JP2001164564A - Installation method of drain structure for impervious wall and wall joint section - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an impervious wall for improving an underground continuous wall partitioning the inside and outside of a site in order to prevent the leakage of polluted water from sewage disposal plant or the like. SOLUTION: A connecting drainage route 20 is formed in a wall of an underground continuous wall 10 constructed so as to partition the inside and outside areas in a site. The water level in the connecting drainage route 20 is lowered from any groundwater level of the outside of the site. By the constitution, polluted water leaked through the inside of the wall from the inside of the site is made to flow in the connecting drainage route 20, and the polluted water is discharged to the outside by a lifting pump P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of installing a drainage structure for a water impervious wall and a wall joint, and more particularly to an underground continuous method used to partition the inside and outside of a site such as a waste disposal site or a chemical factory. The present invention relates to a method for installing a drainage structure of a water-impervious wall and a wall joint part, in which a wall has a drainage function so as to exhibit sufficient water-impermeability.

[0002]

2. Description of the Related Art In a disposal site for general waste, industrial waste, and the like, a water impervious work is constructed to divide the site of the disposal site from the outside. This impervious work involves the removal of harmful substances from wastewater into the retained water of rainwater and stored waste that has penetrated through the ground inside the repository, and the water that has accumulated in the repository (hereinafter referred to as “contaminated water”) It plays a role in preventing leaching and contaminating surrounding groundwater. If there is an impermeable layer on the entire lower surface of the disposal site among the various types of impermeable works, insert the end of the underground continuous wall into the impermeable layer to divide the inside and outside of the site, and block the wall. Can be used as a water wall. The water permeability of the concrete that composes the wall is about 1 × 10 ⁻⁷ cm / sec. It can be said that it is almost impervious. There is also a risk of cracks generated by the above and water leakage from the joint between the elements.

[0003] In order to prevent the seepage of contaminated water caused by the slight permeability of the impermeable wall, a waste disposal site having an impermeable wall structure utilizing a head difference in groundwater has been proposed. This waste disposal site is equipped with a double-walled underground wall that is embedded in the water-impervious layer, and the groundwater level of the boundary ground sandwiched between these two walls is disposed of. The groundwater level inside the site and the groundwater level outside the disposal site are adjusted and controlled so that the contaminated water does not leach outside.

FIG. 10 is a schematic sectional view showing the structure of an example of this type of waste disposal site. As shown in the figure,
Double impermeable walls 55 and 56 composed of underground continuous walls so as to partition the inside 51 of the site and the outside 52 of the illustrated disposal site 50
Has been created. These water impermeable walls 55 and 56 are constructed with a gap of about several meters, and the tip portions 55a and 56a are deeply rooted to the lower impermeable layer 53. Known pumping means 57, for example, well points and the like are arranged at predetermined intervals in the boundary ground 54 sandwiched between the inner and outer impermeable walls 55 and 56. The pumping means 57 monitors the groundwater level W ₂ of the groundwater level W ₁ and disposal site outside 52 of the continuous disposal site inside 51 by ground water level detecting means (not shown), the water level W ₁ water level W ₃ boundary ground 54 , to be lower by a predetermined level difference than W ₂ pumping groundwater internal 51. Thus, even contaminated water W _C which accumulated on the disposal site inside 51 is leached boundary ground 54 penetrates the inner impervious wall 55, due to the high water table W ₂ of the external 52, further boundary There is no leakage from the ground 54 to the outside 52.

[0005]

However, in the impermeable wall structure shown in FIG. 10, a double impermeable wall adjacent to the disposal site area must be formed by a continuous underground wall. In addition, pumping equipment with a relatively large capacity is required to lower the groundwater level at the boundary ground between the inner and outer impermeable walls. For this reason, there is a problem that construction costs and equipment costs for preventing leaching of contaminated water increase.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a drainage passage in the underground continuous wall and at a joint between the elements, and to introduce and permeate the contamination flowing into the drainage passage. It is an object of the present invention to provide a method of installing a water impermeable wall for pumping water to the ground and a drainage structure of the joint.

[0007]

In order to achieve the above object, the present invention is constructed as a continuous wall to divide the inside and outside area of a site, and a communication drainage channel is formed in the wall, and the communication drainage channel is formed inside the wall. The contaminated water leached from the premises through the wall into the communication drainage channel by lowering the water level of the groundwater level inside or outside the premises, and the contaminated water is pumped by the pumping means. It is characterized by draining to the outside.

The connecting wall is constructed as a continuous wall so as to divide the inside and outside areas of the site, and a communication channel is formed in the wall, and the water level in the communication channel is higher than the groundwater level inside or outside the site. The contaminated water leached into the communication channel from the premises into the wall is prevented from flowing into the communication channel.

[0009] In the impermeable wall which is constructed by connecting the leading element and the trailing element alternately as a continuous wall and divides the inside and outside area of the site, a drain pipe is provided on an end face of the joint part on the leading element side. It is characterized by.

[0010] Both sides of the joint on the preceding element side of the impermeable wall constructed by alternately connecting the preceding element and the following element so as to partition the inner and outer regions of the site as a continuous wall, and a shape member inside. Install the drainage pipe frame material accommodated to construct a preceding element concrete wall, and remove a part of the drainage pipe frame material in a state where the mold remains, when excavating for a subsequent element, After the subsequent element concrete is constructed, the mold is removed to form a drain pipe at the joint of the preceding element.

In this case, it is preferable that the cross section of the drainage pipe frame material has a trapezoidal shape in which the short side of the parallel side is located on the following element side.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the method for installing a drainage structure for a water impermeable wall and a wall joint according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic cross-sectional view showing the entire disposal site surrounded by impermeable walls of the present invention and the outside ground thereof, and FIG. 2 is a cross-sectional view showing the impermeable walls along a II-II cross-sectional line when viewed from above. FIG. 3 is a cross-sectional view taken along the line III-III in a side view of the impermeable wall.

As shown in FIG. 1, a communication drainage pipe 20 as a drainage path is supported inside a water-impervious wall 10 and supported by a reinforced car (see FIG. 2). This communication drainage pipe 20
In the present embodiment, as shown in FIGS. 2 and 3, three vertical pipes 20A are connected to each other by a horizontal pipe 20B disposed at the bottom of the wall in one element. The communication drainage pipe 20 is assembled in the reinforcing cage 12 in a state of being connected in advance, and is installed in the groove at the same time when the reinforcing cage 12 is installed. A predetermined number of well points (not shown) in the pipe after the wall is completed
Is installed so that water can be pumped from inside the communicating pipe. In addition, since the drainage path is configured as the communication drainage pipe 20, swabbing can be efficiently performed when a strainer described later is clogged.

FIG. 2 is a plan sectional view showing one element (leading element) 10A of the impermeable wall 10 and a part of a succeeding element 10B connected to both sides thereof. As shown in the figure, the preceding element 10A and the following element 10B
A joint drainage pipe 25 (the configuration and installation method will be described later) is disposed in the joint portion 11 in place of the conventional water stopping means such as a water stop plate. Further, on the side of the disposal site, a waterproofing film 13 made of a synthetic resin sheet is deployed. This impermeable film 1
Reference numeral 3 denotes a high-density polyethylene sheet having a thickness of 1.5 mm in the present embodiment. As substitutes, various vulcanized rubber sheets, polyvinyl chloride sheets and the like are suitable. The water barrier film 13 is previously bound to a part of the reinforcing bar cage 12 at the end of the reinforcing bar using a fixing band or the like (not shown), and when the reinforcing steel cage 12 and the water barrier film 13 are simultaneously accommodated in the wall groove. It is preferable that the water barrier film 13 is not turned over or broken. It is also possible to attach a thin steel plate to the inner surface of the wall instead of the water barrier film 13.

FIG. 4 is a partially enlarged view of the communication drainage pipe 20. As shown in the figure, the communication drainage pipe 20 is a perforated pipe 21.
Has a double structure covered with a strainer 22. In the present embodiment, a cylindrical nonwoven fabric is used as the strainer 22. The perforated pipe 21 has a diameter of 15 mm.
A 0 mm perforated vinyl chloride tube is used. The nonwoven fabric as the strainer 22 plays a role in preventing the perforated pipe 21 from being clogged by the mortar during casting of the wall concrete. Note that, in FIG.
A portion of the perforated tube 21 with 2 removed is shown. Further, a water-permeable pipe or the like formed by entanglement of a fibrous resin filament known as a trade name “CP drain” in a three-dimensional net shape to form a cylinder having a predetermined rigidity can be used alone.

FIG. 5 shows a modified example of the impermeable wall 10 which increases the efficiency of collecting contaminated water leached from the inside of the disposal site to the impermeable wall 10 side. In this modified example, a drainage mat 15 is arranged so as to overlap along the back surface of the water barrier film. This drain mat 15 is formed into a mat shape by entangling a resin filament into a three-dimensional net-like predetermined thickness, and covering both surfaces thereof with a nonwoven fabric-like water-permeable sheet (not shown), and forming a planar drain passage therein. It is drainage material. Further, a plurality of water collecting pipes 16 are attached to predetermined positions of the drainage mat 15 so that the contaminated water in the drainage mat 15 can be collected on the communication drainage pipe 20 side. Also in this case, the water impermeable film 13 and the drain mat 15
Cannot be connected, and in order to prevent leakage of contaminated water from this gap, the leading element 10A
A drain pipe 25 is provided at the side end 10a.

FIG. 6 is a schematic explanatory view showing the structure of a drain pipe 25 as a drain structure of a wall joint and its installation procedure. FIG. 6A is a partial plan view showing the end of the preceding element 10A immediately after the concrete has been cast. A drainage pipe frame member 30 is attached to a part of the reinforcing rod cage 12 and attached in the depth direction of the wall outside the end surface 12a of the reinforcing rod cage 12 in the preceding element 10A.
The drainage pipe frame member 30 is a synthetic resin molded pipe having a trapezoidal cross section in which the short side of the parallel side is positioned on the side of the following element, and has a rod-like shape substantially matching the cross section so as to close the inside. A mold material 31 molded of styrene foam resin is accommodated.

FIG. 6 (b) shows the excavation of the following element 10B adjacent to the preceding element 10A, and the inside of the reinforcing cage 1
2 is stored. As shown in the figure,
The leading element 10A when excavating the succeeding element 10B
Concretely, the concrete on the wife side on the side of the preceding element 10A, which will be the joint surface with the above, is slightly removed. At this time, drain pipe frame material 30
And a part 31a of the shape member 31 are scraped off together with the concrete. At this time, since the inner hollow shape of the drain pipe frame member 30 has a trapezoidal shape such that the short side of the parallel side thereof is located on the following element side, the styrofoam resin material as the internal mold member 31 is placed on the following element 10B side. Do not escape. In this state, concrete placement of the succeeding element 10B is performed. When the concrete of the succeeding element 10B has a predetermined strength, the shape member 31 is removed. As shown in FIG. 6C, the drainage pipe frame member 30 from which the mold material 31 has been removed is left buried in the concrete of the preceding element 10A to form the drainage pipe 25. At this time, since the pipe frame member 30 and the mold member 31 are scraped off at the joint portion 11, a part of the joint surface 11 is exposed to a part of the drainage pipe frame member 30. For this reason, the drainage pipe 25 can reliably collect the contaminated water that leaks to the outside along the joint surface 11.

Next, a configuration of a modified example of the drainage pipe frame member will be described. Each figure in FIG. 7 is a partial plan view showing a configuration and a working example of the drain pipe frame member 33. The drain pipe frame member 33 shown in FIG. 7 (a) is also formed of a resin plate molded product, and the center of each of the opposed long side members having a rectangular cross section is bent in a substantially V-shape to form a cross-section defect portion 32. . Further, a shape member 31 is accommodated so as to fill this cross section. As shown in FIG. 7B, in the drainage pipe frame material 33, the trailing element 10B side of the shape member 31 is broken at the cross-section defect portion 32 and removed by the excavator at the time of trailing element excavation. Thereafter, concrete is cast on the succeeding element 10B, and the mold 31 remaining on the preceding element 10A side is removed. As a result, the cut surface 3 formed by breaking the mold 31 on the side of the succeeding element 10B
5 constitutes a part of the joint surface. Contaminated water flows into the drainage pipe 25 as a joint drainage structure from the cut surface 35,
Leaching to the outside can be prevented.

FIG. 8 is a partial plan view showing the structure and construction example of the drain pipe frame member 37. The figure shows an example in which a drain pipe structure is applied to the partition plate method. The drain pipe frame member 37 shown in FIG. 8 (a) is made of a channel steel, and a shape member 31 is accommodated in the inside thereof so as to fill the recess as in the case described above. The drain pipe frame members 37 are previously attached to both sides of the partition steel plate 40 at substantially the center in the width direction. At this time, as shown in FIG. 8C, the drain pipe frame member 37 is fixed by spot welding at a predetermined interval in the wall depth direction. Also, as shown in FIG.
7 and a partition steel plate 40, a slit 41 having a predetermined width is formed so as to extend in the wall depth direction.
Are provided so as to maintain the welding position. The partition steel plate 40 to which the drain pipe frame member 37 is attached in this manner.
The following element is excavated at the boundary (FIG. 8A)
After that, the subsequent element 10B is cast into concrete, and the shape member 31 accommodated in the drainage pipe frame material is removed, whereby the drainage pipe 25 can be provided on both sides of the partition steel plate 40. As a result, the contaminated water transmitted along the surface of the partition steel plate 40 and permeated therein flows into the drain pipe 25 serving as the joint drainage structure, and can be prevented from seeping out (see FIG. 8B). The drain pipe frame 37
For example, a resin molded product having a cross section similar to that of the channel steel may be attached to the partition steel plate. In this case, a slit having a predetermined width is secured through a mounting hardware or the like, and the slit is mounted at a predetermined position on the partition steel plate.

FIG. 9 shows a modification of the impermeable wall. The drawing adjusts control of the water level of the communicating drain pipe 20 of the impervious wall 10, as a high water level W ₄ is obtained for the ground water level W _1, W ₂ of the repository out of the ground, the A water impermeable wall 10 is shown that prevents contaminated water inside the disposal site 51 from seeping out to the outside 52 by using a head difference. In this modification, the water level W ₄ in the drain pipe is always higher than the ground water levels W ₁ , W ₂ inside and outside the disposal site for the impermeable wall 10 which collects and collects the contaminated water by the drain pipe described above. Adjustment control is performed so that To realize this, the drain pipe 2 in the impermeable wall 10 is required.
0 is provided with a facility for injecting water from the external tank 40 or an appropriate water source via the pump P to raise the water level in the drain pipe 20. In this case, the contaminated water can be completely sealed in the repository 51.

In the above description, an example in which a reinforced concrete underground continuous wall is used as the impermeable wall 10 has been described.
The same configuration can be applied to a soil cement continuous wall or the like. In this case, it is preferable that the communication drainage pipe 20 is supported by a core member (not shown) such as a shaped steel which is disposed at a predetermined interval.

[0023]

As described above, the drainage pipe is provided at the joint between the impermeable walls and the drainage path is formed in the impermeable wall. By making the structure higher, the structure in which the construction cost is reduced can effectively prevent the contaminated water in the disposal site from leaching to the outside.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a water impermeable wall according to the present invention.

FIG. 2 is a partial cross-sectional view of the impermeable wall shown in FIG. 1 taken along the line II-II.

FIG. 3 is a partial cross-sectional view showing one element from the side along the line III-III of the impermeable wall shown in FIG. 1;

FIG. 4 is a schematic perspective view showing an enlarged part of a drain pipe.

FIG. 5 is a partial plan view showing a configuration of a water impermeable wall provided with a drainage mat.

FIG. 6 is a schematic explanatory view showing an installation procedure of a drainage structure of a wall joint part.

FIG. 7 is a schematic explanatory view showing a modified example of the drainage structure of the wall joint.

FIG. 8 is a schematic explanatory view showing another modification of the drainage structure of the wall joint.

FIG. 9 is a schematic configuration diagram showing a modified example of the impermeable wall.

FIG. 10 is a schematic sectional view showing an example of a conventional impermeable wall having a double wall structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Water impervious wall 12 Rebar cage 13 Water impervious film 20 Communication drainage pipe 25 Joint drainage pipe 30, 33, 37 Drainage pipe frame material 31 Model material 40 Partition steel plate

Claims (5)

[Claims] 1. A continuous wall is constructed to divide the inside and outside area of a site, a communication drainage channel is formed in the wall, and the water level in the communication drainage channel is set higher than the groundwater level inside or outside the site. The contaminated water leached from the premises through the wall into the communication drainage channel, and drains the contaminated water to the outside by means of pumping means. . 2. A continuous wall is formed so as to divide the inside and outside of the site as a continuous wall, a communication channel is formed in the wall, and the water level in the communication channel is higher than the groundwater level in both the site and outside the site. The water impervious wall is characterized in that the contaminated water leached into the wall from the site is prevented from flowing into the communication channel. 3. A drainage pipe is provided on an end face of a joint on the preceding element side in a water-blocking wall which is constructed as a continuous wall in which a preceding element and a succeeding element are alternately connected, and divides the inside and outside areas of the site. Impermeable wall characterized by the following. 4. A water impervious wall constructed as a continuous wall in which a preceding element and a succeeding element are alternately connected so as to partition the inside and outside area of the site as a continuous wall, on both end surfaces of a joint portion on the preceding element side of a water impermeable wall. The drainage pipe frame material in which the shape material is accommodated is installed to construct a preceding element concrete wall, and the frame is left in the frame material when excavating for the succeeding element. After removing a part of the material and constructing the subsequent element concrete, the mold material is removed to form a drain pipe on the end face of the joint portion on the preceding element side, and Installation method of drainage structure. 5. The installation of a drainage structure for a wall joint part according to claim 4, wherein the cross section of said drainage pipe frame member has a trapezoidal shape in which a short side of a parallel side is located on the following element side. Method.