JP3811441B2 - Leakage detection device and method for internally retained water from areas controlled by impermeable walls, and leak repair method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and method for detecting leakage of internally retained water containing hazardous substances in a management area such as a waste disposal site that is blocked from external groundwater by a water shielding wall, and a leakage repair method when leakage is detected. It is about.
[0002]
[Prior art]
In landfills and sea-level disposal sites where industrial waste or general waste is reclaimed, and in public water areas such as rivers and lakes and contaminated soils that may cause groundwater contamination, the contaminated internal retained water is discharged to the outside. It is extremely important for the environment to prevent leakage.
[0003]
For example, when creating a sea surface landfill site as a waste landfill site in the coastal area, a landfill site that has been built off the sea by building a revetment (water-impervious wall) along the boundary at the planned sea surface landfill site. Made and dumped waste in this disposal site. Steel pipe sheet pile revetment, steel box-type sheet pile revetment, steel sheet pile cell type revetment, double steel sheet pile revetment, and the like are known.
[0004]
In seawater reclamation revetment using these, the revetment (water-impervious wall) is composed of multiple wall members with joints that may leak internal retained water, so there is no leakage of internal retained water containing harmful substances It is important how to detect the leak and how to identify the part and take corrective action if a leak is detected.
[0005]
Many methods have been proposed for detecting leakage from a revetment (water-impervious wall) at a waste disposal site and for dealing with water leakage. For example, in Japanese Patent Laid-Open No. 7-42130 (Patent Document 1), a water level gauge is provided in a double-walled impermeable wall to monitor the water level. The water level is set higher than the water level in the disposal site to prevent water leakage.
[0006]
Moreover, in Unexamined-Japanese-Patent No. 2001-28739 (patent document 2), the mortar, asphalt mixture, etc. which are provided in the vertical direction of the impermeable wall comprised from a steel pipe sheet pile, a steel box-type sheet pile, etc. in a sea surface disposal site Install monitoring wells that manage internally retained water that passes through joints filled with water-stopping materials at joints such as steel pipe sheet piles and steel box sheet piles, and manage the water level, water quality, and concentration inside the wells. Thus, the leaching of the internal water is detected and managed, and when the specified control value is exceeded, the water stop material is forcibly filled and the permeation path is blocked.
[0007]
[Patent Document 1]
JP-A-7-42130 [Patent Document 2]
[Patent Document 1] Japanese Patent Application Laid-Open No. 2001-288839
[Problems to be solved by the invention]
In the management method for detecting leakage disclosed in JP-A-10-165916, the inside of the double wall is continuous over the entire length of the revetment, and the bottom, inner wall, or outer wall is specified as a defect or defective part. It is difficult. Also, if several missing or defective parts occur on both the double walls at the same time, it is more difficult to identify, the repair is slowed down, and there is a drawback that the internal retained water leaches out to the open sea.
[0009]
In addition, it has been proposed that the water level inside the double wall be made higher than the disposal site to prevent the outflow of retained water. The plane area in the heavy wall is very large, and it takes a very large amount of equipment and time to inject water (harmless seawater and water), and the cost for maintaining a constant high water level is also high.
[0010]
Furthermore, the above method requires time to identify the location where a defect or defect 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 is mixed with the internal retained water from the disposal site that stays inside the double wall to become new internal retained water, and the water that has flowed into the disposal site also becomes new internal retained water. The amount of water pumped up and processed at the sewage treatment facility is enormous, so there is a disadvantage that the cost required for it is high.
[0011]
On the other hand, in the management method disclosed in Japanese Patent Laid-Open No. 2001-28839, a monitoring well is disposed in a hollow portion including a joint of a steel member such as a steel pipe sheet pile or a steel box-type sheet pile, or the inside of the joint. It has been proposed to monitor the water level, water quality, and concentration of a well, but since a water-permeable monitoring well should be installed in the joint to ensure water shielding, it is necessary to There was a problem of lowering the performance.
[0012]
In any of the above management methods, when leakage is detected, it is impossible to specify the depth direction of the leaked portion of the internal retained water, and the repair range must be the entire depth direction near the wall body. It has the disadvantage of increasing costs.
[0013]
The present invention solves the above-mentioned problems, economically and reliably detects the leakage of internal retained water from an area controlled by a water shielding wall, and promptly repairs the leakage if there is a leakage. It aims to provide a way to do.
[0014]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the leakage detection device and method and the impermeable wall repair method 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 internal retained water in an area (management area) managed by a water shielding wall composed of a plurality of impermeable material wall members having joints, A monitoring pipe for monitoring the water quality in the pipe having openings at predetermined intervals in the vertical direction is provided on the outer surface of the management area of the water shielding wall member, and the monitoring pipes are arranged at arbitrary intervals in the horizontal direction. In addition, it is possible to detect leakage of the internal retained water by monitoring the water quality inside the monitoring pipe.
[0016]
The water leakage detection device according to a second aspect of the present invention is characterized in that, in the first aspect, the monitoring pipe is attached in the vicinity of a joint portion on the outer side of the management area of all or a plurality of the wall members.
[0017]
In the water leakage detection method of the third aspect of the invention, the first or second leakage detection device is used to planarly identify the leakage location of the internal retained water and then investigate the depth direction distribution of the water quality inside the monitoring pipe. And specifying in the depth direction.
[0018]
The leakage detection method of the fourth invention is characterized in that the water quality monitoring inside the monitoring pipe in the third invention is performed by a water quality sensor inserted in 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 leakage repair method for internally retained water in a management area managed by a water shielding wall composed of a plurality of impermeable material wall members having joints. 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, arranging 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 internal retained water from the management area and specifying the leakage location in a plane, the depth distribution of the water quality inside the monitoring pipe is investigated and specified in the depth direction, and the vicinity of the leakage location It is characterized in that repair measures are taken at the position of.
[0020]
In the leakage repair method of the sixth invention, the repair measures of the fifth invention are carried out by injecting a chemical solution using an injection tube, making water impermeable around the leakage site by high-pressure jet agitation, or filling a water stop material by excavation It is characterized by.
[0021]
[Action]
According to the present invention, leakage of water retained inside a management area managed by a water shielding wall composed of a plurality of impermeable material wall members having joints is provided on the outer surface of the management area of the water shielding wall member. In addition, the monitoring is performed by monitoring the water quality in the monitoring pipes having holes at predetermined intervals in the vertical direction and arranged at predetermined intervals in the horizontal direction. Therefore, the monitoring pipe is disposed outside the water-impervious wall as viewed from the management area and in a portion of the soil where the surroundings are permeable. For this reason, it is possible to detect the water retained inside without impairing the water shielding performance of the joint portion of the water shielding wall.
[0022]
In addition, if there is a leakage of internal water from the management area, the location of the leakage can be identified in the depth direction from the depth distribution of the water quality by investigating the water quality inside the monitoring pipe in the depth direction. In addition, it becomes 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, Including dichloromethane, carbon tetrachloride, trichloroethylene, benzene, etc.). Which of these water quality changes is to be investigated may be selected according to the managed substance in the controlled area.
[0024]
DETAILED DESCRIPTION OF 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 generally used as a water-impervious wall in a sea surface waste disposal site (management area) 1, that is, an outer wall 2a and an inner wall 2b. In the steel pipe sheet pile double revetment (water-impervious wall 2) filled with medium-filled earth and sand 11, the outer surface of the steel pipe sheet pile 3 of the sheet pile row of the inner wall 2 b located at the waste disposal site 1 (that is, the waste disposal site 1 On the outside), pipe-shaped monitoring pipes 5 with openings 4 (FIG. 2) provided at predetermined intervals in the vertical direction are installed, and by monitoring the water quality in the monitoring pipe 5, the joint of the steel pipe sheet pile 3 The figure which manages the internal water holding of 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 enters. In addition, a resin filter or a wire net is attached to the opening 4 before the steel pipe sheet pile 3 is placed 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 mountain shape shown in the figure, and may be any cross-sectional shape such as a semicircle, a U-shape, a circle, or a rectangle.
[0027]
FIG. 3 is a plan view of a steel pipe sheet pile double revetment (water-impervious wall 2) that is 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 steel pipe sheet pile array is installed, and may be a structure in which a single row impermeable wall is formed with only the steel pipe sheet pile 3 on the inner wall 2b.
[0028]
As shown in FIG. 4, each steel pipe sheet pile on the outer wall (outer sea side) 2a and the inner wall (disposal site side) 2b as a double impermeable wall between the left outer sea side and the right waste disposal site side The rows are laid down to a depth that penetrates the water-permeable stratum (sand layer) 6 below the seabed to reach the water-impervious strata or the impermeable strata (clay layer) 7. Thereby, it has the structure which prevents that the internal holding water of a waste disposal site leaks to the sea level 8 side. In addition, in order to prevent the leakage of the water retained in the waste disposal site in the vertical direction, a water shielding sheet is applied to the bottom surface of the waste disposal site, that is, the boundary portion between the waste 10 and the water permeable formation 6. There is also (not shown). Moreover, instead of using the steel pipe sheet pile 3, a steel sheet pile, a box-type steel sheet pile, etc. may be used.
[0029]
As described above, the permeable formation 6 exists on the hardly permeable formation or the impermeable formation 7, and the middle soil 11 is filled above the permeable formation 6 and between the inner wall 2b and the outer wall 2a. Yes. Moreover, the steel pipe member with a slit and a T-shaped joint member are used for the joint member which comprises the joint part 3a of each steel pipe sheet pile 3, and a pipe joint member and a T-shaped joint member are extended in a perpendicular direction, respectively. It is welded to the steel pipe sheet pile 3. At the time of connecting the joint portion 3a, the pipe joint members or the pipe joint member and the T-shaped joint member are combined and connected. A space is secured inside the pipe joint member, and the interior space is filled with a water-stopping material such as mortar and asphalt mixture, so that the joint portion is watertight.
[0030]
The impervious wall 2 in which the steel pipe sheet piles constituting the inner wall 2b and the outer wall 2a are driven to a depth reaching the impermeable layer 7 or the impermeable layer 7 below the seabed is internally held from the waste disposal site 1 When water leakage occurs, the leakage path is limited to the joint portion 3 a of the steel pipe sheet pile 3. Therefore, as shown in FIG. 1 and FIG. 2, the management of the water retained in the waste disposal site 1 leaked from the joint portion 3a of the steel pipe sheet pile 3 is performed by using the sheet pile row of the inner wall 2b located on the waste disposal site 1 side. On the outer surface of each steel pipe sheet pile 3 (medium-filled earth and sand 11 side), a pipe-shaped monitoring pipe 5 having openings 4 in the vertical direction at predetermined intervals is installed, and the 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 arranged in the pipe in advance, or the water in the pipe is sampled and periodically analyzed.
[0031]
In addition, if leakage of internal retained water from the waste disposal site is confirmed, if the water quality inside the plurality of monitoring pipes 5 attached to the impermeable wall at a predetermined interval is measured, the wall member such as the steel pipe sheet pile 3 can be used. The position of the leak location from the joint part 3a which is the leak path of the internal retained water in the impermeable wall 2 can be specified in a plane. As a result, countermeasures such as leakage repair of internal water can be made early. As shown in FIG. 1, when the monitoring pipes 5 are arranged at intervals L, both sides of the steel pipe sheet pile direction around each of the monitoring pipes 5 are in the detection zones (1), (2), 3 ▼. Further, as shown in FIG. 5, if the monitoring pipe 5 is arranged in the vicinity of the joint portion 3a of all the steel pipe sheet piles 3, it is possible to more accurately identify the leak location in a plane and the range of leak repair is more accurate. This makes it 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]
If leakage from the waste disposal site 1 to the filled sediment 11 side of the internal retained water is confirmed, specify the leakage location in a plane using the method of the first embodiment, and then specify the leakage position in the depth direction. Then, the repair location can be specified. FIG. 6A shows a sensor 12 for measuring electrical conductivity at predetermined intervals in order to measure the water quality distribution in the depth direction in the monitoring pipe 5.
[0034]
In order to specify the leak location in the depth direction using this sensor 12, the following procedure is used.
[0035]
The internal water in the monitoring pipe 5 in the vicinity of the location where the contaminated internal water leaked from the waste disposal site 1 has a distribution state in which components with heavy specific gravity have settled downward, and the water quality is measured as it is. However, it is difficult to specify the leak location in the depth direction. Therefore, first, as shown in FIG. 6B, the pipe 13 is inserted into the monitoring pipe 5, the internal water is sucked and removed by the pump 14, and then replaced with fresh water to obtain a clean state.
[0036]
Next, as shown in FIG. 6A, a plurality of sensors 12 for measuring electrical conductivity are inserted and installed in the monitoring tube 5, and the electrical conductivity in the monitoring tube 5 is measured.
[0037]
FIG. 7 shows an example of the distribution in the depth direction of the electrical conductivity of the internal water of the monitoring pipe 5 measured by a plurality of sensors 12 for measuring electrical conductivity arranged at predetermined intervals in the depth direction. The electrical conductivity changes so as to draw a horizontal mountain-shaped curve at the depth-direction water leakage location (A) indicated by the mark, thereby identifying the depth-direction water leakage location (A).
[0038]
The groundwater near the impervious wall where the contaminated internal water leaks from the waste disposal site 1 shows a higher electrical conductivity than the surroundings. By measuring the depth direction distribution of the rate, the depth of the leak location can be identified.
[0039]
Note that the electrical conductivity measurement sensor 12 shown in FIG. 6A may be fixedly installed in advance in each monitoring tube 5 or a string-like 15 may be suspended and inserted during measurement. In addition, as a means for specifying the leak location in the depth direction, water at each depth may be collected from the mortaring pipe 5 and analyzed for water quality.
[0040]
If the leakage location of the internal retained water is specified in a plane and then further specified in the depth direction, as shown in FIGS. 8 (a) and 8 (b), from the waste disposal site to the leakage location (I). Then, the injection pipe 16 is inserted, and the ground around the leakage location of the impermeable wall is made impermeable by chemical injection, high-pressure jet agitation, etc., and the repair range 17 of the leakage portion can be limited and repaired. In addition, when the depth (h) of the leak location (a) is shallow, it is of course possible to excavate the vicinity of the leak location and repair the leak location of the impermeable wall using a water blocking material or the like.
[0041]
In this way, according to the second embodiment, together with the first embodiment, the leakage location of the water-impervious wall can be accurately specified in a plane and in the depth direction, and the repair is economical and early. It becomes possible to carry out. It should be noted that the first and second embodiments may be implemented with a design change.
[0042]
【The invention's effect】
According to the present invention, leakage of water retained in the management area managed by the impermeable wall composed of a plurality of impermeable material wall members having joints is caused on the outer surface of the management area of the impermeable wall member. Because the monitoring pipes that are provided at predetermined intervals in the horizontal direction and that have openings at predetermined intervals in the vertical direction are monitored by monitoring the water quality in the pipes, the watertightness of the joints is impaired with a simple configuration. Therefore, it is possible to detect water leakage and take quick repair measures. In addition, when there is a leakage of internal water from the management area, it is possible to easily and reliably identify the leak location in the depth direction from the distribution of the water quality of the monitoring pipe in the depth direction, and it is economical to repair the leak location. And it becomes possible to implement reliably.
[Brief description of the drawings]
FIG. 1 is an overall plan view showing a first embodiment of the present invention, in which monitoring tubes are arranged at a predetermined interval.
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.
FIG. 6A is a diagram in which an electrical conductivity measurement sensor for measuring the water quality distribution in the depth direction in the monitoring pipe is arranged in the monitoring pipe, and FIG. 6B is a drawing of the water held in the monitoring pipe by a pump. FIG.
FIG. 7 shows an example of the depth direction distribution of the electrical conductivity of water retained in the monitoring pipe, measured after leaving a plurality of electrical conductivity measurement sensors arranged at predetermined intervals in the depth direction for a predetermined time. FIG.
[Fig. 8] (a) is a plan view of the situation where the ground around the leaked part of the impermeable wall is made impermeable by repairing the leaked part from the inside of the waste disposal site by chemical injection, high-pressure jet stirring, etc. The figure shown in (b) is a figure shown with a vertical side.
[Explanation of symbols]
1 Waste disposal site 2 Impermeable wall 2a
3 Steel pipe sheet pile 3a Joint part 4 Opening hole 5 Monitoring pipe 6 Permeable formation (sand layer)
7 Impervious formation (clay layer)
8 Sea surface 10 Waste 11 Filled sand 12 Conductivity measurement sensor 13 Pipe 14 Pump 15 String 16 Injection pipe 17 Repair range

Claims (6)

A leak detection device for internal retained water in a management area managed by a water-impervious wall made up of a plurality of impermeable material wall members having joints, which is vertically disposed on the outer surface of the control area of the water-shield wall member 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 A device for detecting leakage of internally retained water from an area controlled by a water shielding wall, characterized by enabling detection of leakage of internally retained water. The internal retention water from the area managed by the impermeable wall according to claim 1, wherein the monitoring pipe is attached in the vicinity of the joint part of the outer side of the management area of all or a plurality of the wall members. Leak detection device. After identifying the leak location of the internal retained water using the leak detection device according to claim 1 or 2, the depth direction distribution of the water quality inside the monitoring pipe is investigated and specified in the depth direction. A method for detecting leakage of internal retained water from areas controlled by impermeable walls. The water quality monitoring 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, etc. To detect leakage of internal retained water. A method for repairing leakage of internal retained water in a management area managed by a water-impervious wall composed of a plurality of impermeable material wall members having joints, wherein the vertical surface is disposed on the outer surface of the control area of the water-impervious wall member. Leakage of the internal retained water from the management area by 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 pipe After detecting the leak and identifying the leakage location in a plane, the depth direction distribution of the water quality inside the monitoring pipe is investigated and identified in the depth direction, and repair measures are taken at positions near the leakage location. A method for repairing leakage of internally retained water from an area controlled by a characteristic impermeable wall. 6. The impermeable wall according to claim 5, wherein the repair measures are performed by injecting a chemical solution using an injection pipe, making water impermeable around the leaked place by high-pressure jet agitation, or filling a water blocking material by excavation. Repair method for leakage of internal water from the area controlled by

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