JP2014001577A - Injection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an injection method which can prevent a structure whose strength is relatively low from being damaged by a fluid pressure of solidification materials when injecting (filling) the solidification materials into a cavity on a back of the structure, and can shorten a construction period.SOLUTION: Solidification materials are injected (filled) into an area to be constructed separately in a plurality of times. The solidification materials contain water and cement. After the solidification materials precedently injected (filled) into the area become non-flowable (being in a state of not flowing), the following solidification materials are injected (filled) into the area. When the penetration resistant value of the solidification materials precedently injected (filled) into the area reaches to 0.01 N/mm, it is determined that they are in a non-flowable state (a state of not flowing).

Description

  The present invention relates to an injection method, and more particularly to an injection method that performs so-called “backfilling” in which a solidified material is injected (filled) into a back space of a structure.

  In the prior art, in the method of injecting (filling) the solidification material into the back gap of the structure (so-called “backfill filling”), when the solidification material is injected (filled) over the entire back gap (so-called “total injection”) However, if the strength of the structure is weak, there is a problem that the region below the structure is damaged by the liquid pressure of the injected (filled) solidified material.

  In order to cope with such a problem, conventionally, when injecting (filling) the solidified material into the back space, the solidified material is injected (filled) in multiple times, and the previously injected (filled) solidified material is solidified. After that, the solidifying material of the next stage was injected (filled). Since the solidified material previously injected (filled) solidifies, the liquid pressure of the solidified solidified material does not act on the region below the structure, so the solidified material pressure acting on the region below the structure decreases. This is because damage to the lower region of the structure is prevented. If the solidifying material is solidified, it is not necessary to support the liquid pressure of the solidifying material in the lower region of the structure, and damage due to the solidifying material liquid pressure is prevented.

However, it takes time for the solidified material to solidify. Usually, it takes a whole day from injecting (filling) the solidified material to solidifying.
In the above prior art, if the solidifying material is injected (filled) in a plurality of times, the work period for injecting (filling) the solidified material into the back space of the structure becomes longer, and the construction cost increases. Resulting in.

Here, if the chemical | medical agent (rapid hardening agent, quick setting agent) which accelerates | stimulates solidification is added with respect to a solidification material, the time until it solidifies is shortened.
However, if the time until solidification is shortened, the fluidity of the solidified material deteriorates, and a new problem arises that the solidified material is not sufficiently injected (filled) into the voids on the back surface of the structure.

As another conventional technique, for example, a technique of mixing cement milk and a plasticizing material immediately before pouring (filling) has been proposed.
However, when the flowability of the mixed injection material is good, the construction period becomes long, and if the time until solidification is short, the above-described problem that the gap is not injected (filled) cannot be solved.

JP 2010-235721 A

  The present invention has been proposed in view of the above-mentioned problems of the prior art, and when the solidifying material is injected (filled) into the back space of the structure having relatively low strength, the structure is subjected to the liquid pressure of the solidifying material. The purpose of the present invention is to provide an injection method that can be prevented from being damaged and that can shorten the construction period.

As a result of research, the inventor divided and injected the solidified material into a plurality of times, and if the previously injected (filled) solidified material is not fluidized (non-fluidized state), the region above it Even if the solidified material is injected (filled) into the structure, the liquid pressure of the non-solidified solidified material that has not solidified and the liquid pressure of the newly injected (filled) solidified material should not act on the lower region of the structure. I found
In other words, the inventor is injecting (filling) the non-flowing solidified material into the liquid pressure of the non-flowing solidified material and the liquid pressure of the newly injected (filled) fluidized solidifying material. It was discovered that a solidified material in a fluidized state can be newly injected (filled) into a region above the solidified material in a non-flowable state without acting on the region.
The present invention has been created based on such knowledge.

The injection method of the present invention is to inject (fill) the solidified material in multiple times for the area to be constructed,
The solidifying material includes water and cement,
After the solidified material previously injected (filled) into the region is in a non-flowing state (non-flowing state), the solidifying material following the region is injected (filled),
When the penetration resistance value of the solidified material previously injected (filled) into the region becomes 0.01 N / mm ² , it is characterized in that it is determined as a non-flowing state (non-flowing state).

In the present invention, the state where the penetration resistance value is 0.01 N / mm ² is the state where the flow value measured using a slump cone having an inner diameter of 80 mm is 80 mm.
In carrying out the present invention, the time until the penetration resistance value of the solidified material becomes 0.01 N / mm ² in advance, or the time until the flow value measured using a slump cone having an inner diameter of 80 mm becomes 80 mm. It is preferable to determine that “the solidified material has become non-flowing” if the measured time has elapsed since the measurement and the solidified material was produced by mixing and stirring water and cement.

In the present invention, the solidifying material includes a non-fluidizing agent (rapid hardener, quick setting agent) and a water reducing agent, and adjusts the time until the solidifying material becomes non-flowing depending on the amount of the water reducing agent added. Is preferred.
Here, as the non-fluidizing agent, for example, a calcium aluminate-based rapid hardener is preferable.
As the water reducing agent, a water reducing agent mainly composed of naphthalenesulfonic acid / formalin condensate soda (for example, trade name “Mighty 150R” sold by Kao Corporation) is preferable.

According to the present invention having the above-described configuration, the solidified material that has become non-flowing is subjected to frictional resistance from the periphery of the injected (filled) region, and the liquid of the solidified material in which this frictional resistance acts downward in the vertical direction. It is estimated that the fluid pressure is canceled out by resisting the pressure.
As a result, even when the strength is injected (filled) into the structure back space, the structure is not damaged because the liquid pressure of the solidifying material does not act below the structure. .
Since the time until the solidified material becomes non-flowing is much shorter than the solidifying time, according to the present invention, the solidified material is divided into a plurality of times for the region to be injected (filled). Even if it is injected (filled) in this way, the working time is greatly reduced as compared with the prior art which waits for a long time until the solidified material is solidified.

In the present invention, the solidifying material includes a non-fluidizing agent (rapid hardener, quick setting agent) and a water reducing agent, and the time until the solidifying material becomes non-flowing is adjusted by the amount of the water reducing agent added. If it makes it, the permeability of a solidification material can be adjusted suitably.
In other words, the amount of water reducing agent added is adjusted according to the conditions of the construction area where the solidifying material is to be injected (filled), and thus the time until the solidifying material becomes non-flowing is set. It is possible to optimally adjust the permeability of the solidified material according to the conditions (construction conditions) at the site where the material is to be injected (filled).

It is sectional drawing which shows the slope and structure to which embodiment of this invention is applied. In embodiment of this invention, it is sectional drawing which shows the state which inject | poured (filled) the solidification material only to the downward area | region of the space | gap of a structure back surface. In embodiment of this invention, it is sectional drawing which shows the state which inject | poured (filled) the solidification material after the solidification material lost fluidity | liquidity. It is sectional drawing which shows the case where a solidification material is newly inject | poured (filled) in the state which has not lost the fluidity | liquidity. It is a flowchart which shows the procedure of solidification material injection | pouring (filling) of embodiment. It is explanatory drawing which shows the experimental apparatus used in Experimental example 1. FIG. It is explanatory drawing which shows the experimental apparatus used in Experimental example 2. FIG. FIG. 10 is a process diagram illustrating a procedure of Experimental Example 2. It is a characteristic figure which is the result of Experimental example 2 and shows the relationship between the penetration resistance value and the loaded load. FIG. 10 is a characteristic diagram showing the correlation between the penetration resistance value and the loading stress obtained by eliminating the inaccurate data in FIG. It is explanatory drawing which shows the experimental apparatus used in Experimental example 3. FIG. FIG. 12 is a characteristic diagram showing a time-dependent change characteristic of a flow value obtained in Experimental Example 3. It is a characteristic view which shows the time-dependent change characteristic of the penetration resistance value calculated | required in Experimental example 3. FIG. It is a characteristic view which shows the relationship between the flow value calculated | required in Experimental example 3, and penetration resistance value. It is explanatory drawing which shows the experimental apparatus used in Experimental example 4. It is the characteristic view calculated | required in Experimental example 4, Comprising: The relationship between the flow value and the penetration length of a solidification material is shown. It is the characteristic figure calculated | required in Experimental example 5, Comprising: The water reducing agent addition amount and the relationship between time until a solidification material becomes non-fluidized are shown. FIG. 17 is a characteristic diagram obtained in Experimental Example 5 using samples with different blending, and shows the relationship between the amount of the water reducing agent added and the time until the solidifying material becomes non-fluidized. FIG. 11 is a characteristic diagram showing the relationship between the amount of water reducing agent added and the time until the solidified material becomes non-fluidized when water reducing agent addition is pre-added, and shows the experimental results of Experimental Example 6. FIG. 10 is a characteristic diagram showing the relationship between the amount of water reducing agent added and the time until the solidified material becomes non-fluidized when the water reducing agent addition is post-addition, and shows the experimental results of Experimental Example 6. It is a characteristic view which shows the time-dependent change of the flow value of the solidification material calculated | required in Experimental example 7. In Experimental example 7, it is a characteristic view which shows the time-dependent change of the flow value of the solidification material calculated | required on the temperature conditions different from FIG. In Experimental Example 7, it is a characteristic figure which shows the time-dependent change of the flow value of the solidification material calculated | required by changing the temperature conditions different from FIG. 21, FIG. In Experimental Example 7, it is a characteristic view showing the change over time of the flow value of the solidified material obtained under a temperature condition different from that in FIG. In Experimental example 7, it is a characteristic view which shows the time-dependent change of the flow value of the solidification material calculated | required by changing the temperature conditions different from FIGS. 21-24, and a water reducing agent addition ratio.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Initially, with reference to FIGS. 1-5 and Table 1, the procedure of the injection construction method which concerns on embodiment of this invention is demonstrated.
In FIG. 1, a structure 4 (for example, a wall surface formed by spraying concrete) is built on the slope 3 of the natural ground 2. A gap 1 (a back gap of the structure 4) is generated in the back part of the structure 4 (the natural mountain 2 side: the right side in FIG. 1). The gap 1 is a space that exists between the structure 4 and the natural ground 2 (the slope 3), and is a cavity that extends substantially parallel to the slope 3.
The presence of the back gap 1 adversely affects the stability of the structure 4. Therefore, the solidification material is injected (filled) into the back gap 1 by an injection method.
In FIG. 1, the distance between the back gap 1 (the distance between the structure 4 and the natural ground 2 (or slope 3)) is indicated by the symbol D. However, the distance D is not always constant in the entire vertical direction of the back gap 1. Further, the inclination angle of the natural ground 2 (or slope 3) is indicated by the symbol θ.

In the first step S1 in FIG. 5, a solidifying material is injected (filled) into the back gap 1 shown in FIG. Here, the solidified material is not injected (filled) into the entire region of the back gap 1. It is injected (filled) only into a predetermined range below the back gap 1. The “predetermined range” in which the solidifying material is injected (filled) is set so that the structure 4 is not broken by the liquid pressure of the injected (filled) solidifying material.
FIG. 2 shows a state in which the solidifying material is injected (filled) in a predetermined range. In FIG. 2, the fluid pressure of the injected (filled) solidified material is indicated by the symbol Pw, the height dimension of “predetermined range” where the solidified material is injected (filled) is H1, and the solidified material (filler). If the weight (specific gravity) per unit volume of Mk is γ, the hydraulic pressure Pw at the bottom 1b of the back gap 1 is
Pw = γ · H1

In the second step S <b> 2 of FIG. 5, it is determined whether or not a predetermined amount of solidified material has been injected (filled) into the back space 1. If the solidified material is not injected (filled) into the back space 1 by a predetermined amount (NO in the second step S2), the injection (filling) operation is performed until a predetermined amount of solidified material is injected (filled) into the back space 1. To continue.
If the solidifying material is injected (filled) into the back gap 1 by a predetermined amount (the second step S2 is YES: the state shown in FIG. 2), the process proceeds to the third step S3.
In the illustrated embodiment, the injection (filling) of the solidified material into the back space 1 is performed in two layers. FIG. 2 shows a state where the first layer (first lift L1) of solidifying material is injected (filled).

In the third step S3 in FIG. 5, it is determined whether or not the solidified material injected (filled) into the back space 1 has been non-fluidized (the solidified material has changed from a fluidized state to a non-fluidized state).
If the solidified material is not yet fluidized (NO in the third step S3), the process waits until the solidified material is fluidized (the third step S3 is a NO loop).
If the solidified material has become non-fluidized (the third step S3 is YES), the process proceeds to the fourth step S4.

Here, whether or not the solidified material is in a non-flowing state is determined by whether or not the penetration resistance value of the solidified material is 0.01 N / mm ² . Or it is judged by whether the flow value measured using the slump cone with an inner diameter of 80 mm has reached 80 mm. Of course, on condition that both the penetration resistance value of the solidified material becomes 0.01 N / mm ² and the flow value measured using the slump cone with an inner diameter of 80 mm becomes 80 mm. Also good.
At the time of construction, for example, the time until the penetration resistance value becomes 0.01 N / mm ² after the solidified material to be used is measured is measured in advance, or the inner diameter is 80 mm after the solidified material to be used is manufactured. The time until the flow value measured using the slump cone reaches 80 mm is measured in advance. And in construction, after mixing and stirring water and cement to produce a solidified material, whether or not the measured time has elapsed determines whether or not the solidified material has become non-flowing. .

In the fourth step S4 in FIG. 5, it is determined whether or not it is necessary to inject (fill) the solidified material in a region above the region in which the solidified material has been injected (filled).
As described above, in the illustrated embodiment, the injection (filling) of the solidified material into the back space 1 is performed in a plurality of layers (two layers) as shown in FIGS. That is, in the step shown in FIG. 2, the solidified material is injected (filled) into the first layer (first lift L1), and in the step shown in FIG. 3, the solidified material is injected into the second layer (second lift L2) ( Filled).
The height direction dimension H1 in FIGS. 2 and 3 is a prescribed height of the first layer (first lift L1). The hydraulic pressure Pw at the bottom 1b of the back gap 1 is expressed by the formula Pw = γ · H1 (where γ is the specific gravity of the solidified material) as described above.

In the fourth step S4 of FIG. 5, for example, in the state shown in FIG. 2, the second layer (second lift L2) is not yet injected (filled). In such a case, it is necessary to inject (fill) the solidified material into a region (second layer: second lift L2) above the region (first layer: first lift L1) where the solidified material is injected (filled). (The fourth step S4 is YES), the process returns to the first step S1, and the first step S1 and subsequent steps are repeated for the second layer (second lift L2) of solidifying material injection (filling). . And the state which solidification material injection | pouring (filling) of the 2nd layer (2nd lift L2) was completed is shown by FIG.
On the other hand, in the state shown in FIG. 3, the solidification material injection (filling) of the second layer (second lift L2) is also completed, and in the illustrated embodiment, the second layer (second lift L2) is located above the second layer (second lift L2). There is no need to inject (fill) the solidified material. Therefore, it is determined that it is not necessary to inject (fill) the solidified material into the region above the region (second layer: second lift L2) in which the solidified material is injected (filled) (fourth step S4). Is NO), the process proceeds to the fifth step S5 in FIG.

In the fifth step S5 of FIG. 5, whether or not to move to a region different from the region where the solidification material of the back gap 1 is injected (filled) and inject (fill) the solidification material into the other region. Determine whether.
If it is necessary to inject (fill) the solidified material in another region of the back gap 1 (YES in the first step S5), the process returns to the first step S1, and the first step S1 and subsequent steps are performed in the other region. Repeat again for.
If there is no region to be filled (filled) with the back gap 1, it is determined that there is no need to fill (fill) the solidified material into another filling (filling) location, and the operation is terminated.

FIG. 4 shows that the solidified material injected (filled) into the first layer (first lift L1) is not fluidized and is in a fluid state, and the solidified material is applied to the second layer (second lift L2). An injected (filled) state is shown.
In FIG. 4, the hydraulic pressure Pw of the solidified material at the bottom 1b of the back gap 1 is
Pw = γ · H1 + γ · H2 = γ (H1 + H2)
It becomes high pressure. Therefore, there exists a possibility that the area | region corresponding to the bottom part 1b of the structure 4 may destroy.

On the other hand, after the solidified material injected (filled) in the first layer (first lift L1) is non-fluidized as shown in FIG. 3, the solidified material is applied to the second layer (second lift L2). In the case of injection (filling), the distribution of the hydraulic pressure Pw is different from the state shown in FIG.
That is, the distribution of the hydraulic pressure Pw in FIG. 3 is maximum (Pwmx = γ) at the boundary between the first injection (filling) (first lift L1) and the second injection (filling) (second lift L2). H1), and the hydraulic pressure is lower in the region closer to the bottom 1b below the boundary (first lift L1). In FIG. 3, the hydraulic pressure Pw is zero at a position below the boundary by the dimension H3).
In other words, the hydraulic pressure Pw increases in the downward direction in FIG. 4, but goes downward in the region below the boundary between the first lift L1 and the second lift L2 (first lift L1) in FIG. The hydraulic pressure Pw is lowered as much as possible.

  In FIG. 3, in the region below the boundary between the first lift L1 and the second lift L2 (first lift L1), the reason why the hydraulic pressure Pw decreases as it goes downward is the non-flowing solidified material (first This is presumably because the solidified material in the lift L1 receives frictional resistance from the surroundings, and this frictional resistance resists the hydraulic pressure Pw acting downward in the vertical direction, thereby canceling out the hydraulic pressure Pw.

In FIG. 3, from the boundary between the first injection (fill) (1 lift L1) and the second injection (fill) (2 lift L2), the position where the hydraulic pressure Pw does not exist (Pw = 0). When the vertical distance to the position) is H3, the vertical distance H3 can be calculated by the following procedure.
By injecting (filling) the solidified material into the second lift L2, the load W directly generated on the upper surface of the first lift L1 is assumed to be constant in the width direction dimension D of the cavity 1.
W = γ · H 2 · D (Expression 1)
In FIG. 3, the frictional resistance F between the solidified material (filler) Mk existing in the region of the distance H3, the structure 4, and the natural ground 2 is
F = f · 2 (H3 / sin θ) (Expression 2)
Here, θ is the slope (tilt angle) of the slope 3.
When W = F, from Equation 1 and Equation 2,
H3 = (γ · H2 · D · sinθ) / 2f (Expression 3)
From this equation (3), H3 is obtained.

Assuming that D (cavity width) = 10 cm, θ (slope of slope) = 60 °, and γ = 15.68 kN / m ³ (density 1.6 g / cm ³ ), The results of calculating the value of H2 are shown in Table 1.
In addition, about the frictional resistance, the value of the loading model test by a VP pipe (vinyl chloride pipe) was used.

Table 1

According to Table 1, when the strength of the non-fluidized solidified material is P = 0.01 N / mm ² , even if the second lift is injected (filled) to a height of 1 m, the back gap of the structure 4 In FIG. 1, the hydraulic pressure Pw acts in the range of 24 cm from the first lift L1 (the range of 24 cm above the first lift L1), and the solidified material is injected without any problem (without destroying the structure 4). Filling).
In the calculation of Table 1, the value of the VP pipe is used as the frictional resistance. However, it is considered that the actual frictional resistance with the structure 4 and the natural ground 3 is larger than this. That is, in the calculation of Table 1, the frictional resistance is calculated to be smaller than that of the actual construction, which is a so-called “safe side” calculation.

As shown in Table 1, since H3 is much smaller than H2, there is no hydraulic pressure due to the solidified material injected (filled) in the lowermost part of the structure 4 (the part corresponding to the bottom 1b). It is understood that not.
Then, according to the injection method according to the illustrated embodiment, even if the solidifying material is injected (filled) into the back space 1 of the structure 4, excessive hydraulic pressure may act on the lower portion of the structure 4. It is understood that there is no.

Here, the time until the solidified material becomes non-fluid varies depending on the type of non-fluidizing agent and water reducing agent, addition method, and temperature conditions. Therefore, when constructing the injection method according to the illustrated embodiment, the time until the solidifying material is non-fluidized corresponds to the conditions at the construction site, and the type and amount of non-fluidizing agent and / or water reducing agent. It is possible to change freely by appropriately adjusting.
As the non-fluidizing agent, for example, a calcium aluminate-based rapid hardening agent can be used. As the water reducing agent, a water reducing agent mainly composed of naphthalenesulfonic acid / formalin condensate soda (for example, trade name “Mighty 150R” sold by Kao Corporation) can be used.

[Experimental Example 1]
In Experimental Example 1, even if a solidified material in a fluidized state is injected (filled) above the non-fluidized solidified material, the fluid pressure acts on the region where the non-fluidized solidified material is injected (filled). It is an experiment to confirm that it does not.
FIG. 6 shows the experimental apparatus 10 used in Experimental Example 1. In FIG. 6, the experimental apparatus 10 is configured as a casing, and includes a back plate 11, a pair of opposing side plates 12, a bottom plate 13, a front plate 14, and a lower opening / closing plate 15. Other members excluding the side plate 12 and the bottom plate 13 are acrylic plates.

Adjacent sides of the back plate 11, a pair of opposing side plates 12, and the front plate 14 are joined, and the upper end portion opens upward, and the opening is indicated by reference numeral 18.
In FIG. 6, the height direction dimension of the surface plate 14 and the height direction dimension of the lower opening / closing plate 15 are set to be approximately equal. The lower end of the surface plate 14 and the upper end of the lower opening / closing plate 15 are connected by a pair of hinges 16, and the lower opening / closing plate 15 rotates and can be opened and closed as indicated by an arrow R.
When the lower opening / closing plate 15 is closed, the lower end surface of the lower opening / closing plate 15 is flush with the bottom plate 13.

Table 2 shows the solidified material used in Experimental Example 1.
Table 2

As shown in Table 2, there are four types of materials used: ordinary Portland cement (symbol C), water (symbol W), non-fluidizing agent (symbol G), and water reducing agent (symbol SP). Here, a calcium aluminate-based rapid hardener was used as the non-fluidizing agent.
As a result of various tests, the test was carried out with a solidified material prepared by blending the materials in Table 1 in the proportions shown in Table 3 below.

Table 3

  In Table 3, W / C represents the mass ratio of tap water W to cement C, G / C represents the mass ratio of non-fluidizing agent G to cement C, and SP / C represents the mass ratio of water reducing agent to cement C. Is shown.

In Experimental Example 1, first, the lower opening / closing plate 15 in the experimental device 10 of FIG. 6 is kept closed by a lock mechanism (not shown), and the region below the experimental device 10 from the opening 18 (region of the lower opening / closing plate 15). The solidified material having the composition shown in Table 3 was injected (filled) into a region (region in the surface plate 14) above a predetermined range (a region corresponding to the height H3 in FIG. 3). Then, after the solidified material became non-fluid, the lower opening / closing plate 15 was rotated to be in an open state, and the newly adjusted solidified material was injected (filled) into the experimental apparatus 10 from the opening 18.
Whether or not the solidified material has become non-fluid, after the solidified material is manufactured in advance, the elapsed time when the flow value measured using a slump cone with an inner diameter of 80 mm is 80 mm is measured, and the solidified material is manufactured. When the elapsed time passed, it was determined that “the solidified material was non-fluidized”.
In the solidified material used in Experimental Example 1, after the solidified material was manufactured, the elapsed time when the flow value measured using a slump cone having an inner diameter of 80 mm was 80 mm, and the penetration resistance value was 0.01 N after the solidified material was manufactured. It has been confirmed by experiments by the inventors that the elapsed time of / mm ² is equal.

In Experimental Example 1, after the solidification material in the region of the lower opening / closing plate 15 and the region above the region by a predetermined range is non-fluidized, the newly produced solidification material in a state where the lower opening / closing plate 15 is opened. Injecting (filling) the solidified material was not pushed out of the open area.
This means that the fluid pressure of the solidifying material does not act on the region of the lower opening / closing plate 15, that is, the region where the non-fluidized solidifying material is injected (filled).
And if it is the area | region where the non-fluidized solidification material was inject | poured (filled), since a hydraulic pressure does not act even if it injects (fills) a new solidification material on the upper part, the injection construction method which concerns on illustration embodiment It was proved that there is no possibility that the structure 4 (see FIGS. 1 to 4) is destroyed by hydraulic pressure.

On the other hand, as a comparative experiment in Experimental Example 1, the stage before the solidified material injected (filled) into the region of the lower opening / closing plate 15 and the region above the region by a predetermined range is non-fluidized (the flow value is 80 mm). In the state before the intrusion value or the intrusion value before 0.01 N / mm ² ), the newly adjusted solidified material is injected (filled) from the opening 18 with the lower opening / closing plate 15 opened. )did.
In this case, the solidified material flowed out from the location where the lower opening / closing plate 15 was opened.
Therefore, when the solidified material injected (filled) in the region where the lower opening / closing plate 15 is located before the non-fluidized solidified material is injected (filled) from the opening 18, the liquid pressure of the solidified material is reduced. It was confirmed that it would work.

The non-fluidized solidified material receives a frictional resistance from a region above the lower opening / closing plate 15 (a region corresponding to the height H3 in FIG. 3) from the lower opening / closing plate 15 and is subjected to the friction. The hydraulic pressure resulting from the total mass of the solidified material that has become non-fluidized and the newly injected (filled) solidified (hydraulic pressure acting downward in the vertical direction: hydraulic pressure acting on the area of the lower opening / closing plate 15) It is estimated that the hydraulic pressure (hydraulic pressure acting downward in the vertical direction) is canceled out due to sufficient resistance.
On the other hand, for the solidified material that has not been fluidized, the above-described frictional force does not act sufficiently and is insufficient to cancel the hydraulic pressure due to the solidified material, so the opened lower opening / closing plate 15 is opened. It is estimated that the solidified material has flowed out from the location.

[Experiment 2]
Next, after the solidified material is non-fluidized, how much penetration resistance value can be injected (filled) above the non-fluidized solidified material (how much) An experiment was conducted (loading model experiment).
In addition, the solidification material used in Experimental Example 2 is the same as the solidification material used in Experimental Example 1.

FIG. 7 shows an experimental apparatus 20 used in Experimental Example 2 (loading model experiment).
In FIG. 7, the experimental apparatus 20 includes a resin pipe (for example, a vinyl chloride pipe: VP pipe) 21, a T-shaped joint pipe 22, two male screw adapters 23, and two caps 24.
Three openings 221, 222, and 223 are formed in the T-shaped joint tube 22. Although not shown, a pipe connecting female screw is formed on the inner peripheral surface in the vicinity of the openings 221, 222, and 223.
In the experimental apparatus 20, the opening 222 is particularly displayed as “discharge port”.

Although not explicitly shown, a male screw is formed at one end (the lower end in FIG. 7) of the VP tube 21, and the male screw is screwed into a female screw formed in the T-shaped joint tube 22. The two caps 24 are fitted into the open ends of the openings 222 and 223, respectively.
When performing Experimental Example 2, the experimental apparatus 20 is installed on the floor surface 40 of the experimental site on the side where the cap 24 (see FIG. 7) of the opening 223 in FIG. It is carried out in the state.

  In FIG. 7, the male screw of the adapter 23 is screwed into the female screw of the opening (discharge port) 222 facing leftward of the T-shaped joint tube 22 and the female screw of the opening 223 facing downward. And the inner peripheral side of the adapter 23 is a smooth surface (as it is a raw tube). Here, if the adapter 23 is not screwed into the female threads of the openings 222 and 223, the irregularities of the female threads of the openings 222 and 223 will be exposed in the tube, thereby preventing the flow of the solidified material. For this reason, the adapter 23 is screwed into the openings 222 and 223 so that the surface roughness in the tube is the same as that of the raw tube, and accurate experimental data is obtained.

In FIG. 8 schematically showing the experimental procedure of Experimental Example 2, in the procedure of “A” in FIG. 8, the solidification material (filling material) Mk is placed in the experimental device 20 up to a predetermined height (filling height Hk). Inject (fill).
After the predetermined time has elapsed, as shown in FIG. 8B, the cap 24 of the discharge port 222 is removed, and the weight 60 is placed on the upper surface of the solidified material (filler) Mk via the piston 50.
Then, as indicated by “C” in FIG. 8, the weights 60 are sequentially applied until the upper surface of the solidified material (filler) Mk and the piston 50 are lowered and the solidified material (filler) Mk is discharged from the discharge port 222. Add and load.
Thereby, the weight of the weight when the solidifying material (filling material) Mk is discharged from the discharge port 222 is set as the yield load of the solidifying material (filling material) Mk, and the penetration resistance of the solidifying material (filling material) Mk at that time By comparing the value and the flow value, it is possible to determine to what extent the solidification material (filler) can be passed up to what level of flow value or penetration resistance value.

Table 4 shows the types (test cases) of the experimental data of Experimental Example 2.
Table 4

According to Table 4, there are four types of water reducing agent addition amounts: 0%, 0.5%, 1.0%, and 1.5%. The time from mixing the materials to producing the solidified material to injecting (filling) (loading) it into the experimental apparatus 20 is five for each variable of the water reducing agent addition amount. .
Furthermore, there are two types of solidification material (filler) placement heights of 25 cm and 50 cm, and a total of 40 types of experiments were conducted.
In Experimental Example 2, in addition to the loading test, a penetration resistance test and a test (flow test) for measuring a flow value using a φ80 mm cylinder cone were performed, and the relationship between the loading load, the flow value, and the penetration resistance value was also examined. Examined.

9 and 10 show the experimental results of Experimental Example 2.
FIG. 9 shows the relationship between the loaded load and the penetration resistance value. For data with a loading load of 100 kg or more, the test was stopped before the material yielded in consideration of work safety, and such data is also included in the plot of FIG.
FIG. 10 omits from the data shown in the plot of FIG. 9 data when the test is stopped midway, data that is specifically different from other data, and is not related to the loaded load. FIG. 6 is a characteristic diagram showing a relationship with loading stress.
In particular, referring to FIG. 10, it can be seen that if the placement height is basically the same, the loading stress and the penetration resistance value are roughly proportional. Moreover, if the penetration resistance value is comparable, it can be understood that the higher the placement height, the greater the load stress can be withstood.

Here, the difference in loading stress between the casting height of 50 cm and the casting height of 25 cm can be considered as the frictional resistance of 25 cm of the VP pipe 21 in the experimental apparatus 20 (see FIG. 7) as it is.
From the relationship between the loading stress and the penetration resistance value shown in FIG. 10, when the data of the placement heights of 25 cm and 50 cm are approximated by the least square method, the following equations are obtained.
S ₂₅ = 3.3697P-0.0122 (Formula 4)
S ₅₀ = 5.9966P-0.0094 (Formula 5)
_{Here, S 25} is a loading stress in the droplet設高 _{^{25cm (N / mm 2),}} S 50 is loading stress in the droplet設高^{50cm (N / mm 2),} P is penetration resistance value (N / mm ²⁾ .

Based on the above-described contents, the difference in loading stress (symbol “S _50-25 ”) between the casting height of 50 cm and the casting height of 25 cm is expressed by the following equation (6).
S _50-25 = 2.5966P + 0.0028 (Expression 6)
The inner diameter (D) of the VP tube 21 of the test apparatus 20 is 100 mm.
The difference in loading stress between the casting height of 50 cm and the casting height of 25 cm can be considered as the friction resistance of 25 cm of the VP pipe 21 in the experimental apparatus 20 (see FIG. 7) as it is. (Filler) The frictional resistance (f) with Mk is expressed by the following equation.
f = S _50-25 × (deposition per unit length of the VP tube 21) / (peripheral area in the tube per 25 cm of the VP tube 21)
Here, the peripheral area in the pipe per 25 cm of the VP pipe 21 is
100 × 3.14 × 250 = 78500 mm ²
Therefore, the frictional resistance (f) between the VP pipe 21 and the solidifying material (filler) Mk is
f = S ₅₀₋₂₅ × 50 ² × 3.14 ÷ 78500
= 0.25966P + 0.00028 (N / mm ² )
It becomes.

[Experiment 3]
Next, in Experimental Example 3, the relationship or characteristic between the flow value measured in the flow test using a φ80 mm cylinder cone and the penetration resistance value was obtained.
FIG. 11 shows an experimental apparatus used in Experimental Example 3 for measuring the penetration resistance value.
The experimental apparatus shown in FIG. 11 includes a container 31 for storing a solidifying material (the material described with reference to Tables 2 and 3), only electrons 32, and a penetrating needle 33.
Here, the penetration resistance value at the time when the solidified material is not fluidized is a very small value as compared with the penetration resistance value at the start and end of the concrete. For this reason, when an experiment is performed on the non-fluidized solidified material as it is using the penetration resistance test apparatus used for the setting test, it is very difficult in terms of measurement accuracy. Therefore, the experimental apparatus shown in FIG. 11 has only electrons 32 that are highly accurate and can read minute differences.

As a specific measuring method, first, the container 31 containing the solidifying material was placed on the electrons 32 and zero adjustment was performed.
Then, the penetrating needle 33 penetrated 2.5 cm downward from the upper surface of the material over 10 seconds, and the maximum load at the time of penetrating was measured with only the electrons 32. (See FIG. 11).
Furthermore, the penetration resistance value (N / mm ² ) was calculated by the following calculation formula (Formula 7).
Penetration resistance value (N / mm ² ) = P × g / (D ² × 3.14 / 4) (Expression 7)
In Equation 7, P is the maximum load (kg) at the time of penetration read from only the electrons 32, D is the diameter (mm) of the tip of the penetration needle, and g is the gravitational acceleration (m / s ² ).

In Experimental Example 3, a flow test using a φ80 mm cylinder cone was also performed to obtain a flow value. And the relationship between the penetration resistance value calculated | required with the experimental apparatus of FIG. 11 and the flow value calculated | required by the flow test was examined.
In Experimental Example 3, four types of solidifying materials (added amount of water reducing agent 0%, 0.5%, 1.0%, 1.5%) in which the amount of water reducing agent (SP) was changed were used. Performed.

FIG. 12 shows the change over time in the flow value, and FIG. 13 shows the change over time in the penetration resistance value. 12 and 13, it was found that the strength of the non-fluidized solidified material can be expressed by the penetration resistance value at the stage after the flow value reaches 80 mm.
FIG. 14 shows the relationship between the flow value and the penetration resistance value. According to FIG. 14, it was found that, regardless of the amount of water reducing agent added, when the penetration resistance value is basically 0.01 N / mm ² or more, the flow value is 80 mm (the solidified material is self-supporting).
In Experimental Example 3, “the solidified material has become non-fluidized” is appropriately set to a flow value of 80 mm in which the solidified material is self-supporting. From the relationship (characteristics) between the flow value and the penetration resistance value shown in FIG. 14, it was confirmed that “flow value 80 mm” corresponds to “penetration resistance value 0.01 N / mm ² ”.

[Experimental Example 4]
Next, an experiment was conducted on the relationship between the flow value of the solidified material and the slit width dimension through which the solidified material can permeate, thereby examining the fluidity of the solidified material.
In FIG. 15 showing the front and side surfaces of the experimental device 40 used in the crack model experiment, a pair of side frames (grooved steel) 41 is fixed to a lower base (not shown). A translucent acrylic plate 42 and a resin plate 43 are attached. The upper end 40u of the experimental device 40 is open.
The height direction dimension H of the experimental device 40 is 700 mm in the illustrated example, and the dimension B between the flange inner methods in the side frame (grooved steel) 41 is 56 mm in the illustrated example. The full width dimension of the experimental apparatus 40 is appropriately set according to the number of samples.

In FIG. 15, in the width direction of the front surface near the lower end of the experimental apparatus 40, slits having different slit widths (the length of the slit is 100 mm in common) s1 to s5 are formed at five equal intervals.
The widths of the slits s1 to s5 are 0.2 mm for the slit s1, 0.5 mm for the slit s2, 1.0 mm for the slit s3, 2.0 mm for the slit s4, and 3.0 mm for the slit s5.
Here, the experimental apparatus 40 is a large size that can be carried out indoors with reference to the non-leakage test method in NEXCO's “Applicability Confirmation Test Method for Backfill Cavity Injection Material (Draft)”, which is a quality standard test for plastic grout. This is an experimental apparatus in which the crack (slit) width is set small.

In Experimental Example 4, a solidifying material (filling material) is introduced from the upper opening 40u of the experimental device 40, and the penetration length of the solidifying material (filling material) in each of the slits s1 to s5 is measured, and the solidifying material (filling material). The relationship between flow value and permeation length was investigated.
As a sample, only a solidifying material (filler) to which a water reducing agent was not added was used.
The elapsed time after producing the solidified material (filler) is not defined, the solidified material (filler) (sample) having a flow value of about 300 mm immediately after the production of the solidified material (filler), the solidified material having a flow value of about 200 mm (sample) Using a filler (sample), a solidified material (filler) (sample) with a flow value of about 150 mm, and a solidified material (filler) (sample) with a flow value of about 100 mm, the slits s1 to s5 at the respective flow values The penetration length was measured.

FIG. 16 shows the results of Experimental Example 4.
According to FIG. 16, in the solidified material (filler) (sample) having a flow value of 295 mm immediately after manufacture, it penetrates 10 cm or more into the 0.5 mm slit, and the distance penetrated through the slit as the flow value decreases. Tend to be shorter. The solidified material (filler) (sample) having a flow value of 115 mm obtained a result that only 8 cm penetrated into a 3 mm slit.
Here, a long permeation length means that the solidified material (filler) is likely to permeate, and a short permeation length means that the solidified material (filler) is difficult to permeate. .
From Experimental Example 4, it was confirmed that the solidified material (filler) easily penetrated as the flow value increased, and the solidified material (filler) became difficult to penetrate as the flow value decreased.

[Experimental Example 5]
Next, an experiment was conducted to see how the time from adjusting the solidifying material (filler) to non-fluidizing by adding a water reducing agent was affected.
In Experimental Example 5, as shown in Table 5, normal Portland cement (C), water (W: tap water), non-fluidizing agent (G: rapid setting material, rapid hardening) as a solidifying material (filler) material Agent).
In Experimental Example 5, a calcium aluminate-based rapid hardening agent was employed as the non-fluidizing agent.
As a water reducing agent, a water reducing agent mainly composed of naphthalenesulfonic acid / formalin condensate soda (for example, trade name “Mighty 150R” sold by Kao Corporation) was used.

Table 5

The experiment was performed under conditions of 20 ° C. for both room temperature and water temperature.
There were three test items: raw specific gravity measurement in fresh properties, flow test, and material temperature measurement. Table 6 shows the test methods for these three test items and the implementation formulations.
The mixer used in the above three test items was a Hobart type mortar mixer, the volume was 20 liters (the total volume of the bowl), the rotation speed was 400 rpm with a speed change, and the stirring blade was a whipper.

Table 6

The blending of the solidifying material (filler) in Experimental Example 5 is selected from the high-strength type and the low-strength type according to the past test results. did.
The selected formulations are shown in Table 7.
Table 7

In Experimental Example 5, with respect to the solidified materials (fillers) having two kinds of blends shown in Table 7, the amount of water reducing agent added was changed to measure the flow value, the time until non-fluidization, and the like.
Here, as a procedure for producing the solidified material (filler), a so-called “first addition” procedure in which water, a water reducing agent, cement, and a non-fluidizing agent are added to the mixer before high-speed stirring by the mixer is adopted. .
FIG. 17 (time characteristic of the flow value of the high strength type “W / C = 80%”) and FIG. 18 (time characteristic of the flow value of the low strength type “W / C = 150%”) are shown in FIG. ).

As is clear from FIGS. 17 and 18 (in either case of high strength type “W / C = 80%”, low strength type “W / C = 150%”), the amount of water reducing agent added is increased. As time goes on, the time until defluidization slows down.
Experimental Example 5 confirmed that if the amount of water reducing agent added was increased, the time until de-fluidization increased, and if the amount of water reducing agent added decreased, the time required for non-fluidization decreased. And it became clear by adjusting the addition amount of a water reducing agent that the time until non-fluidization can be matched with the construction conditions.

[Experimental Example 6]
Next, whether or not there is a change in the time from the production of the solidified material (filler) to the non-fluidization by changing the order in which the water reducing agents are added during the production of the solidified material (filler) We experimented.
In addition, about the solidification material (filler) used in Experimental example 6, it is the same as that of Experimental example 5 except the part regarding a water reducing agent injection | throwing-in order.

In Experimental Example 6, as a method of mixing materials, a method of adding a water reducing agent at a stage before high-speed stirring with a mixer (first addition), and a water reducing agent after high-speed stirring of water, cement, and non-fluidizing agent with a mixer are performed. The experiment was conducted by two methods, ie, a method of adding (post-addition).
In Experimental Example 6, “first addition”
Put the materials in the order of water, water reducing agent, cement, non-fluidizing agent to the mixer,
Stir at high speed in a mixer for 30 seconds,
Remove the material stuck to the mixer bowl with a spatula,
The procedure was to stir at high speed with a mixer for 30 seconds.
On the other hand, in “post-addition”,
Put materials into the mixer in the order of water, cement, and non-fluidizing agent,
Stir at high speed in a mixer for 30 seconds,
Remove the material stuck to the mixer bowl with a spatula,
Put water reducing agent into the mixer,
The procedure was to stir at high speed with a mixer for 30 seconds.

Table 8 shows the composition of the solidified material in Experimental Example 6.
Table 8

In Experimental Example 6, the solidified material having the composition shown in Table 8 was manufactured by kneading with “pre-addition” and “post-addition”, and the change in flow value with time was compared.
The results of Experimental Example 6 (change in flow value with time) are shown in FIG. 19 (pre-addition) and FIG. 20 (post-addition).
19 and 20, the ratio of water to cement (W / C = 80%) and the ratio of non-fluidizing agent to cement (G / C = 30%) are the same (see Table 8). The same applies to the parameters (0%, 1.5%, 3.0%) of (SP / C).
As apparent from FIGS. 19 and 20, it was found that the “post-addition” can adjust the time until non-fluidization is achieved by adding a small amount of water reducing agent. Here, it is more economical to reduce the amount of the water reducing agent added.

According to Experimental Example 6, water, cement, and non-fluidizing agent (quick hardener, quick setting agent) were stirred with a mixer, and then the manufacturing procedure ("post-addition") in which the water reducing agent was added and stirred was water, water reducing Compared to the manufacturing procedure (“additional addition”) in which the agent, cement, and non-fluidizing agent are simultaneously stirred in the mixer, it is confirmed that the time until de-fluidization can be changed with a small amount of water reducing agent added. It was done.
Therefore, at the construction site, there is a manufacturing procedure ("post-addition") in which water, cement and non-fluidizing agent (quick hardener, quick setting agent) are stirred with a mixer and then a water reducing agent is added and stirred with a mixer. It was revealed by Experimental Example 6 that it was suitable.

[Experimental Example 7]
In Experimental Example 7, an experiment was conducted on the influence of temperature conditions on flow value change characteristics.
The material of the solidifying material used in Experimental Example 7 is the same as that of Experimental Example 5.
The solidifying material (filler) used in the injection method according to the embodiment contains a cement-based material, and it is considered that the properties greatly vary depending on the temperature conditions (outside temperature, mixing water temperature).
In Experimental Example 7, the properties (change in flow value with time) when the temperature conditions (outside temperature, mixing water temperature) were changed were examined.

Table 9 shows the composition of the solidifying material (filler) used in Experimental Example 7.
Table 9

In Table 9, the ratio of water to cement (W / C = 80%) and the ratio of non-fluidizing agent to cement (G / C = 30%) are the same as in Table 8, but the amount of water reducing agent added SP / Seven C parameters are set between 0% and 3.0%.
In Experimental Example 7, as variables (parameters), three types (5 ° C., 20 ° C., 30 ° C.) at the outside air temperature, five types (5 ° C., 25 ° C., 35 ° C., 20 ° C., 30 ° C.) at the mixing water temperature, Seven kinds (0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%) of water reducing agent addition amounts are set.
These variables (parameters) are shown in Table 10.

Table 10

FIG. 21 to FIG. 25 show the results of Experimental Example 7, that is, changes in flow values with time (changes in flow values with time in each temperature condition) when the temperature conditions (outside temperature, kneading water temperature) are changed.
FIG. 21 shows the change over time of the flow value when the water reducing agent is 0% and the outside air temperature and the mixing water temperature are the same (all at 5 ° C., 20 ° C., 30 ° C.).
From FIG. 21, the lower the outside air temperature and the mixing water temperature, the longer the time until defluidization, and it was confirmed that no defluidization occurred even at 120 ° C. at 5 ° C.

FIG. 22 shows the change over time in the flow value when the outside air temperature is fixed at 5 ° C., the water reducing agent addition amount is fixed at 0%, and the mixing water temperature is changed.
From FIG. 22, even when the outside air temperature is low (5 ° C.), if the mixing water temperature is increased, the time until non-fluidization is shortened, and if the mixing water temperature is 30 ° C. (parameter C), It was found that the solidifying material (filler) became non-fluidized within 60 minutes (30 minutes).

FIG. 23 shows the change over time in the flow value when the outside air temperature is 5 ° C. and the water temperature is 35 ° C., and the amount of water reducing agent added is changed (in five steps from 0% to 2.0%).
From FIG. 23, it was found that as the amount of the water reducing agent was increased, the time until de-fluidization became longer. The contents found from FIG. 23 agree with the experimental result of Experimental Example 5.

24 and 25 show changes over time in the flow value when the amount of water reducing agent added is changed when the outside air temperature is 20 ° C. and 30 ° C. and the mixing water temperature is the same as the outside air temperature.
From FIG. 24 and FIG. 25, it was found that the time until de-fluidization becomes longer by increasing the addition amount of the water reducing agent at both the outside air temperatures of 20 ° C. and 30 ° C. However, it was also confirmed that it was necessary to add more water reducing agent at the outside air temperature of 30 ° C. in order to lengthen the time until non-fluidization.

Experimental Example 7 confirmed that the outside air temperature and the temperature of the water used for producing the solidifying material (filler) (mixing water temperature) affect the flow value.
Therefore, it became clear that both the outside air temperature and the mixing water temperature should be taken into account in order to manufacture the solidifying material (filler) until it becomes non-fluid so as to match the construction conditions. .

  It should be noted that the illustrated embodiment is merely an example, and is not a description to limit the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Back part gap 2 ... Ground mountain 3 ... Slope 4 ... Structure 10 ... Experimental apparatus 11 ... Back plate 12 ... Side plate 13 ... Bottom plate 14 ... Surface plate 15 ... lower opening / closing plate 20 ... experimental apparatus 21 ... resin pipe / VP pipe 22 ... T-shaped joint pipe 50 ... piston 60 ... weight

Claims (4)

The solidification material is injected into the area to be constructed in several batches, and the solidification material contains water and cement, and the solidification material previously injected into the area is in a non-flowing state. An injection method characterized by injecting a solidifying material that follows a region and determining that the infiltration resistance value of the solidified material previously injected into the region is 0.01 N / mm ² , indicating a non-flowing state. The injection method according to claim 1, wherein the penetration resistance value is 0.01 N / mm ² and the flow value measured using a slump cone having an inner diameter of 80 mm is 80 mm. The time until the penetration resistance value of the solidified material reaches 0.01 N / mm ² or the time until the flow value measured using a slump cone with an inner diameter of 80 mm reaches 80 mm is measured in advance. The injection method according to claim 2, wherein if the measured time has elapsed after mixing and stirring to produce a solidified material, the solidified material is judged to be in a non-flowing state.   The injection method according to any one of claims 1 to 3, wherein the solidifying material includes a non-fluidizing agent and a water reducing agent, and the time until the solidifying material is brought into a non-flowing state is adjusted by an amount of the water reducing agent added.

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