JP4228307B2 - Construction method of impermeable sheet and impermeable wall - Google Patents

Description

  The present invention relates to a water shielding sheet that is installed in the ground and blocks the passage of fluid in the ground, and a method for constructing a water shielding wall using the water shielding sheet.

  In industrial waste final disposal sites, etc., it is necessary to enclose the final disposal site with a water-impervious wall to prevent the outflow of contaminants. As the water-impervious wall, a water-impervious sheet construction method using a water-impervious sheet that can ensure a simple and high water-tightness is often employed in the case of ground with high water permeability or ground with low ground strength. Conventionally, as a method for constructing a water shielding wall made of a water shielding sheet vertically in the ground, there is a method in which a plurality of water shielding sheet pieces cut into rectangles are vertically inserted to join adjacent water shielding sheet pieces together. (For example, refer to Patent Document 1). In this method, first, the ground is loosened into a groove shape and water is mixed to replace the inside of the groove with muddy water, and then a plurality of water shielding sheet pieces are sequentially inserted into the groove replaced with the muddy water. At this time, adjacent water-impervious sheet pieces are joined together by a joint device to form one water-impervious sheet.

In recent years, a method for constructing a water shielding wall using a water shielding sheet (sheet roll) wound in a roll shape has been proposed in order to reduce the number of joint portions of the water shielding sheet as much as possible. This is a method of installing a water shielding sheet in a groove by inserting a sheet roll into the groove and developing the water shielding sheet wound in a roll shape in the groove. According to this method, the number of joints is reduced compared to the method of forming a single sheet of water shielding sheet by joining pieces of water shielding sheet pieces, and it is possible to improve the water shielding performance and construction efficiency and reduce costs. can do.
Japanese Patent No. 3094186

  However, in the method of constructing a water-impervious wall using the above-described sheet roll, since the diameter of the sheet roll needs to be at least the groove width or less, there is a limit to the length of the water-impervious sheet wound in a roll shape, In the case of constructing a water shielding wall over a long range, there is a problem that the water shielding sheets must be joined together. In addition, when the water-impervious sheet wound in a roll shape is developed in the groove, the end of the water-impervious sheet is pulled or moved while rotating the sheet roll, so that the water-impervious sheet may be damaged. Exists.

  In the present invention, the above-described conventional problems are taken into consideration, and the length is not limited by the groove width, and can be applied to the construction of a long span without joining together. An object of the present invention is to provide a water shielding sheet and a method for constructing a water shielding wall that can reduce external force applied to the water shielding sheet and prevent damage to the water shielding sheet.

  According to the first aspect of the present invention, in the water-impervious sheet installed in the groove formed in the ground, the foldable sheet portion that blocks passage of fluid in the ground has a groove in the depth direction of the groove. It is characterized by being folded in a bellows shape with a width smaller than the width and being held in a roll shape.

  With such a feature, even if the water-impervious sheet is long, the diameter of the roll-shaped water-impervious sheet is increased, but the sheet part is folded in a bellows shape and wound in a roll shape. The width of the water shielding sheet is smaller than the width of the groove. In addition, the roll-shaped water-impervious sheet in the above-described state rotates in the vertical direction, so that the water-impervious sheet is fed into the groove, and the sheet portion folded in the bellows shape of the fed-out portion is spread and blocked. The water sheet is unfolded.

  The invention described in claim 2 is characterized in that, in the water-impervious sheet according to claim 1, flanges for sandwiching the folded sheet part are respectively provided on the upper and lower ends of the folded sheet part. .

  With such a feature, since the sheet portion folded in a bellows shape is protected by the flange, the sheet portion is prevented from being damaged when the sheet portion is expanded in the groove.

  According to a third aspect of the present invention, in the water-impervious sheet according to the second aspect, the flange provided at the upper end portion of the sheet portion is provided with a suspending portion through which a bridge member extending over the groove is inserted. It is characterized by being.

  With such a feature, the water-impervious sheet is suspended from the frame member inserted into the suspension part, and the folded sheet part spreads and is disposed substantially vertically in the groove.

  The invention described in claim 4 is characterized in that, in the water shielding sheet according to claim 2 or 3, a plurality of notches are respectively formed on both side portions of the flange.

  Such a feature makes it possible to bend the flange in the horizontal direction.

  Invention of Claim 5 is the construction method of the impermeable wall using the impermeable sheet in any one of Claim 1 to 4, Comprising: The process of forming the said groove | channel on the said ground, and winding in roll shape Rotating the water shielding sheet, the sheet portion is folded in a bellows-like shape, and the folded sheet portion is expanded in the groove while disposing the water shielding sheet in the groove. And a step of developing the water shielding sheet.

  Due to such characteristics, a water shielding wall made of a single water shielding sheet disposed in the groove is constructed in the ground.

  The invention described in claim 6 is characterized in that, in the construction method of the impermeable wall according to claim 5, the sheet portion folded in a bellows shape is stretched by a stretching device that stretches the sheet portion.

  With such a feature, the folded sheet portion is firmly stretched.

  According to the water-impervious sheet according to the present invention, since the sheet portion is folded in a bellows shape and held in a roll shape, the roll-shaped sheet is rolled even when the water-impervious sheet is long. Although the diameter of the water-impervious sheet increases, the width of the roll-shaped water-impervious sheet is smaller than the groove width. Further, the roll-shaped water-impervious sheet is spread vertically by being rotated and sent out in the vertical direction. Therefore, since the width of the water-impervious sheet when folded is smaller than the groove width, the length of the water-impervious sheet can be determined without being limited by the groove width. It can respond without matching. Therefore, a joint location can be eliminated, water shielding performance and construction efficiency can be improved, and cost reduction can be achieved. In addition, the water-impervious sheet is fed into the groove when the roll-shaped impermeable sheet rotates in the vertical direction, and the fed-out part of the folded sheet part is expanded and expanded in the groove. In doing so, there is almost no external force applied to the water-impervious sheet, and damage during installation of the water-impervious sheet can be prevented. Thereby, there is no possibility of flooding from the damaged part, and the water shielding performance can be surely exhibited.

  Further, according to the construction method of the impermeable wall according to the present invention, the impermeable sheet wound in a roll shape is rotated, and the impermeable sheet with the sheet portion folded in a bellows shape is disposed in the groove. On the other hand, because it has a step of expanding the sheet part folded in the groove and deploying the water shielding sheet, a water shielding wall consisting of a single water shielding sheet with no joints is built in the ground. The As a result, it is possible to construct a water shielding wall with good water shielding performance and construction efficiency at a low cost.

  Hereinafter, an embodiment of a construction method for a water shielding sheet and a water shielding wall according to the present invention will be described with reference to the drawings.

  FIG. 1 is a plan view of a closed type impermeable wall 1 formed in the ground G. FIG. As shown in FIG. 1, the impermeable wall 1 is formed in an annular shape so as to surround the impermeable area A. The impermeable wall 1 is arranged substantially vertically so that a slit-like groove 2 formed in the ground G is filled with soil cement or water and a long sheet of impermeable sheet 3 reaches the impermeable layer. This is a structure for preventing groundwater or the like from flowing into the impermeable area A.

  FIG. 2 is a perspective view showing the water shielding sheet 3. As shown in FIG. 2, the water-impervious sheet 3 includes a sheet part 4 that blocks passage of groundwater or the like in the ground G, a flange 5 provided at each of the upper and lower ends of the sheet part 4, and a plurality of the upper-side flange 5 It is comprised from the suspended | suspended part 6 arrange | positioned.

The sheet | seat part 4 is a sheet-like site | part which has the water-blocking property for blocking | preventing passage of groundwater etc. in the ground G, for example, consists of synthetic resin sheets, such as a high-density polyethylene sheet.
The flange 5 is a band-shaped part made of the same material as the sheet part 4 and is a part that is thicker than the sheet part 4 and has a strength that does not easily bend. The width d of the flange 5 is smaller than the width D of the groove 2 and is such a width that a slight gap is formed on both sides when the flange 5 is disposed in the groove 2. The flange 5 is formed integrally with the seat portion 4 and is formed substantially perpendicular to the seat portion 4. A plurality of cutout portions 7 extending in a direction orthogonal to the axial direction of the flange 5 are formed on both sides of the flange 5 at substantially equal intervals, respectively. The end of the flange 5 is widened in a circular shape, extending from the side surface to the vicinity of the center position of the flange 5 in the direction of the center axis.

  The suspension part 6 is a part through which a bridge member (steel pipe) P extending over the groove 2 is inserted, and is made of, for example, a plate-like plastic material. The lower end portion of the hanging portion 6 is fixed to the upper surface of the upper flange 5 by welding, an adhesive, or the like, and is formed in a cylindrical shape so that the bridge member P is inserted through the upper end portion. Further, the hanging part 6 is formed so as to be foldable. When folded, the suspension part 6 falls in the axial direction of the flange 5 so as to overlap the upper surface of the flange 5 and becomes substantially flush with the upper surface of the flange 5. On the other hand, it is raised substantially vertically and its upper end is formed in a cylindrical shape. A hinge portion 6a such as a PP hinge is formed at a portion that is bent when folded, and can be easily folded.

  FIG. 3 is a perspective view illustrating a folding state of the water-impervious sheet 3, and FIG. 4 is a perspective view illustrating a winding state of the water-impervious sheet 3. As shown in FIGS. 3 and 4, the seat portion 4 is foldable, and the width d of the flange 5 is smaller than the width D of the groove 2 in the depth direction (vertical direction) of the groove 2 shown in FIG. 2. And is folded in a bellows shape with substantially the same width d ′. The folded sheet part 4 is sandwiched from above and below by flanges 5 provided at the upper and lower ends of the sheet part 4, respectively, and the water shielding sheet 3 is formed in a band shape.

  The folded water-impervious sheet 3 is wound around the cylindrical bobbin 8 in a roll shape while the hanging portion 6 is folded. Bands 9 that hold the water shielding sheet 3 in a folded state are attached to both ends of the folded band-shaped water shielding sheet 3. Moreover, the front-end | tip part (end part which comes out when the water-impervious sheet | seat 3 is wound in roll shape) of the flange 5 is formed shorter than the sheet | seat part 4, and the front-end | tip part of the sheet | seat part 4 is a horizontal direction rather than the flange 5. As shown in FIG. 1, the projecting portion is an adhesive surface 4a when the impermeable wall 1 is formed in an annular shape.

  Next, a method for constructing the water shielding structure 1 using the water shielding sheet 3 having the above-described configuration will be described.

  First, as shown in FIG. 1, an excavation process is performed in which the ground G is loosened into a groove shape and replaced with soil cement using an excavator and agitator (not shown). Specifically, the ground 2 is excavated (unraveled) by the excavator and agitator to form the groove 2. At this time, the cement milk is discharged from the excavation part of the excavator and agitator, and the loosened soil and the cement milk in the groove 2 are agitated to make a soil cement having excellent fluidity. Then, the excavator and agitator are slowly self-propelled and continuously excavated to form an annular groove 2.

  Next, the folded sheet portion 4 while rotating the water shielding sheet 3 wound in a roll shape and disposing the water shielding sheet 3 in a state where the sheet portion 4 is folded in a bellows shape in the groove 2. An unfolding process is performed in which the water-impervious sheet 3 is unfolded in the groove 2.

  Specifically, as shown in FIG. 5, the water-impervious sheet 3 wound in a roll shape is attached to the support base 10 mounted on the loading platform of the truck T and is held rotatably in the vertical direction. Next, the front end portion of the water shielding sheet 3 fastened with the band 9 on the ground is slightly pulled out, and the expansion device 11 is attached to the portion that is pulled out while the front end portion is fastened with the band 9. And the front-end | tip part of the water-impervious sheet 3 fastened with the band 9 is left on the ground, and the drawn-out part of the water-impervious sheet 3 is inserted into the groove 2 together with the expansion device 11.

  Here, the spreading device 11 will be described. FIG. 6 is a cross-sectional view showing the stretching device 11. As shown in FIG. 5 and FIG. 6, the extension device 11 includes a hollow carriage 12 that is disposed across the groove 2, a frame member 13 that is suspended downward from the carriage 12, and the inside of the carriage 12. It is comprised from a pair of upper roller part 14 provided in this and arrange | positioned facing each other, and a pair of lower roller part 15 provided in the lower end part of the frame material 13, and mutually arrange | positioned mutually.

  The carriage part 12 has an opening through which the water-impervious sheet 3 passes in the front and rear parts, and the lower end part is opened, and the sectional view shape is formed in a gate shape. Wheels 16 are provided in the front and rear sides on both outer side surfaces of the carriage unit 12, and the carriage unit 12 travels on the ground G along the groove 2 by the wheels 16.

  The pair of upper roller portions 14 receives the upper flange 5 from below so as to sandwich the upper end portion of the sheet portion 4, and is engaged with the upper end portion of the water shielding sheet 3. Further, the pair of upper roller portions 14 are respectively provided in the front and rear portions of the hollow cart portion 12, and each upper roller portion 14 is projected inward from both inner side surfaces of the hollow cart portion 12. It is attached via a bracket 17 so as to be rotatable in the vertical direction.

  The frame member 13 is hung downward from both inner side surfaces of the carriage unit 12, and the two frame members 13 are arranged to face each other in the groove 2. Substrates 18 extending in the front-rear direction are respectively attached to the lower ends of the two frame members 13.

  The pair of lower roller portions 15 is disposed above the lower flange 5 so as to sandwich the lower end portion of the sheet portion 4, and is engaged with the lower end portion of the water shielding sheet 3. A plurality of lower roller portions 15 are arranged in the front-rear direction between two opposing substrates 18 and are attached to the substrate 18 so as to be rotatable in the vertical direction.

  By the extending device 11 having the above-described configuration, the upper end portion of the drawn water-impervious sheet 3 is supported by the upper roller portion 14 and the lower end portion of the drawn water-impervious sheet 3 is guided downward by the lower roller portion 15. Then, the sheet portion 4 folded in a bellows shape is spread.

  Next, as shown in FIG. 5, the track T is gradually advanced along the groove 2, and the folded water-impervious sheet 3 is fed into the groove 2 while rotating the water-impervious sheet 3 wound in a roll shape. The water shielding sheet 3 is arranged in the groove 2. At this time, the extension device 11 is also moved forward after the track T, and the water-impervious sheet 3 fed into the groove 2 is successively spread. Moreover, the suspended portion 6 of the folded water-impervious sheet 3 is sequentially raised when it passes through the stretching device 11, and the bridge member P is inserted into the raised suspended portion 6. Then, the frame P is bridged above the groove 2 and the water shielding sheet 3 is suspended by the frame P.

  The above-described operation of installing the water shielding sheet 3 is continuously performed in the direction of the arrow starting from the start point S shown in FIG. 1, and one sheet of the water shielding sheet 3 is installed in the groove 2. And when it returns to the start point S, the process of joining the front-end | tip part of the impermeable sheet 3 and the base end part of the impermeable sheet 3 which have come out on the ground is performed.

FIG. 7 is a perspective view illustrating a joining state between both end portions of the water shielding sheet 3. As shown in FIG. 7, the band 9 that fastens both ends of the water-impervious sheet 3 is removed, and an adhesive is applied to the adhesive surface 4 a at the tip of the sheet portion 4 that projects in the lateral direction, and the adhesive surface 4 a The adherend surface of the base end of the sheet part 4 is overlapped. At this time, since the flange 5 on the distal end side is shorter than the sheet portion 4, the flange 5 at the distal end of the water shielding sheet 3 and the flange 5 at the proximal end of the water shielding sheet 3 face each other and are joined together. Both ends are substantially flush.
And the soil cement replaced in the groove | channel 2 is solidified by setting a predetermined curing period, and the impermeable wall 1 in which the impermeable sheet 3 is vertically arranged in the ground G is formed.

  According to the construction method of the water-impervious sheet 3 and the water-impervious wall 1 having the above-described configuration, the sheet part 4 is folded in a bellows shape and is held in a roll shape. Although the diameter of the water-impervious sheet 3 wound in a roll shape increases, the widths d and d ′ of the water-impervious sheet 3 wound in a roll shape are the width D of the groove 2. Smaller than. Moreover, the roll-shaped water-impervious sheet 3 is spread vertically in the groove 2 by being rotated in the vertical direction and sent out. Therefore, the length of the water-impervious sheet 3 can be determined without being limited to the width D of the groove 2, and it is possible to cope with the construction of a long span without joining. Therefore, the joint location can be eliminated except for the start location S, the water shielding performance and the construction efficiency can be improved, and the cost can be reduced.

  In addition, the water-impervious sheet 3 is fed into the groove 2 by rotating the roll-shaped impermeable sheet 3 in the vertical direction, and the fed-out portion of the folded sheet part 4 is expanded and expanded in the groove 2. Therefore, there is almost no external force applied to the water-impervious sheet 3 when deployed, and damage when the water-impervious sheet 3 is installed can be prevented. Thereby, there is no possibility of flooding from the damaged part, and the water shielding performance can be surely exhibited.

  Further, since the flanges 5 that sandwich the folded sheet portion 4 are provided at the upper and lower ends of the sheet portion 4, the sheet portion 4 folded in a bellows shape is protected by the flange 5, When the sheet part 4 is expanded, the sheet part 4 is prevented from being damaged. Thereby, there is no possibility of flooding from the damaged part, and the water shielding performance can be surely exhibited.

  Further, since the flange 5 provided at the upper end portion of the seat portion 4 is provided with a suspension portion 6 through which the bridge member P extending over the groove 2 is inserted, the water-impervious sheet 3 is provided with the suspension portion 6. It is suspended by the base material P inserted through the inside, and is arranged substantially vertically in the groove 2. Thereby, the water shielding sheet 3 arrange | positioned in the groove | channel 2 can be hold | maintained in a perpendicular state.

  In addition, since a plurality of notches 7 are formed on both sides of the flange 5, the flange can be bent in the horizontal direction. Thereby, it can arrange | position continuously also in the groove | channel 2 formed in the curve shape, and can respond also to the curved water shielding wall 1. FIG.

  Moreover, according to the construction method of the water-impervious wall 1 described above, the water-impervious sheet 3 in a state in which the sheet part 4 is folded in a bellows shape is rotated in the groove 2 by rotating the water-impervious sheet 3 wound in a roll shape. 1 is provided with a step of expanding the sheet portion 4 folded in the groove 2 and deploying the water shielding sheet 3, so that the ground G has a single water shielding sheet 3 having no joints. The impermeable wall 1 is constructed. Thereby, the impermeable wall 1 with good impermeable performance and construction efficiency can be constructed at low cost.

  Further, since the sheet device 4 folded in a bellows shape is expanded by the stretching device 11 that stretches the sheet unit 3, the folded sheet unit 4 is firmly stretched and spreads the waterproof sheet 3 in the groove 2. It can be reliably formed in the range.

  As mentioned above, although embodiment of the construction method of the impermeable sheet and impermeable wall concerning the present invention was described, the present invention is not limited to the above-mentioned embodiment, and changes suitably in the range which does not deviate from the meaning. Is possible. For example, in the above-described embodiment, the water-impervious sheet 3 wound in a roll shape is attached to the support base 10 mounted on the loading platform of the truck T so as to be freely rotatable in the vertical direction. A support base to which the water-impervious sheet wound in a shape is attached is movable, and the water-impervious sheet may be sent into the groove by pulling the support base with a heavy machine or the like.

  Further, in the above-described embodiment, the water-impervious sheet 3 is sent obliquely rearward from the support base 10 and is spread by the expansion device 11, but the present invention can be applied from the support base 104 as shown in FIG. The folded sheet portion 102 may be spread after the sent water-impervious sheet 101 is once wound around a roller 103 that is disposed directly below the roll-shaped water-impervious sheet 101 and is rotatable in the vertical direction. The roller 103 is disposed substantially in the middle of the depth H of the groove 100, and is attached to a support arm 105 that is suspended from the support base 104. Thereby, the distance in the process of spreading the water-impervious sheet 101 can be shortened, and damage to the water-impervious sheet 101 can be prevented by pulling the upper and lower ends of the water-impervious sheet 101 evenly.

It is a top view showing embodiment of the construction method of the impermeable sheet and impermeable wall concerning the present invention. It is a perspective view showing embodiment of the water-impervious sheet concerning this invention. It is a perspective view showing the folding condition of the impermeable sheet in embodiment of the impermeable sheet concerning this invention. It is a perspective view showing the winding-up condition of the waterproof sheet in embodiment of the waterproof sheet concerning this invention. It is sectional drawing showing embodiment of the construction method of the impermeable sheet and impermeable wall concerning this invention. It is sectional drawing showing the extending | stretching apparatus in embodiment of the construction method of the impermeable sheet and impermeable wall concerning this invention. It is a fragmentary perspective view showing embodiment of the construction method of the impermeable sheet and impermeable wall concerning the present invention. It is sectional drawing showing other embodiment of the construction method of the impermeable sheet and impermeable wall concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water shielding wall 2 Groove 3 Water shielding sheet 4 Sheet part 5 Flange 6 Hanging part 7 Notch part 11 Extension apparatus G Ground P Construction material

Claims (6)

In the water shielding sheet installed in the groove formed in the ground,
The collapsible sheet portion that blocks the passage of fluid in the ground is folded in a bellows shape with a width smaller than the width of the groove in the depth direction of the groove, and held in a roll shape. A water shielding sheet characterized by The water shielding sheet according to claim 1,
A water-impervious sheet, characterized in that flanges for sandwiching the folded sheet part are provided on upper and lower ends of the folded sheet part. The water shielding sheet according to claim 2,
The water-impervious sheet, wherein the flange provided at the upper end portion of the sheet portion is provided with a suspension portion through which a bridge member extending over the groove is inserted. In the water shielding sheet according to claim 2 or 3,
A water-impervious sheet, wherein a plurality of notches are formed on both sides of the flange. A construction method of a water shielding wall using the water shielding sheet according to any one of claims 1 to 4,
Forming the groove in the ground;
Rotating the water-impervious sheet wound in a roll shape, placing the water-impervious sheet in a state in which the sheet part is folded in an accordion shape in the groove, the folded sheet part being the groove A method for constructing a water-impervious wall, comprising the step of spreading the water-impervious sheet by spreading it inside. In the construction method of the impermeable wall according to claim 5,
A construction method of a water-impervious wall, characterized in that the sheet portion folded in a bellows shape is stretched by a stretching device that stretches the sheet portion.

Images