JPH0718170B2 - Construction method of impermeable membrane wall - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an impermeable membrane wall that uses an impermeable sheet in the construction of an underground dam, an impermeable wall of a waste treatment plant, an impermeable wall of a dam, etc. Regarding the construction method.

[Conventional technology]

Conventionally, a chemical injection method, a concrete replacement method, an in-situ agitation mixing method, etc. are used to construct the impermeable wall.

However, the construction area (volume) of the chemical injection method and the in-situ agitation mixing method is wide, which is disadvantageous in terms of workability and cost. Need to be wide.

In order to solve this problem, in recent years, a water-impervious membrane wall construction method has been performed in which a water-impermeable sheet is inserted into a groove to construct an impermeable wall. According to this construction method, a high water-blocking property can be secured by the water-blocking sheet even if the construction area is reduced.

FIG. 8 shows an outline of such a water-blocking film wall construction method, in which the band-shaped groove 1 is formed by trench excavating with a chain cutter as disclosed in JP-A-64-80624 and JP-A-1-121491. The water-blocking sheet 2 is inserted into the band-shaped groove 1, and a filler 3 such as mortar is poured into the gap.

As the water-blocking sheet 2, a sheet having a thickness of several mm in which a non-woven fabric is used as a core material and coated with rubber asphalt is optimal, and the sheet is pulled out from the roll-shaped groove 1 from the roll-shaped state as shown in the drawing.

Although not shown, the filling material 3 such as mortar may be filled with a tremie tube or the like.

[Problems to be Solved by the Invention]

By the way, the water-impervious sheet 2 is adapted to be fed along a rod-shaped guide roller when the depth is shallow, and although not shown in the figure, when the depth becomes deep, a weight such as a steel bar is attached in parallel along the lower end. I'm trying to drop it.

However, since the band-shaped groove 1 has a narrow width and is likely to be bent when the depth is increased, the tip of the sheet 2 may come into contact with the hole wall of the groove 1 or may be displaced in the horizontal direction with high accuracy. I can't insert it.

Further, the water-impervious sheet 2 needs to be provided with a joint portion 2a in order to have continuity in the horizontal direction, and the joint portions 2a need to be joined to each other, but it is difficult to secure or manage the wrap width of the joint portion 2a. Become.

An object of the present invention is to eliminate the disadvantages of the conventional example, and to provide a water shield film wall construction method capable of smoothly and accurately inserting a water shield sheet to a predetermined depth of a band-shaped groove.

[Means for Solving the Problems]

In order to achieve the above object, the present invention is a method of constructing an impermeable membrane wall in which a waterproof sheet is inserted into a strip groove, and a gap around the sheet is filled with a hook or pulley at the top of the bottom portion of the strip groove. Place the weight that you have and place concrete on the bottom of the strip groove to consolidate this weight with the hook or pulley exposed, and insert the rope connected to the lower end of the impermeable sheet into the hook or pulley. Then, the gist is to pull the lower end of the water-blocking sheet to the bottom of the band-shaped groove by pulling the cord.

[Action]

According to the present invention, by pulling the cord, the end of the water-impervious sheet is pulled downward by the hook or pulley at the bottom of the band-shaped groove as a reaction force, and can be pulled as it is to the bottom of the band-shaped groove.

〔Example〕

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 to 5 are side views showing an embodiment of the water-permeable film wall construction method of the present invention.

First, as in the conventional case, trenches are excavated on the ground with a chain cutter as disclosed in JP-A-64-80624 and JP-A-1-121491, and the strip-shaped groove 1 is formed in the impermeable layer (the boundary between the impermeable layer and the impermeable layer). However, prior to the insertion of the water-impervious sheet 2 described later, a weight 5 having a hook 4 on the upper portion as shown in FIG. 6 is placed on the bottom of the band-shaped groove 1. In this case, the rope 4 may be previously inserted through the hook 4 of the weight 5 and then suspended.

The weights 5 are arranged on the bottom of the band-shaped groove 1 at appropriate intervals, but if the position is a place where the joint portion 2a of the water-impervious sheet 2 should come, it should be adjusted to this position.

After arranging the weight 5 in this way, as shown in FIG. 2, concrete 7 for root consolidation is placed on the bottom of the band-shaped groove 1,
The weight 5 is embedded and fixed in the concrete 7 with the hook 4 exposed.

Next, as shown in FIG. 3, the water-impervious sheet 2 is inserted into the strip-shaped groove 1. At that time, a rope,
One end of the cord 6 such as a piano wire or a wire is connected, and the other end of the cord 6 is pulled on the ground while the hook 6 is inserted through the hook 4.

Since the weight 5 of the hook 4 is fixed by the concrete 7, the rope 6 can be pulled in by the hook 4 as a reaction force, and as shown in FIG. It can be pulled up to the bottom of the groove 1.

In this way, if the preceding water-impervious sheet 2 is suspended in the band-shaped groove 1, then the adjacent water-impermeable sheet 2'to which the water-impermeable sheet 2 is joined is also similarly wound in the band-shaped groove as shown in FIG. 1
Hang on.

At that time, if the same hook 4 is used to pull in the adjoining portions of the water-impervious sheets 2 and 2 ', the joints can be simply selected by selecting the connecting portion of the rope 6 to the water-impermeable sheet 2'. Department
You can ensure the wrap of 2a.

Further, as another embodiment, as shown in FIG. 7, a pulley 8 may be used instead of the hook 4 provided on the upper portion of the weight 5.

If the pulley 8 is used in this way, the rope 6 around which the pulley 6 is wound
The frictional resistance with the pulley 8 is small and can be smoothly drawn in.

In addition, the impermeable sheets 2 and 2'are set in this way, and the joint portions 2a are mutually connected to the outer periphery of the impermeable sheet 2 and 2'and the band-shaped groove 1.
The filling of the filler 3 such as mortar into the gap between and is the same as in the conventional example.

〔The invention's effect〕

As described above, the water-permeable membrane wall construction method of the present invention, when the water-impermeable sheet is inserted into the band-shaped groove, and when the surrounding gap is filled with a filler such as mortar, the water-impermeable sheet has a predetermined width of the band-shaped groove. It can be inserted easily and smoothly up to the depth and with high accuracy.

[Brief description of drawings]

1 to 5 are side views of each step showing one embodiment of the water-permeable membrane wall construction method of the present invention, FIG. 6 is a perspective view of a weight with a hook to be used, and FIG. 7 is another of the present invention. FIG. 8 is a perspective view of a pulley-equipped weight used in the embodiment, and FIG. 8 is a perspective view showing a conventional example. 1 ... Band-shaped groove 2,2 '... water-proof sheet, 2a ... joint part 3 ... filling material, 4 ... hook 5 ... weight, 6 ... filament 7 ... concrete, 8 ... pulley

Claims (2)

[Claims] 1. A method of constructing a water-impervious membrane wall in which a water-impermeable sheet is inserted into a strip groove, and a gap is surrounded by a filler, in which a weight having a hook at the top is placed at the bottom of the strip groove, and concrete is used. The weight is fixed in a state where the hook is exposed at the bottom of the belt-like groove and the weight is solidified, and the cord connected to the end of the water-blocking sheet is inserted into the hook, and the water is shielded by pulling the cord. A method of constructing a water-permeable membrane wall, characterized in that the sheet is drawn into the bottom of the band-shaped groove. 2. A method of constructing a water-impervious membrane wall, wherein a water-impermeable sheet is inserted into a band-like groove and a gap is surrounded by a filler, and a weight having a pulley at the top thereof is placed at the bottom of the band-like groove, and concrete is used. This weight is fixed in a state where the pulley is exposed to the bottom of the belt-like groove, and the rope connected to the end of the water-impervious sheet is wound around the pulley, and water is pulled by pulling the rope. A method of constructing a water-permeable membrane wall, characterized in that the sheet is drawn into the bottom of the band-shaped groove.