JP2019100131A - Method for placing impervious sheet - Google Patents

Abstract

To complete placing an impervious sheet quickly.SOLUTION: A method includes: developing a work ground 22 exposed to air over the whole width of the coast direction of a closed region 16; excavating an original ground 12a in a range of deep water on an offshore SO side to obtain sediment 20 used at the time of developing the work ground 22; forming a large panel 30L of an impervious sheet with a predetermined width on the work ground 22, over the whole width of the coast direction of the closed region 16 and in the offshore SO direction in order to secure a place with a wide area for formation work of the large panel 30L on the work ground 22 exposed to air; forming an integrated impervious sheet panel having an area in which a water surface 16W can be covered with the large panel 30L by repeating work to move the large panel 30L onto the water in the closed region 16 and in which a water bottom 16SF in the closed region 16 can be covered by joining only the adjacent sides of the plurality of large panels 30L on the water; and sinking the integrated impervious sheet panel into the water bottom 16SF to cover the water bottom 16SF.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method of laying a water blocking sheet.

  For example, in the case where a management type sea surface disposal site or the like is created in a water area where the underlying seabed is sandy, the water area may be a partition (in the present description, only the vertical structure In addition, it is a broad concept that is also included in the case where the same water-impervious sheet as the bottom is laid on the sloped surface with stone etc. and the side is sealed and closed on the water bottom in the closed area. It is necessary to lay a waterproof sheet. About this laying method of a water-impervious sheet, various examination is made | formed conventionally (for example, patent document 1).

JP 2012-92512 A

  When laying the water-impervious sheet, the band-shaped raw fabric of the water-impervious sheet is carried to the construction site, the raw fabric is spread, and the raw fabric is joined so as to have a predetermined width and a predetermined length, that is, a predetermined area. Need to However, in the case of the management-type sea surface disposal site as described above, the laying area of the water-impervious sheet is large, and it takes a considerable number of man-hours and time to join the water-impervious sheet. In particular, in places where the weather conditions and sea conditions of the construction site are severe, it has been difficult to smoothly progress the joining operation of the water-impervious sheet, resulting in an increase in the construction period and the construction cost.

  This invention is made in view of the said subject, and the place made as the objective is that the laying area of a water-impervious sheet is large, and it is quick also in the place where the weather conditions and sea conditions of a construction site are severe. To complete the laying of the impermeable sheet.

(Aspects of the Invention)
The following aspects of the invention illustrate the configuration of the present invention and are described in sections to facilitate understanding of the various configurations of the present invention. Each section is not intended to limit the technical scope of the present invention, and some of the components of each section may be replaced, deleted, or any of the other while taking into consideration the best mode for carrying out the invention. What added the component of the above can also be included in the technical scope of the present invention.

  (1) A method of closing a water area adjacent to a shore by a partition wall and laying a water-impervious sheet on the water bottom in the closed area, which is obtained by excavating the ground in the deep water depth range of the closed area. To fill the shallow depth of water near the shore, and create a working ground exposed to the air over the entire width in the direction along the shore within the closed area, and on the working ground, the shore of the closed area is After forming a large panel of a water-impervious sheet having a predetermined length in the offshore direction across the entire width in the longitudinal direction, the operation of moving the large panel onto the water in the closed region is repeated to join a plurality of the large panels Method of laying a water-impervious sheet, which covers the bottom of the water within the closed area (claim 1).

In the method of laying a water-impervious sheet described in this paragraph, when the water area adjacent to the shore is closed by a partition wall and the water-impervious sheet is laid on the water bottom in the closed area, the entire width along the shore of the closed area is It creates the working ground exposed inside. The earth and sand can be easily procured by obtaining the earth and sand used for the construction of the working ground by excavating the ground in the deep water depth area near the seashore.
And by forming a large panel of a water-impervious sheet having a predetermined length in the offshore direction across the entire width of the closed area on the working ground on the working ground, a place for forming the large panel having a large area, It secures on the working ground in the air. Also, the working ground is adjacent to the surface of the stored water remaining in the closed area, and the distance when moving the large panel to the water is minimized.
Then, by repeating the operation of moving the large panel to the water in the closed area, the water surface is covered with the large panel, and only the adjacent sides of the plurality of large panels are joined on the water to cover the water bottom in the closed area. Form an integral impermeable sheet panel having an area that can be
Finally, the integral impermeable sheet panel is allowed to settle to the bottom of the water, thereby covering the bottom of the water in the closed area.
As described later, when the closed area is the creation site of a controlled surface disposal site, the working ground is reclaimed and the volume of waste input decreases, so the water in the closed area is excavated in the area where earth and sand are excavated. Because the depth of the bottom surface is increased, the volume of waste input in the entire managed sea surface disposal site is not reduced.

  (2) In the above item (1), a large panel of a water-impervious sheet having a predetermined length in the offshore direction across the full width of the closed area from the raw fabric of the water-impervious sheet to the shoreline of the closed area Forming a large panel forming step, fixing the floating means to the large panel, raising the water level in the closed area to make the working ground submerged, and floating the large panel by the floating means, the working ground submerged step A large panel moving step of moving the raised large panel offshore of the closed area across the entire width of the closed area along the shore, and lowering the water level in the closed area to move the working ground A method of laying a water-impervious sheet, comprising the step of exposing to the air, and a work ground restoration step (claim 2).

The method of laying a water-impervious sheet described in this section relates to each step performed on the working ground.
First, in the large panel formation step, by forming a large panel of water blocking sheet having a predetermined length in the offshore direction across the entire width of the closed area from the raw fabric of the water blocking sheet on the working ground. The work of forming a large panel having a large area is performed on the working ground in air.
In addition, in the working ground submersion step, the floating means is fixed to the large panel formed on the working ground, and the water level in the closed area is raised to make the working ground submerged, thereby utilizing the buoyancy of the floating means. Float on the water surface.
In the large panel movement step that follows, the movement of the large panel that spreads over the entire width in the direction along the shore of the closed area from the working ground to the place where the large panel is to be installed is performed with the large panel floating on the water surface is there.
Then, after the large panel moves from the working ground to the offshore side, the water level in the closed area is lowered in the working ground recovery step to form the large panels again by exposing the working ground to air. A place for forming work is to be secured on the working ground in the air.
In order to increase or decrease the water level in the closed area, a pump and piping are provided to pump water from the water outside the closed area into the closed area, or pump water from inside the closed area to the water outside the closed area. To be.

(3) In the above item (2), each step from the large panel forming step to the working ground restoration step is repeated several cycles as one cycle, and the large panel formed in each cycle is headed from the shore to the offshore direction A method of laying a water-impervious sheet, comprising: a large panel bonding step in which members adjacent to each other are joined and integrated on a water surface; and a large panel sinking step in which the large panel is sunk to the water bottom (claim 3).
The method of laying a water-impervious sheet described in this section relates to each step performed in the water area of the closed area.
First, in the large-panel joining step, each step from the large-panel forming step to the working ground recovery step is repeated several cycles as one cycle, and the large panels formed in each cycle are adjacent from the shore toward the offshore direction By joining and integrating on the water surface, an integral water-impervious sheet panel having an area capable of covering the water bottom in the closed region is formed.
Then, in the large panel settlement step, the integral water blocking sheet panel is sunk to the water bottom to cover the water bottom in the closed area.

(4) In the above (2) and (3), each step from the large panel formation step to the working ground recovery step is repeated several cycles as one cycle, and the large panel formed in each cycle is The laying method of the water-impervious sheet which covers the whole of the water surface in the said closed area by several large panels by arranging to a side (Claim 4).
In the method of laying a water-impervious sheet described in this section, the large panels formed in each cycle are arranged from the offshore side toward the shore side, and the entire water surface in the closed area is covered with a plurality of large panels. is there. Then, as described above, they are integrated and submerged in the water bottom, thereby covering the water bottom in the closed area.

  (5) In the above items (2) to (4), each step from the large panel forming step to the working ground restoration step is repeated for a plurality of cycles as one cycle, and the shore side of the closed area does not reach the offshore end A front step which covers the range from the middle position or the offshore end to the middle position not reaching the shore end with a plurality of large panels, joins the large panels on the water surface and then temporarily sinks to the water bottom and temporarily fixes to the water bottom After that, each step from the large panel formation step to the working ground recovery step is repeated multiple cycles as one cycle, and the area on the offshore side or the shore side of the preceding step is covered with a plurality of large panels in the closed area. And a post-sealing step including joining a large panel located at the shore or offshore end with the large panel located at the offshore or shore end temporarily fixed to the water bottom in the previous step. The method of laying (claim 5).

In the method of laying a water-impervious sheet described in this paragraph, the process of forming an integral water-impervious sheet panel having an area capable of covering the water bottom in the closed area is divided into a plurality of construction periods and finally closed. It covers the bottom of the water in the area.
First, in the first step, the area from the shore side of the closed area to the midway position that does not reach the offshore end or the midway position where the offshore end does not reach the shore side is covered with multiple large panels, After bonding, it is once settled to the water bottom and temporarily fixed to the water bottom. In this state, the implementation period of the construction period will be postponed as necessary. In addition, by sinking the joined large panel to the bottom of the water, damage caused by the large panel being located on the surface of the water (for example, strong wind or waves may cause wrinkles or tearing of the fixed sheet end) Such events can be included). Then, by performing a post-process after a predetermined time has elapsed, an integral water-impervious sheet panel having an area capable of finally covering the water bottom in the closed region is formed.
In addition, the work period may be divided into three or more steps by performing a plurality of times in the post process, and in this case, at the end of each process, the large panel which has already been joined is once sunk to the water bottom and the water bottom Will be fixed temporarily.

  (6) In the above (2) to (5), prior to the large panel forming step, in the land yard adjacent to the closed region, from the raw fabric of the water-impervious sheet to the large panel, Form a unit panel whose width in the direction along the shore is narrow, and repeat the work of moving the unit panel onto the work ground, and on the work ground, a plurality of the unit panels in the entire width along the shore of the closed area. A method of laying a water-impervious sheet, including a work ground covering step, forming a large panel by joining unit panels on the work ground to form a large panel, and arranging them so as to cross the work ground (Claim 6).

In the method of laying a water-impervious sheet described in this section, each step from the large panel formation step to the working ground recovery step listed in the above (2) to (5) is repeated several cycles as one cycle. The work ground is covered in advance with a large panel. That is, in the land yard adjacent to the closed area, a unit panel is formed in which the width along the shore of the closed area is narrower than that of the large panel from the raw material of the water blocking sheet. Arrange across the full width of the closed area along the shore. Then, by joining adjacent sides of each unit panel on the work ground to form a large panel, the work ground is covered with the large panel.
In the land yard, a rigid panel suitable for pressure welding is laid when a band-shaped sheet with a certain width is spread from the raw material of the water-impervious sheet, and a plurality of them are lined up and joined to adjacent sides. . Also, the land yard may be formed to have an area equal to or slightly larger than the unit panel.

(7) In said (6), the laying method of the water-impervious sheet which covers the large panel which covers the said working ground further with a rigid panel (Claim 7).
In the method of laying a water-impervious sheet described in this paragraph, a rigid panel is installed on a large panel covering the working ground to obtain a water-impervious sheet prior to the large panel forming step mentioned in the item (2). A rigid panel suitable for pressure welding, which is necessary when forming a large panel of a water-impervious sheet with a predetermined length in the offshore direction from the material web to the full width of the closed area along the shore, It is something to cover. In the large panel formation step, the rigid panel is installed on the large panel covering the working ground, and on the wide rigid panel equivalent to the large panel, the entire width in the direction along the shore of the closed area And a large panel of water-impervious sheet having a predetermined length in the offshore direction. As long as a rigid panel is installed on the work ground, joining work of the water-impervious sheet on the work ground will be efficiently performed over the entire width of the closed area along the shore.
When the large panel covering the working ground is further covered with the rigid panel, the exposed portion is formed in a later step if exposed for a predetermined length along the offshore edge of the large panel. It becomes possible to use as a joining margin with an adjacent large panel.

(8) In the above item (7), after laying sand on the large panel covering the working ground, the method of laying a water-impervious sheet covered by the hard panel (claim 8).
In the method of laying a water-impervious sheet described in this section, sand is laid on a large panel that covers the working ground (in the present description, "bed sand" is a broad concept including spreading material that can be procured from crushed stone or soil. By covering the large panel with the rigid panel after applying the), it is possible to prevent the large panel from being damaged by the rigid panel by the laying sand.

(9) The laying method of the water-impervious sheet which covers the said working ground with a rigid panel prior to the said large panel formation step in said (2) to (5) term. (Claim 9).
In the method of laying a water-impervious sheet described in this paragraph, a rigid panel is installed on a large panel covering the working ground, so that in the large-panel forming step mentioned in the above item (2), To cover the working ground with a rigid panel suitable for pressure welding, which is necessary when forming a large panel of impermeable sheet having a predetermined length in the offshore direction and across the entire width of the closed area from the opposite side. It is something to remember. And, in the large panel forming step, on a wide range of rigid panels equivalent to large panels, from the raw material of the impermeable sheet to the full width in the direction along the shore of the closed area, the impermeable sheet having a predetermined length in the offshore direction It forms a panel. As long as a rigid panel is installed on the work ground, joining work of the water-impervious sheet on the work ground will be efficiently performed over the entire width of the closed area along the shore.

(10) In the above-mentioned item (9), in the land yard adjacent to the closed area after removing the rigid panel, from the raw fabric of the water-impervious sheet to the shoreline direction of the closed area than the large panel Repeat the work of forming a narrow unit panel, moving the unit panel onto the working ground, and arranging a plurality of the unit panels across the entire width of the closed area along the shore on the working ground. A method of laying a water-impervious sheet, including a work ground covering step, joining the unit panels on the work ground to create a large panel and covering the work ground. (Claim 10).
In the method of laying a water-impervious sheet described in this paragraph, after removing the hard panel from the work ground, specifically, each cycle from the large panel formation step to the work ground recovery step is a plurality of cycles as one cycle. After covering the whole of the water surface in the said closed area with a plurality of large panels by arranging the large panels formed in each cycle from the offshore side to the shore side repeatedly, the working ground is covered with the large panels It is. The procedure and action are the same as in the case where the working ground is covered with the large panel in advance as a step before repeating the multiple cycles with each step from the large panel forming step to the working ground restoration step as one cycle. .

(11) In the above items (7) to (9), a method of laying a water-impervious sheet for covering the hard panel with a friction reducing sheet (claim 11).
In the method of laying a water-impervious sheet described in this section, the hard panel is covered with a friction reducing sheet so that the raw sheet of the water-impervious sheet is directed toward the shoreline of the closed area on a wide range of hard panels equivalent to large panels. When forming a large panel of a water-impervious sheet having a predetermined length in the offshore direction across the entire width, positioning of the water-impervious sheet is facilitated, and the workability is enhanced.

(12) In the above (6) to (11), the shore-side edge of the large panel located closest to the shore among the large panels created in the steps from the large panel forming step to the working ground recovery step. And a method of laying a water-impervious sheet that joins the offshore edge of the large panel covering the working ground (claim 12).
In the method of laying a water-impervious sheet described in this section, of the large panels created in each step from the large panel forming step to the working ground recovery step, the shore side edge of the large panel located closest to the shore Finally, by joining the offshore edge of the large panel covering the working ground, it is possible to cover the area where the impermeable sheet needs to be laid for the bottom and working ground in the entire closed area. It forms an integral, impermeable sheet panel having an area.

(13) A method of laying a water-impervious sheet, wherein the sloped surface is formed such that the offshore side is lower than the shore side in the working ground formation steps according to (2) to (12).
In the method of laying a water-impervious sheet described in this section, the sloped surface is formed so that the offshore side is lower than the shore side in the working ground formation step, whereby the water shielding is performed on the working ground in the large panel formation step. When forming a large panel of impermeable sheet having a predetermined length in the offshore direction from the original sheet of the sheet over the entire width of the closed area along the shore, the unrolling of the original sheet is used and the inclined surface of the working ground is used To do it smoothly.

(14) In the above (1) to (13), a method of laying a water-impervious sheet, wherein the closed area is a creation site of a controlled surface disposal site (claim 14).
In the method of laying a water-impervious sheet described in this paragraph, the effects of the above items (1) to (13) can be obtained at the construction site of a controlled sea surface disposal site.

  Since the present invention is configured as described above, it is possible to quickly complete the laying of the water blocking sheet even in a place where the laying area of the water blocking sheet is large and the weather conditions and sea conditions of the construction site are severe. It becomes.

It is sectional drawing of the closed area peripheral part for demonstrating the construction method of the water-impervious sheet at the time of creating a management type sea surface disposal site etc. based on embodiment of this invention. FIG. 2 is a bird's-eye view of the perimeter of the closed area shown in FIG. 1, showing the steps of forming a unit panel to cover the work site. It is a bird's-eye view which shows the working ground covering step which covers a working ground with a large panel following FIG. It is a bird's-eye view which shows the large panel creation step which produces a large panel on a working ground following FIG. It is a bird's-eye view which shows a working ground submersion step which sinks a working ground and floats the large panel which fixed the floating means following FIG. FIG. 5 is a bird's-eye view showing a large panel moving step in which the large raised panel is moved to the offshore direction of the closed region across the entire width of the closed region along the shore. Continuing from FIG. 6, by arranging the plurality of large panels from the offshore side toward the shore, the water surface in the closed area is covered with the plurality of large panels, and the adjacent large panels are joined and integrated. It is a bird's-eye view which shows a panel joining step. It is a bird's-eye view which shows the large panel settlement step which sinks an integral impermeable sheet panel to a water bottom following FIG. It is a bird's-eye view which shows the state in which the integral water-impervious sheet panel was laid by the water bottom following FIG. The structure of the water-impervious sheet used when creating a management type sea surface disposal site etc. based on embodiment of this invention is shown, (a) is sectional drawing of a three-layer integral type, (b) is five. It is a sectional view of a layer integrated type. (A) is the top view which showed typically the joining part of the large panel based on embodiment of this invention, (b) showed the joining part in the case of using a unit panel as a comparative example typically. It is a top view.

Hereinafter, the best mode for carrying out the present invention will be described based on the attached drawings. In the figure, the offshore side (offshore side) is SO, and the shoreside (shore side) is SL. Also, let AS be the direction along the shore of the closed area.
In the embodiment of the present invention, the method of laying the water-impervious sheet according to the present invention will be described by exemplifying the case of using the construction of the water-impervious sheet when constructing the control type sea surface disposal site 10 shown in FIG. Do.
First, a partition 14 such as an arrowhead is placed on the original ground 12 of the water area adjacent to the shore to close the water area. In addition, as shown in FIG. 1, when it is set as offshore SO rather than a coastline, the closed area | region 16 divided by the partition 14 lands with respect to the closed area 16 in order to ensure workability. The water area 18 of SL is also reclaimed and landed as illustrated.

And the earth and sand 20 obtained by excavating the ground 12a in the range where the depth of offshore SO is deep in the closed area 16 is embedded in the shallow range of the depth of SL and the full width in the direction along the shore of the closed area Create a working ground 22 exposed to the atmosphere.
On this working ground 22, from the material 30 (see FIG. 2) of the water-impervious sheet to the full width in the direction along the shore of the closed region 16 (direction orthogonal to the page of FIG. 1) After forming the large panel 30L of the water-impervious sheet, the operation of moving the large panel 30L to the on-water (water surface) 16W of the closed area 16 is repeated.
A plurality of large panels 30L1... 30Ln are joined (see FIG. 8) to cover the bottom 16SF of the closed area 16 and the working ground 22.

  The working ground 22 may be a horizontal plane as shown in FIG. 1, but as shown in FIG. 2 to FIG. 8, an inclined plane should be formed so that the offshore SO is lower than the shoreside SL. It may be In the latter case, in the large panel forming step (see FIG. 4) described later, the entire width of the closing direction AS along the shoreline direction AS of the closed region 16 and the offshore direction SO When forming the large panels 30L1 ... 30Ln of the water-impervious sheet having a predetermined length, the work of spreading the raw fabric 30 in which the band-shaped water-impervious sheet is in the form of a roll is performed using the inclined surface of the working ground 22 Can be done smoothly. In addition, although illustration is abbreviate | omitted, when extending a strip-like water-impervious sheet from the original strip 30, the roll-shaped original strip 30 is mounted on a mount frame, and the belt center of the original strip 30 is fixed. Can be reduced to reduce the friction between the belt-like sheet and the work ground 22. Further, in a state in which the band-like sheet end portion is fixed to the shore side, if the raw fabric 30 is rolled and spread along with the shaft core, it can be expanded using the weight of the band-like sheet.

Then, the whole process of the laying method of the water-impervious sheet which concerns on embodiment of this invention is more concretely demonstrated, referring FIGS. 2-8.
(Work ground covering step)
As shown in FIG. 2, in the land yard 24 adjacent to the closed area 16, a band-shaped sheet 30 S of a certain width is drawn out from the raw sheet 30 of the water-impervious sheet, spreads, and connected to unit panels 30 M of a certain length. Form. The work in the land yard 24 adopts, in principle, a method in which the roll-shaped raw fabric 30 is placed on a rack and the sheet end is drawn out and spread. Further, the unit panel 30M may be formed not on the land yard 24 but also on a site such as a distant factory. The unit panel 30M is narrower in the shore direction AS of the closed area 16 than the large panel 30L. As a specific example, when the width of the closing area 16 along the shore direction AS is about 300 m in the large panel 30L, the width of the original fabric 30 and the sheet 30S drawn is about 2 m, and the width of the unit panel 30 M is 6 m to 30 m And the degree. Further, the predetermined length of the original fabric 30, the sheet 30S fed out, the unit panel 30M and the large panel 30L is about 8 m to 100 m.
In the land yard 24, a rigid panel suitable for pressure welding when laying a plurality of strip-like sheets 30S of a certain width from the raw fabric 30 of the water-impervious sheet and joining them in a row is laid ing. An iron plate etc. are used as a rigid panel. The land yard 24 may be formed to have an area equal to or slightly larger than that of the unit panel 30M.
Then, after the unit panel 30M is created on the land yard 24, it is moved onto the work ground 22 using a crane or the like. The work of creating and moving the unit panels 30M is repeated, and as shown in FIG. 3, a plurality of unit panels 30M are arranged on the working ground 22 so as to extend across the entire width AS of the closed area 16 along the shore. Furthermore, the unit panels 30M are joined on the work ground 22 to form a large panel 30L, and the entire surface of the work ground 22 is covered.

Subsequently, after laying sand on the large panel 30L covering the working ground 22, the large panel 30L is covered with the rigid panel 26 through the laying sand as shown in FIG. A plurality of rigid panels 26 equivalent to the rigid panels laid in the land yard 24 are arranged so as to cover the entire width of the closing area 16 along the shore direction AS so as to cover the large panel 30L. In addition, in FIG. 4, illustration of the boundary line of several rigid panels is abbreviate | omitted for convenience. Furthermore, the rigid panel 26 is covered with a friction reducing sheet 27 (only shown in the lower right view of FIG. 5). As the friction reducing sheet 27, a polymer sheet such as polyethylene or vinyl chloride is used.
Further, when the large panel 30L covering the working ground 22 is further covered with the rigid panel 26, if the large panel 30L is exposed for a predetermined length along the edge of the offshore SO of the large panel 30L, It becomes possible to use as a junction margin with the adjacent large panel 30Ln in which the exposed portion is formed in a later step.

(Large panel formation step)
Subsequently, as shown in FIG. 4, on the working ground 22, the impermeable sheet having a predetermined length in the offshore direction SO from the original web 30 of the impermeable sheet to the full width of the closed area 16 along the shore AS Form a large panel 30L1.
In this step, on the hard panel 26 covering the entire width of the closed area 16 along the shore direction AS, the large panel 30L1 is directly (without performing the process of creating the unit panel 30M) from the raw sheet 30 of the water blocking sheet. Create
(Work ground submersion step)
As shown in FIG. 5, the floating means 28 such as a float is fixed to the large panel 30L1, the water level in the closed area 16 is raised, and the working ground 22 is submerged. As shown in the lower right of FIG. 5, the water level LWL is the water level (low water level) in the large panel forming step described above, and the water level HWL is the water level (high water level) in this step. Thus, in this step, by raising the water surface level of the water surface 16W (see the upward arrow), the large panel 30L1 on the rigid panel 26 is floated using the buoyancy of the floating means 28. For the sake of convenience, in the lower right drawing of FIG. 5, a state in which the third panel 30L1 is raised is shown in a virtual battle. It also shows the change in water level in the "ground restoration step" described later.

(Large panel movement step)
By raising the water level in the closed area 16, the large panel 30L1 which floats above the submerged working ground 22 is moved in the offshore direction SO of the closed area 16 across the entire width AS of the closed area 16 along the shore . A large panel 30L1 tow in the offshore direction S is performed by a crane, a winch, and a ship, as appropriate, in this moving operation.
The first large panel 30L1 formed on the working ground 22 is, as shown in FIG. 6, the first large panel 30L1 when the laying work of the water blocking sheet is completed in one construction period. Are moved to the offshore end of the closed area 16.
(Working ground recovery step)
The water level in the closed area 16 is lowered again from the water level HWL to the water level LWL to expose the working ground 22 in the air (see the downward arrow in the lower right view of FIG. 5).

(Large panel bonding step)
Furthermore, each step (FIG. 4 to FIG. 6) from the large panel formation step to the working ground recovery step is repeated as one cycle for a plurality of cycles, and the large panel 30L1 formed in each cycle as shown in FIG. -Move 30 Ln from the shore direction LS toward the offshore direction SO. Then, as shown in FIG. 8, the large panels 30L1... 30Ln (n = 6 in the illustrated example) adjacent to each other in the offshore direction SO toward the shore direction LS are joined and integrated on the water surface 16W. Let
The large panel L30L1 ... 30L6 on the water surface 16W is joined by floating a large vessel (for example, about 2m in width and about 10m to 20m in length) on the water surface 16W, and this large vessel 30L1 · · each large panel · While moving along the adjacent side of 30 L 6, perform bonding across the entire width in the direction AS along the shore of the closed region 16. Further, the joining operation of the large panels 30L1 to 30L6 on the water surface 16W is performed every time the large panel 30Ln + 1 is moved to a position adjacent to the large panel 30Ln already sent in by the large panel moving step. And, in the large panel forming step, it is performed in parallel with the forming operation of the large panel 30Ln on the working ground 22.
Then, as shown in FIG. 8, the entire water surface 16W in the closed region 16 is covered with a plurality of large panels 30L... 30L6.

After that, the large panel 30L covering the working ground 22 is the edge of the bank side SL of the large panel 30L6 located among the large panels formed by each step from the large panel formation step to the working ground recovery step. Is joined to the edge of the offshore SO to form an integral impermeable sheet panel 30U having an area capable of covering the area where the impermeable sheet needs to be laid.
The final joining operation is performed after removing the hard panel 26 and the friction reducing sheet 27 which further cover the large panel 30L covering the working ground 22.
As described above, when the large panel 30L covering the working ground 22 is further covered by the hard panel 26, the large panel 30L is exposed by a predetermined length along the offshore edge of the large panel 30L. Since this exposed portion becomes a joining margin with the adjacent large panel 30L, before removing the hard panel 26 and the friction reducing sheet 27, or without removing the hard panel 26 and the friction reducing sheet 27, Bonding work can be performed.

(Large Panel Settlement Step)
Finally, by removing the floating means 28 as shown in FIG. 8 and submerging the integral water blocking sheet panel 30U on the water bottom 16SF as shown in FIG. 9, the water bottom 16SF in the closed area 16 and the working ground 22 is covered with an integral water-impervious sheet panel 30U.
In addition, this step is not limited after the formation of the integral water blocking sheet panel 30U, but when the large panels 30L1 to 30Ln are joined by a certain number of sheets, the large panels 30L1 to 30Ln of the offshore SO are sequentially The floating means 28 may be removed, and 30L1... 30Ln may be sequentially sedimented. In this case, it is possible to reduce the required number of floating means 28 by recycling the removed floating means 28 to a post-process.

In the above embodiment, the large panel 30L covering the working ground 22 is formed first, and then the large panels 30L1 to 30Ln covering the bottom 16SF are formed. However, the large panel 30L covering the working ground 22 is last It may be formed in The procedure in this case is as follows.
Prior to the large panel forming step, the working ground 22 is directly covered with the hard panel 26 and the friction reducing sheet 27, and the large panels 30L1... 30Ln are formed on the friction reducing sheet 27. Then, after the working ground recovery step is performed in the forming cycle according to the large panel 30Ln, the hard panel 26 and the friction reducing sheet 27 are removed.
Thereafter, as shown in FIG. 2, in the land yard 24 adjacent to the closed area 16, the strip 30 </ b> S of a certain width is unwound from the original sheet 30 of the water blocking sheet as shown in FIG. It spreads and forms unit panel 30M. Or, form and transport the unit panel 30M at the factory. Then, the unit panel 30M is moved onto the work ground 22 using a crane or the like. The work of creating and moving the unit panels 30M is repeated, and as shown in FIG. 3, a plurality of unit panels 30M are arranged on the working ground 22 so as to extend across the entire width AS of the closed area 16 along the shore. Furthermore, the unit panels 30M are joined on the work ground 22 to form a large panel 30L, and the work ground 22 is covered. Then, the edge of the offshore SO of the large panel 30L created last and the edge of the shore SL of the large panel 30L6 located closest to the shore are joined.

Furthermore, in the above embodiment, on the premise that the rigid panel 26 and the friction reducing sheet 27 are recovered, the large panel 30L covering the working ground 22 is first formed, and the rigid panel 26 and the rigid panel 26L are formed on the large panel 30L. The friction reducing sheet 27 is stacked, and the hard panel 26 and the friction reducing sheet 27 are used as work yards for forming the large panels 30L1 to 30Ln.
However, if the rigid panel 26 is not recovered, the working ground 22 is covered with the rigid panel 26 and the friction reducing sheet 27 prior to the large panel forming step, and the large panels 30L1. Finally, the large panel 30L may be formed, and the large panel 30L and the large panel 30Ln may be connected while the rigid panel 26 is covered by the large panel 30L.

  In addition, sectional drawing of the strip | belt-shaped sheet | seat 30S of the fixed width unwound from the raw fabric 30 of the water-impregnated sheet is shown by FIG. The water-impervious sheet used in the embodiment of the present invention may be a three-layer integral type in which the front and back surfaces of the water-impervious sheet 30a are covered with the protective mat 30b, as shown in FIG. As shown in FIG. 10 (b), it may be a five-layer integral type in which the front and back surfaces and the middle of two water-impervious sheets 30a are covered with a protective mat 30b. These are suitably selected according to the conditions etc. of a construction site. The water-impervious sheet 30a is made of vinyl chloride, polyethylene, or other polymer material, and the protective mat 30b is made of a material such as a long fiber non-woven fabric, a short fiber non-woven fabric, or an anti-hair felt. The thickness and weight of each may vary.

Now, according to the embodiment of the present invention having the above configuration, the following effects can be obtained.
That is, according to the laying method of the water blocking sheet according to the embodiment of the present invention, when the water area adjacent to the shore is closed by the partition wall 14 and the water blocking sheet is laid on the water bottom 16SF in the closed region 16 A work ground 22 exposed to air is created over the entire width of the region 16 along the shore direction AS. The earth and sand 20 used in the construction of the working ground 22 can be obtained by excavating the ground in a range where the water depth of the offshore SO is deep, so that the earth and sand can be easily procured.
Then, by forming a large panel 30L of a water-impervious sheet having a predetermined length in the offshore direction SO over the entire width in the shoreline direction AS of the closed region 16 on the working ground 22, a large panel 30L having a wide area It becomes possible to secure the place of the formation work on the working ground 22 in the air where the joining work of the raw sheet 30 of the water blocking sheet can be performed in a short time. In addition, the working ground 22 is adjacent to the water surface 16W of the stored water remaining in the closed region 16, and the distance when moving the large panel 30L onto the water surface 16W can be minimized.
Then, by repeating the operation of moving the large panel 30L onto the water in the closed region 16, the water surface 16W is covered with the large panel 30L, and the bonding operation takes time on water, and the bonding is performed for a plurality of large panels 30L1 ... 30Ln. By setting only the adjacent sides, it is possible to form an integral water-impervious sheet panel 30U having an area capable of covering the water bottom 16SF in the closed area 16.
Lastly, by sinking the integral water blocking sheet panel 30U to the bottom 16SF, the bottom 16SF in the closed region 16 can be covered.
In addition, although the reclamation height 10h of the management type sea surface disposal site 10 is schematically shown in FIG. 1, the working ground 22 is reclaimed and excavated sediment 20 because the input volume of waste decreases. Since the depth of the bottom surface 16SF of the closed area 16 is increased in the above range, the waste input bulk of the controlled sea surface disposal site does not decrease.

More specifically, in the large panel forming step, water shielding is performed on the working ground 22 from the original sheet 30 of the water shielding sheet to the entire width of the closed area 16 along the shore direction AS and having a predetermined length in the offshore direction SO. By forming the large panel 30L of the sheet, the forming operation of the large panel 30L having a wide area is performed on the working ground 22 in the air.
Furthermore, in the working ground submersion step, the floating means 28 is fixed to the large panels 30L1 ... 30Ln formed on the working ground 22, and the water level in the closed region 16 is raised to submerge the working ground 22. The large panels 30L1... 30Ln can be floated on the water surface using the buoyancy of 28.
In the large panel moving step, the large panel 30L extending over the entire width in the direction AS along the shore of the closed area 16 is moved from the working ground 22 to the place where the large panels 30L1 ... 30Ln are to be installed. It becomes possible to carry out in the state where 30L1 ... 30Ln floated on the water surface 16W. Therefore, it is possible to easily move the large panels 30L1... 30Ln having a large area.
Then, after the large panels 30L1 ... 30Ln move from the upper side of the working ground 22 to the offshore SO, the water level of the closed area 16 is lowered in the working ground recovery step to expose the working ground 22 in the air Thus, it is possible to secure a place for forming work for forming the large panels 30L1 to 30Ln on the working ground 22 in the air again.
In order to increase or decrease the water level in the closed area 16 in the working ground inundation step and the working ground restoration step, water is pumped from the water area outside the closed area 16 into the closed area 16 as shown in FIG. A pump 40 and piping 42 for pumping water from inside the closed area 16 to the water outside the closed area 16 are installed at or near the closed area 16.

Also, in the large panel joining step, each step from the large panel forming step to the working ground recovery step is repeated several cycles as one cycle, and the large panels 30L1 ... 30Ln formed in each cycle are It arranges toward the side SL, and covers the whole of the water surface 16SF in the closed area 16 with a plurality of large panels 30L1 ... 30Ln. And it is an integral impermeable sheet panel which has an area which can cover the bottom of the water in closed area 16 by joining on the water surface and making it adjoin on the water surface, adjoining each other from shore direction SO toward offshore direction SL. It forms 30 U.
Then, in the large panel settlement step, by sinking the integral water blocking sheet panel 30U to the water bottom, the water bottom 16SF and the working ground 22 in the closed region 16 can be covered.

In the embodiment of the present invention, the process of forming an integral water-impervious sheet panel having an area capable of covering the water bottom in the closed area 16 is divided into a plurality of construction periods, and finally the closed area is It is also possible to cover the entire surface of the water bottom of the For example, there may be cases where it is necessary to divide the construction period into two or more phases across severe weather conditions in a year.
In this case, first, in the preceding step, the range from the shore side SL of the closed area 16 to the intermediate position not reaching the offshore SO end is covered with a plurality of large panels 30L1 ... 30Ln, and the large panels are on the water surface 16W. After joining at the bottom, it is made to sink once to the bottom 16SF and temporarily fixed to the bottom 16SF. In this state, the implementation period of the construction period will be postponed as necessary. Moreover, by once sinking the joined large panels 30L1... 30Ln in the bottom of the water, the large panels 30L1... 30Ln are prevented from being damaged due to being temporarily moored on the water surface. Then, by performing the post-process after a predetermined time has elapsed, it is possible to form an integral water-impervious sheet panel 30U having an area that can finally cover the water bottom 16SF in the closed region 16.
The work period may be divided into three or more work periods. In this case, the large panels 30L1 ... 30Ln that have already been joined are temporarily settled in the bottom 16SF in the same manner as in the previous step at the end of the later steps. And temporarily fix to the bottom 16SF. Also, if necessary, in the first step, the area from the offshore SO end of the closed area 16 to the intermediate position not reaching the shore SL end is covered with a plurality of large panels 30L1. It is good also as order to cover with sheet panel 30Ln + 1 ... afterward toward Kishi side SL.

  Further, in the embodiment of the present invention, the working ground 22 is covered in advance with the large panel 30L as a step before repeating each step from the large panel forming step to the working ground recovery step as a single cycle for a plurality of cycles. . At this time, in the land yard 24 adjacent to the closed area 16, the unit panel 30M is formed such that the width along the shore direction AS of the closed area 16 is narrower than the large panel 30L from the raw sheet 30 of the water blocking sheet. A plurality of panels 30M are arranged on the working ground 22 so as to extend over the entire width of the closed area 16 along the shore direction AS. Then, by joining the adjacent sides of each unit panel 30M on the work ground 16 to form the large panel 30L, the work ground 22 can be covered with the large panel.

Then, by installing the hard panel 26 and the friction reducing sheet 27 on the large panel 30L covering the working ground 22, prior to the large panel forming step described above, from the raw fabric 30 of the water blocking sheet to the shore of the closed area 16 The work ground 22 is formed by a hard panel 26 and a friction reduction sheet 27 suitable for pressure welding, which are necessary when forming a large panel of water-impervious sheet having a predetermined length in the offshore direction across the entire width in the longitudinal direction AS. It is something to cover.
The rigid panel 26 and the friction reducing sheet 27 are disposed on the large panel 30L covering the working ground 22 so that, in the large panel forming step, the original of the water-impervious sheet is formed on the wide rigid panel 26 equivalent to the large panel. It becomes possible to form a large panel 30L of water-impervious sheets having a predetermined length in the offshore direction SO across the entire width in the shoreline direction AS of the closed region 16 from the opposite side 30. As long as the rigid panel 26 is installed on the working ground 22, the work of joining the water-impervious sheet on the working ground 22 can be efficiently performed over the entire width of the closed area 16 along the shore direction AS. Become.

In addition, after the laying sand is applied on the large panel 30L covering the working ground 22, by covering the large panel 30L with the hard panel 26, it is avoided by the laying sand that the large panel 30L is damaged by the rigid panel 26. It is possible to
Also, by covering the rigid panel 26 with the friction reducing sheet 27, over the wide area of the rigid panel 26 equivalent to the large panel, from the raw sheet 30 of the water blocking sheet to the entire width AS of the closed area 16 When forming the large panel 30L of the water-impervious sheet having a predetermined length in the direction SO, it is possible to facilitate the alignment for superposing the bonding portions of the band-like sheets 30S having a constant width, and to improve the workability.

  Then, of the large panels 30L1 to 30Ln created by the steps from the large panel forming step to the working ground recovery step, the working side 22 of the large side panel 30Ln located closest to the shore is selected as the working ground 22. By joining with the offshore edge of the large panel 30L to be covered, finally, it is possible to cover the area where the impermeable sheet needs to be laid for the bottom 16SF and the working ground 22 in the entire closed area 16 It is possible to form an integral impermeable sheet panel 30U having an area.

FIG. 11 (a) shows a joint line of large panels 30L1... 30Ln and 30L constituting an integral water-impervious sheet panel 30U according to the embodiment of the present invention on the water 16 W between the large panels. The JLX is schematically shown. Further, in FIG. 11B, as a comparative example, a joint line JLX, JLY at a water 16 W between unit panels of an integral water-impervious sheet panel 30 U ′ formed by joining unit panels 30 M. Is schematically shown.
The integral water-impervious sheet panel 30U according to the embodiment of the present invention shown in FIG. 11 (a) can be joined on the water surface along the shore according to the joining line JLX of each large panel 30L1. It is obtained by performing n lines across the entire width of the direction AS. On the other hand, the integral water-impervious sheet panel 30U 'according to the reference example shown in FIG. 11 (b) is the joint line JLY from the shore side SL of each unit panel 30M to the offshore side SO on the water surface. Joining work will also be added. Joining work on the water surface is inefficient compared to joining work on the working ground in the air, and the efficiency is further reduced depending on weather conditions and sea conditions.

For example, in the comparison of the integral impermeable sheet panels 30U and 30U 'having a length of 300 m along the shore AS and a length of 600 m from the land side SL toward the offshore SO, the junction line along the shore direction AS When JLX is 11 lines and joining work of joining line JLY from shore side SL to offshore side SO is 9 lines, a joining line for obtaining integral water-impervious sheet panel 30U shown in FIG. 11 (a) While the total length of JLX is 3,300 m, the total length of joint lines JLX and JLY shown in FIG. 11 (b) is 8,700 mm to obtain integral water-impervious sheet panel 30U '. Become. Moreover, if the joining work on the working ground proceeds, for example, about 140 m per day, the joining work on the water surface becomes inefficient, for example, about 40 m per day. For this reason, the joining operation of the one-piece water-impervious sheet panel 30U shown in FIG. 11 (a) with 16 W on water is completed in 3300 m / 40 m = 82.5 days, whereas it is shown in FIG. 11 (b). Integrated waterproof sheet panel 30U 'will be 217.5 days.
Moreover, as described above, the joining operation of the large panels 30L1 to 30L6 on the water surface 16W moves the new large panel 30Ln + 1 to a position adjacent to the large panel 30Ln already sent in by the large panel moving step. Since this operation is carried out each time and is carried out in parallel with the work of forming the large panel 30Ln on the working ground 22 in the large panel forming step, the main work in the case where the number of joining work on water is made the same The time shortening effect of the laying operation | work of a water-permeable sheet by the laying method of the water-permeable sheet which concerns on embodiment of invention is clear.

  In the embodiment of the present invention, although the case of constructing the water blocking sheet is illustrated and described at the construction site of the management type sea surface disposal site, the laying area of the water blocking sheet is large similarly to this. It is understood that the present invention is similarly applicable to a facility that requires considerable man-hours and time for joining the water-impervious sheet when the water level of the water-impervious sheet laying section can be controlled to rise and fall. It will

  10: Managed sea surface disposal site, 12: Raw ground, 12a: Raw ground of deep water depth range 14: Partition wall, 16: Closed area, 16 SF: Water bottom, 16 W: Water surface, 20: Sediment, 22: Work Ground, 24: Land yard, 26: Hard panel, 27: Friction reducing sheet, 28: Floating means, 30: Raw sheet of water blocking sheet, 30S: Band-shaped sheet of a fixed width, 30M: Unit panel, 30L, 30L1 ···・ ・ 30Ln: Large panel, 30U: One-piece impermeable sheet panel

Claims (14)

A method of closing a water area adjacent to a shore by a bulkhead and laying a water blocking sheet on the water bottom in the closed area,
The soil obtained by excavating the ground in the deep water depth area in the closed area is embedded in the shallow water area near the shore, and the entire width along the shore in the closed area is in the air Create an exposed working ground,
After forming a large panel of a water-impervious sheet having a predetermined length in the offshore direction across the entire width of the closed area along the shore on the work ground, the large panel is moved onto the water of the closed area Repeat
A method of laying a water-impervious sheet, characterized in that a plurality of the large panels are joined to cover the water bottom in a closed area. A large panel forming step of forming a large panel of a water-impervious sheet having a predetermined length in the offshore direction from the raw fabric of the water-impervious sheet to the entire width of the closed area along the shore on the work ground;
A working ground submersion step in which floating means is fixed to the large panel, the water level in the closed area is raised, the working ground is submerged, and the large panel is floated by the floating means;
A large panel moving step of moving the raised large panel offshore of the closed region across the entire width of the closed region along the shore;
The method for laying a water-impervious sheet according to claim 1, further comprising: a work ground restoration step of lowering the water level in the closed area to expose the work ground in air. Each step from the large panel formation step to the working ground recovery step is repeated multiple cycles as one cycle, and the large panels formed in each cycle are joined on the water surface, adjacent from the shore direction toward the offshore direction Integrated into a large panel bonding step,
3. A method of laying a water-impervious sheet according to claim 2, further comprising the steps of: a large panel settlement step of sinking the large panel to the bottom of the water.   Each step from the large panel formation step to the working ground recovery step is repeated as one cycle for a plurality of cycles, and the large panels formed in each cycle are arranged from the offshore side to the shore side in the closed region. The method for laying a water-impervious sheet according to claim 2 or 3, wherein the entire water surface is covered with a plurality of large panels. Each step from the large panel formation step to the working ground recovery step is repeated as a single cycle for a plurality of cycles, and an intermediate position not reaching from the shore side to the offshore end of the closed area or an intermediate position not reaching from the offshore end to the shore side After covering the range up to the position with multiple large panels and joining the large panels on the water surface, after the previous step of temporarily sinking to the water bottom and temporarily fixing to the water bottom,
Each step from the large panel formation step to the working ground recovery step is repeated multiple cycles as one cycle, and the area on the offshore side or the shore side of the previous step in the closed area is covered with a plurality of large panels. 5. The method according to claim 2, further comprising the step of joining the large panel located at the offshore end with the large panel located at the offshore or shore end temporarily fixed to the water bottom in the previous step. The laying method of the water-impervious sheet according to any one of the above. Prior to the large panel formation step,
In the land yard adjacent to the closed area,
From the material of the water-impervious sheet, form a unit panel whose width in the direction along the shore of the closed area is narrower than that of the large panel, and repeat the work of moving the unit panel onto the work ground
A plurality of unit panels are arranged on the working ground so as to extend across the entire width of the closed area along the shore, and the unit panels are joined on the working ground to create a large panel and cover the working ground. The method for laying a water-impervious sheet according to any one of claims 2 to 5, further comprising a working ground covering step.   The laying method of the water-impervious sheet according to claim 6, characterized in that the large panel covering the working ground is further covered by a rigid panel.   The laying method of the water-impervious sheet according to claim 7, characterized in that after laying sand is applied on the large panel covering the working ground, it is covered by the hard panel. Prior to the large panel formation step,
The method according to any one of claims 2 to 5, wherein the work ground is covered with a rigid panel. At the onshore yard adjacent to the closed area after removing the rigid panel,
From the material of the water-impervious sheet, form a unit panel whose width in the direction along the shore of the closed area is narrower than that of the large panel, and repeat the work of moving the unit panel onto the work ground
A plurality of unit panels are arranged on the working ground so as to extend across the entire width of the closed area along the shore, and the unit panels are joined on the working ground to create a large panel and cover the working ground. The method according to claim 9, further comprising a working ground covering step.   The method for laying a water-impervious sheet according to any one of claims 7 to 9, wherein the hard panel is covered with a friction reducing sheet.   Of the large panels created in the steps from the large panel formation step to the working ground recovery step, the shore side edge of the large panel located closest to the shore is the offshore side edge of the large panel covering the working ground The method for laying a water-impervious sheet according to any one of claims 6 to 11, wherein the method is used for bonding to a sheet.   The method for laying a water-impervious sheet according to any one of claims 2 to 12, wherein in the work ground formation step, the inclined surface is formed so that the offshore side is lower than the shore side.   The method for laying a water-impervious sheet according to any one of claims 1 to 13, wherein the closed area is a creation site of a controlled sea surface disposal site.

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