JP4486312B2 - Construction method of impermeable wall structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for constructing a water-impervious wall structure, particularly a water-impervious wall structure used in a sea surface landfill disposal site or the like.
[0002]
[Prior art]
Conventionally, as the impermeable wall structure used in sea surface landfill sites, etc., after installing a vertical wall structure that constitutes a continuous wall using caisson, steel sheet piles, cells, steel pipe sheet piles, etc., There is known a water-impervious wall structure characterized by improving water-imperviousness by filling a water-impervious material or attaching a water-impervious sheet.
[0003]
[Problems to be solved by the invention]
In the conventional water-impervious wall structure as described above, when the vertical wall structure uses a steel material, corrosion has occurred, and when concrete is used, deterioration due to the retained water has been a problem. Therefore, in order to prevent this, install the water shielding sheet after attaching the water shielding sheet so that the wall structure and the water shielding sheet are in close contact so that no liquid exists between the vertical wall structure and the water shielding sheet. It was thought that.
[0004]
However, when a water barrier for a management-type revetment is to be constructed by the above-described method, the work of attaching a water-impervious sheet to the wall structure is carried out in the sea. ) Is very difficult to avoid.
[0005]
In addition, since the means for confirming the presence or absence of a breakage point on the water shielding sheet depends on visual observation of the surface of the water shielding sheet, it takes a lot of time for the work, and it is impossible to confirm when the waste is dumped. Met.
[0006]
In addition, since the vertical wall structure and the water shielding sheet are in close contact with each other, if there is a damaged part of the water shielding sheet, it is necessary to apply a repair agent to the surface of the sheet. Is not easy.
[0007]
This invention was made in order to solve the above problems, and is a case where a water shielding sheet is attached to a vertical wall structure in a state where a liquid exists between the vertical wall structure and the water shielding sheet. Even if it exists, it aims at preventing the corrosion and deterioration of a vertical wall surface structure, or suppressing in a certain range.
[0008]
Another object of the present invention is to confirm whether or not the water-impervious sheet is damaged by a simple method without relying on visual observation of the surface of the water-impervious sheet.
[0009]
Furthermore, an object of the present invention is to promptly repair when the water shielding sheet is damaged.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a method for constructing a water-impervious wall structure for storing retained water, wherein a substantially vertical wall surface structure constituting a continuous wall surface such as a caisson, a sheet pile, or a cell. The process of installing the body on the sea floor, the process of installing the pipe so that the tip of the wall surface structure is in contact with the inner surface of the installed wall structure, and the water barrier among the wall surfaces are required. A step of installing a water-impervious sheet having a water-impervious property so as to cover a portion on the inner side of the wall structure, a step of impermeable to a lower end of the water-impervious sheet with respect to the seabed, and a wall structure. A step of removing all remaining liquid existing between the water-impervious sheet through the pipe and bringing the water-impervious sheet into close contact with the inner surface of the wall structure by the water pressure of the retained water.
[0011]
When configured in this way, since all the remaining liquid is discharged through the pipe, there is no liquid between the wall structure and the water shielding sheet, so the water from the retained water side surrounded by the water shielding wall structure The water shielding sheet adheres to the wall structure by pressure.
[0012]
According to a second aspect of the invention, in the configuration of the first aspect of the invention, the presence or absence of breakage of the water shielding sheet is detected by detecting the presence or absence of liquid between the wall structure and the water shielding sheet through a pipe. The method further includes a detecting step.
[0013]
When configured in this way, when it is detected via a pipe that there is liquid between the wall structure and the impermeable sheet, the retained water surrounded by the impermeable wall structure is damaged by the impermeable sheet or It shows that it entered from the lower end part of the water-impervious sheet.
[0014]
According to the third aspect of the present invention, in the configuration of the second aspect of the present invention, when it is confirmed that there is breakage due to the detection of the liquid, the water shielding is provided between the wall structure and the water shielding sheet via a pipe. The method further includes a step of repairing the damaged portion by filling the material.
[0015]
When configured in this way, a water barrier material composed of asphalt mixture, mortar, bentonite and other soil-based water barrier materials, water-swelling resin, water glass, etc. is filled between the wall structure and the water barrier sheet. By doing so, a new water shielding layer can be formed between the wall structure and the water shielding sheet.
[0038]
【The invention's effect】
As described above, according to the first aspect of the present invention, all of the remaining liquid can be easily discharged by the pipe that is in contact with the seabed. Therefore, since the water shielding sheet is in close contact with the wall structure, the attachment of the water shielding sheet is stable, and since no liquid exists between the water shielding sheet and the wall structure, the durability of the wall structure is improved.
[0039]
In addition to the effect of the invention described in claim 1, the invention described in claim 2 provides the impermeable wall structure by detecting the presence of liquid between the wall structure and the impermeable sheet using a pipe. It can be confirmed that there is a damaged part.
[0040]
In addition to the effect of the invention described in claim 2, the invention described in claim 3 forms a new water shielding layer between the wall structure and the water shielding sheet using a pipe, It becomes a double structure of a new impermeable layer, and can maintain the function as a impermeable wall structure.
[0052]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view showing a schematic configuration of a waste disposal site according to the first embodiment of the present invention.
[0053]
Referring to the figure, a vertical wall surface structure 13 made of caisson is installed on a water-impermeable seabed 14 to constitute a waste disposal site 11. On the inner surface side of the vertical wall surface structure 13, a tube 21 having an opening at least at its tip is installed so as to follow the vertical wall surface structure 13. Next, a water shielding sheet 15 made of a total rubber sheet is installed on the sea floor 14 in the vertical direction on the inner side of the vertical wall structure 13. A water-impermeable layer 17 made of an asphalt mixture or the like is formed on the inner side of the lower end portion of the water-impervious sheet 15 and the upper surface of the seabed 14, and water is shielded on the lower part of the water-impervious sheet 15.
[0054]
In such a state, the liquid level of the retained water 18 surrounded by the water shielding sheet 15 and the liquid level of the remaining liquid 20 remaining between the vertical wall surface structure 13 and the water shielding sheet 15. Is the same. Since the remaining liquid 20 and the retained water 18 are separated by the water shielding sheet 15, the amount of the remaining liquid 20 is constant regardless of the change in the water level of the retained water 18. Since the residual liquid 20 becomes a certain amount, it becomes possible to suppress the progress of corrosion and deterioration of the vertical wall surface structure 13 within a certain range.
[0055]
Next, a method for detecting a damaged portion of the water shielding sheet 15 in this configuration will be described.
[0056]
Since the tip of the tube 21 penetrates into the remaining liquid 20, a pump or the like is connected to the outer end of the tube 21 and a part of the remaining liquid 20 is taken out through the tube 21. A part of the taken-out residual liquid 20 is continuously analyzed to check for changes in its components. When there is no change, the liquid level can be kept constant by returning a part of the removed residual liquid 20 to the residual liquid 20.
[0057]
On the other hand, when a change is found in some components of the extracted remaining liquid 20, it can be determined that a part of the retained water 18 has entered the remaining liquid 20. That is, a part of the water-impervious sheet 15 is damaged, or the retained water 18 moves toward the remaining liquid 20 from the joint surface between the water-impervious sheet 15 and the impermeable layer 17 or the installation surface of the impermeable layer 17 and the seabed 14. It can be considered intruded.
[0058]
When the analysis of the residual liquid 20 confirms the presence of a damaged portion in the impermeable wall structure as described above, a impermeable material is injected between the vertical wall structure 13 and the impermeable sheet 15 through the tube 21. . As the water-stopping material, a material that solidifies over time such as an asphalt mixture, a curable resin such as mortar or polyurethane, or a material composed of a soil-based water shielding material such as bentonite, a water-swellable resin, or the like is used.
[0059]
FIG. 2 is a schematic cross-sectional view showing a state where the water shielding material is injected in this manner.
[0060]
Referring to the figure, a new water shielding layer made of water blocking material 23 injected through tube 21 is formed between vertical wall surface structure 13 and water shielding sheet 15. By forming such a new water-impervious layer, it becomes a double structure that exhibits a water-blocking function in combination with the vertical wall surface structure 13, and improves the reliability of the water-blocking wall structure.
[0061]
In the above embodiment, a caisson is used as the vertical wall surface structure 13, but a steel sheet pile or a steel pipe sheet pile may be used instead. Further, although the total rubber sheet is used as the water shielding sheet 15, instead of this, a polyethylene sheet, a vinyl chloride sheet, a rubber sheet or a vinyl chloride sheet in which fibers and a wire net are embedded may be used instead. . Further, a part of the remaining liquid 20 is taken out in order to analyze the remaining liquid 20, but instead of this, an electrode may be immersed in the remaining liquid 20 and the electrical resistance may be measured. That is, you may comprise so that it may judge that the breakage of the impermeable wall structure arose by the change of electrical resistance.
[0062]
FIG. 3 is an enlarged cross-sectional view showing a schematic structure of the impermeable wall structure according to the second embodiment of the present invention.
[0063]
Referring to the drawing, the basic structure is the same as that of the first embodiment, but in this embodiment, the shape of tube 21 is slightly different. That is, as shown in (1), the lower end of the tube 21 is in an open state, but a plurality of through holes 25 are formed from the lower end to the upper predetermined range. For this reason, when injecting the water shielding material through the tube 21, the water shielding material 27 is discharged from the lower end of the tube 21 in the initial state, and is enclosed between the vertical wall surface structure 13 and the water shielding sheet 15. The water shielding material 26 is deposited on the upper surface of the sea floor 14.
[0064]
When the discharge of the water shielding material is further continued, the upper surface position of the accumulated water shielding material 26 rises along the tube 21 as shown in FIG. However, since a plurality of through holes 25 are formed in the tube 21, the discharge of the water shielding material from the lower end of the tube 21 and the through holes 25 included in the water shielding material 26 is stopped by the hardening of the water shielding material 26. Even in this case, the discharge from the upper through hole 25 is smoothly performed. Thus, even when the water shielding material 27 having a high curing rate is used, the water shielding material 23 can be easily filled up to the position shown in FIG.
[0065]
FIG. 4 is a sectional view showing a schematic structure of a water shielding wall structure according to a third embodiment of the present invention.
[0066]
Referring to the drawing, the basic structure is the same as that according to the first embodiment, and the description thereof will not be repeated here. The difference is that a steel sheet pile or a cell made of a steel sheet pile, a steel pipe sheet pile or the like is used for the vertical wall structure 13 and the residual liquid existing between the vertical wall structure 13 and the water shielding sheet 15. The liquid level of the residual liquid 20 is set higher than the liquid level of the retained water 18. Thus, even if the water shielding sheet 15 is damaged or there is a problem in the construction of the impermeable layer 17, there is no possibility that the retained water 18 flows out to the remaining liquid 20 due to the difference in the water level. In addition, when the liquid level of the retained water 18 rises or falls due to the weather, the liquid level of the remaining liquid 20 is adjusted to maintain a constant water level with respect to the retained water 18.
[0067]
In this embodiment, the water level of the residual liquid 20 is constantly observed. When the water level of the residual liquid 20 is kept constant, it is determined that the water shielding performance of the water shielding sheet 15 is sufficiently exhibited. On the other hand, when the water level of the residual liquid 20 is lowered, it is possible to determine that the water shielding performance has been lowered due to the breakage of the water shielding sheet 15 or the failure of the joint surface of the impermeable layer 17.
[0068]
FIG. 5 is a schematic cross-sectional view of the impermeable wall structure showing such a state.
[0069]
Referring to the drawing, a state in which the liquid level of the residual liquid 20 is lowered by the length of L from the initial state indicated by the two-dot chain line is shown. The remaining liquid 20 corresponding to the lowered water level has entered the retained water 18 side through the water shielding sheet 15 or the impermeable layer 17. Thus, when it turns out that the water-impervious sheet 15 or the impermeable layer 17 is damaged, the vertical wall structure 13 and the water-impervious sheet 15 are similar to those in the first embodiment. It is possible to ensure the water shielding performance of the water shielding wall structure 12 by injecting a water shielding material between them and curing it. In this case, if the water shielding material is injected before the liquid level of the residual liquid 20 falls below the liquid level of the retained water 18, the impermeable water does not enter the remaining liquid 20 side. The wall structure can be repaired, and the reliability of the water shielding structure is further improved.
[0070]
In the above embodiment, the water level of the residual liquid 20 is set higher than the water level of the retained water 18, but the water level of the residual liquid 20 may be set lower than the water level of the retained water 18. In this case, since the water pressure on the retained water 18 side is greater than the water pressure on the residual liquid 20 side, the water shielding sheet 15 above the water surface of the residual liquid 20 moves so as to be in close contact with the vertical wall surface structure 13. Thereby, the fixed state with respect to the vertical wall surface structure 13 of the water shielding sheet 15 is stabilized.
[0071]
FIG. 6 is a cross-sectional view showing a schematic structure of the impermeable wall structure according to the fourth embodiment of the present invention.
[0072]
Referring to the drawing, a steel sheet pile or cell is used for the vertical wall surface structure 13 installed on the seabed 14 to constitute the impermeable wall structure 12. The pipe 29 is arranged so that the tip of the pipe 29 comes into contact with the seabed 14 so as to follow the inner surface side of the vertical wall surface structure 13. Unlike the tube according to the first embodiment, the pipe 29 has a cross-sectional strength that does not flatten even when the water pressure of the retained water 18 is applied, as will be described later.
[0073]
FIG. 7 is a view showing the shape of the lower end of the pipe 29 shown in FIG.
[0074]
Referring to the figure, the lower end of pipe 29 is cut obliquely to form inclined portion 31. As a result, even when the tip of the pipe 29 is in contact with the seabed 14, the residual liquid 20 shown in FIG. 6 can be sucked through the inclined portion 31.
[0075]
Returning to FIG. 6, after the pipe 29 is installed along the vertical wall surface structure 13, the water shielding sheet 15 is installed further inward of the vertical wall surface structure 13. After the lower end of the water shielding sheet 15 is shielded against the seabed 14, the outer end of the pipe 29 is connected to a pump or the like to discharge the remaining liquid 20. As described above, since the pipe 29 is in contact with the seabed 14, it is possible to discharge all the remaining liquid 20 from the space between the vertical wall surface structure 13 and the water shielding sheet 15.
[0076]
FIG. 8 is a cross-sectional view showing a state in which all the remaining liquid 20 is discharged from the state of FIG.
[0077]
Referring to the drawing, the water shielding sheet 15 moves to the vertical wall surface structure 13 side due to the water pressure of the retained water 18 as the residual liquid 20 is discharged. When the remaining liquid 20 is completely discharged, the water shielding sheet 15 is brought into close contact with the inner surface of the vertical wall surface structure 13 including the pipe 29. For this reason, since the mounting state with respect to the vertical wall surface structure 13 of the water-impervious sheet 15 is stable and no liquid exists between the vertical wall structure 13 and the water-impervious sheet 15, the durability of the water-impervious wall structure 12 is improved. improves. In this case, the water pressure of the retained water 18 is applied to the pipe 29 via the water shielding sheet 15, but the pipe 29 has a predetermined cross-sectional strength as described above, so that the pipe 29 is deformed into a flat state. There is no.
[0078]
And the presence or absence of the liquid of the space between the vertical wall surface structure 13 and the water shielding sheet 15 is observed by attracting | sucking regularly through the pipe 29. FIG. When the presence of the liquid is detected, it is found that the water shielding performance by the water shielding sheet 15 is lowered. In this case, the water shielding material is injected through the pipe 29 as in the first embodiment. Thereby, a new water shielding layer is formed between the vertical wall surface structure 13 and the water shielding sheet 15, and the water shielding performance of the water shielding wall structure 12 is maintained.
[0079]
FIG. 9 is a view showing a lower end shape of a pipe used in the impermeable wall structure according to the fifth embodiment of the present invention.
[0080]
The impermeable wall structure according to this embodiment is almost the same as that according to the embodiment shown in FIG. 6, but only the lower end shape of the pipe 29 used therefor is different.
[0081]
Referring to FIG. 9, the lower end of the pipe 29 is a notch 32 whose center is notched inward. As a result, all the remaining liquid 20 can be discharged through the pipe 29 with the lower end of the pipe 29 in contact with the seabed 14.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a schematic shape of a water shielding wall structure according to a first embodiment of the present invention.
2 is a cross-sectional view showing a state where a water shielding material is injected into the water shielding wall structure shown in FIG. 1;
FIG. 3 is a view showing a schematic shape of a tube used in a water shielding wall structure according to a second embodiment of the present invention.
FIG. 4 is a sectional view showing a schematic shape of a water shielding wall structure according to a third embodiment of the present invention.
FIG. 5 is a view showing a state where the water level of the residual liquid is lowered in the impermeable wall structure shown in FIG. 4;
FIG. 6 is a sectional view showing a schematic shape of a water shielding wall structure according to a fourth embodiment of the present invention.
7 is a view showing a lower end shape of the pipe shown in FIG. 6;
8 is a view showing a state in which all of the remaining liquid is discharged in the impermeable wall structure shown in FIG. 6. FIG.
FIG. 9 is a view showing a lower end shape of a pipe used in a water shielding wall structure according to a fifth embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 12 ... Water shielding wall structure 13 ... Vertical wall surface structure 15 ... Water shielding sheet 18 ... Retained water 20 ... Remaining liquid 21 ... Tube 23, 26, 27 ... Water stop material 25 ... Through-hole 29 ... Pipe In addition, it is the same in each figure The code | symbol shows the same or an equivalent part.

Claims (3)

A method for constructing a impermeable wall structure for storing retained water,
A step of installing a substantially vertical wall surface structure constituting a continuous wall surface such as a caisson, a sheet pile, a cell, etc. on the seabed;
A step of installing the pipe along the inner surface side of the installed wall surface structure so that the tip thereof is in contact with the seabed;
A step of installing a water shielding sheet having a water shielding property on the inner side of the wall surface structure so as to cover a portion of the wall surface that is required to have a water shielding property;
Water shielding the lower end of the water shielding sheet against the seabed;
Removing all remaining liquid existing between the wall structure and the water-impervious sheet through the pipe, and bringing the water-impervious sheet into close contact with the inner surface of the wall structure by water pressure of the retained water; The construction method of the impermeable wall structure provided with.   The barrier according to claim 1, further comprising a step of detecting the presence or absence of breakage of the waterproof sheet by detecting the presence or absence of liquid between the wall structure and the waterproof sheet through the pipe. Construction method of water wall structure. When it is confirmed that there is damage by detection of the liquid,
The construction of the impermeable wall structure according to claim 2, further comprising a step of repairing a damaged portion by filling a impermeable material between the wall structure and the impermeable sheet via the pipe. Method.

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