JP7364188B2 - Water stop performance evaluation device and water stop performance evaluation method - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus and method for evaluating water stop performance of soil improvement chemicals.

In construction work that is affected by groundwater levels, it is necessary to take appropriate water-stopping measures in order to proceed safely and efficiently. Groundwater can be stopped by constructing a water-stopping wall around the excavation area using steel sheet piles, etc., by forming an improved solidified body with low permeability using a solidifying material, or by forming a similar improved solidified body by injecting a chemical solution. There are several methods, including methods of lowering the groundwater level using wells, etc.
Water-stop walls made of steel sheet piles are constructed from above the ground, which limits the depth at which water can be stopped. Furthermore, improved bodies that utilize a solidifying agent such as cement require time for the solidifying agent to harden. Furthermore, methods of lowering the groundwater level using wells and the like also require time for the groundwater level to drop. Although the chemical solution injected gels (hardens) in a relatively short time, it may be washed away by underground water flow before it gels, and it may be difficult to form an improved body at a desired location.
For this reason, Patent Document 1 describes a method for stopping water in the ground for groundwater bodies with high flow rates, after supplying granular material with a particle size and high specific gravity that will not be washed away by groundwater into the ground, and then applying a chemical solution to the area where the granular material was supplied. A method is disclosed in which the material is injected and gelled or solidified in the interstices of the granular material.
By the way, the water-stopping effect of conventional soil improvement chemicals is generally judged only by the gel time of the soil improvement chemicals (the time it takes for the injected chemicals to harden and lose their fluidity). However, the water-stopping effect of chemical injection depends largely on the physical and chemical characteristics of the target ground, water flow conditions, water flow rate, and temperature conditions. Therefore, in order to ensure the desired water-stopping properties through chemical injection, it is necessary to select a soil improvement chemical that is appropriate for the local ground conditions.

Japanese Patent Application Publication No. 2010-053589

The present invention proposes a water stop performance evaluation device and a water stop performance evaluation method that make it possible to check the water stop performance of a ground improvement chemical solution according to construction conditions (geology, groundwater level, groundwater flow velocity, etc.). The task is to

A water stop performance evaluation device of the present invention for solving the above problem includes: a cylindrical container filled with granular material; a water supply means for supplying a certain amount of water from one end of the container; and the other end of the container. The container includes a drainage measuring means for measuring the amount of liquid discharged from the container, and an injection means for supplying an injection material to an intermediate portion between the one end and the other end of the container.
Further, the water stop performance evaluation method of the present invention includes passing water at a constant flow rate from one end of the container to the other end of the virtual ground formed by filling a cylindrical container with granular materials, and The injection material is injected from an intermediate portion between the one end and the other end of the container, and the change over time in the amount (flow rate) of liquid discharged from the virtual ground is measured.
According to this water stop performance evaluation device and water stop performance evaluation method, the effect of injecting a ground improvement chemical (injection material) into groundwater flowing at a constant flow rate can be evaluated based on the amount of water discharged (flow rate of discharged water). can be grasped. Therefore, the injection material can be appropriately selected according to the conditions of the ground (geology, groundwater level, groundwater flow rate, etc.).

In addition, when the water supply means of the water stop performance evaluation device includes a water storage tank and a water supply pipe leading from the water storage tank to the container, the water level in the water storage tank may be higher than the container. By arranging the water tank, water can be supplied by gravity at a constant flow rate.
Furthermore, if a temperature adjustment means for cooling or heating the container (granular material), water, or injection material is provided, it becomes possible to cool or heat the virtual ground, for example, by freezing the surrounding ground. You can check the performance of soil improvement chemicals under special conditions, such as when the ground is frozen.

According to the water stop performance evaluation device and the water stop performance evaluation method of the present invention, it is possible to check the performance of a ground improvement chemical solution according to construction conditions.

FIG. 1 is a schematic diagram of an evaluation device according to a first embodiment. It is a schematic diagram of the evaluation device concerning a second embodiment. It is a graph showing the relationship between the temperature of the chemical solution used in the experiment and the gel time. It is a diagram showing the results of a demonstration experiment, and is a graph showing the relationship between elapsed time and drainage speed in Case 1. It is a diagram showing the results of a demonstration experiment, and is a graph showing the relationship between elapsed time and drainage speed in Case 2. It is a diagram showing the results of a demonstration experiment, and is a graph showing the relationship between elapsed time and drainage speed in Case 3. It is a figure which shows the result of a demonstration experiment, Comprising: It is a graph which shows the relationship between the elapsed time and the drainage speed of Case 4. 3 is a graph showing the relationship between elapsed time and water supply and drainage rate in Cases 1 to 4.

<First embodiment>
In the first embodiment, a water stop performance evaluation device 1 for checking the performance of a ground improvement chemical solution will be described. As shown in FIG. 1, the water stop performance evaluation device 1 of this embodiment includes a container 2, a water supply means 3, a drained liquid measuring means 4, an injection means 5, and a temperature adjustment means 6.
The container 2 has a cylindrical shape. The container 2 is filled with granular materials 20 such as sand and gravel as a virtual ground. The container 2 of this embodiment includes a cylindrical body 21 made of a transparent vinyl chloride pipe, a lid member 22 that shields both ends of the cylindrical body 21, and a plurality of fixing bolts 23 disposed along the outer periphery of the cylindrical body 21. It is equipped with That is, the inside of the container 2 can be visually recognized. The cylindrical body 21 is arranged so that its central axis is vertical. A pair of lid members 22 provided at the upper and lower ends of the cylindrical body 21 are fixed to the ends of the cylindrical body 21 by tightening fixing bolts 23 that connect the lid members 22 together. Note that the material constituting the cylinder 21 is not limited, and may be, for example, an acrylic cylinder. Further, the cylinder body 21 does not need to be cylindrical, and may be, for example, a rectangular tube. Further, the cylindrical body 21 may be formed by connecting a plurality of cylindrical members. Further, the cylindrical body 21 may be arranged so that the central axis thereof is oriented laterally. Furthermore, the method of fixing the lid 22 is not limited, and if a flange is formed at the end of the cylindrical body 21, the lid 22 may be fixed to the flange.

The water supply means 3 supplies a certain amount of water from one end (lower end) of the container 2 . The water supply means 3 of this embodiment includes a water storage tank 31, a water supply pipe 32 extending from the water storage tank 31 to the container 2, and an overflow water measurement tank 33. The water tank 31 is arranged such that the water level in the water tank 31 is higher than the upper end of the container 2. The inside of the water storage tank 31 is separated into a water storage section 35 and an overflow section 36 by a partition wall 34 . Water is continuously supplied to the water tank 31, and a predetermined amount of water is always stored in the water storage section 35. A water supply pipe 32 is connected to the water storage section 35 . In this embodiment, one end of the water supply pipe 32 is connected to the bottom surface of the water storage section 35 (water storage tank 31). The other end of the water supply pipe 32 is connected to the lower end of the container 2 (lower lid member 22). Of the water supplied to the water storage section 35, water that has overcome the partition wall 34 flows into the overflow section 36. A connecting pipe 37 leading to the overflow water measurement tank 33 is connected to the bottom of the overflow section 36 . The overflow water measuring tank 33 is arranged at a lower position than the water storage tank 31. The overflow water that has flowed into the overflow section 36 flows down to the overflow water measurement tank 33 via the connecting pipe 37. The overflow water measurement tank 33 measures the amount of overflow water that has flowed down over the partition wall 34. The amount of water in the overflow water measurement tank 33 is measured using an electronic balance 38. The amount of water supplied to the water storage tank 31 is adjusted by measuring the change over time in the amount of overflow water.

The drained liquid measuring means 4 measures the amount of liquid drained from the other end (upper end) of the container 2 . The drain liquid measuring means 4 includes a drain tank 41 that stores the liquid discharged from the container 2, a drain pipe 42 leading from the container 2 to the drain tank 41, and an electronic balance that measures the amount of liquid in the drain tank 41. 43. The drain pipe 42 is connected to the lid member 22 fixed to the upper end of the cylindrical body 21. The liquid discharged from the upper end of the container 2 is transported to the drain tank 41 through the drain pipe 42. The amount of liquid stored in the drain tank 41 is measured by an electronic balance 43. The method of measuring the liquid is not limited to the measurement using the electronic balance 43, and may be measured by reading the memory of the drain tank 41, for example.

The injection means 5 supplies the injection material to the container 2 . In this embodiment, the injection material used is a solution-type, instant-setting type that gels within several seconds to several tens of seconds after injection. The injection material is a two-component mixture type and is mixed immediately before injection. The injection means 5 includes a first tank 51 for storing liquid A, a second tank 52 for storing liquid B, and a metering device for simultaneously discharging liquid A and liquid B from the first tank 51 and the second tank 52. It includes a supply device 53, an injection part 54 connected to the middle part in the height direction of the container 2 (cylindrical body 21), and a liquid feeding pipe 55 leading from the first tank 51 or the second tank 52 to the injection part 54. There is. The reason why the injection material was not supplied to the lower end of the cylinder 21 was to avoid the backflow of the injection material clogging the water flow path and making it impossible to properly evaluate the water-stopping effect within the model ground. . Note that the injection material to be evaluated by the water stop performance evaluation device 1 is not limited to the two-component mixture type. If a one-liquid type injection material is used, only one tank should be used. Further, the injection material is not necessarily limited to an instant setting type, and may be a suspension type injection material such as cement milk.
The quantitative supply device 53 is connected to the first tank 51 and the second tank 52. The quantitative supply device 53 of this embodiment is a piston that simultaneously applies a pushing force to liquid A in the first tank 51 and liquid B in the second tank 52. A gasket is attached to the piston. When the quantitative supply device 53 operates, the piston applies a pushing force to the A liquid in the first tank 51 and the B liquid in the second tank 52. When a pushing force is applied by the quantitative supply device 53, liquid A and liquid B are simultaneously discharged from the first tank 51 or the second tank 52, respectively, and are supplied to the container 2 via the liquid feeding pipe 55.
The injection unit 54 is equipped with a line mixer (static mixer), and mixes the A liquid supplied from the first tank 51 and the B liquid supplied from the second tank 52 and supplies the mixture to the container 2.

The temperature adjustment means 6 cools or warms the container 2. The temperature adjustment means 6 of this embodiment is a water tank (cylindrical member) into which the container 2 is inserted. For example, when the container 2 is cooled to near 0° C., a cold agent (salt water soaked with ice, potassium chloride aqueous solution, calcium chloride aqueous solution, etc.) is stored in the temperature adjusting means 6. On the other hand, when performing the evaluation at room temperature, the test is performed with the temperature adjustment means 6 empty or with room temperature liquid (water, saline, etc.) stored therein. Furthermore, when heating the container 2, hot water at a predetermined temperature is stored in the temperature adjustment means 6. Furthermore, as a simple evaluation method, it is also effective to cool or heat the injection material in advance while keeping the container 2 at room temperature.

Next, a water stop performance evaluation method using the water stop performance evaluation device 1 of this embodiment will be explained.
First, water is passed at a constant flow rate through a virtual ground formed by filling a container 2 with sand. Water is injected from the water storage tank 31 through the water supply pipe 32 from the lower end of the cylindrical body 21 and discharged from the upper end of the cylindrical body 21 . Water is constantly being supplied to the water tank 31, and excess water flows over the partition wall 34 to maintain a constant water level. Therefore, water is supplied to the container 2 at a constant pressure.
Note that the temperature of the container 2 (virtual ground) can be adjusted by cooling or heating by the temperature adjustment means 6.
When the water flow rate becomes stable, the injection material is injected from the middle of the container 2. The injection material is supplied via a quantitative supply device 53, and fixed amounts of liquid A and liquid B are supplied at the same time. The A liquid and the B liquid are injected into the cylinder 21 in a mixed state by the line mixer of the injection part 54. The injection material injected into the cylinder 21 hardens while flowing upward along the flow of water in the container 2. The liquid discharged from the container 2 flows down to the drained liquid measuring means 4. In the water-stopping property evaluation method of the present embodiment, the time-dependent change in the flow rate (weight change rate) of the drained liquid is calculated based on the amount of the drained liquid that has flowed down to the drained liquid measuring means 4, and the water-stopping property of the injection material is evaluated. . Moreover, when the injection material hardens within the cylinder 21, the water permeability (water permeability coefficient) within the cylinder 21 decreases, and thus the amount of water passing through the cylinder 21 decreases. As a result, overflow water in the water tank 31 increases.

According to the water stop performance evaluation device 1 and the water stop performance evaluation method of the present embodiment, the effect of injecting a ground improvement chemical solution (injection material) into groundwater flowing at a constant flow rate is evaluated by the discharge of effluent (water). It can be determined by the amount (flow rate of drained liquid). Therefore, the injection material can be appropriately selected according to the conditions of the ground (geology, groundwater level, groundwater flow rate, temperature, etc.). Furthermore, the water supply means 3 can adjust the supply amount of groundwater (water pressure in the container 2) and the flow rate of groundwater, and the temperature adjustment means 6 can change the temperature conditions. Therefore, it is possible to select an injection material that exhibits water-stopping performance according to the ground conditions and construction conditions of the ground to be improved. That is, in cases where the groundwater flow rate is high or the surrounding ground is frozen, it is possible to select an injection material that gels within a desired range after injection and exhibits water-stopping properties.
Moreover, since the water storage tank 31 is arranged so that the water level in the water storage tank 31 is higher than that in the container 2, water can be supplied at a constant flow rate by gravity. Therefore, no power or the like is required to supply water.
In addition, since the virtual ground can be cooled or heated by the temperature adjustment means 6, the performance of the ground improvement chemical solution on the ground under special conditions, such as when the surrounding ground is frozen due to freezing methods, etc. can be improved. It can be confirmed.

<Second embodiment>
In the second embodiment, similarly to the first embodiment, a water stop performance evaluation device 1 for confirming the performance of a soil improvement chemical solution will be described. In this embodiment, by evaluating the water-stopping properties of the injection material when cooled or heated and injected into the virtual ground, we can confirm the influence of the temperature condition of the ground on the performance of the injection material. conduct. The water stop performance evaluation device 1 of this embodiment includes a container 2, a water supply means 3, a drained liquid measuring means 4, an injection means 5, and a temperature adjustment means 6, as shown in FIG. Note that the details of the container 2, water supply means 3, waste liquid measuring means 4, and injection means 5 are the same as those shown in the first embodiment, so detailed explanations will be omitted.

The temperature adjustment means 6 cools or warms the injection material. The temperature adjustment means 6 consists of a water tank that can accommodate both the first tank 51 and the second tank 52. When the injection material is cooled to near 0° C., a cold agent (salt water soaked with ice, potassium chloride aqueous solution, calcium chloride aqueous solution, etc.) is stored in the temperature adjustment means 6. On the other hand, when performing evaluation at room temperature, the test is performed with a liquid at room temperature stored in the temperature adjustment means 6 or with the temperature adjustment means 6 empty. Furthermore, when heating the injection material, hot water at a predetermined temperature is stored in the temperature adjustment means 6. Note that the temperature adjustment means 6 may be constituted by a water tank housing the first tank 51 and the second tank 52 individually, or an ice pack or a water tank provided around the first tank 51 or the second tank 52. is also possible.

Next, a water stop performance evaluation method using the water stop performance evaluation device 1 of this embodiment will be explained.
First, water is passed at a constant flow rate through a virtual ground formed by filling a container 2 with sand. Water is injected from the lower end of the cylinder 21 and discharged from the upper end of the cylinder 21. When the water flow rate becomes stable, the injection material is injected from the middle of the container 2. The injection material is supplied via a quantitative supply device 53, and fixed amounts of liquid A and liquid B are supplied at the same time. At this time, the injection material may be cooled or heated by the temperature adjustment means 6. The A liquid and the B liquid are injected into the cylinder 21 in a mixed state by the line mixer of the injection part 54. The injection material injected into the cylinder 21 hardens while flowing upward along the flow of water in the container 2. The liquid discharged from the container 2 flows down to the drained liquid measuring means 4. In the water-stopping property evaluation method, the time-dependent change in the flow rate of the drained liquid is calculated based on the amount of the drained liquid that has flowed down to the drained liquid measuring means 4, and the water-stopping property of the injection material is evaluated.
According to the water stop performance evaluation device 1 and the water stop performance evaluation method of the present embodiment, the same effects as the water stop performance evaluation device 1 and the water stop performance evaluation method of the first embodiment can be obtained.

Hereinafter, experimental results using the water stop performance evaluation method of the second embodiment will be explained.
In this experiment, a cylindrical transparent vinyl chloride pipe with a diameter of 50 mm and a length of 1000 mm was used as the model ground (cylindrical body 21) to be injected. A constant water flow was ensured from the bottom to the top of the container 2 by the head difference h, and the amount of discharged water was weighed over time to determine the degree of water-stopping performance. At this time, the opening of the faucet is fixed and tap water is continued to be directly supplied to the water storage tank 31 provided to fix the head on the supply side, allowing for an understanding of changes in the actual inflow amount and further understanding of the infiltration situation. The weight of the water flowing down into the overflow water measuring tank 33 was measured in order to connect it to the overflow water measurement tank 33. A supply point for the injection material was provided at the center height of the cylinder body 21. The reason why the injection material was not supplied to the lower end of the cylinder 21 was to avoid the backflow of the injection material clogging the water flow path and making it impossible to properly evaluate the water-stopping effect within the model ground. .
Since the injection material uses an instant-setting solution type formulation in which two liquids are mixed in equal amounts, liquid A is prepared in the first tank 51 and liquid B is individually prepared in the second tank 52, and the supply rate of the injection material is adjusted accordingly. The quantitative feeder 53 was pushed out and fed in an equal amount under displacement control according to the above. When supplying the injection material via the liquid supply pipe 55, the injection material is mixed in a line mixer (injection section 54) immediately before flowing into the model ground.

Since the purpose of this test is to verify the water-stopping performance of the injection material used under water flow conditions, the water flow rate can be set by adjusting the water flow head as a model ground material, and it is relatively easy to obtain. A certain material, coarse aggregate with a diameter of 5 to 10 mm, was used.
Two types of solution-type chemicals (chemical solution A and drug solution B) shown in Table 1 were used as injection materials. Although there are differences in the constituent materials of chemical solutions A and B, the content and density of the curing agent are roughly equivalent.

FIG. 3 shows the relationship between the temperature and gel time of chemical solutions A and B, which are characteristic values generally presented for ground injection materials. As shown in FIG. 3, although there is a difference of about 2 seconds below 5° C., the relationship between temperature and gel time for chemical solutions A and B are generally the same. Based on the above basic characteristics, chemical solutions A and B are considered to be equivalent in physical properties such as the concentration and density of sodium silicate, and chemical properties such as gel time, and there is a clear difference in performance. It doesn't reach that point.

When using the ground freezing method to stop water, if the groundwater flow exceeds 1 m/day, the growth of frozen soil will be inhibited, so a chemical injection method using a solution-type instant setting method is used as an auxiliary method to reduce the flow velocity. Ru. Therefore, the water flow conditions were set to a speed that sufficiently exceeded the above guideline values and to ensure conciseness and clarity as the experimental conditions, such that the water flow would pass through a hypothetical ground with a total length of 1000 mm in 3 minutes. Therefore, the apparent water flow rate is set as 1000 mm/3 mins = 33 cm/min (480 m/day), and the set value of water flow and drainage amount is set as 291 cm ³ /min (= 33 cm/min x 2.5 cm x 2.5 cm x 3. 14×0.45 (gap ratio equivalent value)). Further, the head difference (water head difference) h between the partition wall 34 and the upper end of the cylindrical body 21 was set to 30 cm (see FIG. 2).
As shown in Table 2, injection of the injection material was carried out in two cases for chemical solutions A and B, respectively: at room temperature of 20°C and in a state cooled to below 0°C. Regarding the latter (cases 3 and 4), keep in mind the case where the injection material is cooled when used in combination with the ground freezing method. In addition, the supplying speed of the injection material was controlled to be equal to the water flow rate described above, considering only the simplicity and clarity of the experimental conditions.

In the experiment, water was first passed through the container 2. Once it is confirmed that the water flow is in a steady state, the injection material is injected at a constant rate and the change in drainage volume over time is measured. While supplying the injection material at a constant rate, visually observe how the amount of water passing through and draining gradually decreases, and when the amount of drainage water disappears or when it is confirmed that the steady state of a small amount of drainage has settled, remove the injection material. supply will be stopped. The injection material supply time in each case 1 to 4 was about 1 minute to 1.5 minutes.
FIG. 4 shows the relationship between elapsed time and drainage speed for case 1, FIG. 5 for case 2, FIG. 6 for case 3, and FIG. 7 for case 4. In addition, "water passing" in the figure is the water drained into the drain liquid measuring means 4, and "overflow water" is the water drained into the overflow water measuring tank 33 beyond the partition wall 34 of the water supply means 3. It refers to water that has been washed.

In all of Cases 1 to 4, it was confirmed that the injection material became cloudy and gelled within several tens of seconds from the start of supply of the injection material. The clouding of the injection material developed within a range of approximately 100 mm from the supply port (the connection portion of the injection means 5), and then spread to an area of 50 to 100 mm below the supply port.
In addition, as shown in Figures 4 to 7, in all cases 1 to 4, after the injection material supply starts, the water drainage rate increases temporarily, but after that, gel formation does not increase. As an effect, the water drainage rate tended to decrease. Furthermore, in case 1 under room temperature conditions (normal temperature conditions), as shown in FIG. 4, the water permeation and drainage rate suddenly decreased about 20 seconds after the start of supply of the injection material. As shown in FIG. 5, in Case 2, which was also at room temperature (normal temperature condition), similarly to Case 1, the water permeation and drainage rate suddenly decreased about 20 seconds after the start of supply of the injection material. As a result, the timing at which the supply of the injection material was stopped was 1 minute after the start of supply in Cases 1 and 2 under room temperature conditions. On the other hand, in Case 3 in the low temperature state, as shown in FIG. 6, the water permeation and drainage rate gradually decreased several seconds after the start of supply of the injection material. Furthermore, in Case 4 in the low temperature state, as shown in FIG. 7, the water permeation and drainage rate gradually decreased from about 15 seconds after the start of supply of the injection material. As a result, in Cases 1 and 2, the supply of injection material was stopped 1 minute after the start of supply (see Figures 4 and 5), in Case 3 after 1 minute and 30 seconds (see Figure 6), and in Case 4 after 1 minute and 20 seconds. After a few seconds (see FIG. 7), the injection material supply was stopped.
On the other hand, changes in the drainage rate of the overflow indicate that the level and stability of the drainage rate were not maintained sufficiently prior to the start of supply of the injection material.

As a result of the observations in Cases 1 to 4, it was confirmed that the use of water drainage rate is considered to be a promising indicator for evaluating water stoppage performance. Therefore, in FIG. 8, the water permeation and drainage speeds of Cases 1 to 4 were summarized and compared.
As shown in FIG. 8, under room temperature conditions, chemical liquid A (case 1) and chemical liquid B (case 2) showed similar trajectories. On the other hand, under low-temperature conditions, for chemical solution A (case 3), the water flow and drainage rate suddenly decreases from about 1 minute and 10 seconds after injection material is supplied, whereas for chemical solution A (case 4), the water flow rate decreases rapidly after 1 minute and 10 seconds after injection material supply starts. After about 15 seconds, the decrease in water drainage rate (weight change rate) was approximately constant, and there was a clear difference in the rate of decrease in water drainage rate between chemical solution A and chemical solution B.
Since the change in drainage speed that can be seen in Figure 8 can be used as an index representing the performance of the chemical solution, an approximate line was drawn in the section where the drainage speed decreased linearly, and its slope was extracted as the rate of change in drainage speed. Table 3 shows the extracted drainage rate change rates. As shown in Table 3, it can be expressed that chemical solution A can exhibit a water-stopping effect about 1.3 times more efficiently at room temperature and about 1.8 times more efficiently at low temperatures than chemical solution B.
In this way, when comparing gel times (see FIG. 3), it was confirmed that even if the medicinal materials had the same performance, there were differences in water-stopping performance due to differences in temperature conditions, etc.

Although the embodiments according to the present invention have been described above, the present invention is not limited to the above-described embodiments, and each of the above-mentioned components can be modified as appropriate without departing from the spirit of the present invention.
For example, by changing the amount and flow rate of water supplied by the water supply means 3 or by changing the temperature by the temperature adjustment means 6, the soil improvement chemical solution (injection material) can be evaluated under conditions according to the ground conditions and construction conditions. It can be performed. Therefore, when selecting an appropriate injection material for a location where groundwater flows in a concentrated manner and has a large flow velocity and flow rate, it is possible to perform evaluation by setting conditions according to the ground conditions.
Further, in the embodiment described above, the temperature of the container 2 or the injection material is adjusted by the temperature adjustment means 6, but the temperature of the water flowing into the container 2 may be adjusted.
Furthermore, the method of supplying water to the container 2 is not limited to gravity flow, and, for example, a pump may be used to supply water under pressure.
The granular material 20 to be filled into the container 2 is not limited to sand, and can be set depending on the local ground to be evaluated.

1 Water stop performance evaluation device 2 Container 3 Water supply means 31 Water tank 32 Water supply pipe 4 Drainage measuring means 5 Injection means 6 Temperature adjustment means

Claims (5)

a cylindrical container filled with granules;
Water supply means for supplying a certain amount of water from one end of the container;
drained liquid measuring means for measuring the amount of liquid drained from the other end of the container;
A water stop performance evaluation device comprising: injection means for supplying an injection material to an intermediate portion between the one end and the other end of the container. The water supply means includes a water tank and a water supply pipe extending from the water tank to the container,
The water stop performance evaluation device according to claim 1, wherein the water tank is arranged such that the water level in the water tank is higher than the water level in the container. The water stop performance evaluation device according to claim 1 or 2, further comprising a temperature adjustment means for cooling or heating the container. Water is passed at a constant flow rate from one end of the container to the other end of the virtual ground formed by filling a cylindrical container with granular materials, and between the one end and the other end of the container. A method for evaluating water stoppage performance, comprising injecting an injection material from a certain intermediate portion and measuring changes over time in the amount of liquid discharged from the virtual ground. The water stop performance evaluation method according to claim 4, wherein the water or the injection material is cooled or heated.

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