more detail below.

The primary and secondary rubber asphalt waterproof layers are formed by simultaneously spraying a rubber asphalt emulsion and its decomposing agent aqueous solution using a special spraying machine.

The rubber asphalt emulsion used is an asphalt emulsion containing an emulsifier that is relatively easily decomposed and mixed with rubber latex in an amount of 5 to 30% based on the asphalt emulsion. Further, as the decomposing agent aqueous solution, a 2 to 10% aqueous solution of calcium chloride, calcium nitrate, alum, etc. is used. This decomposer aqueous solution is
It reacts with the rubber asphalt emulsion and instantaneously decomposes and separates it into rubber asphalt and water.

Simultaneous spraying of the rubber asphalt emulsion and decomposer aqueous solution uses a special spray machine with each spray nozzle arranged at a fixed angle, and sprays the rubber asphalt emulsion and decomposer aqueous solution while uniformly mixing them in the air. This method forms a rubber asphalt film on the sprayed surface.

The water collection pipe or water collection zone that has the ability to collect and conduct water can be made of any material such as synthetic resin or synthetic rubber. The hose-like water collection pipe is
This is a preferable example in terms of workability, properties, etc. The water catchment zone is made of synthetic resin and is woven into a non-woven fabric with a wire diameter of 0.1 to 0.5 mm, with a thickness of 10 to 30 mm, and then cut to the appropriate width and length.

Any sheet can be used as the flexible waterproof sheet 10 as long as it has both flexibility and waterproofness. For example, synthetic resin sheets such as polyethylene and polyvinyl chloride, sheets with water-permeable nonwoven fabrics or resin foams attached to these sheets, and sheet-like materials such as woven or nonwoven fabrics made of synthetic fibers or mineral fibers. There are flexible waterproof sheets impregnated with or coated with bitumen, synthetic resin, synthetic rubber, or a mixture of two or more of these, and waterproof sheets made of a synthetic resin sheet with low water permeability laminated with a rubber asphalt layer. Among them, a waterproof sheet made of polyethylene laminated with rubber asphalt is excellent in flexibility, has heat fusion properties, and is easily integrated with the sprayed rubber asphalt film, so it is practically preferable.

When covering the water collection pipe 4 with such a flexible waterproof sheet 10, cut this sheet to an arbitrary width, cover the water collection pipe or water collection zone with the cut sheet, and cut it as shown in Fig. 3. Both ends of the sheet 10 are bonded across the water collection pipe 4 with a rubber asphalt adhesive or fused to the primary rubber asphalt waterproof layer 3 by heat from a torch lamp or the like. In this way, the water collection pipe 4 or the water collection zone itself and its surroundings 12 serve as a drainage channel.

Next, examples of the present invention will be described.

(b) Rubber asphalt emulsion and 5% calcium chloride are applied to the wall surface of shotcrete layer 1 constructed at the construction site using the special spraying machine mentioned above.
A primary rubber asphalt waterproofing layer 3 having a thickness of approximately 2 mm was formed by simultaneously spraying with an aqueous solution. At this time, the separated moisture flowed away, and the rubber asphalt particles from which the moisture was separated adhered to the wall surface to form a waterproof layer 3.

(b) Water dripping or flowing down from the tunnel wall is
This primary rubber-asphalt waterproofing layer 3 cannot completely waterproof the water and the water drips or flows down from the leakage point 8, so the water collection pipe 4 is installed along the tunnel wall from the leakage point 8 to the lower drainage ditch 7. This was then secured with concrete nails or fasteners. Next, a laminated sheet of polyethylene sheet and rubber asphalt is cut into strips and used as a flexible waterproof sheet 10, and this sheet 10 is covered over the water collection pipe 4 as shown in FIG.
The entire surfaces of both ends of the sheet 10 were thermally fused to the primary rubber asphalt waterproofing layer via the welded portion 11 using a torch lamp, straddling the water collection pipe.

Thus, a hollow portion 12 was formed around the water collection pipe 4, and together with the water collection pipe itself, a discharge channel was formed.

(c) Finally, the flexible waterproof sheet 10 covering the primary rubber asphalt waterproof layer 3 and the water collection pipe 4
A rubber asphalt emulsion and a 5% calcium chloride aqueous solution were simultaneously sprayed onto the entire surface of the rubber asphalt in the same manner as in (a) to form a secondary rubber asphalt waterproof layer 5 having a thickness of approximately 2 mm.

Through the above steps (a), (b), and (c), a waterproof layer in the form of a tunnel with a built-in drainage channel for water leakage from the shotcrete wall of the present invention was completed.

As a result of inspecting the entire structure, no water was found to leak or drip onto the surface of the waterproof layer, or water flowing down along the surface of the waterproof layer. Water that has been dripping or flowing down from the small holes in the shotcrete layer 1 and the primary rubber asphalt waterproofing layer 3 flows out into the drain groove 7 using the water collection pipe 4 and the hollow part 12 around it as a drain path. The situation was observed. In combination with the formation of the above-mentioned drainage channels, the strong primary and secondary rubber asphalt layers are extremely effective in blocking dripping water. These waterproof layers are easily formed by simultaneous spraying of a rubber asphalt emulsion and an aqueous decomposer solution, reducing construction time and improving efficiency. To provide the present invention as an extremely excellent method for constructing a waterproof layer that can be formed in the same shape and, in combination with the alternate layer construction method, can be expected to be durable and have a complete waterproof effect.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of the tunnel, FIG. 2 is an enlarged view of the same part A, and FIG. 3 is a cross-sectional view showing the condition of the discharge path. 1...Shotcrete layer, 2...Rock bolt, 3...Primary rubber asphalt waterproof layer, 4
... Water collection pipe or water collection zone, 5 ... Secondary rubber asphalt waterproof layer, 6 ... Concrete lining layer, 7
. . . Drain pipe, 8 . . . Water leakage point, 9 .

Claims (1)

[Claims] 1. In a tunnel construction method in which after excavation, a shotcrete layer is formed, lock bolts are driven, and a lining concrete layer is formed, (a) a rubber asphalt emulsion and a decomposition agent are applied to the shotcrete wall surface; (b) A water collection pipe having the ability to collect and conduct water along the inner wall from the leakage point where water is still dripping from the waterproof layer to the lower drainage ditch. Alternatively, place a water collection zone, cover it with a flexible waterproof sheet, and then glue both ends of this sheet to the primary rubber asphalt waterproof layer to form a water collection pipe or water collection zone and a drainage channel around this area. Step (c) The step of forming a secondary rubber asphalt waterproof layer by simultaneously spraying an asphalt emulsion and a decomposer aqueous solution onto the entire surface of the primary rubber asphalt waterproof layer and the flexible waterproof sheet. A method of waterproofing a tunnel, which is characterized by having a built-in drainage channel for leakage water, and in which the entire waterproofing layer adheres to the exact shape of the tunnel.