JP4850158B2 - Construction method of underground impermeable walls - Google Patents

Description

  The present invention relates to a method for constructing an underground impermeable wall composed of a impermeable sheet.

  For example, in an industrial waste final disposal site, it is necessary to enclose the final disposal site with an underground impermeable wall and partition it from the outside in order to prevent the outflow of contaminants. Some underground water-impervious walls use a high-density polyethylene water-impervious sheet that can ensure simple and high water-tightness. The underground water-impervious wall made of this water-impervious sheet is made of soil cement, etc. It is composed of a structure in which a water shielding sheet is embedded in a groove made of, and is often employed in the case of ground with high water permeability or ground with low ground strength.

As a construction method of the above-mentioned underground impermeable wall, first, a groove filled with fluid is created in the ground. Next, the roll-shaped water-impervious sheet is inserted into the groove, and the roll-shaped water-impervious sheet is developed and stretched in the groove. A male seat joiner (joint portion) is attached to one end of the water shielding sheet, and a female sheet joiner (joint portion) is attached to the other end. Next, a new roll-shaped water-impervious sheet is inserted into the groove, and the previously installed water-impervious sheet is joined to the new water-impervious sheet. More specifically, a female sheet joiner is attached to the end of the waterproof sheet at the development start point side, and a male sheet joiner is attached to the end of the development end point side. Then, a new roll-shaped water-impervious sheet is inserted while fitting the female sheet-joiner of the new water-impervious sheet into the male sheet-joiner of the water-impervious sheet installed in advance. Next, as with the preceding water-impervious sheet, a new water-impervious sheet is developed and stretched in the groove. By repeating the above steps, a plurality of water-impervious sheets jointed to each other are installed in the groove (see, for example, Patent Document 1).
JP 2006-283474 A

  However, in the construction method of the conventional underground water-impervious wall described above, when a new water-impervious sheet is constructed after a certain period or time after constructing the preceding water-impervious sheet, When the fluid is solidified, there is a problem that the joint of the water-impervious sheet cannot be made and a discontinuous portion of the water-impervious sheet occurs. For example, when resuming the construction that has been suspended for a plurality of days, there is a high possibility that the fluid in the groove is solidified, and there is a problem that it cannot be jointed to the already constructed waterproof sheet. Moreover, when the solidification property of the fluid in a groove | channel is high, the fluid in the groove | channel constructed on the previous day or the previous week may solidify, and it may be unable to join.

  In the present invention, the above-described conventional problems are considered, and even when there is a construction interval between adjacent water-impervious sheets, the water-impervious sheets can be joined to each other, and adjacent water-impervious sheets are continuously provided. The purpose is to provide a construction method for underground impermeable walls.

  The method for constructing an underground impermeable wall according to the present invention is the method for constructing an underground impermeable wall comprising a water impervious sheet, the step of creating a first groove filled with a solidified fluid in the ground, and a roll A step of spreading the first water-impervious sheet wound in a shape and stretching the first water-impervious sheet in the first groove, provided at the end of the first water-impervious sheet on the development end point side Connecting a dummy joint member to the first end-side joint jig and installing the dummy joint member in the first groove; and after solidifying the fluid in the first groove, the dummy from the first groove A step of pulling out the joint member, and a step of forming the second groove filled with the solidified fluid in the ground by connecting to the portion of the first groove where the dummy joint member is disposed; The dummy joint member is pulled out and solidified in the first groove. A step of inserting a joint member into a hole formed in the moving body and connecting the joint member to the first end-point side joint jig, and providing the joint member at an end of the second water-impervious sheet on the expansion start point side Connecting the first starting point side joint jig, and expanding the second water-impervious sheet wound in a roll shape and stretching the second water-impervious sheet in the second groove, It is characterized by providing.

  Due to such characteristics, when the underground impermeable wall was constructed halfway, it was temporarily interrupted, and then when the construction of the underground impermeable wall was resumed, the fluid in the first groove constructed earlier had solidified. Moreover, the 1st water-impervious sheet constructed | assembled previously and the 2nd water-impermeable sheet constructed | assembled later are connected through a joint member.

  Further, in the method for constructing an underground impermeable wall according to the present invention, a water-expandable seal is formed on a surface of a joint portion engaged with a joint jig on the start point side or the end point side of the water impervious sheet among the joint members. It is preferably coated.

  Thereby, after constructing the joint member, the water-expandable seal provided on the surface of the joint portion of the joint member comes into contact with moisture and expands to be brought into close contact with the joint jig of the water shielding sheet.

  According to the construction method of the underground impermeable wall according to the present invention, even when there is a construction interval between adjacent impermeable sheets, these impermeable sheets can be joined together, and the adjacent impermeable sheets are continuously Can be provided.

Hereinafter, an embodiment of a construction method of an underground impermeable wall according to the present invention will be described with reference to the drawings. Will be described later, "the first groove 2A" correspond to the "first groove" in the present invention, will be described later, "the second groove 2B" corresponds to the "second groove" in the present invention.

  First, the structure of the underground impermeable wall 1 built in the ground G is demonstrated based on FIG. FIG. 1 is a plan view showing the underground water-impervious wall 1, and particularly shows a joint portion of the water-impervious sheet 3.

  As shown in FIG. 1, the underground impermeable wall 1 includes a groove 2 formed vertically in the ground G, and a plurality of impermeable substances embedded in the groove 2 and connected to each other adjacent to each other. And a sheet 3. The underground impermeable wall 1 is constructed over a plurality of days, and the second section B on the right side in FIG. 1 is constructed on the next day after the construction of the first section A on the left side in FIG. The

  The groove 2 is formed in the ground G by stirring the ground G and mixing additives such as water, bentonite, cement and fly ash. The groove 2 is filled with a fluid having fluidity at the beginning of stirring. However, since the additive described above includes a solidifying material such as cement, the fluid in the groove 2 Over time, the ground stirrer loses fluidity and solidifies. In addition, in the ground with high groundwater, it may have fluidity only by stirring without adding water or bentonite, and in this case, water or the like may not be added. In addition, in the case of ground with low groundwater, even if a solidifying material such as cement is not added, fluidity may be lost due to dehydration, resulting in a solidified state. In this case, the solidifying material may not be added.

  The water-impervious sheet 3 is, for example, a sheet made of a flexible polymer alloy, and is made of a soft material having high water tightness and elasticity, and further has a strength and a thickness that does not break when installed. It is what has. Among the plurality of water shielding sheets 3, the first water shielding sheet 3A to be constructed in one day and the intermediate water shielding sheet 3B to be constructed thereafter are side end portions on the exhibition start side (left side in FIG. 1). A cylindrical female joint jig 5 having a C-shaped cross section is provided, and a round tubular male joint jig 4 is attached to a side end portion on the development end point side (right side in FIG. 1). On the other hand, the water-impervious sheet 3C to be constructed last in one day is provided with a cylindrical female joint jig 5 having a C-shaped cross section at both side end portions thereof.

  The male joint jig 4 is made of, for example, a 2.5 inch diameter steel pipe, and the length dimension of the male joint jig 4 is longer than at least the vertical dimension (height dimension) of the water shielding sheet 3. The upper and lower ends of 4 protrude from the upper and lower ends of the water shielding sheet 3, respectively. The male joint jig 4 is inserted and attached in the side end portion of the water shielding sheet 3 folded back into a cylindrical shape, and the outer peripheral surface of the male joint jig 4 is covered by the side end portion of the water shielding sheet 3. It is wrapped as if The male joint jig 4 and the end portion on the side of the water shielding sheet 3 are attached to the outer peripheral surface of the male joint jig 4 by welding or the like so as to extend in the axial direction, and the water shielding sheet is attached to the plate. May be attached by bonding or the like.

  The female joint jig 5 has an inner diameter larger than the diameter of the male joint jig 4, and is made of a steel pipe having a diameter of 5.0 inches, for example. The length dimension of the female joint jig 5 is the same as the vertical dimension of the water shielding sheet 3 or longer than the vertical dimension of the water shielding sheet 3. The female joint jig 5 is formed with a slit 5a extending in the axial direction over the entire length. The width of the slit 5a is narrower than the outer diameter of the male joint jig 4, and even if a horizontal force acts on the male joint jig 4 that is loosely inserted into the female joint jig 5, it is caught by the slit 5a. The female joint jig 5 does not come out of the inside. The female joint jig 5 is inserted into a side end portion of the water shielding sheet 3 folded back into a cylindrical shape having a C-shaped cross section, and the female joint jig 5 is inserted by the end portion of the water shielding sheet 3 side. The outer peripheral surface and the inner peripheral surface are wrapped so as to be covered. In addition, the attachment of the female joint jig 5 and the other side end portion of the water shielding sheet 3 is performed by welding the plate so as to extend in the axial direction on the outer peripheral surface of the female joint jig 5 opposite to the slit 5a. Etc., and a water shielding sheet may be attached to the plate by adhesion or the like.

The first water-impervious sheet 3A and the intermediate water-impervious sheet 3B, the adjacent intermediate water-impervious sheets 3B, and the intermediate water-impervious sheet 3B and the last water-impervious sheet 3C are the male joint jig 4 The joints are respectively made by loosely inserting into the female joint jig 5.
On the other hand, the last water-impervious sheet 3 </ b> C described above and the water-impervious sheet 3 </ b > A to be constructed at the beginning of the day following the construction date of the water-impervious sheet 3 </ b> C are jointed via a joint member 6.

The joint member 6 is made of a flat plate-like steel plate extending along the height direction of the groove 2, and has a round tubular shape having a configuration similar to that of the male joint jig 4 described above at both side end portions thereof. Male joint portions 6a and 6b are respectively provided. The joint member 6 is disposed so as to straddle the boundary between the first section A and the second section B, and the male joint portion 6a on the first section A side is the last water shielding sheet described above. 3C is loosely inserted into the female joint jig 5 on the development end side and connected to the female joint jig 5, and the male joint portion 6b on the second section B side is the first water shielding sheet 3A described above. The female joint jig 5 is loosely inserted into the female joint jig 5 and connected to the female joint jig 5.

  Further, the surfaces of the joint portions 6a and 6b are covered with a water-expandable seal 7. The water-expandable seal 7 is a liquid or viscous sealing material applied to the surfaces of the joint portions 6a and 6b. In addition, as the water-expandable seal 7, it is also possible to use a sheet-like material adhered to the surfaces of the joint portions 6a and 6b, and it is possible to use various preventive materials having water expandability. is there. In addition to the joint portions 6a and 6b, the surface of the flat plate portion 6c between the joint portions 6a and 6b on both sides may be covered with the water-expandable seal 7.

  Alternatively, the male joint jig 4 may be fixed in place by inserting a fixed anchor inserted into the male joint jig 4 so as to pierce the bottom surface of the groove 2. Further, a filler made of, for example, mortar is formed in a gap between the outer peripheral surface of the male joint jig 4 covered with the water shielding sheet 3 and the inner peripheral surface of the female joint jig 5 covered with the water shielding sheet 3. May be filled.

Next, a construction procedure for constructing the underground impermeable wall 1 having the above-described configuration will be described with reference to FIGS. FIG. 2 is an overall perspective view showing a construction situation of the underground water-impervious wall 1, and FIGS. 3 to 11 are plan views showing respective steps when the underground impermeable wall 1 is constructed.
In addition, this Embodiment is a case where the underground impermeable wall 1 is constructed over the outer periphery of the target area X as shown in FIG. A case where the construction is divided into the second section B will be described as an example.

[Preparation process]
First, as shown in FIG. 2, preparation for performing construction for constructing the underground impermeable wall 1 is performed. More specifically, the heavy machinery 10 and 11 for constructing the underground water-impervious wall 1 and equipment equipment (not shown) are brought into the site and assembled, and a construction yard is created. As the heavy machinery 10, 11, for example, a stirrer / mixer 10 such as a trencher type ground improvement machine for creating the groove 2, a sheet unfolding device 11 for installing the water shielding sheet 3 in the groove 2, residual soil treatment or leveling Prepare a backhoe, etc. (not shown) for performing the above. In addition, as equipment, an unillustrated plant for preparing an additive to be added when creating the groove 2 filled with fluid, or water used when creating the groove 2 filled with fluid is stored. Prepare a tank (not shown) or a generator (not shown). Moreover, as construction of a construction yard, the above-mentioned heavy machinery 10 and 11 and equipment are leveled in a range where the equipment is installed and traveled, and an iron plate or the like is laid.

  Subsequently, the underground impermeable wall 1A of the first section A is constructed in the following procedure. The underground impermeable wall 1A in the first section A is constructed without leaving a construction interval (period or time).

[Stirring and mixing step]
First, as shown in FIG. 3, a groove 2 (first groove 2 </ b> A) is formed in the ground G for the day construction (first section A). More specifically, the stirring mixer 10 shown in FIG. 2 is used to continuously stir at a predetermined depth and a predetermined width along the outer periphery of the target area X from the construction start point S to the construction interruption point D. Go. At this time, stirring is performed while mixing the above-described additive, and the stirred portion is made into a fluid. Thereby, the 1st groove | channel 2A filled with the fluid is created.

[Dummy joint member installation process]
Next, after the creation of the first groove 2A at the construction start point S is completed, as shown in FIG. 4, the first dummy joint member 8 is installed in the first groove 2A. The first dummy joint member 8 is a member formed in accordance with the joint member 6. Specifically, the first dummy joint member 8 has a shape without one male joint portion 6 a of the joint member 6. That is, the first dummy joint member 8 has a configuration in which a round tubular male joint portion 8a is provided at one side end portion of a flat steel plate. The first dummy joint member 8 is arranged at the end of the first groove 2A on the construction start point S side so as to extend in the height direction of the first groove 2A, and the lower end of the first dummy joint member 8 is the first. The bottom of the groove 2A is pierced or held at its upper end and fixed in place. In addition, the first dummy joint member 8 is arranged with its male joint portion 8a facing away from the end surface on the first point side of the first groove 2A (the right side in FIG. 4).

[Water shielding sheet insertion / joint process]
Next, as shown in FIG. 5, the first water shielding sheet 3 </ b> A is inserted into the first groove 2 </ b> A, and the female joint jig 5 of the first water shielding sheet 3 </ b> A is inserted. A is connected to the first dummy joint member 8. More specifically, first, the first water shielding sheet 3A is wound around the male joint jig 4 in a roll shape. Then, the roll-shaped first water-impervious sheet 3A is inserted straight into the first groove 2A substantially straight by the sheet developing device 11 shown in FIG. At this time, while fitting the female joint jig 5A of the first water shielding sheet 3A to the male joint portion 8a of the first dummy joint member 8, the roll-shaped first water shielding sheet 3A is lowered. As a result, the male joint portion 8a of the first dummy joint member 8 is loosely inserted into the female joint jig 5A of the first water-impervious sheet 3A, and the starting point of the first water-impervious sheet 3A is engaged. The side end is fixed.

[Water shielding sheet deployment process]
Next, as shown in FIG. 5, the roll-shaped first water-impervious sheet 3 </ b> A is developed, and the first water-impervious sheet 3 </ b> A is stretched in the first groove 2 </ b> A. More specifically, the roll developing unit 11 shown in FIG. 2 slides the roll portion of the water-impervious sheet 3A along the first groove 2A while rotating the shaft, and the roll-shaped water-impervious sheet 3A is moved within the first groove 2A. Expand.

[Water shielding sheet insertion / joint process / water shielding sheet deployment process]
Next, as shown in FIG. 6, the second and subsequent water-impervious sheets 3 </ b> B are inserted and jointed and deployed in the same procedure as the first water-impervious sheet 3 </ b> A described above. At this time, when the second and subsequent water shielding sheets 3B are inserted into the first groove 2A, the male joint jig 4 of the n-th (n is a natural number) water shielding sheet 3B (3A) previously constructed is used. Then, the n + 1 first water shielding sheet 3B (3C) is lowered while fitting the female joint jig 5 of the n + 1 first water shielding sheet 3B (3C) to be constructed next.

[Dummy joint member installation process]
Next, as shown in FIG. 7, the female joint jig 5B (the first part of the present invention) on the development end point side of the final water shielding sheet 3C in the first section A (corresponding to the first water shielding sheet of the present invention). The second dummy joint member 9 is connected to the end point side joint jig), and the second dummy joint member 9 is installed in the first groove 2A. The second dummy joint member 9 has the same configuration as the first dummy joint member 8 described above. The second dummy joint member 9 is lowered into the first groove 2A while the male joint portion 9a is inserted into the female joint jig 5B on the deployment end point side of the final water shielding sheet 3C. As a result, the male joint portion 9a of the second dummy joint member 9 is loosely inserted into and engaged with the female joint jig 5B on the development end point side of the final water shielding sheet 3C. The second dummy joint member 9 is arranged at the end of the first groove 2A on the end point (construction interruption point D) side so as to extend in the height direction of the first groove 2A. The male joint portion 9a is arranged toward the opposite side (left side in FIG. 7) of the end surface on the end side of the first groove 2A. Further, the second dummy joint member 9 is fixed at a fixed position by piercing its bottom end into the bottom surface of the first groove 2A or holding its upper end. Thereby, the end point side end part of the last water-impervious sheet 3C is fixed.

As described above, when the underground impermeable wall 1A in the first section A is constructed, the work is temporarily ended.
And the underground water-impervious wall 1B of the remaining second section B will be constructed in the following procedure at a later date. In addition, the underground impermeable wall 1B of the second section B is constructed without leaving a construction interval (period or time) in the same manner as the underground impermeable wall 1A of the first section A.

[Dummy joint member removal process]
First, as shown in FIG. 8, the second dummy joint member 9 is pulled out from the fluid solidified in the first groove 2A and removed. More specifically, the upper end of the second dummy joint member 9 is pulled up vertically by a heavy machine (such as the stirring and mixing machine 10, the sheet developing device 11, and a backhoe not shown) shown in FIG. 2. Thereby, the hole 20 extended in the height direction of the 1st groove | channel 2A is formed in the end point side edge part of the solidified fluid in the 1st groove | channel 2A. The hole 20 is formed in a circular shape inside the female joint jig 5B on the development end point side of the final water-impervious sheet 3C in the first section A in plan view, and further, from the circular portion, the end point of the first groove 2A An elongated rectangular portion extends toward the side end surface.

[Stirring and mixing step]
Next, as shown in FIG. 9, the groove 2 (second groove 2 </ b> B) for the ground construction (second section B) is formed on the ground G on the end side (second dummy joint) of the first groove 2 </ b> A described above. The member 9 is connected to the portion where the member 9 is disposed. More specifically, the second groove 2B is formed along the outer periphery of the target area X from the construction interruption point D to the construction end point E (same as the construction start point S) in the same manner as the first groove 2A described above. To do. At this time, stirring and mixing are started from a position as close as possible to the female joint jig 5B on the development end point side of the final water-impervious sheet 3C in the first section A.

[Fitting member installation process]
Next, after the creation of the second groove 2B at the construction interruption point D is completed, as shown in FIG. 10, the second dummy joint member 9 is pulled out to form a solidified fluid in the first groove 2A. The joint member 6 is inserted into the formed hole 20, and the joint member 6 is connected to the female joint jig 5 </ b> B on the development end point side of the final water shielding sheet 3 </ b> C in the first section A. More specifically, one side portion of the joint member 6 is inserted into the hole 20, and the male joint portion 6a on one side of the joint member 6 is loosely inserted into the female joint jig 5B. At this time, the other side portion of the joint member 6 is embedded in the end portion on the start point side of the fluid in the fluid second groove 2B.

[Water shielding sheet insertion / joint process / water shielding sheet deployment process]
Next, in the same procedure as the first water-impervious sheet 3A in the first section A described above, as shown in FIG. 11, the first sheet of water-impervious sheet 3A in the second section B (second of the present invention). Equivalent to a water shielding sheet.) At this time, when the first impermeable sheet 3A in the second section B is inserted into the second groove 2B, the first impermeable sheet 3A is inserted into the male joint portion 6b on the other side of the joint member 6. While fitting the female joint jig 5C (corresponding to the first starting point side joint jig of the present invention), the first water shielding sheet 3A is lowered.
Subsequently, the second and subsequent water-impervious sheets 3B in the second section B are inserted and jointed and developed in the same procedure as the second and subsequent impermeable sheets 3B in the first section A described above.

[Dummy joint member removal process]
On the other hand, before the construction of the second groove 2B at the construction end point E, as shown in FIG. 8, from the fluid solidified in the first groove 2A in the same procedure as the second dummy joint member 9 described above. The first dummy joint member 8 described above is pulled out and removed. Thereby, the hole 21 similar to the hole 20 by the above-mentioned 2nd dummy joint member 9 is formed in the start point side edge part of the solidified fluid in the 1st groove | channel 2A. That is, the hole 21 is formed in a circular shape inside the female joint jig 5A of the first water shielding sheet 3A in plan view, and further, from the circular portion toward the start side end surface of the first groove 2A. An elongated rectangular portion is extended.

[Stirring and mixing step]
Next, as shown in FIG. 9, the end point side end portion of the second groove 2B (the portion of the construction end point E) is the start point side end portion (first dummy joint member 8) of the first groove 2A described above. Connected to the other part). At this time, stirring and mixing are performed to a position as close as possible to the female joint jig 5A of the first water shielding sheet 3A.

[Fitting member installation process]
Next, as shown in FIG. 10, when the first dummy joint member 8 is pulled out, the joint member 6 is inserted into the hole 21 formed in the fluid solidified in the first groove 2A. The joint member 6 is connected to the female joint jig 5A of the water shielding sheet 3A. More specifically, one portion of the joint member 6 is inserted into the hole 21 described above, and the male joint portion 6a on one side of the joint member 6 is loosely inserted into the female joint jig 5A. At this time, the other side portion of the joint member 6 is embedded in the end point side end portion of the fluid in the fluid second groove 2B.

[Water shielding sheet insertion / joint process / water shielding sheet deployment process]
Next, as shown in FIG. 11, the final water-barrier sheet 3 C in the second zone B, it is expanded by inserting and fitting the same procedure as intermediate water shield sheets 3B in the second section B mentioned above.

[Water shielding sheet closing process]
Finally, as shown in FIG. 11, for connecting the female joint jig 5 D of the final water shield sheet 3C to the joint member 6 (in the same. And construction starting point S) Construction end point E in the second section B. More specifically, the female joint jig 5D of the final water shielding sheet 3C is fitted into the male joint portion 6b on the other side of the joint member 6 described above. Thereby, the several water-impervious sheet | seat 3 connected mutually adjacently is closed.
As described above, the construction of the underground impermeable wall 1 surrounding the target area X is completed.

  According to the construction method of the underground impermeable wall 1 described above, even when there is a construction interval between the first section A and the second section B, the final impermeable sheet 3C in the first section A and 1 in the second section B Since the third water-impervious sheet 3A is joined, a plurality of water-impervious sheets 3 can be provided continuously. Thereby, the water leakage from the joint between the water-impervious sheets 3C and 3A at the construction interruption point D can be prevented, and the water stoppage of the underground impermeable wall 1 can be improved.

  Moreover, according to the construction method of the above-mentioned underground impermeable wall 1, when the underground impermeable wall 1 is constructed over the entire circumference of the target area X, the deployment end side of the lastly constructed impermeable sheet 3C The end portion can be jointed to the end portion of the water shielding sheet 3A that has been initially constructed, and the plurality of water shielding sheets 3 can be closed. Thereby, it is possible to prevent water leakage from the joint between the water-impervious sheets 3C and 3A at the closing point (construction start point S, construction end point E), and improve the water-stopping property of the underground impermeable wall 1. it can.

  Furthermore, according to the construction method of the above-described underground water-impervious wall 1, since the water-expandable seal 7 is coated on the surfaces of the male joint portions 6 a and 6 b of the joint member 6, The water-expandable seal 7 expands in contact with moisture, and is in close contact with the inner peripheral surfaces of the female joint jigs 5A to 5D of the water shielding sheets 3A and 3C. Thereby, the water leak from the fitting location of the male joint parts 6a and 6b of the joint member 6 and the female joint jigs 5A to 5D of the water shielding sheets 3A and 3C can be prevented.

As mentioned above, although embodiment of the construction method of the underground water-impervious wall according to the present invention has been described, the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist thereof. .
For example, in the above-described embodiment, the female joint jig 5 is provided at the end of the water shielding sheets 3A and 3B on the side of the development start point, and the male joint jig 4 is provided at the end of the development end point. In the present invention, the male joint jig 4 may be provided at the end of the water shielding sheets 3A and 3B on the side of the development start point, and the female joint jig 5 may be provided on the end of the development end point.

  Further, in the above-described embodiment, the female joint jig 5 is provided at the end of the final water-impervious sheet 3C on the development end point side, and the male joint portion is provided at the ends of the joint member 6 and the dummy joint members 8 and 9. 6a, 6b, 8a, 9a are provided, but in the present invention, the male joint jig 4 is provided at the end of the final water shielding sheet 3C on the development end point side, and the joint member 6 and the dummy joint member 8, A female joint portion may be provided at the end of 9.

  In the above-described embodiment, the male joint jig 4 and the male joint parts 6a, 6b, 8a, and 9a are round tubular, and the female joint jig 5 is a cylinder having a C-shaped cross section. However, in the present invention, the shapes of the joint jig and the joint portion can be appropriately changed.

  Moreover, in above-mentioned embodiment, the groove | channel 2 filled with the fluid is created by stirring the ground G continuously and mixing a liquid additive or a powder-form additive, and water. However, in the present invention, the method of forming the groove 2 can be changed as appropriate. For example, the groove 2 may be formed in the ground, and muddy water or soil cement (stabilizing liquid) for preventing collapse may be poured into the groove 2 to form the groove 2 filled with fluid.

  In the above-described embodiment, the water-impervious sheet 3 wound in a roll shape is inserted into the groove 2, and the roll part of the water-impervious sheet 3 is slid while rotating about the axis, so that the water-impervious sheet 3 is Although the water-impervious sheet 3 is stretched and stretched in the groove 2, in the present invention, the method of deploying the roll-shaped water-impervious sheet 3 and stretching it in the groove 2 can be appropriately changed. For example, a method may be used in which the roll portion of the water-impervious sheet is axially rotated and the outer end of the water-impervious sheet is pulled to expand the water-impervious sheet, or a roll-shaped impermeable sheet The method may be a method in which the waterproof sheet is developed by holding the sheet outside the groove and sequentially feeding the waterproof sheet into the groove.

  In the above-described embodiment, the surface of the male joint portions 6a and 6b of the joint member 6 is covered with the water-expandable seal 7, but the present invention omits the above-described water-expandable seal 7. It is also possible to make it.

  In addition, in the range which does not deviate from the main point of this invention, it is possible to replace suitably the component in above-mentioned embodiment with a well-known component, and you may combine the above-mentioned modification suitably.

It is a top view showing the composition of underground impermeable wall 1 for describing an embodiment of the invention. It is a whole perspective view showing the construction situation of underground impermeable wall 1 for explaining an embodiment of the invention. It is a partial top view of underground water-impervious wall 1 showing the construction situation of underground water-impervious wall 1 for describing an embodiment of the present invention. It is a partial top view of underground water-impervious wall 1 showing the construction situation of underground water-impervious wall 1 for describing an embodiment of the present invention. It is a partial top view of underground water-impervious wall 1 showing the construction situation of underground water-impervious wall 1 for describing an embodiment of the present invention. It is a partial top view of underground water-impervious wall 1 showing the construction situation of underground water-impervious wall 1 for describing an embodiment of the present invention. It is a partial top view of underground water-impervious wall 1 showing the construction situation of underground water-impervious wall 1 for describing an embodiment of the present invention. It is a partial top view of underground water-impervious wall 1 showing the construction situation of underground water-impervious wall 1 for describing an embodiment of the present invention. It is a partial top view of underground water-impervious wall 1 showing the construction situation of underground water-impervious wall 1 for describing an embodiment of the present invention. It is a partial top view of underground water-impervious wall 1 showing the construction situation of underground water-impervious wall 1 for describing an embodiment of the present invention. It is a partial top view of underground water-impervious wall 1 showing the construction situation of underground water-impervious wall 1 for describing an embodiment of the present invention.

Explanation of symbols

1 underground impervious wall 2A first groove 2B second groove 3 water shield sheet 3A 1 sheet of water-impervious sheet (second impermeable sheet)
3C final water barrier sheet (first water-impervious sheet)
5A female joint冶device 5B female joint jig (first end point joint jig)
5C Female joint jig (first starting joint jig)
5D female joint冶device 6 joint member 6a, 6b male joint portion (joint portion)
7 Water-expandable seal 8 First dummy joint member (dummy joint member)
9 Second dummy joint member (dummy joint member)

Claims (2)

In the construction method of underground impermeable walls consisting of impermeable sheets,
Creating a first groove filled with solidified fluid in the ground;
Expanding the first impermeable sheet wound in a roll and stretching the first impermeable sheet in the first groove;
Connecting a dummy joint member to a first end-point side joint jig provided at an end of the first water-impervious sheet on the development end point side, and installing the dummy joint member in the first groove;
After solidifying the fluid in the first groove, withdrawing the dummy joint member from the first groove;
Connecting the second groove filled with the solidified fluid to the ground and connecting the portion of the first groove where the dummy joint member is disposed;
Connecting the joint member to the first end point side joint jig by inserting the joint member into a hole formed in the solidified fluid in the first groove by pulling out the dummy joint member;
Connecting the first starting point side joint jig provided at the end of the second water-impervious sheet on the side of the expansion start point to the joint member;
Expanding the second impermeable sheet wound in a roll shape and stretching the second impermeable sheet in the second groove;
A method for constructing an underground impermeable wall, comprising: In construction method according to claim 1 Symbol placement of underground water shield wall,
Construction of an underground impermeable wall characterized in that a water-expandable seal is coated on a surface of a joint portion engaged with a joint jig on the start point side or end point side of the water shielding sheet among the joint members. Method.

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