Method for estimating flow value, method for determining flow value, and method for adjusting the mix of fluidized soil.

Abstract

This paper proposes a method for estimating flow values, a method for determining flow values, and a method for adjusting the mix of fluidized soil using these results, in order to confirm in a manufacturing plant that the fluidized soil has the desired initial fluidity. [Solution] The system includes an initial flow value measurement step for measuring the initial flow value, which is the cylinder flow value of the fluidized soil immediately after manufacturing; a resting step for leaving the fluidized soil undisturbed for a period longer than the expected transport time; a resting flow value measurement step for measuring the resting flow value, which is the cylinder flow value of the rested fluidized soil; and a stirred flow value calculation step for determining the stirred flow value, which is the cylinder flow value after stirring that corresponds to the resting flow value, based on a relationship between the cylinder flow value of the fluidized soil left undisturbed according to the transport time and the cylinder flow value of the fluidized soil stirred according to the transport time, thereby estimating the stirred flow value as the cylinder flow value after transport.

Description

Technical Field

[0001] The present invention relates to a flow value estimation method, a flow value determination method, and a mix adjustment method for fluidized treated soil.

Background Art

[0002] Fluidized treated soil produced by adding and mixing a solidifying material and water to soil is sometimes used as a backfilling material or a filling material for cavities and the like. Since fluidized treated soil has fluidity and does not require rolling or compaction, it can be used for backfilling and filling places where rolling compaction is difficult, such as narrow spaces.

[0003] In urban construction sites, due to factors such as site area constraints, it is difficult to install a fluidized treated soil production plant on site, so the material is sometimes carried in from a production plant installed at a remote location. On the other hand, since the hydration reaction of fluidized treated soil progresses over time, when the material is carried in from a production plant outside the construction site, there is concern about a decrease in the fluidity of the fluidized treated soil.

[0004] For this reason, Patent Document 1 discloses a method of producing fluidized treated soil at a construction site: after transporting muddy water obtained by adding water to soil to the construction site by a mixer truck, a solidifying material slurry is charged into the mixer truck at the construction site and stirred and mixed.

Prior Art Literature

Patent Literature

[0005]

Patent Document 1

Summary of Invention

Problem to be Solved by the Invention

[0006] The construction method for fluidized soil described in Patent Document 1 requires either installing a plant for manufacturing the solidifying agent slurry on the construction site or transporting the solidifying agent slurry from a manufacturing plant located at a separate location. Therefore, it cannot be used at construction sites where it is difficult to place a manufacturing plant for the solidifying agent slurry or where it is difficult to deploy multiple transport vehicles. In addition, it is necessary to conduct on-site inspections to confirm that the manufactured fluidized soil has the desired quality, which is time-consuming.

[0007] From this perspective, the present invention aims to propose a flow value estimation method, a flow value determination method, and a method for adjusting the mix of fluidized soil using these results, for confirming at the manufacturing plant that the fluidized soil manufactured at the manufacturing plant has secured the desired initial fluidity, even when the fluidized soil manufactured at the manufacturing plant is transported to a construction site far from the manufacturing plant. [Means for solving the problem]

[0008] The present invention provides a flow value estimation method for solving the aforementioned problems, which estimates the cylinder flow value after transport of fluidized soil prepared under predetermined mixing conditions, and comprises: an initial flow value measurement step of measuring an initial flow value, which is the cylinder flow value of the fluidized soil immediately after production; a resting step of letting the fluidized soil stand for a period longer than the expected transport time; a resting flow measurement step of measuring a resting flow value, which is the cylinder flow value of the rested fluidized soil; and a stirred flow value calculation step of determining a stirred flow value, which is the cylinder flow value after stirring corresponding to the resting flow value, using a relationship formula between the cylinder flow value of the fluidized soil after resting for a predetermined time and the cylinder flow value of the fluidized soil after stirring for a predetermined time, thereby estimating the stirred flow value as the cylinder flow value after transport. It is preferable to use equations 1 and 2 in the relationship formula.

[0009]

number

[0010] According to this flow value estimation method, the fluidity after transportation can be estimated from the change in fluidity over time in the static state of the manufactured fluidized soil. In other words, by determining whether the cylinder flow value estimated by the flow value estimation method satisfies the cylinder flow value required for the construction of the fluidized soil, it is possible to determine whether the manufactured fluidized soil has secured the initial fluidity required for construction. Therefore, it becomes possible to determine whether the fluidized soil has secured the desired initial fluidity, taking into account the elapsed time from manufacturing to construction. Furthermore, since the work of checking the properties of the fluidized soil at the construction site can be omitted, it offers excellent workability.

[0011] Furthermore, if it is determined that the cylinder flow value estimated by the flow value estimation method does not meet the cylinder flow value required for the construction of the fluidized soil, it is desirable to calculate the difference between the agitated flow value and the cylinder flow value required for construction, and adjust the mixing conditions so that the cylinder flow value of the fluidized soil immediately after production is the initial flow value plus the difference α. In this way, the mixing ratio is determined taking into account the decrease in fluidity over time, making it possible to produce fluidized soil that is appropriate for the construction site. [Effects of the Invention]

[0012] According to the flow value estimation method, flow value determination method, and mixture adjustment method for fluidized soil of the present invention, it is possible to determine whether the fluidized soil has secured the desired initial fluidity, taking into account the elapsed time from manufacturing to construction (transportation time from the manufacturing plant to the construction site), and to set mixture conditions suitable for the construction conditions. [Brief explanation of the drawing]

[0013] [Figure 1] This flowchart shows the procedure for the flow value estimation method according to an embodiment of the present invention. [Figure 2] This graph shows the change in cylinder flow value over time, where (a) is for formulation 1 and (b) is for formulation 2. [Figure 3] This graph shows the ratio of flow values ​​under mixing conditions and static conditions. [Figure 4] This is a reference diagram illustrating an example of a method for determining initial liquidity. [Modes for carrying out the invention]

[0014] In an embodiment of the present invention, when fluidized soil manufactured at a manufacturing plant is transported to a construction site located away from the manufacturing plant, a reasonable initial fluidity is determined considering the amount of decrease in fluidity during transportation of the fluidized soil, and the mix of the fluidized soil is determined so as to ensure this initial fluidity. Specifically, first, the cylinder flow value after transportation of the fluidized soil prepared under predetermined mix conditions is estimated, and then it is determined whether the estimated cylinder flow value after transportation meets the cylinder flow value required for the construction of the fluidized soil, that is, whether mix adjustment is necessary (flow value determination method). If it is determined as a result of the determination that mix adjustment is necessary, the mix is ​​adjusted so as to ensure initial fluidity (mix adjustment method for fluidized soil).

[0015] First, we will explain the flow value estimation method for estimating the cylinder flow value after transport. Figure 1 shows the procedure for the flow value estimation method. As shown in Figure 1, the flow value estimation method comprises an initial flow value measurement step S1, a standing step S2, a standing flow value measurement step S3, and a stirring flow value calculation step S4. The method for measuring the cylinder flow value is not limited, but in this embodiment, we use "NEXCO Test Method 313 1999 Test Method for Air Mortar and Air Milk".

[0016] In the initial flow value measurement process S1, the initial flow value, which is the cylinder flow value of the fluidized soil immediately after production, is measured. The fluidized soil is produced by mixing soil, water, a solidifying agent, and a foaming agent in a mixer according to predetermined mixing conditions. The materials that make up the fluidized soil are not limited.

[0017] In the standing process S2, the fluidized soil is left to stand for a period longer than the expected transport time (a predetermined time). In the static flow value measurement step S3, the static flow value, which is the cylinder flow value of the static fluidized treated soil, is measured. That is, the cylinder flow value is measured after the standing step S2, and the obtained cylinder flow value is taken as the static flow value.

[0018] In the stirring flow value calculation step S4, the stirring flow value, which is the cylinder flow value after stirring corresponding to the static flow value, is obtained. Then, this stirring flow value is estimated as the cylinder flow value after transportation. The stirring flow value is obtained by relational expressions (Equations 1 and 2) between the cylinder flow value of the fluidized treated soil that has been left standing according to the transportation time and the cylinder flow value of the fluidized treated soil that has been stirred according to the transportation time. These relational expressions relate to the measured cylinder flow value F obtained when the fluidized treated soil is left standing immediately after production, and the elapsed time from production reaches a predetermined time t l and the measured cylinder flow value Fm obtained when the fluidized treated soil is stirred immediately after production, and the elapsed time from production reaches the predetermined time t (see FIG. 3). For the relational expressions, those preset according to the mixing conditions are used.

[0019]

Mathematics

[0020] Next, it is determined whether the estimated cylinder flow value after transportation satisfies the cylinder flow value required for the construction of the fluidized treated soil. The cylinder flow value required for the construction of the fluidized treated soil is set in advance.

[0021] As a result of the determination, when it is determined that the estimated cylinder flow value after transportation does not satisfy the cylinder flow value required for the construction of the fluidized treated soil, a difference α between the stirring flow value and the cylinder flow value required for the construction is calculated, and the mixing conditions are adjusted so that the cylinder flow value of the fluidized treated soil immediately after production becomes a value obtained by adding the difference α to the initial flow value (for example, increasing the water content ratio).

[0022] Hereinafter, an example of the method for setting the relational expression will be described. First, fluidized soil was produced using the two formulations shown in Table 1. The change in cylinder flow value over time was measured under two conditions: when the soil was left undisturbed in a bucket until measurement (static conditions) and when it was mixed in an agitator truck (transport conditions). The measurement results are shown in Figure 2.

[0023] [Table 1]

[0024] As shown in Figures 2(a) and (b), both formulations exhibited similar fluidity under both conditions for the first 60 minutes after production. After 60 minutes, differences in fluidity (slope) emerged depending on the conditions (static conditions and transport conditions).

[0025] Figure 3 shows the relationship between the ratio K of cylinder flow values ​​and elapsed time under the transport and static conditions shown in Figure 2. The relationship between the ratio K of cylinder flow values ​​and elapsed time t was fitted by assuming K=1 up to 60 minutes, and then increasing linearly thereafter. As a result, a good coefficient of determination was obtained, as shown in Figure 3. Equations 3 and 4 are relational equations in which coefficients a, b, and T were set based on Figure 3.

[0026]

number

[0027] According to the flow value estimation method of this embodiment, the fluidity after transportation can be estimated from the change in fluidity over time in the static state of the manufactured fluidized soil. In other words, by determining whether the cylinder flow value estimated by the flow value estimation method of this embodiment (a cylinder flow value that takes into account the elapsed time from manufacturing to construction) satisfies the cylinder flow value required for the construction of the fluidized soil, it is possible to determine whether the manufactured fluidized soil has secured the initial fluidity necessary for construction. Therefore, it is possible to determine whether the fluidized soil has secured the desired initial fluidity, taking into account the elapsed time from manufacturing to construction. Furthermore, since it is not necessary to check the properties of the fluidized soil at the construction site, it offers excellent workability.

[0028] Furthermore, if the cylinder flow value estimated by the flow value estimation method is determined to be insufficient to meet the cylinder flow value required for the construction of the fluidized soil, the difference between the agitated flow value and the cylinder flow value required for construction is calculated. By adjusting the mixing conditions so that the cylinder flow value of the fluidized soil immediately after production is equal to the initial flow value plus the aforementioned difference α, the mixing ratio can be determined while anticipating the decrease in fluidity over time, and consequently, fluidized soil can be manufactured to suit the construction site (see Figure 4).

[0029] Embodiments of the present invention have been described above. However, the present invention is not limited to the embodiments described above, and each of the above-described components can be modified as appropriate without departing from the spirit of the present invention. Each coefficient in Equations 1 and 2 may be set based on existing data using the same raw materials (soil and solidifying agent), or it may be determined by conducting tests based on the mixing conditions in advance. [Explanation of Symbols]

[0030] S1 Initial flow value measurement process S2 Standing process S3 Static flow value measurement process S4 Stirring flow value calculation process

Claims

1. A flow value estimation method for estimating the cylinder flow value after transportation of fluidized soil prepared under predetermined mixing conditions, An initial flow value measurement step, which measures the initial flow value, which is the cylinder flow value of the fluidized soil immediately after manufacturing, A settling process in which the aforementioned fluidized soil is left to stand for a period longer than the expected transport time, A static flow value measurement step is performed to measure the static flow value, which is the cylinder flow value of the fluidized soil that has been left to stand. The system includes a stirring flow value calculation step, which determines the stirred flow value, which is the cylinder flow value after stirring that corresponds to the static flow value, based on a relationship formula between the cylinder flow value of fluidized soil that has been left to stand for a predetermined time and the cylinder flow value of fluidized soil that has been stirred for a predetermined time. A flow value estimation method characterized by estimating the aforementioned agitation flow value as the cylinder flow value after transport.

2. The flow value estimation method according to claim 1, characterized in that the stirring flow value is determined using the relational equations shown in equations 1 and 2 in the stirring flow value calculation step. [Math 1]

3. A flow value determination method characterized by determining whether the cylinder flow value after transport, estimated by the flow value estimation method described in claim 1 or claim 2, satisfies the cylinder flow value required for the construction of fluidized soil.

4. In the flow value determination method described in claim 3, if it is determined that the cylinder flow value required for the construction of the fluidized soil is not met, The difference α between the aforementioned stirring flow value and the cylinder flow value required for construction is calculated. A method for adjusting the mix of fluidized soil, characterized by adjusting the mix conditions so that the cylinder flow value of the fluidized soil immediately after manufacturing is the initial flow value plus the difference α.

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