JPH08311881A - Construction method for water impermeable film wall - Google Patents

Abstract

PURPOSE: To insert a water impermeable sheet in a linear groove surely with an extent of surface to a designated depth, to decrease the number of joint parts so as to improve the work efficiency of joint construction and improve water impermeable performance, and to reduce the width of the linear groove to the upmost so as to minimize the quantity of excavated soil and waste muddy water. CONSTITUTION: A sheet roll 21 is inserted in its erected state in a start hole 22. Starting is conducted from the start hole, injection of water jets 14 from nozzles of a force-feed tube 12, pumping by a drain pipe 8 and mucking by an auger 9 are simultaneously executed to advance in a linear groove 15, and a water impermeable sheet 20 is drawn from the sheet roll into the linear groove and expanded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the construction of a water blocking wall for a waste disposal site, a water blocking wall for isolating contaminated soil, groundwater, etc., a water blocking wall for a dam (underground dam), etc. The present invention relates to a method of constructing a water-permeable membrane wall that forms a water-permeable membrane in the ground with a water-permeable sheet.

[0002]

2. Description of the Related Art Conventionally, construction of a band-shaped groove for inserting a water-blocking sheet has mainly been carried out by the following two methods. An earth drill or trench cutter is used to excavate from the ground surface to a specified depth, and this is repeatedly extended along the wall construction direction. After excavating with a ground drill from the ground surface to a predetermined depth, excavating between the preceding excavation holes with a chain cutter and repeating the work.

However, in these methods, a groove having a width greater than necessary (in the case of several tens of cm or more, in the case of about 20 cm) is excavated in a thin water-permeable sheet having a thickness of only a few mm at the maximum. Therefore, there is a problem that a large amount of excavated soil is generated and the amount of wall surface mud is also used according to the groove width, resulting in a large amount of waste.

Further, conventionally, in order to insert the water-impermeable sheet into the band-shaped groove, the water-impermeable sheet is hung from the ground for each element of the excavation groove excavated by the above method. However, with the insertion method in which the water shield sheet is simply hung, the water shield sheet may not reach the predetermined depth with a planar spread, and it is also difficult to make the insertion depth of the water shield sheet uniform. Therefore, conventionally, the method disclosed in the following publication has been proposed.

(1) Japanese Examined Patent Publication No. 7-18170 A weight having a hook on the top is placed at the bottom of the band-shaped groove, the weight is fixed with concrete, and a cord connected to the lower end of the water-impervious sheet is inserted into the hook. Then, the impermeable sheet is pulled into the bottom of the band-shaped groove by pulling it with a cord.

(2) Japanese Unexamined Patent Publication No. 4-366227 A U-shaped pipe having a large number of suction holes in the horizontal portion is inserted into the excavation groove, the horizontal portion is installed at the bottom of the excavation groove, and negative pressure is applied to this pipe. Is applied to suck air from a large number of suction holes, generate a downward air flow in the excavation groove, and draw in the water blocking sheet.

(3) Japanese Patent Application Laid-Open No. 63-289122 Japanese Laid-Open Patent Publication No. 63-289122 A roll of water-impervious sheets having adhesive portions formed on the left and right edges thereof while being rewound in sequence along a guide metal fitting previously installed in the excavation groove. It is suspended in the excavation trench. At that time, the weight is attached to the roll, and the guide roller is attached to the upper end of the guide metal object.

However, these conventional techniques require a special device for retracting the water-blocking sheet. In addition, since a water blocking sheet is droopingly inserted into each element of the excavation groove, a joint section is required each time, and the number of joint constructions increases, which requires a lot of time and materials for the work, and the water blocking performance deteriorates. There was a problem to do.

[0009]

SUMMARY OF THE INVENTION A first object of the present invention is to insert a water-impervious sheet into a band-shaped groove with a sure planar spread, and to prevent the water-impermeable sheet from reaching a predetermined depth. The purpose is to ensure that the depth is aligned in the longitudinal direction of the band-shaped groove. A second object of the present invention is to make it possible to minimize the number of joints, thereby improving workability in joint construction and improving water impermeability. A third object of the present invention is to make the band-shaped groove as thin as possible and to excavate efficiently, and to minimize the amount of excavated soil and waste mud. A fourth object of the present invention is to facilitate the construction of a joint between water-impervious sheets.

[0010]

In order to achieve the above first and second objects, in the present invention, a sheet roll wound with a waterproof sheet is inserted into the ground, and the waterproof sheet is striped from the sheet roll. Pull out along the groove to deploy. in this case,
It is preferable to insert the sheet roll upright in the starting hole and to pull out the water-blocking sheet from the sheet roll in the starting hole while starting from the starting hole and digging the belt-shaped groove in the horizontal direction.

In order to achieve the third object in addition to the first and second objects, in the present invention, the sheet roll is inserted in a standing position in the starting hole, and the sheet roll is started from this starting hole to form the belt-shaped groove in the water. While digging with the water pressure of the jet, the water-blocking sheet is pulled out from the sheet roll in the launch hole. In this case, if the jetting of the water jet from the nozzle of the pressure-feeding tube, the pumping of water by the drainage pipe, and the slipping out by the auger are carried out at the same time, the band-shaped groove can be dug efficiently.

Further, in order to achieve the fourth object, in the present invention, the water-impermeable sheet developed in the band-shaped groove is overlapped through the slit inside the joint pipe with a slit inserted into the hole, and Fix the lap part in the slit joint pipe.

[0013]

According to the present invention, the water-impervious sheet is inserted to a predetermined depth in the roll state and then horizontally pulled out along the band-shaped groove to be developed. It can be installed with a predetermined insertion depth. The excavation by the water jet can not only narrow the groove width, but can also pull out the impermeable sheet while advancing the excavation horizontally.

Since the water-impervious sheet is laterally drawn out along the band-shaped groove as described above and deployed, the number of joints connecting the water-impervious sheets is extremely small. This can be done simply by inserting the pipe into the hole and fixing the end of the water-blocking sheet to this joint pipe with slit.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows an excavator for carrying out the construction method according to the invention. This excavator 1 is equipped with a take-up drum 3, a pressure pump 4, a pumping pump 5 and a settling tank 6 on a trolley 2, and the trolley 2 has a tube guide 7 and a drain pipe as shown in FIG. 8, the auger 9, and the membrane wall 10 are vertically arranged side by side in the order of front and rear, and a slide-out chute 11 is provided below the carriage 2.

The winding drum 3 winds up the pressure-feeding tube 12 connected to the pressure-feeding pump 4. The pressure-feeding tube 12 fed from the winding drum 3 is guided by the tube guide 7 and vertically hung from the carriage 2. A nozzle 13 (FIG. 3) is provided at the tip (lower end) of the hanging portion, and water from the pressure feed pump 4 is jetted forward from the nozzle 13 as a water jet 14 as shown in FIGS. 3 and 4. To be done. The hanging portion of the pressure feeding tube 12 is repeatedly moved up and down while jetting the water jet 14.
While the truck 2 is traveling on the ground, such an injection is performed in the ground to continuously excavate the narrow strip groove 15. The tube guide 7 has a pressure feeding tube 12 on its inner surface.
It has a C-shaped cross section to guide passengers.

A filter 16 is provided at the lower end of the drain pipe 8, and the upper end of the drain pipe 8 is connected to the pumping pump 5. The water in the excavated band-shaped groove 15 is filtered by the filter 16, pumped by the drainage pipe 8, once collected in the settling tank 6, and then pressure-fed by the pressure-feed pump 4 to the pressure-feed tube 12 again for injection.

The auger 9 has a shaft portion 17 as shown in FIG.
A slip receiving portion 18 having a large number of projections on the bottom surface and a spill preventing peripheral wall portion 19 are provided around the spiral in a spiral shape, and the slip generated by excavating the band-shaped groove 15 is conveyed to the ground. The misalignment is carried to the side of the band-shaped groove 15 by the misalignment chute 11 (FIG. 1) on the ground. If the grain size of the gap is fine and the depth of the band-shaped groove 15 is shallow, the auger 9 is omitted and the gap and the water are sucked up together by the drain pipe 8.

The membrane wall 10 is made of hard rubber or the like and has a C-shaped cross section. This membrane wall 10 is for partitioning the inside of the band-shaped groove 15 in the front thereof into a rear side and a front side and a rear side as an excavation work area for excavating by the water jet 14, pumping by the drain pipe 8 and slipping out by the auger 9.

In this embodiment, while the excavator 1 traveling on the ground excavates the strip-shaped groove 15 as described above, the water-blocking sheet 20 is provided behind the membrane wall 10 as the excavator 1 travels. It is pulled out laterally into 15, and the operation will be described next.

Before starting the excavation of the band-shaped groove 15, as shown in FIG. 4, an excavation hole 22 having a size and a depth into which the sheet roll 21 wound with the water-impervious sheet 20 can be inserted is drilled. The starter hole 2
The excavation of the band-shaped groove 15 is started from 2. Muddy water is supplied to the starting hole 22 for stabilizing the wall surface of the strip groove 15, and the amount thereof is adjusted as the excavation of the strip groove 15 progresses.

The sheet roll 21 is vertically inserted into the starting hole 22, but is freely rotatable at the lower end of the core member 23 of the sheet roll 21 so that the impermeable sheet 20 can be pulled out smoothly. Attach the pedestal 24. A receiving frame 25 is provided on the outer periphery of the pedestal 24. Furthermore,
In order to prevent the sheet roll 21 from swinging and rising, the pressing plate 26 is detachably attached to the core member 23 on the ground. The pressing plate 26 is provided with a hole that allows the core member 23 to rotatably pass therethrough.

A rigid sheet end guide 27 is attached to the leading end of the water-impervious sheet 20, and the sheet end guide 27 is suspended from the rear portion of the bogie 2 of the excavator 1 for running the excavator 1. Along with this, the waterproof sheet 20 is automatically pulled out.

The starting hole 2 is provided at a position apart from the starting hole 22.
The same reaching hole (not shown) as 2 is preliminarily drilled, and two guide rails 2 are provided on the ground surface between the starting hole 22 and the reaching hole.
8 is laid (temporarily provided), and the groove 15 is dug along these guide rails 28. When the wall length is short, the starting hole and the reaching hole are the same. The two guide rails 28 are located on both sides of the excavation of the band-shaped groove 15. Therefore, the waterproof sheet 20 is provided by using a plurality of required suspenders 29 that travel along these guide rails 28.
Is hung in a curtain shape, and the guide rail 28 is pulled out while guiding the impermeable sheet 20 like a curtain rail. As shown in FIG. 6, the suspending tool 29 is in a form of straddling the guide rails 28 on both sides, and a clip 30 such as a clip and a hook 30 attached to the center of the suspending tool 29 allows the upper edge portion of the water blocking sheet 20. Hold. The suspenders 29 are connected to each other by a wire 31 connected to the excavator 1.

In this state, the excavator 1 is allowed to travel on the surface of the ground, and the water jet 14 is moved while vertically moving the hanging portion of the pressure feeding tube 12 together with the nozzle 13 at the lower end thereof.
Is ejected from the starting hole 22 toward the reaching hole and the belt-shaped groove 15
The water in the strip groove 15 is drained by the drainage pipe 8, and the water impregnated sheet 15 is hung from the sheet roll 21 in the starting hole 22 in a curtain shape while being slid out by the auger 9. Then, the membrane wall is constructed by unfolding it into the strip-shaped groove 15.

When reaching the reaching hole, the sheet end guide 27 at the tip of the water-blocking sheet 20 is separated from the excavator 1. Next, a new sheet roll 21 is inserted into this reaching hole, and the water-blocking sheet 20 is pulled out and developed while digging the strip-shaped groove 15 from this reaching hole toward the next reaching hole in the same manner to construct a membrane wall. .

In the reaching hole, the tip portion of the water blocking sheet 20 reaching the reaching hole from the starting hole 22 and the base end portion of another water blocking sheet 20 remaining in the reaching hole together with the core material 23 are overlaid. Lapping is performed, and the overlapped portion is joined as follows using a joint pipe 32 with a slit as shown in FIG. 7.

The joint pipe 32 with slits is one in which two slits 33 are provided in parallel from one end (lower end) to the other end (upper end) of a circular steel pipe.
The fitting pipe 32 with the slit is inserted into the reaching hole (or the starting hole) along the core member 23 while fitting the one water-blocking sheet 20 and the overlapping part of both the water-blocking sheets as shown in FIG. . At this time, the joint pipe with slit 3
The lower end of 2 is fitted in the receiving frame 25 of the pedestal 24 so that the slit 33 does not widen.

Then, the space between the water-permeable sheet 20 and the joint pipe 32 with slits (outside of the site separated by the water-permeable sheet 20) is filled with the filling material 34 through a stretchable bag, The overlapping portion of the water-impervious sheet 20 is tightly fixed in the slit joint pipe 32 by pressurizing the filler 34. As the filler 34, an expansive material such as expansive mortar is preferable. The filling material 34 may be put in a bag in advance and inserted into the slit joint pipe 32 at the same time as the bag.

Finally, the muddy water inside the band-shaped groove 15, the starting hole and the reaching hole is replaced with the solidifying material to complete the water shield film wall.

In the above embodiment, the excavation of the band-shaped groove was performed by the water jet, but if the band-shaped groove is previously excavated from the starting hole to the reaching hole by the conventional excavation method,
After that, by expanding the water-impervious sheet while pulling it out from the sheet roll, it is possible to construct a water-impervious film wall having high water impermeability as described above.

[0033]

As described above, according to the inventions according to claims 1 and 2, the water-blocking sheet is inserted in a roll state to a predetermined depth, and then the water-blocking sheet is laterally pulled out along the band-shaped groove to be developed. Therefore, the water-impermeable sheet can be installed in the band-shaped groove at a predetermined insertion depth at the same time as the deployment. Therefore, the water-impervious sheet can be reliably inserted into the band-shaped groove with a planar spread, and the insertion depth can be reliably aligned in the longitudinal direction of the band-shaped groove without reaching the predetermined depth. Further, since the number of joints is reduced, workability in joint construction and water impermeability can be improved.

According to the invention of claim 3, since the band-shaped groove is excavated by the water jet, the groove width can be made as thin as possible to minimize the amount of excavated soil and waste mud, and the excavation can be advanced in the horizontal direction. At the same time, you can pull out the waterproof sheet at the same time.

According to the fourth aspect of the present invention, since the jetting of the water jet, the pumping by the drain pipe, and the slipping out by the auger are simultaneously performed to excavate the strip-shaped groove, the strip-shaped groove having a narrow groove width is efficiently excavated. it can.

According to the invention of claim 5, the joint pipe with the slit is inserted into the hole and the end portion of the waterproof sheet is fixed to the joint pipe with the slit. Can be easily constructed. Further, since the water-impervious sheets are overlapped in the joint pipe with slit, the water impermeability is good.

[Brief description of drawings]

FIG. 1 is a perspective view of an example of an excavator used in a construction method of the present invention.

FIG. 2 is a perspective view showing a positional relationship among a tube guide, a drain pipe, an auger, and a membrane wall which are vertically provided on a bogie of the excavator.

FIG. 3 is a plan view showing a relationship between the tube guide and a nozzle of a pressure feeding pipe.

FIG. 4 is a perspective view showing an implementation state of a construction method according to the present invention.

FIG. 5 is an enlarged perspective view of a part of the auger.

FIG. 6 is a perspective view showing a state in which a waterproof sheet is hung in a curtain shape and pulled out.

FIG. 7 is a perspective view showing a sheet roll, a water-blocking sheet partially pulled out from the sheet roll, a core material of the sheet roll, and a joint pipe with a slit.

FIG. 8 is a plan view showing the structure of a joint section using the joint pipe with slit.

[Explanation of symbols]

 1 Excavator 2 Bogie 3 Winding Drum 4 Pressure Pump 5 Pumping Pump 6 Precipitation Tank 7 Tube Guide 8 Drain Pipe 9 Auger 10 Membrane Wall 11 Sliding Chute 12 Pressure Feed Tube 13 Nozzle 14 Water Jet 15 Banded Groove 16 Filter 17 Shaft 18 Slipper receiving portion 19 Spill-preventing peripheral wall portion 20 Water-impervious sheet 21 Sheet roll 22 Starting hole 23 Core material 24 Pedestal 25 Receiving frame 26 Holding plate 27 Seat end guide 28 Guide rail 29 Suspension tool 30 Fastener 31 Wire 32 Joint pipe with slit 33 Slit 34 Filling material

Claims (5)

[Claims] 1. A method of constructing a water-blocking film wall, wherein a water-blocking sheet is inserted into a band groove to form a water-blocking film in the ground, and a sheet roll wound with the water-blocking sheet is inserted into the ground. A method of constructing a water-permeable membrane wall, which comprises pulling out a water-impermeable sheet from a roll along a band-shaped groove and deploying it. 2. A sheet roll is inserted upright in a starting hole, and the water blocking sheet is pulled out from the sheet roll in the starting hole while starting from this starting hole and digging the belt-like groove horizontally. The method for constructing a water-permeable membrane wall according to claim 1, wherein. 3. A sheet roll is inserted upright in a starting hole, and the water blocking sheet is pulled out from the sheet roll in the starting hole while starting from this starting hole and digging the band-shaped groove by the water pressure of the water jet. The method for constructing a water barrier film wall according to claim 2, wherein the method is performed. 4. The water-impermeable film according to claim 3, wherein the band-shaped groove is dug while the jetting of the water jet from the nozzle of the pressure-feeding tube, the pumping by the drainage pipe, and the slipping-out by the auger are simultaneously performed. Wall construction method. 5. A water-impermeable sheet developed in a band-shaped groove is overlapped through a slit inside a joint pipe with a slit inserted into a hole, and the overlapping portion is fixed in the joint pipe with a slit. The method for constructing the water-permeable membrane wall according to claim 1, 2, 3, or 4.