JP3917453B2 - Concrete dam leakage inspection method and leakage treatment method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water leak inspection method and a water leak treatment method for a concrete dam, and more particularly, to a water leak inspection method and a water leak treatment method performed before dredging after construction of a dam.
[0002]
[Prior art]
Gravity-type concrete dams have a transverse seam, so water leaks in this area to some extent, and it may be difficult to identify and treat the area after flooding. Therefore, conventionally, after constructing the dam, water is flooded, colored powder flows from the reservoir side upstream of the dam, and whether the colored powder is discharged to the joint drainage pipe in the dam monitoring corridor Was inspecting.
[0003]
And when the water leak location was identified by the discharge of colored powder, from the reservoir side of the dam, a filling material was introduced along the transverse seam, and the water leak treatment was performed by sucking this into the water leak location. .
[0004]
Alternatively, before the dam is flooded, a colored powder injection device is attached to all the transverse joints upstream of the dam, and after the flooding, the colored powder is injected via the injection device. A method is also adopted in which a water leak inspection is performed, and when a water leak location is identified, a filling material is injected therein to stop the water leak.
[0005]
However, there are technical problems to be described below in the conventional water leakage inspection method and water leakage treatment method of a concrete dam transverse joint.
[0006]
[Problems to be solved by the invention]
In other words, both of the above-described conventional water leakage inspection method and water leakage treatment method for a concrete dam are performed in a state where the dam is flooded, and it takes time to flood the dam with a predetermined amount of water. In addition, even if the location of the water leakage is identified, there is a difficulty in performing the water leakage treatment in a flooded state, and it is possible to perform a water leakage inspection before the flooding of the dam, and to allow the water leakage treatment before the flooding Was requested.
[0007]
The present invention has been made in view of such problems, and the object of the present invention is to be able to inspect before drowning by a relatively simple method and to identify the location of water leakage. An object of the present invention is to provide a leakage inspection method and a leakage treatment method for a concrete dam that can be easily treated.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, there is provided a leak test method for a concrete dam constructed by connecting a water-stopping material to a transverse joint, before the dam is flooded, from the downstream side of the water-stopping material. Injecting a gas such as nitrogen gas into the transverse joint, applying soapy water along the transverse joint upstream of the water stop material, and from the swelling of the soapy water by the gas discharged from the transverse joint, A water leakage inspection method for identifying a water leakage location of a transverse joint , wherein the water stop material includes a main water stop plate and a sub water stop plate arranged in parallel to each other, and the gas is interposed between the main and sub water stop plates. It injected while detecting the pressure state, and the gap capacity formed between the main and sub waterstops was calculated based on the detected change in pressure value and the estimated width of the transverse joint .
[0009]
According to the leak test method for a concrete dam constructed in this way, before the dam is flooded, a gas such as nitrogen gas is injected into the transverse joint from the downstream side of the water-stopping material, and the horizontal joint on the upstream side of the water-stopping material is injected. Soap water is applied along the line and the location of the water leakage at the seam is identified from the swelling of the soap water due to the gas discharged from the seam. Is possible.
[0011]
When specifying the water leakage location of the horizontal joint, the size of the leakage location (water leakage) of the horizontal joint can be estimated from the size of the swelling of the soapy water.
[0012]
The present invention is also directed to a method for leaking water from a concrete dam constructed by connecting a water stop material to a transverse joint, and before the dam is flooded, nitrogen gas is introduced into the transverse joint from the downstream side of the water stop material. Injecting a gas such as the above, applying soapy water along the horizontal joint on the upstream side of the water-stopping material, and from the swelling of the soapy water by the gas discharged from the horizontal joint, the leakage point of the horizontal joint identified, when it is determined that there is a need for water leakage process, as well as non-pressure injecting a filler such as cement milk to the transverse seam, there in leakage processing method of applying a silicone resin to the leakage location identified The water stop material includes a main water stop plate and a sub water stop plate arranged in parallel to each other, and the gas is injected between the main and sub water stop plates while detecting a pressure state, and the detected pressure is detected. Change in value and the horizontal joint Based on the estimated width, the gap capacity formed between the main and sub waterstop plates is calculated, and when the filler is injected without pressure, the filler capacity is determined based on the relationship with the gap capacity. The filling state was judged .
[0013]
According to the water leakage treatment method for a concrete dam configured as described above, before the dam is flooded, a gas such as nitrogen gas is injected into the transverse joint from the downstream side of the water-stopping material, and the upstream side of the water-stopping material is When soap water is applied along the seam, the location of the water leakage at the seam is determined from the swelling of the soap water by the gas discharged from the seam, and it is determined that there is a need for water leakage treatment. Injecting fillers such as milk without pressure, and applying silicone resin to the specified water leak location, it is easy to identify the water leak location, and when the water leak location is specified, it is not flooded. Water leakage treatment can be easily performed.
[0015]
According to this configuration, the gap capacity formed between the main and sub waterstop plates is calculated and the filler is injected without pressure. Therefore, considering the amount of filler injected without pressure and the gap capacity, The quality of the water leakage treatment can be easily and reliably determined.
[0016]
The necessity determination of the water leakage treatment is performed by converting the amount of air leakage measured from the swelling of the soap water into the amount of water leakage, and is performed based on the converted amount of water leakage. Can be executed in the case of.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. 1 to 4 show an embodiment of a water leak inspection method and a water leak treatment method for a concrete dam according to the present invention.
[0018]
1 and 2 show an example of a gravity concrete dam to which the water leakage inspection method and the water leakage treatment method of the present invention are applied. In the concrete dams shown in these drawings, the dam dam body 10 is provided in a valley between mountains, and a reservoir is formed on the upstream side of the dam dam body 10.
[0019]
The dam dam body 10 is connected and formed by placing concrete through a plurality of transverse seams 12 extending in the vertical direction. The transverse seams 12 are arranged in parallel to each other at substantially equal intervals.
[0020]
As shown in FIG. 2, the transverse seam 12 has a width d having substantially the same size in the transverse direction of the dam dam body 10, and the water stop material 14 wider than the width d is a transverse seam. 12 so as to be orthogonal to 12.
[0021]
In the case of the present embodiment, the water blocking material 14 is arranged in the vicinity of the upstream side of the dam dam body 10 and includes a main water blocking plate 14a made of a flat rubber plate having substantially the same width and a sub water blocking plate 14b. The main and sub water blocking plates 14a and 14b are arranged so as to be parallel to each other.
[0022]
Further, the lower ends of the main and auxiliary water blocking plates 14 a and 14 b are set in the bedrock below the dam dam body 10, and the upper end side is extended to the vicinity of the top end of the dam dam body 10. ing.
[0023]
When the dam dam body 10 having such a configuration is constructed, in the case of the present embodiment, a water leakage inspection is performed before the dam is flooded, and it is determined that the water leakage is found by this inspection and the treatment is necessary. In such a case, water leakage treatment is performed, and an example of the procedure performed at this time is shown in FIG.
[0024]
When the procedure starts, first, in step 1, the width d of the transverse seam 12 is measured. In this measurement, a gondola that moves up and down along the dam dam body 10 is suspended, and the width d of each horizontal joint 12 is measured with a scale, for example, every 2.5 m along the vertical direction. Then, the average value of the actually measured width d is estimated as the width of the inside of the horizontal joint 12 (the portion indicated by the symbol S in FIG. 2).
[0025]
In the next step 2, the gap capacity Vx between the main and auxiliary water stop plates 14a and 14b is calculated .
[0026]
In calculating the gap capacity Vx, an injection device 16 shown in FIG. 4 is used. The injection device 16 shown in the figure includes a cylinder 16a, a receiver tank 16b, and an injection tube 16c.
[0027]
The cylinder 16a, the nitrogen gas N ₂ pressurized to a predetermined pressure is sealed filling, first through a valve 16d and the hose 16e, are connected in communication with the receiver tank 16b.
[0028]
The receiver tank 16b is a pressure tank having a known internal volume V0, and is connected to the injection pipe 16c through a hose 16h provided with first and second opening / closing valves 16f and 16g at both ends. The hose 16h is provided with a pressure gauge 16i in the vicinity of the second opening / closing valve 16g.
[0029]
The injection pipe 16c is a hollow pipe that is open at both ends, and penetrates obliquely downward by 45 ° from the top end of the dam dam body 10, and its tip is located in the transverse seam 12, It is located at the approximate center between the main and sub waterstop plates 14a, 14b.
[0030]
In other words, in the case of the present embodiment, the injection pipe 16c extends from the direction A in FIG. It penetrates from the end diagonally downward by 45 °.
[0031]
In addition, the injection pipe 16 c is disposed at a substantially central portion in the width direction of the transverse seam 12 of the dam dam body 10. When calculating the gap capacity Vx, first, a predetermined amount of nitrogen gas N ₂ in the cylinder 16a is stored in the receiver tank 16b, and a constant amount of nitrogen gas N ₂ is instantaneously passed through the injection pipe 16c. Inject between the main and sub waterstop plates 14a, 14b.
[0032]
Then, read the change in pressure state of the nitrogen gas N ₂ in the immediately pressure gauge 16i. In this case, when the pressure value before injecting the nitrogen gas N ₂ was P0, this value is reduced with the injection, the change point appears that the pressure value increases along the way.
[0033]
This is because there is a slight leakage when nitrogen gas N ₂ is filled in the gap formed between the main and auxiliary water stop plates 14a and 14b and the receiver tank 16b communicated via the injection pipe 16c. Even if there is a state where the pressure is instantaneously balanced, the change point can be read.
[0034]
Now, assuming that the pressure value at this changing point is Pa, a relationship of P0 × V0 (initial state of the receiver tank 16b) ≈Pa × (V0 + Vx) is established according to Boyle's law.
[0035]
Since P0, V0, and Pa are known in this relationship, the gap capacity Vx can be calculated from the above formula. From the calculated gap capacity Vx, the formation state of the gap is known. That is, now, when the area S of the portion of the transverse seam 12 sandwiched between the main and auxiliary waterstop plates 14a and 14b is multiplied by the total length L in the vertical direction of the transverse seam 12, the volume is V. Then, when the gap capacity Vx is smaller than the volume V, the gap is clogged in the middle, and it can be determined that the gap has not reached the lower end of the dam dam body 10. Moreover, the length of the gap in the vertical direction can also be estimated from a comparison between the two.
[0036]
When the calculation of the gap capacity Vx is completed, the total air leakage amount A is measured in the next step 3. This total air leakage amount A is measured in Step 5 to be described later in order to determine whether or not a water leakage treatment is necessary. In the injection device 16 shown in FIG. 4, the nitrogen gas N _{2 having} a constant pressure is measured. Is continuously injected between the main and auxiliary water stop plates 14a and 14b via the injection pipe 16c, and is obtained from the consumption of nitrogen gas N ₂ per unit time.
[0037]
When the measurement of the total air leakage amount A is completed, the air leakage position is specified in step 4 next. Note that this step is executed only when the amount of air leakage per unit time, that is, the total air leakage amount A is equal to or greater than a predetermined value.
[0038]
In the work for identifying the air leakage position, first, in the injection device 16 shown in FIG. 4, while injecting nitrogen gas N ₂ having a constant pressure between the main and auxiliary water stop plates 14 a and 14 b through the injection pipe 16 c, A soap solution is applied along the upstream side of the transverse seam 12.
[0039]
If there is air leakage at the transverse seam 12, nitrogen gas N ₂ is discharged from that portion, and soap water is expanded to form a hemispherical soap bubble, so the surface to which soap water is applied is visually observed. If this is the case, the location of the leak can be identified and easily identified.
[0040]
In this case, the amount of air leakage and the size of the air leakage location can be estimated by measuring the diameter of the soap bubbles formed by the soap water expanding. It should be noted that the leak occurrence location shown in the present embodiment is substantially the same location as the leak occurrence location unless the amount of water leak is considered.
[0041]
In the subsequent step 5, it is determined whether or not there is a need for water leakage treatment. This is based on the following findings. That is, regarding the water stoppage of a concrete structure, it is said that there is a 100-fold difference between gas and water when comparing the amount of air leakage and the amount of water leakage. Processing is not necessary.
[0042]
Therefore, the present inventors have performed a comparative experiment to convert the amount of air leakage into the amount of water leakage, and decided to convert based on this. In the comparative experiment, a rubber hose was used in consideration of the material of the water stop plate, a rubber hose with a 20 mm long slit provided with a knife, and two needle holes opened with water or nitrogen gas N ₂ The pressure of was varied and injected into a rubber hose, and the amount of air leakage was compared with the amount of water leakage.
[0043]
As a result, the amount of air leakage was 59 times larger at the slit and 70 times larger at the needle hole. Therefore, in this example, 65 times the average of these was adopted as the conversion coefficient (air leakage amount / 65 = water leakage amount).
[0044]
Further, in order to compare the injection pressure of the nitrogen gas N ₂ with the water pressure during actual flooding, the amount of air leakage was converted assuming that it increased in direct proportion to the injection pressure. In step 5, when the converted water leak amount is expected to be 10 L / min or more per one location of the transverse joint 12 from the total air leak amount A, it was set as a judgment criterion that the water leak treatment is necessary.
[0045]
If it is determined in step 5 that the determination criteria are not satisfied and the water leakage treatment is not necessary, the procedure ends. On the other hand, if it is determined in step 5 that water leakage treatment is necessary, step 6 is executed.
[0046]
When water leakage treatment is performed, a filler such as cement milk is injected into the horizontal joint 12 without pressure, and a silicone resin is applied to the water leakage location specified by the swelling of the soap water.
[0047]
In this case, the filler can be injected between the main and sub waterstop plates 14a and 14b using the injection pipe 16c shown in FIG. 4, or another injection pipe may be provided. The injection filling amount of the filler can be set based on the gap volume Vx calculated in step 2.
[0048]
That is, when the filler of the amount corresponding to the calculated gap capacity Vx is completely injected without pressure, the water leakage treatment at a place where water leakage may occur can be performed completely. Moreover, the filling state can be confirmed by measuring the amount of filling when filling the filler without pressure and comparing it with the gap volume Vx.
[0049]
That is, if the injection amount is smaller than the gap volume Vx, it can be determined that the filling is insufficient and the water leakage treatment is insufficient .
[0050]
Now, according to the water leak inspection method for a concrete dam configured as described above, before the dam is flooded, gas (nitrogen gas N) flows from the downstream side of the water stop material 14 (main water stop plate 14a) to the transverse seam 12. ₂ ) is injected, soap water is applied along the horizontal joint 12 on the upstream side of the water stop material 14 (main water stop plate 14a), and from the swelling of the soap water by the gas discharged from the horizontal joint 12, Since 12 water leak locations are specified, the water leak can be inspected before drowning by a relatively simple method of visual confirmation.
[0051]
Further, according to the water leakage processing method having the aforementioned configuration, injected before flooding the dam, a gas (nitrogen gas N ₂₎ in the transverse seam 12 from the downstream side of the water stopping member 14 (main waterstop 14a), stop Apply soapy water along the horizontal seam 12 upstream of the water material 14 (main water stop plate 14a), and identify the location of the water leakage of the horizontal seam 12 from the swelling of the soap water by the gas discharged from the horizontal seam 12. When it is determined that a water leakage treatment is necessary, a filler such as cement milk is injected into the transverse joint 12 without pressure, and a silicone resin is applied to the specified water leakage portion, so that the water leakage portion can be easily identified. It is possible to perform the water leakage treatment easily because the water is not flooded when the water leakage location is specified.
[0052]
As described above, when the water leakage location is investigated and the water leakage treatment is performed before the dam is flooded, the dam flood test and the like can be performed smoothly.
[0053]
In addition, in the said Example, although the case where a water leak process was performed following a water leak test was illustrated, implementation of this invention is not restricted to this, You may perform only a water leak test. In the above embodiment, as a gas, it is exemplified nitrogen gas N _2, in the embodiment of the present invention, it is also possible to use other gases such as compressed air or oxygen.
[0054]
【The invention's effect】
As described above in detail, according to the leakage inspection method and the leakage treatment method for a concrete dam according to the present invention, it is possible to inspect before flooding by a relatively simple method, and a leakage point is specified. Can be processed easily.
[Brief description of the drawings]
FIG. 1 is a front view showing an example of a concrete dam to which a water leakage inspection method and a water leakage treatment method according to the present invention are applied.
FIG. 2 is a top view of a main part of FIG.
FIG. 3 is a flowchart of a processing procedure showing an embodiment of the water leakage inspection method and the water leakage processing method according to the present invention.
FIG. 4 is a side view of an installation state of an injection device used in the water leakage inspection method and the water leakage treatment method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Dam dam body 12 Horizontal joint 14 Water stop material 14a Main water stop plate 14b Sub water stop plate 16 Injection apparatus 16a Cylinder 16b Receiver tank 16c Injection pipe

Claims (4)

In a leakage inspection method for a concrete dam constructed by connecting a water stop material to a transverse joint, a gas such as nitrogen gas is injected into the transverse joint from the downstream side of the water stop material before the dam is flooded. In the water leakage inspection method, the soap water is applied along the horizontal joint on the upstream side of the water stop material, and the leakage location of the horizontal joint is specified from the swelling of the soap water due to the gas discharged from the horizontal joint. There,
The water stop material includes a main water stop plate and a sub water stop plate arranged in parallel to each other, and the gas is injected between the main and sub water stop plates while detecting a pressure state, and a detected pressure value is detected. A leak check method for a concrete dam , wherein a gap capacity formed between the main and sub waterstops is calculated based on the change and the estimated width of the transverse seam . 2. The method for inspecting a leak of a concrete dam according to claim 1, wherein when the leak location of the horizontal joint is specified, the size of the leak location of the horizontal joint is estimated from the size of the swelling of the soap water. In a water leak treatment method for a concrete dam constructed by connecting a water stop material to a horizontal joint, a gas such as nitrogen gas is injected into the horizontal joint from the downstream side of the water stop material before the dam is flooded. Applying soapy water along the upstream side seam of the water-stopping material, identifying the water leakage location of the side seam from the swelling of the soapy water due to the gas discharged from the side seam, When it is determined that there is a need, a water leakage treatment method in which a filler such as cement milk is injected without pressure into the transverse joint, and a silicone resin is applied to the specified water leakage location,
  The water stop material includes a main water stop plate and a sub water stop plate arranged in parallel to each other, and the gas is injected between the main and sub water stop plates while detecting a pressure state, and a detected pressure value is detected. Based on the change and the estimated width of the transverse seam, the gap capacity formed between the main and secondary waterstops is calculated, and when the filler is injected without pressure, the relationship with the gap capacity is calculated. A concrete dam leakage treatment method, wherein the filling state of the filler is determined based on the determination. The necessity determination of the water leakage treatment is performed by converting the amount of air leakage measured from the swelling of the soap water into the amount of water leakage, and is performed based on the converted amount of water leakage. 4. The method for leaking water from a concrete dam according to claim 3, wherein the water leakage treatment method is performed in the case of.

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