Method for obtaining quality indicators for plastic grout materials, and method for managing the construction of plastic grout materials.

Abstract

To provide the quality index acquisition method of a plastic injection material allowing evaluation of underwater non-separability of the plastic injection material in water flow, and a construction management method of the plastic injection material.SOLUTION: The quality index acquisition method of a plastic injection material related to the present invention includes steps: (1) of preparing samples for measuring the plastic injection material and samples for charging; (2) of taking prescribed time lapse after preparation of the samples; (3) of measuring vane shearing strength of the measuring samples; (4) of charging the charging samples into flowing water adjusted to a prescribed flow rate; and (5) of measuring water quality of the flowing water after the prescribed time lapse. On the basis of the measured vane shearing strength and the water quality of the flowing water, and by employing the vane shearing strength of the sample when the flowing water satisfies the desired water quality as a quality index of the plastic injection material, a relationship among the time lapse after preparing the samples for measuring and charging, the flow rate in the flowing water, the flowing water quality, and the vane shearing strength being the quality index of the plastic injection material are acquired.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a method for obtaining quality indexes of a plastic injection material and a method for construction management of a plastic injection material.

Background Art

[0002] As an injection material to be injected into a construction site such as a void or a cavity, an injection material containing cement is known. In order to prevent leakage to the surroundings until the injection material is injected into the target void, cavity or the like and hardened, the injection material has sufficient fluidity until construction and gels and aggregates so as not to flow out to the surroundings after construction, that is, it is required to have plasticity.

[0003] Such an injection material having plasticity (hereinafter sometimes referred to as "plastic injection material") includes, for example, those containing a plasticizer as described in Patent Document 1.

[0004] The plastic injection material described in Patent Document 1 is composed of two liquids of cement milk and bentonite milk containing bentonite as a plasticizer. By stirring and mixing the cement milk and the bentonite milk, the bentonite rapidly aggregates due to calcium ions eluted from the cement in the cement milk, and plasticity is obtained.

[0005] By the way, water often exists in a cavity such as the back of a tunnel where a plastic injection material is constructed due to water gushing or the like. Therefore, it is desirable that the plastic injection material does not cause elution of components and separation of materials with respect to water (hereinafter sometimes referred to as "non-separability in water"). Non-Patent Document 1 describes a test method for evaluating the non-separability in water of a plastic injection material. More specifically, the plastic injection material is placed in still water, and the rate of change in the water quality (pH, turbidity, etc.) of the still water in which the plastic injection material is placed is determined.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 11-310779 [Non-patent literature]

[0007] [Non-Patent Document 1] East Nippon Expressway Co., Ltd., Central Nippon Expressway Co., Ltd., West Nippon Expressway Co., Ltd., "Design and Construction Guidelines for Backfill Cavity Injection Work in Sheet Pile Tunnels," October 2006. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, the water in areas where plastic grout is applied is rarely stagnant and still; in most cases, it is flowing water. The test described in Non-Patent Document 1 is conducted in still water, so the environment in which the plastic grout is applied differs significantly from the test environment. Therefore, when the plastic grout is placed under flowing water, the extent to which the flowing water affects the plastic grout is unknown, and there is a risk of component leaching and material separation from the plastic grout. If component leaching and material separation occur from the plastic grout, the leached components and separated materials will contaminate the water at the application site. Therefore, a new method is needed that can evaluate component leaching and material separation from plastic grout under flowing water.

[0009] This invention has been made in view of the above circumstances, and aims to provide a method for obtaining a quality index for a plastic grout that can evaluate the non-separation of the plastic grout underwater conditions, and a method for managing the construction of the plastic grout based on the quality index obtained by this method. [Means for solving the problem]

[0010] The method for obtaining quality indicators for plastic injection materials according to the present invention is a method for obtaining quality indicators for plastic injection materials, The following steps (1) to (5) are included: Based on the vane shear strength of the test specimens measured in steps (3) and (5) below, and the water quality of the flowing water, the vane shear strength of the test specimens when the flowing water satisfies the desired water quality is adopted as a quality indicator for the plastic injection material. The relationship between the elapsed time since the preparation of the measurement specimens and the input specimens, the flow velocity under flowing water, the water quality of the flowing water, and the vane shear strength, which is a quality indicator of the plastic injection material, will be obtained. (1) A process for preparing test specimens for measuring the vane shear strength of plastic injection material and test specimens for immersion in flowing water. (2) A process of allowing a predetermined amount of time to elapse after preparing the test specimens for measurement and the test specimens for input. (3) A step of measuring the vane shear strength of the test specimen after a predetermined time has elapsed in step (2). (4) A step of introducing the test specimens for input, which have elapsed a predetermined time in step (2), into flowing water adjusted to a predetermined flow rate. (5) A step in which the test specimen to be introduced in step (4) is placed under flowing water, and after a predetermined time has elapsed, the water quality of the flowing water is measured.

[0011] The method for obtaining quality indicators according to the present invention, with the above configuration, can evaluate the water non-separation properties of plastic injection material under flowing water.

[0012] In the method for obtaining quality indicators according to the present invention, the measurement of the water quality of the flowing water in step (5) above may be performed by measuring at least one of the amount of suspended solids, turbidity, chromaticity, and pH.

[0013] The method for obtaining quality indicators according to the present invention, with its configuration, allows for a more accurate understanding of the water quality of flowing water.

[0014] The present invention relates to a method for managing the construction of a plastic grout material, which involves injecting the plastic grout material into a construction site, and is a method for managing the construction of the plastic grout material based on quality indicators obtained by the above-described method for obtaining quality indicators. This includes steps (11) to (13) below. (11) A step of determining the flow velocity in the flowing water environment at the construction site. (12) A step of determining the vane shear strength of the plastic injection material when the water quality of the flowing water required at the construction site satisfies the quality index based on the quality index. (13) A step of obtaining the shortest time from the formation of the plastic injection material until the vane shear strength of the plastic injection material determined in the step (12) is obtained at the flow velocity of the flowing water determined in the step (11) based on the quality index.

[0015] The construction management method of the plastic injection material according to the present invention can manage the construction of the plastic injection material based on the quality index evaluating the underwater non-separation property of the plastic injection material under flowing water with such a configuration.

Effects of the Invention

[0016] According to the present invention, a method for obtaining a quality index of a plastic injection material capable of evaluating the underwater non-separation property of the plastic injection material under flowing water and a construction management method of the plastic injection material based on the quality index obtained by the method can be provided.

Brief Description of the Drawings

[0017] [Figure 1] A schematic diagram showing an example of a miniature vane.

Modes for Carrying Out the Invention

[0018] Hereinafter, a method for obtaining a quality index of a plastic injection material and a construction management method of a plastic injection material according to the present embodiment will be described.

[0019] <Method for Obtaining Quality Index of Plastic Injection Material> The method for obtaining a quality index of a plastic injection material according to the present embodiment includes the following steps (1) to (5), and based on the vane shear strength of the measurement test specimen measured in the following steps (3) and (5) and the water quality of the flowing water, the vane shear strength of the measurement test specimen when the flowing water satisfies the desired water quality is adopted as the quality index of the plastic injection material. The relationship between the elapsed time since the preparation of the measurement specimens and the input specimens, the flow velocity under flowing water, the water quality of the flowing water, and the vane shear strength, which is a quality indicator of the plastic injection material, will be obtained.

[0020] (1) A process for preparing test specimens for measuring the vane shear strength of plastic injection material and test specimens for immersion in flowing water. (2) A process of allowing a predetermined amount of time to elapse after preparing the test specimens for measurement and the test specimens for input. (3) A step of measuring the vane shear strength of the test specimen after a predetermined time has elapsed in step (2). (4) A step of introducing the test specimens for input, which have elapsed a predetermined time in step (2), into flowing water adjusted to a predetermined flow rate. (5) A step in which the test specimen to be introduced in step (4) is placed under flowing water, and after a predetermined time has elapsed, the water quality of the flowing water is measured.

[0021] In step (1), test specimens for measurement and test specimens for input are prepared for the plastic injection material. The test specimens for measurement are for measuring the vane shear strength in step (3), which will be described later. The test specimens for input are for being introduced into flowing water in step (4), which will be described later.

[0022] The specimens for measurement and the specimens for placement are formed from a plastic grout. The plastic grout used to form the specimens for measurement and placement is not particularly limited, as long as it is used by being injected into voids or cavities. The plastic grout can be either cement-based or non-cement-based, and if it is cement-based, it can be either air-based or non-air-based. Furthermore, the plastic grout can be a single-component system, or it can be a mixture of multiple liquids, such as a two-component system.

[0023] In step (1), in one embodiment, test specimens for measurement and test specimens for input of a two-component plastic grout material are prepared. The two-component plastic grout material is formed by mixing, for example, liquid A, which is composed of cement and water, and liquid B, which is composed of bentonite and water. Therefore, the test specimens for measurement and test specimens for input of the two-component plastic grout material are prepared by mixing liquid A and liquid B.

[0024] Step (2) is a step in which a predetermined time is allowed to elapse after the preparation of the test specimens for measurement and the test specimens for input. The test specimens for measurement and the test specimens for input solidify as time passes after they are prepared. In the method for obtaining quality indicators of the plastic injection material according to this embodiment, the vane shear strength is measured and the water quality is measured under flowing water at a predetermined flow velocity according to the elapsed time since the preparation of the test specimens for measurement and the test specimens for input. By doing so, the vane shear strength of the test specimens and the water non-separation of the test specimens under flowing water at a predetermined flow velocity can be correlated.

[0025] Furthermore, there are no particular limitations on the time elapsed after the preparation of the test specimens for measurement and the test specimens for input. The time may be appropriately selected depending on the plastic injection material used to form the test specimens for measurement and the test specimens for input. Examples of elapsed time after preparation include 5 minutes, 15 minutes, 30 minutes, 45 minutes, 60 minutes, and 75 minutes. As described above, the method for obtaining quality indicators of the plastic injection material according to this embodiment correlates the vane shear strength of the test specimens with the water non-separation of the test specimens under flowing water at a predetermined flow velocity, based on the time elapsed after the preparation of the test specimens for measurement and the test specimens for input. Therefore, the measurement of vane shear strength and the measurement of water quality under flowing water at a predetermined flow velocity are performed at multiple elapsed times. There are no particular limitations on the number of elapsed time points at which the measurement of vane shear strength and the measurement of water quality under flowing water at a predetermined flow velocity are performed, but it is preferable to perform the measurements at at least three elapsed time points.

[0026] In step (3), the vane shear strength of the test specimens that have been subjected to a predetermined time in step (2) is measured. The vane shear strength of the test specimens is measured by a vane shear test. The shear force measured in the vane shear test is related to the uniaxial compressive strength from Mohr's stress circle. That is, the shear force corresponds to half of the uniaxial compressive strength.

[0027] In the vane shear test in the method for obtaining quality indicators for plastic injection materials according to this embodiment, for example, a miniature vane 1 is used.

[0028] Figure 1 shows an example of a miniature vane 1. In the example shown in Figure 1, the miniature vane 1 comprises a rod 2, a vane blade 3 provided on one side of the rod 2, and a torque meter 4 provided on the other side of the rod 2. The vane blade 3 consists of four rectangular blades arranged in a cross shape.

[0029] In a vane shear test, the vane blade 3 of a miniature vane 1 is pressed vertically into a test specimen to a predetermined position, and the strength of the specimen, i.e., the vane shear strength, is measured from the resistance value when it is rotated.

[0030] Therefore, in step (3), the vane shear strength of the test specimens prepared for measurement is measured after a predetermined time has elapsed. Note that when using a general plastic injection material, the longer the elapsed time in step (2), the greater the vane shear strength.

[0031] In step (4), the test specimens for input, which have been in place for a predetermined time in step (2), are placed under flowing water adjusted to a predetermined flow rate.

[0032] The water into which the test specimens are introduced is not particularly limited, as long as the flow velocity of the water can be controlled to a predetermined flow velocity. As a device for controlling the flow velocity of the water, for example, a circulating water tank may be used. In a circulating water tank, the water in the tank is circulated in a constant direction at a predetermined flow velocity.

[0033] In step (4), the flow velocity of the water into which the test specimens are introduced is preferably 0.1 m / s or more and 1.0 m / s or less. It is preferable to measure the vane shear strength and the water quality under flow at multiple points, at least three points, within this range.

[0034] In step (5), the test specimens used in step (4) are placed under running water, and after a predetermined time has elapsed, the water quality of the running water is measured.

[0035] When the test specimen is exposed to flowing water, components may leach out of the specimen and materials may separate, which will cause a change in the quality of the flowing water. In step (5), in order to investigate the effect of flowing water on the test specimen, the quality of the flowing water is measured after a predetermined time has elapsed since the test specimen was introduced into the flowing water.

[0036] There are no specific time limits for the time between introducing the test specimen and measuring the water quality of the flowing water; it can be determined as appropriate. Examples of such time limits include 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, etc.

[0037] The water quality of the flowing water should be measured for parameters that affect water quality when components leach out from the plastic grout and material separation occurs. Examples of parameters affected by component leaching and material separation include suspended solids, turbidity, color, and pH. Therefore, in step (5), the water quality of the flowing water may be measured by measuring one of the following parameters that affect the water quality due to component leaching and material separation: suspended solids, turbidity, color, pH, etc., or by measuring two or more of these parameters. The water quality can be measured using known methods, such as weight measurement of suspended solids using a filtration device, measurement of turbidity and colorimeter, measurement using a spectrophotometer, and measurement using a pH meter.

[0038] The method for obtaining a quality index for the plastic grout material according to this embodiment involves using the vane shear strength of the test specimen measured in steps (3) and (5) above, and the water quality of the flowing water, and adopting the vane shear strength of the test specimen when the flowing water satisfies the desired water quality as the quality index for the plastic grout material.

[0039] The measurement specimens and the input specimens are prepared and subjected to vane shear measurement and immersion in flowing water at the same time. Therefore, the measurement specimens and the input specimens are considered to be in the same solidified state. Thus, the relationship between the vane shear strength of the measurement specimens and the water quality due to the input specimens can be obtained based on the time elapsed since the preparation of the measurement specimens and the input specimens.

[0040] For example, a test specimen for measurement and a test specimen for input are prepared, allowed to stand for 5 minutes, the vane shear strength of the test specimen is measured, and the test specimen for input is introduced into flowing water. In this case, the value of the vane shear strength of the test specimen after 5 minutes is correlated with the value of the water quality measured in the flowing water into which the test specimen was introduced.

[0041] Furthermore, by varying the elapsed time since the preparation of the test specimens and the test specimens for input, and measuring the vane shear strength of the test specimens and the water quality of the flowing water, it is possible to correlate the values ​​of the vane shear strength of the test specimens with the measured values ​​of the water quality of the flowing water according to each elapsed time.

[0042] By obtaining the relationship between the vane shear strength of the test specimens and the water quality of the flowing water, the vane shear strength of the test specimens can be adopted as a quality indicator for the plastic grout. By measuring the vane shear strength of the plastic grout, which is the quality indicator, it is possible to determine whether the plastic grout will affect the water quality of the flowing water when it is introduced into the flowing water.

[0043] In this specification, "satisfying water quality" means that the value measured in the measurement of the water quality of flowing water falls within a predetermined range. The predetermined value is determined for each item of water quality measurement. There are no particular limitations on the values ​​determined for each item, but they may be determined, for example, based on environmental standards related to the preservation of the living environment. For suspended solids, the water quality may be considered satisfied if the difference between the measurement value obtained in step (5) and the value before the input test specimen is introduced is, for example, less than 25 mg / l. For turbidity, the water quality may be considered satisfied if the difference is, for example, less than 2 degrees. For chromaticity, the water quality may be considered satisfied if the difference is, for example, less than 0.5 degrees. For pH, the water quality may be considered satisfied if the difference is, for example, less than 0.2.

[0044] As described above, the vane shear strength of the test specimen and the water quality of the flowing water are correlated based on the time elapsed since the preparation of the test specimen and the input specimen. In this case, the effect on the water quality of the flowing water from the input specimen changes depending on the flow velocity. Therefore, by changing the flow velocity and measuring the vane shear strength of the test specimen and the water quality of the flowing water at each time elapsed since the preparation of the test specimen and the input specimen, it is possible to correlate the vane shear strength of the test specimen and the water quality of the flowing water based on the elapsed time at each flow velocity.

[0045] Therefore, the method for obtaining quality indicators for plastic grout materials according to this embodiment obtains the relationship between the elapsed time since the preparation of the measurement specimen and the input specimen, the flow velocity under flowing water, the water quality of the flowing water, and the vane shear strength, which is a quality indicator of the plastic grout material.

[0046] The method for obtaining quality indicators for plastic grout according to this embodiment can evaluate the non-separation properties of the plastic grout underwater conditions.

[0047] <Construction management method for plastic grout> The construction management method for the plastic grout material according to this embodiment is a method for managing the construction of the plastic grout material based on quality indicators obtained by the quality indicator acquisition method described above, and includes the following steps (11) to (13).

[0048] (11) A step of determining the flow velocity in the flowing water environment at the construction site. (12) A step of determining the vane shear strength of the plastic injection material when the desired water quality of the flowing water at the construction site is satisfied based on the quality indicators. (13) A step to determine the shortest time from the formation of the plastic injection material to obtaining the vane shear strength of the plastic injection material determined in step (12), based on the quality indicators, at the flow velocity of the flowing water determined in step (11).

[0049] In step (11), the flow velocity of the water at the construction site of the plastic grout is determined. The flow velocity of the water at the construction site, which is in a water-flowing environment, is determined in order to use the relationship between the vane shear strength of the plastic grout obtained by the method for obtaining quality indicators of the plastic grout described above, the flow velocity of the water, and the water quality of the water.

[0050] The flow velocity is determined by measuring the flow velocity of the water in the flowing water environment at the site where the plastic injection material is applied. There are no particular limitations on the method of measuring the flow velocity, and it can be done by known methods. Examples of methods for measuring the flow velocity include measurement using an electromagnetic anemometer, measurement using a propeller anemometer, and measurement using a float.

[0051] In step (12), the vane shear strength of the plastic grout is determined based on quality indicators, so as to satisfy the required water quality of the flowing water at the construction site.

[0052] The above-described method for obtaining quality indicators allows for the acquisition of relationships between the elapsed time since the preparation of the measurement specimens and the injection specimens, the flow velocity under flowing water, the water quality of the flowing water, and the vane shear strength, which is a quality indicator of the plastic grout material. From the acquired relationships, the vane shear strength of the plastic grout material that satisfies the water quality of the flowing water at the construction site where the plastic grout material is injected can be determined. More specifically, the value of the vane shear strength that satisfies the water quality of the flowing water at the flow velocity determined in process (11) is obtained from the relationship between the water quality of the flowing water and the vane shear strength of the plastic grout material.

[0053] The vane shear strength to be determined is not particularly limited as long as it satisfies the water quality requirements of the flowing water. From the viewpoint of the application time of the plastic grout, the vane shear strength to be determined is preferably the minimum vane shear strength that satisfies the water quality requirements.

[0054] In step (13), based on quality indicators, the shortest time from the formation of the plastic injection material to obtaining the vane shear strength of the plastic injection material determined in step (12) is determined at the flow velocity of the water determined in step (11).

[0055] The time it takes for the plastic grout to reach the vane shear strength of the plastic grout determined in process (12) can be determined from the relationship obtained by the quality index acquisition method described above. Processes (11) and (12) determine the required vane shear strength at the construction site in a flowing water environment where the plastic grout is injected. The shortest time it takes for the vane shear strength of the plastic grout to reach the determined vane shear strength can be determined from the relationship between the elapsed time since the preparation of the measurement specimen and the vane shear strength of the measurement specimen in the quality index acquisition method described above.

[0056] The construction management method for the plastic grout material according to this embodiment allows for the management of the construction of the plastic grout material based on a quality index that evaluates the non-separation of the plastic grout material under flowing water. [Examples]

[0057] The following describes embodiments of the present invention, but the present invention is not limited to the following embodiments.

[0058] [Acquisition of quality indicators for plastic injection materials] <Preparation of specimens for measurement and for input> Solution A and Solution B were prepared using the components and proportions shown in Table 1. Specifically, Solution A was prepared by mixing with a hand mixer at 550 rpm for 3 minutes at an ambient temperature of 20°C. Solution B was prepared in the same manner as Solution A, except that the mixing time was 10 minutes. Next, Solution A was added to the container of Solution B in a volume ratio of 1:2, and mixed with a hand mixer at 550 rpm for 20 seconds to prepare cylindrical test specimens for measurement and test specimens for input (diameter 56.4 mm, height 45.6 mm).

[0059] Details of each component are shown below. Material A: Ultra-fast-setting cement (manufactured by Sumitomo Osaka Cement Co., Ltd.) Delaying agent: Oxycarboxylic acid (commercially available) Liquid A fluidizer: Polycarboxylic acid-based high-performance water-reducing agent (commercially available) Material B: Bentonite (commercially available, swelling degree 20ml / 2g or more) Liquid B fluidizer: Polyacrylate-based dispersant (commercially available)

[0060] [Table 1]

[0061] After preparing the test specimens for measurement and the test specimens for input, the test specimens were used for the following measurements of vane shear strength and water quality of the flowing water, respectively, after 5 minutes, 15 minutes, 30 minutes, 45 minutes, 60 minutes, and 75 minutes.

[0062] <Measurement of vane shear strength> The vane shear strength of the test specimens was measured using a vane shear test. The vane shear test used miniature vanes with a blade width of 15 mm and a length of 30 mm, or a blade width of 30 mm and a length of 60 mm. The vane blade was pressed vertically into the test specimen to a predetermined position, and the vane shear strength was measured from the resistance value when it was rotated.

[0063] <Water quality measurement of flowing water> The equipment and measurement conditions used for measuring the water quality of the flowing water are shown below. • Circulating water tank (manufactured by Maruto Seisakusho Co., Ltd.) Flow velocity: 0.1~1.0m / s Water temperature: 17±3℃ Water depth: 8cm Water amount: approx. 0.034m 3 • Suspended Solids (SS) Measurement: Portable Turbidity / SS / Sludge Interface Meter (manufactured by Toa DKK Co., Ltd.) • Chromaticity measurement: Portable colorimeter (manufactured by Nippon Denshoku Industries Co., Ltd.) • pH measurement, turbidity measurement: Simple portable multi-parameter water quality meter (manufactured by Toa DKK Co., Ltd.)

[0064] The water quality of the flowing water was measured using the following procedure. [1] The test specimens for input were placed into the circulating water tank. [2] After introducing the test specimens, expose them to running water for 2 minutes. [3] Remove the test specimens for input from the circulating water tank. [4] The amount of suspended solids (SS), turbidity, color, and pH of the water flowing in the circulating water tank were measured. [5] Increase the flow velocity of the water in the circulating tank by 0.1 to 0.3 m / s. Repeat steps [6][1] to [5].

[0065] Using the prepared test specimens and input specimens, vane shear tests and water quality measurements of the flowing water were performed. The results are shown in Tables 2 and 3.

[0066] [Table 2]

[0067] [Table 3]

[0068] By measuring the vane shear strength of the test specimens and the water quality of the flowing water into which the test specimens were introduced, we were able to obtain the relationship between the time elapsed since the preparation of the test specimens and the test specimens, the flow velocity under flowing water, the water quality of the flowing water, and the vane shear strength of the plastic injection material.

[0069] Furthermore, these relationships demonstrated that the vane shear strength of the test specimens can be used as a quality indicator for plastic grout under flowing water.

[0070] Furthermore, by obtaining the relationship between the elapsed time since the preparation of the measurement specimens and the input specimens, the flow velocity under flowing water, the water quality of the flowing water, and the vane shear strength of the plastic grout, it becomes possible to manage the construction of the plastic grout using the vane shear strength of the plastic grout as a quality indicator.

[0071] For example, suppose the water flow velocity at the site where the plastic grout is applied is 0.5 m / s, and the standard for satisfying the water quality is a suspended solids (SS) amount of less than 25 mg / l. In that case, from Tables 2 and 3, at a water flow velocity of 0.5 m / s, the vane shear strength value is 0.48 kN / m 2 At that time, the SS value was 55 mg / l (elapsed time 15 minutes), and the vane shear strength value was 0.57 kN / m 2 In this case, the SS value is 22 mg / l (after 30 minutes). Therefore, when the water flow velocity is 0.5 m / s, the vane shear strength of this plastic grout that satisfies the water quality requirements is 0.57 kN / m 2 That concludes the explanation.

[0072] Therefore, at the site where the plastic grout is applied, the vane shear strength of the plastic grout is 0.57 kN / m 2 If the values ​​are above these levels, there will be no impact on the water flow environment at the construction site.

[0073] Furthermore, since the relationship between the elapsed time since the preparation of the test specimen and the vane shear strength of the test specimen has also been obtained, it is possible to determine the shortest time required to reach the vane shear strength necessary to satisfy the water quality requirements of the flowing water at the site where the plastic grout is applied. In the above case, the value of the vane shear strength that satisfies the water quality requirements of the flowing water is 0.57 kN / m 2 Based on the above, the shortest time required to achieve the vane shear strength value can be determined to be 30 minutes. Therefore, the application of the plastic injection material can be appropriately managed. [Explanation of symbols]

[0074] 1...Miniature vane, 2...Rod, 3...Vane blade, 4...Torque meter

Claims

1. A method for obtaining quality indicators for plastic injection materials, The following steps (1) to (5) are included: Based on the vane shear strength of the test specimens measured in steps (3) and (5) below, and the water quality of the flowing water, the vane shear strength of the test specimens when the flowing water satisfies the desired water quality is adopted as a quality indicator for the plastic injection material. A method for obtaining quality indicators for plastic grout materials, which involves obtaining the relationship between the elapsed time since the preparation of the measurement specimens and the input specimens, the flow velocity under flowing water, the water quality of the flowing water, and the vane shear strength, which is a quality indicator of the plastic grout material. (1) A process for preparing test specimens for measuring the vane shear strength of plastic injection material and test specimens for immersion in flowing water. (2) A step of allowing a predetermined amount of time to elapse after preparing the test specimens for measurement and the test specimens for input. (3) A step of measuring the vane shear strength of the test specimen after a predetermined time has elapsed in step (2). (4) A step of introducing the test specimens for input, which have elapsed a predetermined time in step (2), into flowing water adjusted to a predetermined flow rate. (5) A step in which the test specimen to be introduced in step (4) is placed under flowing water, and after a predetermined time has elapsed, the water quality of the flowing water is measured.

2. The measurement of the water quality of the flowing water in step (5) involves measuring at least one of the following: amount of suspended solids, turbidity, color, and pH. A method for obtaining quality indicators as described in claim 1.

3. A method for managing the construction of a plastic injection material in a construction site, based on a quality index obtained by the quality index acquisition method described in claim 1 or 2, A method for managing the construction of plastic injection materials, including the following steps (11) to (13). (11) A step of determining the flow velocity in the flowing water environment at the construction site. (12) A step of determining the vane shear strength of the plastic grout when the desired water quality of the flowing water at the construction site is satisfied based on the quality indicators. (13) A step of determining the shortest time from the formation of the plastic injection material to obtaining the vane shear strength of the plastic injection material determined in step (12), based on the quality indicators, at the flow velocity of the flowing water determined in step (11).

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