JP2001329531A - Impervious wall and construction method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impervious wall (soil sealing wall body) capable of reducing construction cost and having high cut-off property and a construction method therefor. SOLUTION: A sheet pile 3 is constructed in the ground 1 so that it reaches an aquiclude 7, the vicinity of a ground surface of the sheet pile 3 is digged to construct a liquid pouring ditch 11, and bentonite slurry 13 is filled therein. Next, the sheet pile 3 is pulled out, and bentonite slurry 13 is filled into a sheet pile pulled out ditch 17. An impervious sheet 21 is constructed in the sheet pile pulled out ditch 17 using a guide jig 19 for hanging the impervious sheet. Grout or mortar 31 is poured in it, and bentonite slurry 13 is discharged. This process is repeated at a fixed interval.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impermeable wall for impermeable groundwater and a method for constructing the same.

[0002]

2. Description of the Related Art Conventionally, as a method of contaminating contaminated soil in the ground, there is a method of constructing a side wall and confining the contaminated soil inside the side wall. And, as the side wall of the contaminated soil containment for temporary storage, it is necessary that the inside contaminant contained in the side wall is not leaked, leaked, or discharged to the outside.
For this reason, it is conceivable to cut the ground thinly and build an ultra-thin wall there.In general, a method of cutting the ground using a saw such as a wire saw or a chain saw and inserting a thin plate material there is proposed. Have been.

[0003]

However, in such a method, the cost is high and the problem of securing the water barrier between the sheets remains, and the method has not yet been put to practical use.

[0004] The present invention has been made in view of such problems, and an object of the present invention is to provide a water impermeable wall which is inexpensive, has high water blocking properties, and a method of constructing the same.

[0005]

According to a first aspect of the present invention for solving the above-mentioned problems, a groove is formed in the ground, a water-blocking sheet is provided inside the groove, and grout or mortar is provided in the groove. It is a water impermeable wall characterized by being provided.

According to a second aspect of the present invention, a step of constructing a groove around the contaminated soil, a step of providing a water-impervious sheet inside the groove, and a step of filling the inside of the groove with grout or mortar are provided. The construction method of the impermeable wall characterized by comprising:

[0007]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 9 are explanatory diagrams of a method for constructing a soil containment wall (water impermeable wall).
9 is a perspective view of FIG. 4, FIG. 7 is a sectional view taken along line AA of FIG.
Is an overall perspective view. As shown in FIG. 1, when a soil containment wall is constructed on the ground 1 around the contaminated soil 9 so as to surround the contaminated soil 9, for example, the sheet pile 3, which is a plate member having a length of about 5 m, is made of a poorly permeable layer. 7 and is driven into the ground 1 by the driving device 5.

Next, as shown in FIG.
Excavation on both sides near the ground surface to construct an injection groove 11,
The injection groove 11 is filled with a bentonite liquid 13. As shown in FIG. 3, the sheet pile 3 that has been cast is extracted by the crane 15. At this time, the injection groove 11
Then, the bentonite liquid 13 enters the sheet pile extraction groove 17 which is a gap from which the sheet pile 3 is extracted. The bentonite liquid serves to prevent the side wall of the sheet pile removal groove 17 from collapsing.

Next, as shown in FIG. 4 and FIG.
A guide jig 19 for dropping a seepage control sheet having legs 22 is provided on the ground 1 and the ground 1. The guide rod 20 is placed on the guide jig 19 for dropping the impermeable sheet. The shape of the water-impervious sheet drop-in guide jig 19 is a shape corresponding to the cross-sectional shape of the sheet pile extraction groove 17. A weight (weight) 23 is provided at the tip of the water-impervious sheet 21. This impermeable sheet 2
1 is placed on the guide rod 20, and an operator grips the end of the impermeable sheet 21. Due to the weight of the weight 23, the impermeable sheet 21 is inserted through the guide rod 20 into the sheet pile withdrawal groove 17 filled with the bentonite liquid 13 and built therein.

FIG. 6 shows a state in which the impermeable sheet 21 is erected in the bentonite liquid 13 in the sheet pile extracting groove 17. FIG. It is A sectional drawing. As shown in FIGS. 6 and 7, the impermeable sheet overlapping portion 29 is provided with the sheet pile removal groove 17.
The water impermeable sheet 21a and the water impermeable sheet 21b are built up in the bentonite liquid 13 inside. This impermeable sheet 21
a and the water impermeable sheet 21b are inserted into the sheet pile extraction grooves 17 at both ends of the overlap margin, and the water impermeable sheet 2 is inserted.
1a and the impermeable sheet 21b are temporarily fixed. Impermeable sheet 2
By injecting the non-shrink mortar 27 into the portion sandwiched between 1a and the water-blocking sheet 21b, water-blocking of the water-blocking sheet overlapping portion 29 is ensured.

Next, as shown in FIG. 8, grout or mortar 31 is injected into both sides of the impermeable sheet 21 in the sheet pile extracting groove 17, the bentonite liquid 13 is discharged, and the filling groove 11 is filled. return. Further, as shown in FIG.
By repeating the above-described method for constructing the soil containment wall at a constant width, a soil containment wall which is an extremely thin impermeable wall is constructed around the contaminated soil 9. In this case, two sets of sheet piles 3 are used, and these two sets of sheet piles 3 are used alternately and alternately. After the construction of the soil containment wall around the contaminated soil 9 is completed, a top cover (not shown) such as asphalt pavement is installed to complete the containment of the contaminated soil 9.

The inflow or outflow of contaminants around the contaminated soil 9 can be prevented in the lateral direction over the depth of the soil containment wall. In the case where a water impervious work is required at the bottom of the contaminated soil 9, a water impervious work is constructed at the bottom of the contaminated soil 9 by the ground improvement method prior to the placement of the sheet pile 3. Thus, according to the present embodiment, the impermeable sheet 2
The use of 1 makes it possible to provide a water-impervious wall (soil-contained wall) having good water-impermeability and low construction cost, and a method of constructing the same.

FIGS. 10 to 12 relate to the case where another weight 33 is used, and FIG.
11 is a perspective view of the weight 33, and FIG. 12 is a view corresponding to a cross-sectional view taken along line BB of FIG. As shown in FIGS. 10 to 12, the weight 33 is similar to the weight 23 described above,
Serves as a weight when it is built into the sheet pile removal groove 17.

As shown in FIG. 12, the cross-sectional shape of the weight 33 is in accordance with the cross-sectional shape of the sheet pile 3, and the necessary number is connected by bolts 35 in accordance with the width of the impermeable sheet 21 to be built. Match. This weight 33
Is imbedded in the sheet pile removal groove 17 via the guide rod 20 provided on the guide jig 19 for dropping the water-impervious sheet.

Next, a description will be given of another embodiment of the present invention, in which a mortar wall construction is provided which also serves as a countermeasure against negative pressure when removing a sheet pile in order to secure workability. 13 to 19 are explanatory diagrams of a method for constructing a soil containment wall according to another embodiment. FIG. 14 is a perspective view of a sheet pile 53 having a press-fitting jig 67, and FIG. 14 is a sectional view taken along line CC, and FIG. 19 is an enlarged view of a portion D in FIG.

When constructing the aforementioned soil containment wall,
When the sheet pile 3 is extracted, even if the bentonite liquid 13 is injected depending on the soil quality of the ground 1, the sheet pile extraction groove 17 is formed.
May collapse. Another embodiment shown in FIG. 13 to FIG. 18 is to reduce the thickness of the driving groove 71 in order to prevent the collapse of the wall of the driving groove 71 due to the negative pressure acting in the driving groove 71 during the work of extracting the sheet pile 53. Jig 6 to increase the size
Mortar 7, and press-fit mortar press-fit pipe 72 to mortar 7
This is a method for constructing a soil containment wall in which the sheet pile 53 is withdrawn while feeding 4 and a mortar 74 wall is constructed.

As shown in FIG. 13, when a soil-contained wall is constructed on the ground 51 surrounding the contaminated soil 59 so as to surround the contaminated soil 59, the ground 51 at the construction position of the soil-contained wall is constructed.
The filling groove 61 is excavated, and the bentonite liquid 63 is filled in the filling groove 61. Reference numeral 57 denotes a poorly permeable layer.

Next, as shown in FIGS. 14 and 15, an angle 66 is provided at the tip of the sheet pile 53, and the support portion 68 of the press-fitting jig 67 having a V-shaped cross section is attached to the gum tape 69.
Temporarily attach with etc. Then, as shown in FIG. 16, immediately before the press-fitting jig 67 is press-fitted from the temporarily fixed sheet pile 53, the gum tape 69 is peeled off, and the pouring device 55 is used to drive down the liquid injection groove 61. FIG. 14 is a perspective view written to conceptually understand the positional relationship between the press-fitting jig 67 and the sheet pile 53. At the time of construction, the press-fitting jig 67 is set so that a becomes zero. It is attached to the sheet pile 53.

As shown in FIG. 17, the sheet pile 53
Is cast so as to reach the poorly permeable layer 57. The cross section of the press-fitting jig 67 is V-shaped, and when the sheet pile 53 is driven, a driving groove 71 thicker than the thickness of the sheet pile 53 is formed. A mortar press-fitting pipe 72 is separately inserted into the casting groove 71, and the mortar 74 is filled from the inner bottom surface of the casting groove 71 to form a wall body with the mortar 74.

Next, as shown in FIGS. 18 and 19, the driven sheet pile 53 is removed by a crane 65. The press-fitting jig 67 simultaneously removes the sheet pile 53,
It is separated from the sheet pile 53 and stands at the bottom of the driving groove 71. Since the driving groove 71 is thicker than the thickness of the sheet pile 3, when the sheet pile 53 is extracted, the sheet pile 5
3 does not contact the side wall of the casting groove 71, and does not generate a negative pressure by pumping the mortar 74 from the mortar injection pipe 72. The mortar 74 is filled to form a wall made of the mortar 74. A waterproof sheet is provided in the wall of the mortar 74. Subsequent steps are the same as in the above-described embodiment.

[0021]

As described above in detail, according to the present invention, since a water impervious sheet is used in place of a steel sheet pile, the construction cost is low, the water impervious wall (soil containment wall) having high water stoppage and The construction method can be provided. In addition, in the conventional method, from the viewpoint of life cycle cost (LCC), if the removal of the wall is required in the future, the removal and disposal of the concrete wall will require enormous costs. In addition, problems such as disposal of corroded steel material occur. The cost of the future removal of the water-impervious sheet according to the present invention is only the cost of cutting and removing the excavated portion by ordinary excavation work and disposing of industrial waste.

[Brief description of the drawings]

FIG. 1 is an illustration of a method for constructing a soil containment wall.

FIG. 2 is an explanatory view of a method for constructing a soil containment wall.

FIG. 3 is an illustration of a method for constructing a soil containment wall.

FIG. 4 is an illustration of a method for constructing a soil containment wall.

FIG. 5 is a perspective view of FIG. 4;

FIG. 6 is an explanatory view of a method for constructing a soil containment wall.

FIG. 7 is a sectional view taken along line AA of FIG. 6;

FIG. 8 is an explanatory view of a method for constructing a soil containment wall.

FIG. 9 is an overall perspective view of a method for constructing a soil containment wall.

FIG. 10 is a perspective view when the impermeable sheet 21 is installed.

11 is a perspective view of a weight 33. FIG.

FIG. 12 is a sectional view taken along line BB of FIG. 11;

FIG. 13 is an explanatory diagram of a method for constructing a soil containment wall.

FIG. 14 is a perspective view of a sheet pile 53 having a press-fitting jig 67.

15 is a sectional view taken along the line CC in FIG.

FIG. 16 is an explanatory diagram of a method for constructing a soil containment wall.

FIG. 17 is an explanatory view of a method for constructing a soil containment wall.

FIG. 18 is an explanatory view of a method for constructing a soil containment wall.

19 is an enlarged view of a portion D in FIG. 18;

[Explanation of symbols]

 1, 51: Ground 3, 53: Sheet pile 9, 59: Contaminated soil 11, 61: Injection groove 13, 63: Bentonite liquid 19: Guide jig for dropping of water-blocking sheet 21: Water-blocking sheet 23, 33 ... Weight 67 ... Press-fitting jig 72 ... Mortar press-fit pipe 74 ... Mortar

Claims (9)

[Claims] A groove is formed in the ground, and inside the groove,
A water impermeable wall, provided with a water impermeable sheet, and grout or mortar provided in the groove. 2. The shielding sheet according to claim 1, wherein the waterproof sheet has a non-shrinkable mortar partially overlapped and filled inside the two waterproof sheets in the overlapped portion. Water wall. 3. building a ditch around the contaminated soil;
A method of constructing a water impermeable wall, comprising: providing a water impermeable sheet inside the groove; and filling grout or mortar inside the groove. 4. The step of constructing the groove includes a step of placing a plate member, and excavating around a ground surface of the plate member,
A step of constructing an injection groove, a step of injecting a bentonite liquid into the injection groove, and extracting the plate member, and injecting the bentonite liquid from the injection groove into the groove formed by the plate member. The method according to claim 3, further comprising the steps of: 5. The step of providing the water-impervious sheet includes the steps of: installing a rod-shaped guide rod on the ground surface above the groove; and attaching the water-impervious sheet to the groove so as to be along the guide rod. The method for constructing a water impermeable wall according to claim 3, comprising a step of providing the inside. 6. The shielding material according to claim 3, wherein the waterproofing sheet has a non-shrinkable mortar that is partially overlapped and filled inside the two waterproofing sheets in the overlapping portion. How to build a water wall. 7. The step of providing the water impermeable sheet, wherein a weight is provided at an end of the water impermeable sheet, and the water impermeable sheet is inserted into the groove. Construction method of the impermeable wall. 8. The step of constructing the groove includes the steps of: constructing an injection groove around contaminated soil; injecting a bentonite liquid into the injection groove; A step of casting a plate member having a press-fitting jig into it, and a step of extracting the plate member, inserting a mortar press-fitting pipe into a groove constructed by the plate member, and injecting mortar. The method for constructing a water impermeable wall according to claim 3. 9. The method according to claim 8, wherein an end of the press-fitting jig has a V-shaped cross section.