JP4651444B2 - Construction method of impermeable wall - Google Patents

Description

  The present invention relates to a method for constructing a water shielding wall, and more particularly to a method for constructing a water shielding wall used in a waste disposal site.

  As one structure of a waste disposal site, there is known a water shielding wall configured by attaching a water shielding sheet to the front surface (disposal site side) of a vertical sheet pile structure formed of steel sheet piles or the like. This makes it possible to isolate articles and the like dropped on the disposal site from the surroundings by the water shielding wall.

  In the conventional water-impervious wall as described above, a sheet pile is dropped into the sea and a sheet pile structure is installed, and then a water-impervious sheet having shape retaining property is stretched on the front surface while being lifted by a crane or the like. And after making the water shielding sheet sink horizontally, the water shielding sheet was made to follow the sheet pile structure, and the adjacent water shielding sheets were connected.

  For this reason, the length in the extending direction that can sink at once is limited, and if it becomes too long, it becomes difficult to lift. On the other hand, there is a method in which the water shielding sheet is spread on the sea and then submerged, but in this case, it is still difficult to keep the upper end of the water shielding sheet horizontal to the sheet pile. Therefore, if the water shielding wall is long, it takes a lot of time to attach the water shielding sheet.

  This invention was made in order to solve the above subjects, and it aims at providing the construction method of the impermeable wall which becomes easy to attach a impermeable sheet.

  In order to achieve the above object, the invention according to claim 1 is a method for constructing a water-impervious wall, wherein a sheet pile installation process in which a sheet pile structure extending in a vertical direction is driven and installed in an impermeable stratum, and a sheet pile structure A pipe attachment process for attaching a pipe extending horizontally along the upper part of the pipe, a suspension attachment process for attaching one end of a plurality of suspenders to the waterproof sheet to be extended, and a pipe for the other end of the suspension. A sheet extending step that extends to the front of the sheet pile in a state where it is connected to the hanger, the lifting device is mounted so as to be movable in the horizontal direction with respect to the tube, and the sheet pile structure alternately appears with flat portions and recesses extending vertically. The waterproof sheet has a shape retaining property, and the sheet stretching step includes a sheet deformation step of deforming the stretched waterproof sheet so as to follow the recess.

  If comprised in this way, a water-impervious sheet is extended in the state hung with the hanger. Moreover, the attachment position with respect to the pipe | tube of a suspension tool becomes free. Furthermore, the water shielding sheet is in a deformed state along the recess.

  The invention according to claim 2 is a construction method of a water-impervious wall, which is a sheet pile installation process in which a sheet pile structure extending in a vertical direction and having a hook attached thereto is driven and installed in an impermeable stratum, and a sheet pile structure A pipe attachment process for attaching a pipe extending in the horizontal direction along the upper part, a suspension attachment process for attaching one end of a plurality of suspensions to the waterproof sheet to be spread, and the waterproof sheet at predetermined intervals in the suspension A sheet extending step of extending the front end of the sheet pile with the other end of the first hanger connected to the pipe, and a second hanger for attaching the other end of the second hanger excluding the first hanger to the hook. The sheet pile structure has a shape in which flat portions and recesses extending in the vertical direction appear alternately, and the hook is attached to the upper portion of the recess, and the first suspension tool moves in the horizontal direction with respect to the tube. Can be installed freely, DOO has shape retention, sheet stretched process are those containing a sheet deformation step for deforming so as to extend along the recess of the water shield sheets stretched.

  If comprised in this way, a water-impervious sheet is extended while being lifted by the 1st hanger, and after the expansion, the lifted state is maintained also by the second hanger. Further, the water shielding sheet is in a deformed state along the recess.

  As described above, in the invention according to claim 1, since the water shielding sheet is expanded in a state where it is suspended by a lifting tool, it is easy to expand the water shielding sheet, and it is possible to quickly construct a water shielding wall. Become. Moreover, since the attachment position with respect to the pipe | tube of a suspender becomes flexible, the freedom degree of the extending direction of a water shielding sheet becomes large, and handling of a water shielding sheet becomes easy. Furthermore, since the water-impervious sheet is deformed along the concave portion, the length of the water-impervious sheet in the extending direction is apparently shortened. However, since the hanger is movable in the horizontal direction, the impermeable sheet smoothly follows the stretched state.

  In the invention according to claim 2, since the water-impervious sheet is stretched while being lifted by the first hanger, and the lifted state is maintained by the second hanger after the expansion, the water-impervious sheet regardless of the shape of the sheet pile structure. Is easy to deploy. Moreover, since the water-impervious sheet is in a deformed state along the recess, the length of the water-impervious sheet in the extending direction is apparently shortened. However, since the hanger is movable in the horizontal direction, the impermeable sheet smoothly follows the stretched state. Further, in this state, the hanging tool is attached to the hook of the recess, so that the deformed state of the water shielding sheet is maintained as it is.

  FIG. 1 is a diagram showing a schematic configuration of a steel sheet pile structure used for a water-impervious wall according to a first embodiment of the present invention, and FIG. 2 is an enlarged sectional view taken along line II-II shown in FIG. FIG. 3 is a schematic perspective view of a part of the sheet pile used in the steel sheet pile structure of FIG.

  With reference to these drawings, the steel sheet pile structure 13 used in this embodiment has a structure in which flat portions 14a to 14c and concave portions 15a to 15c extending in the vertical direction appear alternately. The portion of the recess 15 is constituted by a steel sheet pile 26 as shown in FIG. The steel sheet pile 26 includes a vertical wall portion 27 having an elongated rectangular shape, a pair of side wall portions 28a connected to both sides of the vertical wall portion 27 in the vertical direction, and the distance between them increases as the distance from the vertical wall portion 27 increases. It is mainly comprised from the part 28b.

  An L-shaped hook 20 is attached to the upper portion of the vertical wall portion 27. A pair of sheath tube 17a and sheath tube 17b extending up and down about 100 mm are attached to the lower portion of the vertical wall portion 27 at a position away from the lower end by a certain distance. In this embodiment, the hook 20, the sheath tube 17a, and the sheath tube 17b are each fixed to the steel sheet pile 26 by welding. The sheath tube 17a and the sheath tube 17b are in a state where at least the upper surfaces thereof are opened. Further, a steel pipe 18 is attached above the steel sheet pile structure 13 so as to cross the flat portion 14 and the recess 15. The steel pipe 18 is attached at a predetermined interval from the steel sheet pile structure 13, and the reason will be described later.

  The flat portion 14 of the steel sheet pile structure 13 is configured by a steel sheet pile having substantially the same shape as the steel sheet pile 26 and not having the hook 20, the sheath pipe 17 a, and the sheath pipe 17 b attached thereto. That is, the steel sheet pile structure 13 is configured by driving steel sheet piles 26 and steel sheet piles 26 having substantially the same external shape into the impermeable base layer 23 alternately in a connected state. At this time, the sheath pipe 17a and the sheath pipe 17b are fixed to the vertical wall portion 27 so that the lower ends thereof are positioned on the upper surface of the impermeable formation 23 in a state where the steel sheet pile structure 13 is driven into the impermeable formation 23. ing. As a result, as shown in FIG. 2, the steel sheet pile structure 13 is driven into the impermeable base layer 23, and the lower end of the sheath pipe 17 a is aligned with the upper surface of the impermeable base layer 23.

  Returning to FIG. 1, the sheath tube 17 a and the sheath tube 17 b are attached to all the recesses 15 constituting the steel sheet pile structure 13, and similarly, the hooks 20 are attached to all the recesses 15. Yes. The steel sheet pile structure 13 configured in this way is continuously installed so as to surround the waste disposal site. The outer side of the steel sheet pile structure 13 is filled with medium-filled earth and sand 24, while the retained water 21 exists on the inner surface side of the steel sheet pile structure 13. As described above, since the steel sheet pile structure 13 is installed in a state where it is driven into the water-impermeable stratum 23, the inner surface side and the outer surface side are held in a water-impervious state via the steel sheet pile structure 13.

  FIG. 4 is a schematic view showing a stretched state when a water shielding sheet is stretched on the inner surface side of the steel sheet pile structure 13 shown in FIG.

  With reference to the figure, the water-impervious sheet 31 held in a wound state on the gantry 32 is installed on the paddy earth sand 24 on the outer surface side of the steel sheet pile structure 13. The tip is pulled out from this state and spread on the inner surface side of the steel sheet pile structure 13. At this time, the wire 36 is fixed to the tip side of the water-impervious sheet 31, and the water-impervious sheet 31 is expanded by winding the wire 36 with the winch 35. The stretched water-impervious sheet 31 has a plurality of first suspenders 34 and second suspenders 40 mounted alternately on the side that becomes the upper side during stretching before descending to the inner surface side of the steel sheet pile structure 13.

  In this embodiment, two first suspenders 34 and two second suspenders 40 are attached to each one of the water shielding sheets connected to each other as the water shielding sheet 31. Then, the outer end of the first hanging tool 34 is attached to the steel pipe 18. As a result, the water shielding sheet 31 is in a state of being lifted by the first hanger 34 attached to the steel pipe 18. The attachment state of the first hanger 34 to the steel pipe 18 is configured to be movable in the horizontal direction along the steel pipe 18 as described later. Therefore, by driving the winch 35 and winding the wire 36, the water-impervious sheet 31 advances in the horizontal direction on the inner surface side of the steel sheet pile structure 13 with a part of the water-impervious sheet 21 immersed in the retained water 21. .

  FIG. 5 is a cross-sectional view showing a schematic configuration of the water shielding sheet 31 shown in FIG.

  Referring to the drawing, a water-impervious sheet 31 is configured by integrally forming a water-impervious layer 37 made of ethylene vinyl acetate (EVA) and a protective layer 38 made of a nonwoven fabric such as polyethylene. A wire mesh 39 is embedded inside the water-impervious layer 37, thereby imparting deformability and shape retention to the water-impervious sheet 31.

  6 is a schematic configuration diagram illustrating a stretched state of the water shielding sheet 31 illustrated in FIG. 4 with respect to FIG. 1, and FIG. 7 is an enlarged cross-sectional view of the VII-VII line illustrated in FIG. 6.

  With reference to these figures, the width of the water-impervious sheet 31 extended on the inner surface side of the steel sheet pile structure 13 is such that its upper end is lower than the upper end of the steel sheet pile structure 13, and its lower end is that of the sheath tube 17. The position is set to be slightly higher than the upper end. In addition, this setting is the length of the 1st suspension tool 34 which the outer end engages with the steel pipe 18 among the suspension tools attached to the upper end side of the water shielding sheet 31, and the length of the vertical direction of the water shielding sheet 31. It is a thing in consideration.

  The first hanger 34 includes a flat plate-like connecting body 43 attached to the protective layer 38 of the water-impervious sheet 31 by heat fusion or the like, a steel chain 42 having one end attached to the connecting body 43, and a chain 42. And a shackle 41 that can be detachably engaged with the steel pipe 18. As a result, the first hanger 34 is attached so as to be movable in the horizontal direction while being engaged with the steel pipe 18.

  Note that the second suspender 40 that is attached to the upper end side of the water shielding sheet 31 and does not engage with the steel pipe 18 is basically the same structure as the first suspender 34. The length is set slightly shorter than the first suspension 34. Thus, the water shielding sheet 31 is extended in a state where the first hanging tool 34 and the second hanging tool 40 are alternately attached to the upper end side of the water shielding sheet 31. In this state, as shown in FIG. 7, the water shielding sheet 31 proceeds in a state along the inner surface side of the steel sheet pile 45 a to the steel sheet pile 45 c constituting the flat portion 14.

  FIG. 8 is a schematic view showing a process of deforming and keeping the water shielding sheet from the stretched state of FIG. 6 into a steel sheet pile structure.

  Referring to the drawing, when the water shielding sheet 31 is stretched to a predetermined position by the stretching process shown in FIG. 4, the process of causing the sheet to follow the shape of the recess 15 is started next. Specifically, the molding roller 49 is attached to the tip of a long arm 48 of a hydraulic shovel (not shown) installed on the outer side of the steel sheet pile structure 13 and moved downward. The shape of the pressing surface of the molding roller 49 is set to match the shape of the inner surface side in the horizontal section of the recess 15. Then, from the state of FIG. 6, the molding roller 49 is pressed against the recess 15 against the upper end side of the portion of the water shielding sheet 31 corresponding to the recess 15. Then, by lowering the long arm 48, the molding roller 49 is moved downward in that state. The water-impervious sheet 31 is configured to have deformability and shape retention as described above. Therefore, by the pressing of the molding roller 49 and the downward movement, the portion of the water-impervious sheet 31 is deformed so as to have a cross section along the horizontal cross-sectional shape of the recess 15 and the deformed state is maintained.

  At this time, since the horizontal length of the portion changes with the deformation of the water shielding sheet 31, the undeformed water shielding sheet 31 tends to be drawn toward the deformed portion and move. However, since the first hanger 34 that is engaged with the steel pipe 18 and suspends the water shielding sheet 31 as described above is movable in the horizontal direction, the movement of the water shielding sheet 31 is not restricted. . As a result, an unnecessary tensile force or the like is not generated on the deformed portion of the water shielding sheet 31, so that the deforming operation is performed smoothly. In the portion of the water-impervious sheet 31 deformed by the pressing of the molding roller 49, the water-impervious sheet 31 is deformed into a state along the concave portion 15b as shown in the concave portion 15b, and this state is maintained.

  In this state, the water-impervious sheet 31 is positioned closer to the concave portion 15b than the sheath tube 17a and the sheath tube 17b in plan view. Therefore, in this state, when the steel pipe 47a and the steel pipe 47b are lowered from above and the lower part is inserted into each of the sheath pipe 17a and the sheath pipe 17b, the deformed portions of the water shielding sheet 31 are the steel pipe 47a, the steel pipe 47b, and the recess 15b. It is in a state of being sandwiched between the inner surface side.

  The lengths of the upper ends of the steel pipe 47a and the steel pipe 47b installed in the sheath pipe 17a and the sheath pipe 17b are set so as to be located above the water shielding sheet 31. Therefore, the upper end portions of the steel pipe 47a and the steel pipe 47b are fixed by welding to the inner surface side of the concave portion 15b, and the outer end portion of the second suspension member 40b is engaged with the hook 20b to hold the water shielding sheet 31 in a deformed manner. The process ends. This state is shown as an attachment state to the recess 15a. In this case, the steel pipe 47 also exerts an effect of pressing the water shielding sheet 31 when it is fixed upward and deforming the water shielding sheet 31 with insufficient deformation.

  By doing in this way, while making the deformation | transformation with respect to the recessed part 15 of the water shielding sheet 31 easy, a deformation | transformation is enabled rapidly. In addition, the deformed portion of the water shielding sheet 31 is securely held by the steel pipe 47, and the deformation state of the water shielding sheet 31 is quickly and reliably held by the engagement of the second lifting tool 40 with the hook 20. Become.

  FIG. 9 is a schematic view showing a state in which the long arm 48 is operated with respect to all the recesses 15 from the state of FIG. 10 is an enlarged sectional view taken along line XX shown in FIG.

  As described above, the water-impervious sheet 31 follows the uneven shape on the inner surface side of the steel sheet pile 26a, the steel sheet pile 26b, and the steel sheet pile 45a to the steel sheet pile 45c constituting the steel sheet pile structure 13. For this reason, since the pressure on the retained water 21 applied to the water shielding sheet 31 can be reliably supported on the steel sheet pile structure 13 side, the reliability of the structure of the water shielding wall is improved. Further, since the water shielding sheet 31 is always maintained in a state sandwiched between the steel sheet pile structure 13 side and the steel pipe 47 side, when a liquid flows between the steel sheet pile structure 13 and the water shielding sheet 31, Even if it exists, it becomes possible to prevent the deformation of the water shielding sheet 31. As a result, the initial deformation state of the water-impervious sheet 31 is reliably maintained, so that the reliability of the entire impermeable wall is improved.

  11 is an enlarged cross-sectional view taken along line XI-XI shown in FIG.

  Referring to the drawing, the position of the lower end of the water shielding sheet 31 is slightly above the upper end of the sheath tube 17a as described above. Therefore, the flat part 14a and the recessed part 15b of the steel sheet pile structure are partially exposed between the lower part of the water-impervious sheet 31 and the upper surface of the impermeable base layer 23. For this reason, a water-stopping material 51 such as asphaltmatic is placed and filled on the upper surface of the impermeable base layer 23 so as to cover the lower part of the water-impervious sheet 31. As a result, the lower end portion of the water-impervious sheet 31 is also completely impervious, and the water-impervious function of the impermeable wall becomes perfect.

  In the above-described embodiment, the sheet pile structure has a specific shape. However, instead of this, another uneven sheet pile structure may be used, or even a sheet pile structure having almost no unevenness has the same effect. Play.

  In the above embodiment, the water shielding sheet deformed by two steel pipes is supported from the outside, but the number of replacements may be one or three or more. The same effect can be obtained even if another steel member is used instead of the steel pipe.

  Furthermore, in the above embodiment, the first suspension is attached to the tube so as to be movable in the horizontal direction, but it is not always necessary to be movable in the horizontal direction.

  Furthermore, in the above-described embodiment, the lower part of the steel pipe is supported by the sheath pipe, but other structures may be used as long as the steel pipe can be supported by the lower part other than the sheath pipe.

  Furthermore, in the above-described embodiment, the structure of the water shielding sheet is specified, but the shape retaining property may not be provided, and any other cross-sectional structure may be used as long as it has water shielding properties. It may be composed of other materials.

  Furthermore, in the above embodiment, the molding roller is pressed using a hydraulic excavator as a mechanical pressing means, but other heavy machinery or the like may be used.

  Furthermore, in said embodiment, although the 1st hanging tool and the 2nd hanging tool are made into the specific shape, it replaces with these and the hanging tool of another shape may be sufficient. Moreover, although the 1st hanger and the 2nd hanger are attached alternately, it is sufficient that at least the first hanger is attached at a predetermined interval.

  Furthermore, in said embodiment, although the attachment position of the pipe attached to the upper part of a sheet pile structure is specified, another position may be sufficient.

  Furthermore, in the above embodiment, the lower portion of the water shielding sheet is water-insulated using the water-stopping material. However, the water-stopping material is not necessarily used, and other water-stopping structures may be used. .

It is the perspective view which showed schematic structure of the steel sheet pile structure which comprises the water-impervious wall by 1st Embodiment of this invention. It is an expanded sectional view of the II-II line shown in FIG. It is the perspective view which showed schematic structure of the steel sheet pile used for the steel sheet pile structure of FIG. FIG. 3 is a schematic perspective view showing a stretched state of the water shielding sheet in the construction of the water shielding wall according to the first embodiment of the present invention. It is sectional drawing which showed schematic structure of the water shielding sheet shown in FIG. It is the figure corresponding to FIG. 1, Comprising: It is the schematic perspective view which showed the state which extended the water shielding sheet. It is an expanded sectional view of the VII-VII line shown in FIG. It is the figure corresponding to FIG. 6, Comprising: It is the perspective view which showed the deformation | transformation holding | maintenance process of the water impervious sheet | seat which makes the extended water impervious sheet along the outer surface of steel sheet pile structure. It is the figure corresponding to FIG. 8, Comprising: It is the perspective view which showed the state which the deformation | transformation holding process of the water shielding sheet was complete | finished. It is an expanded sectional view of the XX line shown in FIG. It is an expanded sectional view of the XI-XI line shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 13 ... Steel sheet pile structure 14 ... Flat part 15 ... Recessed part 17 ... Sheath pipe 18 ... Steel pipe 20 ... Hook 23 ... Impervious formation 30 ... Impermeable wall 31 ... Impervious sheet 34 ... First hanging tool 37 ... Impervious layer DESCRIPTION OF SYMBOLS 38 ... Protective layer 39 ... Wire net 40 ... 2nd lifting tool 47 ... Steel pipe 49 ... Molding roller 51 ... Water stop material In addition, the same code | symbol in each figure shows the same or an equivalent part.

Claims (2)

A method for constructing a impermeable wall,
A sheet pile installation process in which a sheet pile structure extending in the vertical direction is driven into an impervious formation and installed,
A pipe attachment step for attaching a pipe extending horizontally along the upper portion of the sheet pile structure;
A suspension attachment process for attaching one end of a plurality of suspensions to the waterproof sheet to be extended;
A sheet extending step of extending the water shielding sheet to the front surface of the sheet pile in a state where the other end of the suspension is connected to the pipe;
The hanger is attached to be movable in a horizontal direction with respect to the tube,
The sheet pile structure has a shape in which flat portions and concave portions extending in the vertical direction appear alternately,
The water shielding sheet has shape retention,
The sheet extending step includes a water shielding wall construction method including a sheet deforming step of deforming the stretched waterproof sheet so as to be along the concave portion. A method for constructing a impermeable wall,
A sheet pile installation process in which a sheet pile structure that extends in the vertical direction and has a hook attached thereto is driven into an impermeable formation,
A pipe attachment step for attaching a pipe extending horizontally along the upper portion of the sheet pile structure;
A suspension attachment process for attaching one end of a plurality of suspensions to the waterproof sheet to be extended;
A sheet extending step of extending the water-impervious sheet on the front surface of the sheet pile in a state where the other end of the first hanger is connected to the pipe at predetermined intervals among the hanger;
A second suspender attaching step of attaching the other end of the second suspender excluding the first suspender to the hook among the suspenders,
The sheet pile structure has a shape in which flat portions and concave portions extending in a vertical direction appear alternately, the hook is attached to the upper portion of the concave portion, and the first suspension is movable in the horizontal direction with respect to the tube. Attached,
The water shielding sheet has shape retention,
The method of constructing a water shielding wall, wherein the sheet stretching step includes a sheet deformation step of deforming the stretched water shielding sheet so as to follow the concave portion.

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