JP2004150968A - Device and method for detecting leakage of internally held water from area controlled by impervious wall, and leakage repair method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suggest a method for economically and surely detecting leakage of internally held water from an area controlled with an impervious wall, and specifying and repairing a leaking part, if a leakage occurs. <P>SOLUTION: This leakage detector detects leakage of the internally held water in the controlled area 1 controlled with the impervious wall 2 composed of two or more wall members (outer wall 2a, inner wall 2b) out of impermeable material having coupling sections. In the external surface on the side opposite to the controlled area 1 of the inner wall 2b, monitoring pipes 5 which have apertures at predetermined vertical intervals, and are used for monitoring the quality of water in each pipe, are arranged at arbitrary horizontal intervals. Leakage of the internally held water is detected by monitoring the quality of water inside each monitoring pipe 5. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a device and a method for detecting leakage of internally held water containing harmful substances in a management area such as a waste disposal site that is shielded from external groundwater by a seepage barrier, and a leakage repair method when a leak is detected. It is about.
[0002]
[Prior art]
Dispose of contaminated internal water in landfills and sea landfills that landfill industrial or general waste, and in public water bodies such as rivers and lakes, and in contaminated soil areas that may cause groundwater contamination. It is extremely important for the environment to prevent leakage.
[0003]
For example, in the case of constructing a sea reclamation site as a waste disposal site in the seaside area, a revetment (water barrier) will be constructed along the border line at the planned sea reclamation site, and the landfill that has been cut off from the open sea. Made and dumped waste in this landfill. As the revetment types, a steel pipe sheet pile revetment, a steel box type sheet pile revetment, a steel sheet pile revetment, a double steel sheet pile revetment, and the like are known.
[0004]
In the sea reclamation revetment using these, the revetment (water barrier) is composed of multiple wall members with joints that may leak the internal retained water, so there is no leakage of the internal retained water containing harmful substances. It is important how to detect the leak, and if a leak is detected, how to identify the site and take repair measures.
[0005]
Conventionally, many methods have been proposed for detecting leakage from a seawall (water barrier) of a waste disposal site and for dealing with water leakage. For example, Japanese Unexamined Patent Publication No. 7-42130 (Patent Document 1) discloses that a water level gauge is provided in a double-walled impermeable wall to monitor the water level, and the water level in the impermeable wall is constantly monitored. The water level is set higher than the water level in the disposal site to prevent water leakage.
[0006]
Also, in Japanese Patent Application Laid-Open No. 2001-288739 (Patent Document 2), a mortar, an asphalt mixture, or the like, which is provided in a vertical direction of a water impervious wall composed of a steel pipe sheet pile, a steel box sheet pile, or the like at a sea surface disposal site. To install monitoring wells in the joints, such as steel pipe sheet piles and steel box sheet piles, to control the water retained inside that penetrates the joints filled with the waterproof material, and to control the water level, water quality and concentration inside the joints. Then, the leaching of the water held in the inside is detected and managed, and when the leaching exceeds a predetermined management value, the waterproofing material is forcibly filled to block the permeation path.
[0007]
[Patent Document 1]
JP-A-7-42130 [Patent Document 2]
Japanese Patent Application Laid-Open No. 2001-288739
[Problems to be solved by the invention]
In the management method for detecting leakage disclosed in Japanese Patent Application Laid-Open No. 10-165916, the inside of the double wall is continuous over the entire length of the revetment, and it is specified which of the bottom, inner wall, and outer wall is defective or defective. Difficult. In addition, when several defects or defects occur at the same time on both double walls, it is more difficult to specify the defect and the repair time is slow, and the internal water leaks into the open sea.
[0009]
In addition, it has been proposed that the water level inside the double wall be higher than that of the disposal site to prevent the outflow of water retained inside. The plane area inside the heavy wall is very large, and injecting water (harmless seawater or water) requires very large facilities and time, and the cost for maintaining a constant high water level is also high.
[0010]
Furthermore, the above method requires time to specify the location where the defect or defect has occurred in the double wall, and it is necessary to inject a large amount of water in order to maintain the inside of the double wall at a high water level, The injected water mixes with the internal water from the disposal site that stays inside the double wall and becomes new internal water, and the water that flows into the repository becomes new internal water. There is a drawback that the amount of water pumped up by the pump and treated in the sewage treatment facility is enormous, and the cost required for the treatment is high.
[0011]
On the other hand, in the management method disclosed in Japanese Patent Application Laid-Open No. 2001-288739, a monitoring well is arranged in a hollow portion including a joint of a steel member such as a steel pipe sheet pile or a steel box sheet pile, or inside the joint, and the monitoring is performed. It is proposed to monitor the water level, water quality, and concentration of the wells. There was a problem of deteriorating performance.
[0012]
Further, in any of the above management methods, when leakage is detected, it is not possible to specify the depth direction of the leaking portion of the internally held water, and the repair range has to be the entire depth direction near the wall, so the repair is required. It has the disadvantage of being expensive.
[0013]
The present invention solves the above-mentioned problems, economically and reliably detects leakage of internally held water from an area controlled by a water impervious wall, and promptly repairs the leakage when there is leakage. It is intended to provide a method for doing so.
[0014]
[Means for Solving the Problems]
Means for Solving the Problems In order to achieve the above object, an apparatus and a method for detecting leakage of water contained in the present invention and a method for repairing a water impermeable wall according to the present invention are configured as follows.
[0015]
A leak detection device according to a first aspect of the present invention is a leak detection device for water retained inside an area (managed area) managed by a water impermeable wall including a plurality of wall members made of a water-impermeable material having a joint, On the outer surface of the control area of the impermeable wall member, a monitoring pipe for monitoring water quality in the pipe having openings at predetermined vertical intervals is provided, and the monitoring pipes are arranged at arbitrary intervals in the horizontal direction. In addition, it is characterized in that the leakage of the water contained inside can be detected by monitoring the water quality inside the monitoring pipe.
[0016]
According to a second aspect of the present invention, in the first aspect of the present invention, the monitoring pipes are attached to all or a plurality of the wall members in the vicinity of a joint on the outside of the management area.
[0017]
The water leakage detection method according to a third aspect of the present invention uses a first or second leakage detection device to specify a leakage location of the internally held water in a planar manner, and then investigates a depth direction distribution of water quality in the monitoring pipe. In the depth direction.
[0018]
A leak detection method according to a fourth invention is characterized in that the monitoring of the water quality inside the monitoring pipe according to the third invention is performed by a water quality sensor inserted into the monitoring pipe or a water quality measurement of water collected in the monitoring pipe. And
[0019]
A leakage repair method according to a fifth aspect of the present invention is a method for repairing leakage of water retained inside a controlled area controlled by a water-impervious wall composed of a plurality of wall members made of a water-impermeable material having a joint, By providing monitoring pipes having openings at predetermined intervals in the vertical direction on the outer surface of the management area of the wall member, disposing the monitoring pipes at predetermined intervals in the horizontal direction, and monitoring the water quality in the monitoring pipe, After detecting the leakage of the internally held water from the management area and specifying the leak location in a plane, the depth distribution of the water quality inside the monitoring pipe is investigated and identified in the depth direction, and the vicinity of the leak location is determined. It is characterized by taking repair measures at the position.
[0020]
The leakage repair method according to the sixth aspect of the present invention is to perform the repair measure of the fifth aspect of the present invention by injecting a chemical solution using an injection pipe, impervious the area around the leaked portion by high-pressure jet stirring, or filling a waterproof material by excavation. It is characterized by.
[0021]
[Action]
The present invention provides a leakage of water retained inside a management area controlled by a water impermeable wall composed of a plurality of water impervious material wall members having joints on an outer surface of the water impervious wall member management area. The monitoring is performed by monitoring water quality in a monitoring pipe having openings at predetermined intervals in the vertical direction and arranged at predetermined intervals in the horizontal direction. Therefore, the monitoring pipe is disposed outside the impermeable wall as viewed from the management area and in a portion of the soil having a water-permeable surrounding. From this, it is possible to detect the water retained inside without impairing the water blocking performance of the joint portion of the water blocking wall.
[0022]
In addition, when there is leakage of water retained inside from the management area, by investigating the water quality inside the monitoring pipe in the depth direction, the location of the leak can be identified in the depth direction from the water quality distribution in the depth direction. Thus, it is possible to repair the leaked portion economically and reliably.
[0023]
The water quality in the monitoring pipe that changes due to leakage from the management area is as follows. Color, transparency, odor, specific gravity, electrical conductivity (or chloride ion concentration), hydrogen ion concentration (PH), harmful components (cadmium, total cyanide, organic phosphorus, lead, hexavalent chromium, arsenic, alkyl silver, PCB, Dichloromethane, carbon tetrachloride, trichloroethylene, benzene, etc.). Which of these water quality changes is to be investigated may be selected depending on the controlled substance in the controlled area.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
[0025]
FIG. 1 shows a water impervious wall in a marine waste disposal site (managed area) 1 which is similar to a commonly used impermeable wall, that is, an outer wall 2a and an inner wall 2b. The outer surface of the steel sheet piles 3 in the sheet pile row on the inner wall 2b located at the waste disposal site 1 (ie, the waste disposal site 1) On the outside), a pipe-shaped monitoring pipe 5 having openings 4 (FIG. 2) provided at predetermined intervals in the vertical direction is installed, and by monitoring the water quality in the monitoring pipe 5, the joint of the steel pipe sheet pile 3 is connected. The figure which manages the water retained inside the waste disposal site leaked from the part 3a is shown.
[0026]
As shown in FIG. 2, the monitoring pipe 5 is provided with openings 4 at predetermined intervals so that surrounding groundwater can enter. Before the steel sheet pile 3 is cast, a resin filter or a wire mesh is attached to the opening 4 so that earth and sand do not enter the monitoring pipe 5. The cross-sectional shape of the monitoring tube 5 is not limited to the illustrated mountain shape, and may be any cross-sectional shape such as a semicircle, a U-shape, a circle, and a rectangle.
[0027]
FIG. 3 is a plan view of a steel pipe sheet pile double revetment (water barrier 2) generally used in a waste disposal site 1 on the sea surface. FIG. 4 is a longitudinal sectional view of the revetment of the waste disposal site 1. The impermeable wall 2 is not limited to a structure in which a double row of steel pipe sheet piles is installed, but may be a structure in which a single row of impermeable walls only of the steel pipe sheet piles 3 on the inner wall 2b is installed.
[0028]
As shown in FIG. 4, each steel pipe sheet pile of the outer wall (open sea side) 2a and the inner wall (disposal site side) 2b as a double impermeable wall between the left open sea side and the right waste disposal site side. The rows are formed to penetrate a water-permeable formation (sand layer) 6 under the sea floor to a depth that reaches a poorly permeable formation or an impermeable formation (clay layer) 7. This structure prevents water retained inside the waste disposal site from leaking to the sea surface 8 side. In addition, in order to prevent the water in the waste disposal site from leaking in the vertical direction, a waterproof sheet is applied to the bottom surface of the waste disposal site, that is, the boundary portion between the waste 10 and the permeable formation 6. There is also (not shown). Further, instead of using the steel pipe sheet pile 3, a steel sheet pile, a box-shaped steel sheet pile or the like may be used.
[0029]
As described above, the permeable formation 6 exists on the poorly permeable formation and the impermeable formation 7, and the filling soil 11 is filled above the permeable formation 6 and between the inner wall 2 b and the outer wall 2 a. I have. Further, a steel pipe member with a slit or a T-shaped joint member is used as a joint member constituting the joint portion 3a between the steel pipe sheet piles 3, and the pipe joint member or the T-shaped joint member extends in the vertical direction and It is welded to the steel sheet pile 3. When connecting the joints 3a, the pipe joint members are connected to each other, or the pipe joint member and the T-shaped joint member are connected to each other. Then, a space is secured inside the pipe joint member, and a water-blocking material such as mortar, asphalt mixture, or the like is filled in the internal space, and the joint portion is configured to be watertight.
[0030]
The water impervious wall 2 in which each row of steel pipe sheet piles constituting the inner wall 2b and the outer wall 2a is cast to a depth of a water-impermeable stratum or a water-impermeable stratum 7 below the seabed, is internally retained from the waste disposal site 1. When water leakage occurs, the leakage path is limited to the joint 3a of the steel sheet pile 3. Therefore, the management of the water retained inside the waste disposal site 1 leaked from the joint portion 3a of the steel pipe sheet pile 3 is performed by changing the sheet pile row of the inner wall 2b located on the waste disposal site 1 side as shown in FIGS. A pipe-shaped monitoring pipe 5 having openings 4 in the vertical direction at predetermined intervals is installed on the outer surface (filled sand 11 side) of each steel pipe sheet pile 3 to constitute, and water quality in the monitoring pipe 5 is measured. This can be done by monitoring. As a means for monitoring the water quality in the monitoring pipe 5, a water quality sensor is disposed in the pipe in advance, or water in the pipe is sampled and the water quality is periodically analyzed.
[0031]
In addition, when the leakage of the internal water from the waste disposal site is confirmed, the water quality inside the plurality of monitoring pipes 5 attached to the impermeable wall at predetermined intervals can be measured from the wall member such as the steel sheet pile 3. The position of the leaked part from the joint portion 3a, which is the leak path of the internally held water in the impermeable wall 2, can be specified in a planar manner. As a result, countermeasures such as repairing leakage of water retained inside can be made possible at an early stage. As shown in FIG. 1, when the monitoring pipes 5 are arranged at intervals L, the detection zones (1), (2), and (2) are located on both sides in the steel sheet pile row direction centered on each monitoring pipe 5. It becomes 3 ▼. Further, as shown in FIG. 5, if the monitoring pipes 5 are arranged in the vicinity of the joints 3a of all the steel sheet piles 3, the leak locations can be more accurately specified in a planar manner, and the range of leak repair can be more accurately determined. It is possible to quickly and economically repair internal water leakage.
[0032]
[Second embodiment]
A second embodiment of the present invention will be described with reference to FIGS.
[0033]
When leakage of the internally held water from the waste disposal site 1 to the filling soil 11 is confirmed, the leakage location is specified two-dimensionally by the method of the first embodiment, and then the leakage position in the depth direction is further specified. Then, the repaired part can be specified. FIG. 6A shows a configuration in which sensors 12 for measuring electric conductivity are arranged at predetermined intervals in order to measure the water quality distribution in the depth direction in the monitoring pipe 5.
[0034]
The following procedure is used to specify a leak location in the depth direction using the sensor 12.
[0035]
The internal water of the monitoring pipe 5 near the location where the contaminated internal water of the waste disposal site 1 leaked has a distribution state in which components having a high specific gravity have settled downward, and the water quality is measured as it is. However, it is difficult to identify the leak location in the depth direction. Therefore, as shown in FIG. 6 (b), first, the pipe 13 is inserted into the monitoring pipe 5, the internal water is removed by suction by the pump 14, and then replaced with fresh water to obtain a clean state.
[0036]
Next, a plurality of sensors 12 for measuring electric conductivity are inserted and installed in the monitoring tube 5 as shown in FIG. 6A, and the electric conductivity in the monitoring tube 5 is measured.
[0037]
FIG. 7 shows an example of the depth direction distribution of the electric conductivity of the water held inside the monitoring pipe 5 measured by the plurality of electric conductivity measuring sensors 12 arranged at predetermined intervals in the depth direction. At the water leakage point (a) in the depth direction indicated by the mark, the electric conductivity changes so as to draw a horizontal mountain-shaped curve, whereby the water leakage point (a) in the depth direction can be specified.
[0038]
The groundwater near the impermeable wall where the contaminated internal water of the waste disposal site 1 leaks shows a higher electric conductivity than the surroundings. By measuring the depth distribution of the rate, the depth of the leak location can be specified.
[0039]
The electric conductivity measurement sensor 12 shown in FIG. 6A may be fixedly installed in each monitoring tube 5 in advance, or a string-shaped one may be suspended and inserted at the time of measurement. In addition, as a means for specifying a leakage point in the depth direction, water at each depth may be sampled from the mortaring pipe 5 to analyze the water quality.
[0040]
If the leakage point of the internal water is specified in a plane and then further in the depth direction, as shown in FIGS. 8 (a) and 8 (b), the leakage point (a) is directed from the inside of the waste disposal site. Then, the ground around the leaked portion of the impermeable wall is made impermeable by chemical solution injection, high-pressure jet stirring, or the like, so that the repaired area 17 of the leaked portion can be limited and repaired. In the case where the depth (h) of the leak location (a) is shallow, a method of excavating the vicinity of the leak location and repairing the leak location of the impermeable wall using a waterproof material or the like can be adopted.
[0041]
In this way, according to the second embodiment, in combination with the first embodiment, it is possible to specify the leaking portion of the impermeable wall in a plane and precisely in the depth direction, and to repair it economically and early. Can be implemented. It should be noted that the first and second embodiments may be changed in design and executed.
[0042]
【The invention's effect】
According to the present invention, leakage of water retained inside the control area controlled by the impermeable wall composed of a plurality of impermeable material wall members having joints is applied to the outer surface of the control area of the impermeable wall member. Since monitoring is performed by monitoring the water quality in the pipe by using a monitoring pipe provided at predetermined intervals in the horizontal direction and having holes at predetermined intervals in the vertical direction, the structure is simple and the watertightness of the joint portion is impaired. It is possible to detect water leakage without any trouble and take quick repair measures. Furthermore, when there is leakage of water from the management area, the leakage point can be easily and reliably identified in the depth direction based on the distribution of the water quality of the monitoring pipe in the depth direction, and repair of the leakage point is economical. And it can be implemented reliably.
[Brief description of the drawings]
FIG. 1 is an overall plan explanatory view showing a first embodiment of the present invention, in which monitoring tubes are arranged at predetermined intervals.
FIG. 2 is a perspective view in which a monitoring pipe is attached to a steel pipe sheet pile.
FIG. 3 is a plan view of a steel pipe sheet pile double wall revetment.
FIG. 4 is a longitudinal sectional view of a steel pipe sheet pile double wall revetment.
FIG. 5 is a plan view in which monitoring pipes are attached to all joints of a steel pipe sheet pile.
6A is a diagram in which an electric conductivity measurement sensor for measuring water quality distribution in a depth direction in the monitoring pipe is arranged in the monitoring pipe, and FIG. 6B is a drawing in which water retained in the monitoring pipe is sucked by a pump. FIG.
FIG. 7 shows an example of a depth direction distribution of the electric conductivity of water held inside a monitoring pipe measured after leaving a plurality of sensors for electric conductivity measurement arranged at predetermined intervals in the depth direction for a predetermined time. FIG.
FIG. 8 (a) is a plan view showing a state in which the ground around the leakage point of the impermeable wall is impervious and the leakage point is repaired from the inside of the waste disposal site by injection of a chemical solution, high-pressure jet stirring, or the like. (B) is a diagram shown by a vertical side surface.
[Explanation of symbols]
1 waste disposal site 2 impermeable wall 2a
3 Steel pipe sheet pile 3a Joint 4 Opening 5 Monitoring pipe 6 Permeable layer (sand layer)
7 Impervious stratum (clay layer)
8 Sea surface 10 Waste 11 Filled sand 12 Electric conductivity measurement sensor 13 Pipe 14 Pump 15 String 16 Injection pipe 17 Repair area

Claims (6)

A leak detection device for water retained in a management area controlled by a water impermeable wall composed of a plurality of water impervious material wall members having joints, wherein the water impervious wall member has a vertical surface on the outer surface of the management area. By providing a monitoring pipe for monitoring the water quality in the pipe having openings at predetermined intervals in the direction, arranging the monitoring pipe at an arbitrary interval in the horizontal direction, and monitoring the water quality inside the monitoring pipe, An apparatus for detecting leakage of internally held water from an area controlled by a water impervious wall, which is configured to detect leakage of internally held water. The water retained in the area controlled by the impermeable wall according to claim 1, wherein the monitoring pipes are mounted near joints on the outside of the control area of all or a plurality of the wall members. Leak detection device. The leakage detection device according to claim 1 or 2 is used to specify the leakage location of the water contained in the plane two-dimensionally, and then investigates the distribution of the water quality in the monitoring pipe in the depth direction and specifies the depth direction. A method for detecting leakage of water retained inside from areas controlled by impermeable walls. 4. The area controlled by the impermeable wall according to claim 3, wherein the monitoring of the water quality inside the monitoring pipe is performed by a water quality sensor inserted in the monitoring pipe or a water quality measurement of water collected in the monitoring pipe. For detecting internal water leakage from water. A method for repairing leakage of water retained inside a control area controlled by a water impermeable wall composed of a plurality of wall members made of a water impervious material having joints, wherein Providing monitoring pipes having openings at predetermined intervals in the direction, arranging the monitoring pipes at predetermined intervals in the horizontal direction, and monitoring the water quality in the monitoring pipes, whereby leakage of the internal retained water from the control area is performed. After detecting the leakage point and specifying the leakage point in a plane, the distribution in the depth direction of the water quality inside the monitoring pipe is investigated and specified in the depth direction, and a repair measure is taken at a position near the leakage point. A method for repairing leakage of water retained inside from areas controlled by impermeable walls. 6. The impermeable wall according to claim 5, wherein the repairing measures are performed by injecting a chemical solution using an injection pipe, impermeability around a leaked portion by high-pressure injection stirring, or filling with a waterproof material by excavation. To repair internal water leaks from areas controlled by

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