JP4614168B2 - Apparatus for testing resistance to separation of water in lightweight soil and test method thereof - Google Patents

Description

  The present invention relates to a test apparatus and a test method for an underwater separation resistance test in which a measurement result conforming to an actual water area can be obtained when placing lightweight soil in water.

  Landfill treatment in water areas partitioned by revetments or rubble has been performed by adding dredged soil, but mud immediately after dredging contains a large amount of water, so excess water is removed to make it moderate. It is necessary to adjust the water content ratio, and it takes time to process surplus water. In view of this, an underwater landfill method has been developed that uses lightweight soil prepared by mixing cement, which is a solidifying material, and lightweight materials such as bubbles, foam beads and / or foaming agents with mud. (For example, Patent Document 1 and Patent Document 2)

  When such lightweight soil is placed in the water, depending on the blending state, placement speed, placement method, etc., the lightweight soil may entrain air or water, and the material may be separated due to the viscous resistance of the water. Problems such as an increase, a decrease in strength, turbidity in the placement water area, and an increase in pH may occur. For this reason, prior to underwater placement, it is possible to quantitatively grasp the resistance to material separation when placing lightweight soil in the water, and to evaluate the good ratio of light soil composition, etc. A simple indoor test has been conducted to confirm the resistance of light soil to water separation.

  An example of a construction method for conducting an underwater separation resistance test is shown in FIG. As shown in the figure, after setting the design conditions, physical tests and blending tests of the raw soil are performed, and blending conditions are determined to prepare a light soil for testing. The driving speed of this lightweight soil is set and an underwater separation resistance test is performed. Compare the test result with the index value, and determine the basic composition and driving speed for those that are suitable, and proceed to the construction on site. On the other hand, for those that do not match the index value, return to the blending condition setting, readjust the conditions to prepare a light soil, conduct an underwater separation resistance test again, and determine blending conditions and driving speed that match the index value.

  An outline of a testing machine used for the underwater separation resistance test is shown in FIG. The apparatus configuration shown in the figure is an example of a testing machine. A water tank (receiving container) 20 for placing a lightweight soil 10, a cylinder 30 filled with the lightweight soil 10, a driving means 31 for the cylinder 30, and a hose extending from the cylinder 30 to the water tank 20. 32. These support bases 40 are provided, and a nozzle is attached to the tip of the hose 32. Yes.

  The volume and the like of each part of the test apparatus used in the prior art is, for example, the inner diameter of the water tank 20 is 200 mm, the height is 200 mm, the inner volume is 6280 mL, the inner diameter of the cylinder 30 is 100 mm, the height is 440 mm, and the inner volume is 3460 mL. The maximum speed is about 140 cm / sec.

Japanese Patent Laid-Open No. 6-264074 JP-A-9-143998

  In the conventional test apparatus, light soil is placed in a circular water tank having the above capacity for about 5 minutes, and turbidity and pH in water are measured. As shown in FIG. Turbidity flowing from the installation position toward the wall 21 of the aquarium is reflected by the wall portion and returns to the central portion, so that it is measured as turbidity and pH exceeding the actual water area in the aquarium. In other words, the conventional test apparatus has a finite inside of the water tank, and there is a problem that the measurement value becomes excessive compared to the actual water area in a semi-infinite state.

  In order to avoid the influence of the reversal of turbidity caused by such a water tank peripheral wall, it is conceivable to use a large water tank (for example, about 2 m in length) as shown in FIG. There is a problem that it cannot be easily tested.

  The present invention solves the above-mentioned problem in the conventional test apparatus, and a test apparatus capable of obtaining a measurement result in conformity with a real water area while using a small water tank for the resistance to water separation of lightweight soil, and a test method thereof The purpose is to provide.

The invention described in claim 1 for achieving the desired object to solve the above-mentioned conventional problems, a test apparatus for measuring the water separation resistance of lightweight soil adjusted as a base material mud, lightweight A water flow attenuating means formed by a water-permeable sponge-like member bonded to the peripheral wall of the water tank in which soil is placed, and a water-absorbing port provided on the water-tank peripheral wall on the back side of the water-permeable sponge-like member; It is an underwater separation resistance test device characterized by comprising water absorption means comprising a connected suction pump .

The invention described in claim 2 is an underwater separation resistance test apparatus in which a plurality of the water inlets are provided on the peripheral wall of the tank so as to surround the inside of the tank .

The invention described in claim 3 is bonded to the peripheral wall of the water tank in which the lightweight soil is placed in the underwater separation resistance test of the lightweight soil to measure the turbidity and pH in the water generated by placing the light soil in the tank . A water absorption means comprising a water flow attenuating means formed by a water-permeable sponge-like member, and comprising a water-absorbing port provided on a water tank peripheral wall on the back side of the water-permeable sponge-like member, and a suction pump connected to the water-absorbing port This is an underwater separation resistance test method characterized in that the above measurement is carried out using a test apparatus equipped with the above, and preventing reversal of the water flow by the peripheral wall of the water tank when a lightweight soil is placed.

  In the present invention, there is a test device for measuring the resistance to separation of lightweight soil placed in water, and a water flow attenuating means and a water absorbing means stage are provided on the peripheral wall of a water tank in which lightweight soil is placed. The flow velocity of the water flow reaching the tank peripheral wall is relaxed by the water flow attenuating means, and the turbid water flow reaching the tank peripheral wall is sucked out of the water tank by the water absorption means, so the turbid water flow does not reverse and the water tank center It is possible to prevent excessive turbidity of the part and an increase in pH. Therefore, even if it is a small water tank, the measured value according to the actual water area can be obtained about the turbidity and pH of water.

  Further, the water flow attenuating means can be formed easily and at low cost by a water-permeable sponge-like member bonded to the peripheral wall of the water tank so as to surround the inside of the water tank. Further, by providing the sponge-like member on the peripheral wall of the water tank so as to surround the inside of the water tank, the turbid water flow does not reverse over the entire water tank, and an accurate measurement value can be obtained.

  Furthermore, by forming the water absorption means by the water suction port provided on the water tank peripheral wall on the back side of the water-permeable sponge-like member and the suction pump connected to the water suction port, the water flow that cannot sufficiently relax the flow rate by the water flow damping means. As for turbidity, turbidity is sucked, so that a more accurate measurement value can be obtained.

  Furthermore, it is possible to obtain a measurement value that matches the actual water area even if a small test tank is used by testing the resistance to separation in water by preventing reversal of the water flow due to the peripheral wall of the tank when placing lightweight soil. it can.

  Next, the present invention will be specifically described based on an embodiment shown in the drawings.

  3 to 4 are test water tanks according to the present invention. As shown in the figure, in the water tank 20 of the present invention, a water-permeable sponge-like member 22 is attached to the water tank peripheral wall 21 so as to surround the inside of the water tank, and the water-damping means is provided on the entire inner surface of the water tank peripheral wall by the sponge-like member 22. Is formed. As the sponge member, a commercially available resin sponge can be used.

  When light soil is cast in the center of the water tank and the water flow generated by this driving reaches the peripheral wall of the water tank, the water flow is absorbed by the sponge-like member on the peripheral wall of the water tank and the flow velocity is reduced, so the water flow does not reverse. In addition, since the sponge-like member is provided on the entire peripheral wall of the water tank, reversal of the water flow is prevented for the entire water tank, and an accurate measurement value can be obtained.

  The water tank 20 of the present invention is further provided with a water suction port 23 on the peripheral wall of the water tank located on the back side of the water-permeable sponge-like member 22, and the water suction port 23 is connected to a suction pump 25 through a water suction path 24 to absorb water. Is forming. The water inlets 23 are provided at a plurality of positions at equal intervals so as to surround the inside of the water tank. Each water inlet 23 is connected to a water absorption path 24, and the water absorption path 24 is connected to a suction pump 25.

  Since the water flow attenuating means is provided in the water tank of the present invention, even if the turbid water flow passes through the sponge-like member and reaches the peripheral wall of the water tank, the turbidity is sucked out of the tank by the water absorbing means. Does not reverse. Further, by providing a plurality of water inlets 23 at equal intervals so as to surround the inside of the water tank, reversal of turbidity can be reliably prevented for the entire inside of the water tank.

  The degree of water absorption of the turbidity by the water absorption means may be controlled by a suction pump while visually confirming that the turbidity is not reversed and a rapid water flow toward the outside of the tank is not generated.

  About the soil shown in Table 1, the lightweight soil was prepared according to the mixing | blending shown in Table 2, and the water separation resistance test was done using the test apparatus shown in FIG. Three types of test water tanks were used: a conventional old water tank (not provided with water flow attenuating means and water absorption means), a new water tank according to the present invention, and a large water tank for actual scale reproduction. The same amount of lightweight soil was cast for each water tank, and the pH and turbidity (SS) in the water tank were measured. The results are shown in Table 3.

  For light-weight soil placement of 1.0 L, the turbidity (SS) of a large tank close to the actual scale is 78 to 81 mg / L and the pH is 9.3 to 9.4, whereas the turbidity (SS of the old tank is ) Is 91 to 100 mg / L, pH is 10.1 to 10.3, and the error is large. On the other hand, in the new water tank of the present invention, the turbidity (SS) is 79 to 83 mg / L and the pH is 9.3, which is close to the result of the large water tank, and the measured value in accordance with the actual scale can be obtained. The same applies to the light soil placing amount of 3.0L.

It is process drawing which shows the test procedure of the lightweight soil which concerns on this invention. It is a schematic diagram of an underwater separation resistance test apparatus same as the above. It is a schematic sectional drawing which shows an example of the water tank which concerns on this invention. It is a schematic cross-sectional view showing an example of a water tank according to the present invention. It is a schematic sectional drawing of the large sized water tank used in the test example. It is a schematic sectional drawing of the conventional old water tank.

DESCRIPTION OF SYMBOLS 10 Light earth 20 Water tank 21 Water tank surrounding wall 22 Sponge-like member 23 Water inlet 24 Water absorption path 25 Water absorption pump 30 Cylinder 31 Drive means 32 Hose 40 Support stand

Claims (3)

A test apparatus for measuring the resistance to separation of light-weight soil adjusted with mud soil as a base material, comprising water-attenuating means formed by a water-permeable sponge-like member bonded to the peripheral wall of a water tank in which light-weight soil is placed. And an underwater separation resistance test apparatus comprising water absorption means including a water suction port provided in a water tank peripheral wall on the back side of the water-permeable sponge-like member and a suction pump connected to the water suction port . The underwater separation resistance test apparatus according to claim 1, wherein a plurality of the water inlets are provided on the peripheral wall of the water tank so as to surround the inside of the water tank . It is formed by a water-permeable sponge-like member pasted on the peripheral wall of a water tank in which lightweight soil is placed in an underwater separation resistance test for lightweight soil to measure the turbidity and pH in water generated by placing light soil in the tank. In addition to the water attenuating means, a test apparatus having a water absorbing means comprising a water suction port provided in the peripheral wall of the water tank on the back side of the water-permeable sponge-like member and a suction pump connected to the water suction port is used. An underwater separation resistance test method characterized in that the measurement is performed while preventing reversal of the water flow by the peripheral wall of the water tank when the soil is cast.

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