JP3440077B2 - Confirmation method of mixing ratio of creature material in ground improvement method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement method for soil-cementing ground soil at a position where a foundation of a building is to be constructed to improve a high-strength structure, and more particularly to such a ground. The present invention relates to a method for confirming the mixing ratio of the building materials (soil, solidifying material, and water) in the improved construction method.

[0002]

BACKGROUND ART ground improvement method of this type, generally referred to as Nidosoiru cement construction method, this Nidosoiru cement method is performed as shown in FIGS.

First, as shown in FIG. 1, soil S in the ground at a position where a foundation of a building is to be constructed is excavated and discharged to form a void 1 having a predetermined area and a predetermined depth. The need soil cement method is generally applied when there is stable ground in a relatively shallow place, and the void 1 is excavated by a bucket 11 of an excavator 10 such as a backhoe. Further, the excavated soil S is piled up in the vicinity of the empty space and used later as a building material. The opening area and depth of the void 1 are determined in consideration of the load applied to the foundation of the building, the soil quality of the ground soil, the bearing capacity, and the like.

Next, as shown in FIG.
The soil S excavated and excavated first, the solidifying material C such as cement, and the water W are put in predetermined proportions. The blending ratio of these building material (soil S, solidifying material C, water W) is determined after performing an indoor blending test in advance using a sample of the on-site soil S.

Subsequently, as shown in FIG. 3, the building materials (soil S, solidifying material C, water W) are mixed in the void 1.
Stir to form a slurry-like soil / solidifying material mixed slurry SC. In this case, when the bucket 12 equipped with the stirrer 13 is used for stirring, each green body material can be uniformly mixed in a short time. When the space 1 is deep, the building material (soil S, solidifying material C, water W) input and mixing / stirring work are divided into several times (two times in the example of FIG. 3). To do.

Then, the soil / solidifying material mixed slurry SC of FIG. 3 is solidified to form a green body 2 by soil cement as shown in FIG. On this formation 2, the foundation 3
Is constructed, and a building is constructed on the foundation 3. The structure 2 is formed at a plurality of locations (all locations where the foundation 3 is constructed) for one building.

By the way, the supporting force of the building body 2 is set based on the load from the building (including the load of the foundation 3 and the backfill soil 4) received by the building body 2, and the load received by the building body 2. The larger the value, the greater the supporting strength in the formed part. Specifically, the building area of the building body 2 is increased, or the design standard strength of the building body 2 (support strength per unit area, hereinafter referred to as FC strength) is increased.

The FC strength of the formed body 2 changes depending on the mixing ratio of the formed body materials (soil S, solidifying material C, water W), the soil quality of the soil S, and the like. For example, soil / solidifying material mixture SC
In the above, when the water content (water / soil) increases, the FC strength decreases (the water content is set in the range of 60 to 180% by weight, but is generally around 100%), and the solidifying material content increases. The higher the strength, the higher the FC strength. Also, soil S
The soil strength increases in the order of clay → silt → sand → gravel → composite soil (a mixture of clay, silt, sand, and gravel), and the pH value is higher (the alkalinity is higher). FC strength increases.

In addition, when performing ground improvement by this kind of need soil cement construction method, a soil sample at the construction site is sampled in advance, and a suitable mixture ratio of the sampled soil S, the solidifying material C and the water W is tested in an indoor mixture test. (FC strength confirmation), and based on the suitable blending ratio, each of the structural body materials (soil S, solidifying material C, and water W) are put into the void 1 in predetermined proportions.

[0010]

By the way, the ratio of each building material to be put into the void 1 is determined based on the mixing ratio obtained in advance by the indoor mixing test. In this kind of need soil cement construction method, Presence / absence of spring water in the void 1, the water content of the input soil, and the inner wall surface of the void 1 (bottom surface 1a, side surface 1b)
Soil) formed in the void 1 due to the soil properties (for example, collapsibility of wall surface soil and water permeability into soil).
The mixing ratio of each building material (soil S, solidifying material C, and water W) in the solidifying material mixed slurry SC may change or the volume of the building 2 may become small.

That is, when spring water (groundwater) is discharged into the void 1 or the water content in the input soil is increased by rainfall due to rainfall, etc., the mixing ratio obtained in the indoor mixing test When each construction material (soil S, solidifying material C and water W) is put into the void 1, the amount of water such as the spring water and the additional water content is added to the soil / solidifying material mixed slurry SC ( The water content in Fig. 3) increases. Therefore, in this case, there arises a problem that the FC strength of the finished structural body 2 is lowered.

In addition, in the void 1, each building material (soil S
Although the solidification material C and water W) are added at predetermined ratios and stirred, the soil on the inner wall surface (especially the side surface 1b) of the void 1 is likely to collapse (or peel) (for example, sandy). And, for example, as shown in FIG. 3, the inner wall surface of the void 1 (particularly the side surface 1b)
The soil Sa of No. 1 is destroyed and mixed in the soil / solidifying material mixed slurry SC. In this case, the mixing ratio of the solidifying material C to the soil S in the soil / solidifying material mixed slurry SC becomes small, and the FC strength of the finished structural body 2 is lowered.

Furthermore, when the soil properties of the inner wall surface (bottom surface 1a, side surface 1b, etc.) of the void 1 have a high water permeability, such as sand, one of the water W introduced into the void 1 is used. The part penetrates into the ground through the void wall surfaces 1a and 1b, and the water content in the soil / solidifying material mixed slurry SC decreases. In this case, the FC strength of the formed body 2 does not change to the dangerous side, but the total volume of the formed body material needs to be increased as the volume of the formed body 2 becomes smaller. As the number increases, there arises a problem that the cost increases.

As described above, in the need soil cement construction method, even if each building material (soil S, solidifying material C and water W) was added in the mixing ratio and amount as designed, it was completed according to various conditions of the void 1. The FC strength and volume of the structure 2 may not be achieved as calculated on the desk. And when constructing the building body 2 by this kind of need soil cement construction method, after the building body 2 solidifies, the test piece is taken out from the building body 2 and whether the FC strength has reached the target strength or not. Confirm (compression inspection), but if that F
When the C strength is insufficient, it is necessary to dig back the constructed body 2 that has already been built and to try again, and in that case, the cost and time become extremely large.

Therefore, conventionally, when building the building body 2 by the need soil cement method, the mixing ratio of the solidifying material C in each building material (soil S, solidifying material C, and water W) is adjusted. Under the present circumstances, the target strength can be sufficiently ensured even if the FC strength is deviated on the dangerous side due to various conditions of the void 1 as described above. That is, the design standard strength is obtained by a calculation formula that triples the safety factor with respect to the load degree (KN / m2) from the building or the like that is added to the building, but this design standard strength is secured securely. for,
In practice, the solidifying material C is often added in a larger amount than necessary. The solidifying material C is another building material (soil S or water W).
It is extremely expensive as compared with the above, and the material cost is increased by increasing the blending ratio of the solidifying material C, but the trouble when the insufficient strength is found in the FC strength inspection after constructing the formed body (retry In consideration of the above), the fact that the material cost is high due to the increase in the amount of solidifying material is ignored even if it is not actually necessary.

In the present invention, in view of the above-mentioned conventional problems in the need soil cement method, the water content and the solidifying material ratio in the soil / solidifying material mixed slurry mixed / stirred in the void should be in the safe range or more. It is an object of the present invention to propose a method for confirming the mixing ratio of the structural body material, which allows easy confirmation of whether or not there is any, and which can be easily corrected when the ratio does not reach the appropriate range.

[0017]

The present invention has the following constitution as means for solving the above problems. still,
The present invention is a soil improvement method called a so-called need soil cement method, in which the water content and the solidification material ratio in the mixed soil / solidification material mixed slurry mixed / stirred in the void where the ground soil is excavated / excavated are FC strength. It is aimed at the method of checking whether or not it is on the safe side.

In the ground improvement method of the present application, as explained in the above-mentioned section of the prior art (FIGS. 1 to 4), the soil in the ground is excavated and discharged to form a void having a predetermined opening area and a predetermined depth. Formed,
Soil previously excavated and soiled, solidifying material such as cement, and water are put into the void at predetermined ratios, and the materials are mixed and stirred in the void, and then the soil-solidifying material mixed slurry Is to be solidified.

The size of the void (opening area × depth) is set so that a structure having a supporting force capable of withstanding a load from a building or the like can be constructed. Also, regarding the mixing ratio of the building material (soil, solidifying material, and water) to be put into the void, the FC strength is confirmed by an indoor mixing test by taking a soil sample at the building site in advance, and mixing under suitable conditions. Find the percentage. In this case, the water content (water / soil) is generally 60 to 1 by weight.
Although it is set in the range of 80%, the actual construction ratio is determined from the range in which the FC strength is sufficiently secured.

Also, during the indoor mixing test, the flow value of the soil / solidifying material mixed slurry of the sample to be actually applied (hereinafter referred to as the target flow value) and the specific gravity of the sample slurry (hereinafter referred to as the target specific gravity) It is good to measure and). The flow value is a value obtained by measuring the settling degree of the soil / solidifying material mixed slurry and serves as an index indicating the water content in the mixed slurry. As the sample slurry, for example, a cylindrical one having a diameter of 80 mm and a height of about 100 mm is used. And, the flow value test, when the cylindrical sample slurry is erected vertically,
It measures how much the diameter of the bottom surface spreads. Further, the specific gravity of the soil / solidifying material mixed slurry changes depending on the mixing ratio of each building material (soil, solidifying material and water). Incidentally, the specific gravity of soil is about 1.7 and the specific gravity of solidifying material is about 3.
0, the specific gravity of water is 1, the flow rate of the sample slurry is measured to measure the water content in the sample slurry, and then the weight of the sample slurry is measured to solidify the soil per unit volume. It is possible to estimate the mixing ratio with wood.

In the method for confirming the mixing ratio of the building material according to claim 1 of the present application, a sample is taken from the slurry-like soil-solidifying material mixed slurry mixed and stirred in the void,
After measuring the flow value of the sample slurry and inspecting the water content in the soil / solidifying material mixed slurry, the specific gravity of the sample slurry is measured to inspect the solidifying material ratio in the soil / solidifying material mixed slurry. I am trying. In the following description, the flow value of the sample slurry sampled from the void is called the actual flow value, and the specific gravity of the sample slurry sampled from the void is called the actual specific gravity.

Into the above-mentioned void, a predetermined amount of each construction material (soil, solidifying material, and water) is added at a blending ratio determined by an indoor blending test, but spring water (groundwater) may come out in the void. If the amount of water in the input soil is greater than the amount in the indoor mixing test, the proportion of water in the soil / solidifying material mixed slurry increases by the amount of water, and the FC strength of the structure after solidification is the indoor mixing test. It becomes lower than the FC strength of the sample made in. On the other hand, if the permeability of water from the wall of the void is high, part of the water injected into the void will penetrate into the ground from the wall of the void, and the water content in the soil / solidifying agent mixed slurry will decrease. However, in this case, the strength of the formed body does not change to the dangerous side, but the volume of the formed body becomes smaller as the water decreases. In addition, it is the current situation that the increase or decrease of water content in the void cannot be directly confirmed from the outside.

By the way, according to the present application, soil in the void
The water content in the solidifying material mixed slurry can be estimated by measuring the actual flow value (deterioration degree) of the sample slurry. That is, the sample slurry is the same as the soil / solidifying material mixed slurry in the void, and the actual flow value (deterioration degree) changes depending on the water content in the sample slurry. If the actual flow value (flow value of the sample slurry in the void) is higher than the target flow value (flow value of the sample slurry in the indoor mixing test) (the degree of sagging is large), the soil / solidification material in the void It means that the water content in the mixed slurry is excessive,
On the other hand, when the actual flow value is lower than the target flow value (the degree of sagging is small), it means that the water content in the soil / solidifying material mixed slurry in the void is insufficient.

When the water content of the soil / solidifying material mixed slurry in the void is excessive (FC strength is uncertain)
Is the amount of soil and solidifying material required (in some cases only solidifying material) is put into the void, and the void is stirred again,
Adjust the water content in the soil / solidifying material mixed slurry in the void (re-measure the actual flow value after stirring). In particular, the adjustment work when the water content is excessive is performed until the actual flow value of the sample slurry in the void approximates the target flow value performed in the indoor mixing test. Also, if the water content in the soil / solidifying material mixed slurry in the void is insufficient (FC strength can be sufficiently secured but the total amount of soil / solidifying material slurry is insufficient), a predetermined amount of When water is added and the inside of the void is stirred again, the total amount can be increased by adjusting the water content in the soil / solidifying material mixed slurry within the void. Also in this case, the safety is confirmed by re-measurement of the actual flow value after stirring.

When the building materials (soil, solidifying material and water) are stirred in the void, the wall surface of the void may collapse and the collapsed soil may be mixed into the soil / solidifying agent mixed slurry. . In that case, the ratio of the solidifying material to the soil in the soil / solidifying material mixed slurry is reduced (in this case, the FC strength of the finished structure is lower than the target FC strength set in the indoor mixing test).

By the way, in the present application, after confirming that the flow value of the soil / solidifying material mixed slurry in the void is within an appropriate range, a sample slurry is sampled from the soil / solidifying material mixed slurry and The specific gravity of the sample slurry is measured.
When mixed in the solidifying material mixed slurry, the specific gravity (actual specific gravity) of the sample slurry becomes smaller than the target specific gravity performed in the indoor mixing test. Incidentally, the specific gravity of soil is about 1.7, and the specific gravity of the solidifying material is about 3.0. Then, as a result of the measurement, if the actual specific gravity is smaller than the target specific gravity, a predetermined amount of the solidifying material is put into the void and re-stirred, and then the actual specific gravity is re-measured to approximate the target specific gravity. Check if

As described above, according to the mixing ratio confirmation method of the present application, it is possible to inspect the ratio of water and the ratio of the solidifying material in the soil / solidifying material mixed slurry formed in the void with a simple method, and the numerical value of the inspection result is obtained. When the deviation from the target value exceeds the allowable range, the soil / solidifying material mixed slurry remains sludge-like, and therefore, a predetermined type of each construction material (soil, solidifying material, and water) is used. The target value can be approximated by adding materials and stirring again.

According to the second aspect of the present invention, in the mixing ratio confirmation method according to the first aspect, the pH value of the soil put into the void is measured, and the lower the pH value is, the more the soil / solidifying material mixed slurry is contained. The ratio of the solidifying material is increased.

In other words, it is known that in the soil cement construction of this type, the lower the pH value of the soil used (the lower the alkalinity), the lower the FC strength. Measure the pH value of
By adjusting the mixing ratio of the solidifying material to meet the requirement, it is possible to construct a structure with higher reliability in terms of FC strength.

In the present application, the pH value of the soil can be measured as described above, and the pH value of the additional water constituting the building material can also be measured to adjust the amount of the solidifying material. By doing so, it is possible to construct a structure with higher reliability in terms of FC strength.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present application will be described below. The ground improvement method of this embodiment is basically performed through the steps of FIGS. 1 to 4, but in the mixing ratio confirmation method of the embodiment of the present application, immediately after the step of mixing and stirring the structural material shown in FIG. As shown in FIG. 5, a sample slurry SCa is sampled from the soil / solidifying material mixed slurry SC in the void 1 and the water content in the soil / solidifying material mixed slurry SC is measured. The solidifying material ratio in the solidifying material mixed slurry SC is measured. Further, FIG. 6 shows a process diagram of the ground improvement method of the present embodiment.

The ground improvement method of the embodiment of the present application overlaps with the description of the prior art, but first, as shown in FIG. 1, the soil S of the ground at the position where the foundation of the building should be constructed is excavated and discharged. Then, a void 1 having a predetermined area and a predetermined depth is formed (step A in FIG. 6). The excavated soil S is used as a building material and is piled up at a position near the void 1.

A sample soil is sampled from the excavated soil S, and the sample soil S, the solidifying material C and the water W are collected.
A suitable blending ratio is determined by an indoor blending test (step B in FIG. 6). At this time, the pH values of the sample soil S and the water W to be used are also obtained, and each construction material (soil S and soil S Solidifying material C and water W)
Calculate the blending ratio of. In this indoor blending test, a compression test was performed on a test piece obtained by blending each solidified building material (soil, solidifying material, and water) at a ratio considered to be suitable and solidifying the mixture.
Check if C strength is reached. Also, in this indoor blending test, each sample material was mixed and mixed at a suitable ratio.
Record the flow value (check the water content in the mixed slurry) and the specific gravity (check the solidification material ratio in the mixed slurry) of the soil / solidifying material mixed slurry formed by stirring.

Next, as shown in FIG. 2, each of the green body materials (soil S, solidifying material C, and water W) in a predetermined ratio in the void 1 based on a suitable mixing ratio determined by an indoor mixing test. It is put into the void 1 (step C in FIG. 6).

Subsequently, as shown in FIG. 3, the building materials (soil S, solidifying material C, water W) are mixed in the void 1.
Stir to form a slurry-like soil / solidifying material mixed slurry SC (step D in FIG. 6). In the example of FIG. 3, the construction material (soil S, solidifying material C, water W) is put into the void 1 and the mixing / stirring operation is performed twice.

By the way, the ratio of each building material (soil S, solidifying material C and water W) to be put into the void 1 is determined based on the mixing ratio previously obtained in the indoor mixing test. Soil formed in the void 1 depending on the presence or absence of spring water inside, the water content in the input soil S, and the soil properties of the wall surface inside the void (for example, collapsibility of wall soil and water permeability into the soil). -Each material of the solidification material mixed slurry SC (soil S and solidification material C
And the mixing ratio of water W) may change or the volume of the formed body 2 may become small.

Therefore, in the present embodiment, after the soil / solidifying material mixed slurry SC in the void 1 is sufficiently stirred as shown in FIG. 3, the slurry-like soil / solidifying material mixture is mixed as shown in FIG. A sample slurry SCa in the slurry SC is sampled (step E in FIG. 6), and a flow value (depression degree) of the sample slurry SCa is measured ((step F in FIG. 6), and the actual flow value and the indoor mixing test are performed. When the flow value of the sample slurry SCa is larger than the target flow value in the indoor mixing test (the degree of sagging is large), the flow rate of the sample slurry SCa is compared with the performed target flow value (step G in FIG. 6). Means that the water content in the sample slurry SCa is higher than the target water content, and conversely
When the flow value of a is smaller than the target flow value in the indoor mixing test, it means that the water content in the sample slurry SCa is less than the target water content.

By the way, as a result of the above flow value measurement, when the soil / solidifying material mixed slurry SC has excessive water content (as a cause, it is considered that spring water is mixed or the water content in the input soil S is large). Since the FC strength when the soil / solidifying material mixed slurry SC is solidified is lower than the target strength, the soil S and the solidifying material C are additionally added to the void 1 by the required amount (in some cases, only the solidifying material C). Then, the soil / solidifying material mixed slurry SC in the void 1 is corrected to an appropriate flow value (step G in FIG. 6). Further, when the soil / solidifying material mixed slurry SC lacks water (as a cause, it is considered that water has penetrated into the ground from the inner wall surface of the void), the strength of the formed body after solidification changes to the dangerous side. However, since the volume of the green body becomes smaller as the water decreases, the water is added in the void 1 in the reduced amount. When a predetermined type of building material (soil, solidifying material, water) is added, the void 1 is re-stirred, and the sample slurry SCa is sampled again so that the actual flow value is relative to the target flow value. Measure whether it is in the proper range.

Next, after confirming that the flow value in the void 1 is within the proper range, the sample slurry SCa (constant volume) is sampled again, and the specific gravity of the sample slurry SCa is measured (see FIG. 6). Step H). The amount of water in a fixed volume of the sample slurry SCa can be estimated by the above flow value measurement, and the residual weight obtained by subtracting the weight of water (the specific gravity of water is 1) from the total weight of the sample slurry SCa is the soil S and the solidifying material C. Of the soil S (specific gravity is about 1.7) and the solidifying material C (based on the residual weight and the residual volume obtained by subtracting the volume of water from the total volume of the sample slurry SCa). The specific gravity can be found to be about 3.0).

When the specific gravity (actual specific gravity) of the sample slurry SCa is smaller than the target specific gravity in the indoor mixing test (as a cause, the collapsed soil Sa on the inner wall surface of the void is the soil / solidifying material mixed slurry SC as shown in FIG. 3). It is estimated that the amount of solidified material with respect to the mass of soil is small (FC strength when the soil / solidified material mixed slurry SC is solidified is lower than the target strength). A predetermined amount of the solidifying material C is additionally charged therein to adjust the mixing ratio of the solidifying material C to the soil S. Further, after the addition of the solidifying material C, the soil / solidifying material mixed slurry SC in the void 1 is stirred and sufficiently mixed, and then the sample slurry SCa is sampled to determine whether its specific gravity is increased to an appropriate range. Is measured (step I in FIG. 6). When each building material (soil, solidifying material, and water) was added according to the blending ratio determined in the indoor blending test, the solidifying material specific gravity (about 3.0) was greater than the soil specific gravity (about 1.7). Since it is large, even if the collapsed soil on the inner wall surface of the void is mixed, the specific gravity of the mixed material of the soil excluding water and the solidifying material in the sample slurry SCa does not change to the larger side.

In this way, by measuring the flow value and the specific gravity of the sample slurry SCa and confirming that the measured values can clear the target measured values at the time of the interior mixing test (step J in FIG. 6), The mixing ratio confirmation method according to the embodiment of the present application is completed, and then the soil / solidifying material mixed slurry SC in the void 1 is allowed to naturally solidify to complete the structure 2 (FIG. 4). K). After solidification of the formed body 2 (after a predetermined number of days), a test piece is taken out from the formed body 2 as usual, and it is confirmed by a compression test whether or not the target strength has been exceeded.

As described above, when the mixing ratio confirmation method of the embodiment of the present application is carried out, each green body material (soil S, solidifying material C and water W in the soil / solidifying material mixed slurry SC formed in the void 1 is formed. Whether or not the mixing ratio of () is appropriate can be confirmed by a simple operation of measuring the flow value and the specific gravity of the sample slurry SCa. Further, if the compounding ratio of each structural material can be approximated to the target compounding ratio that has been subjected to the indoor mixing test in this manner, the reliability of the FC strength of the structural member 2 to be constructed can be ensured while the cost is high. It is not necessary to add an extra (more than necessary) extra solidifying material, and the material cost can be reduced. That is, in the past, since the FC strength of the formed body could not be confirmed only after the formed body 2 (FIG. 4) was constructed in the void 1, the proportion of the solidified material was increased more than necessary in view of safety. Therefore, it took an extra solidifying material cost, but it is possible to check whether or not each building material is mixed in an appropriate ratio in the state of the soil / solidifying material mixed slurry SC formed in the void as in the present application. By doing so, the amount of the expensive solidifying material can be suppressed as much as possible while sufficiently securing the FC strength.

[0043]

According to the present invention, as described above, by measuring the flow value and the specific gravity of the sample slurry SCa in the soil / solidifying material mixed slurry SC formed in the void, the soil / solidifying It is possible to inspect whether or not the water content and the solidified material ratio in the material mixed slurry SC are appropriate, and it is possible to determine whether or not the formed body has sufficient FC strength before solidification. Therefore, it is possible to secure the reliability of the strength of the formed body without using an extra (unnecessarily) expensive solidifying material as in the past, and as a result, it is possible to reduce the material cost, and each formed body material. Since the blending ratio can be measured by a simple method, the cost required for the inspection can be reduced.

Further, since it is possible to inspect the blending ratio of each construction material in the state of slurry-like soil / solidifying material mixed slurry,
If the composition ratio of the structural body material deviates from the target ratio, it can be corrected to an appropriate ratio by a simple work of adding and mixing the insufficient material and re-stirring, and it is possible to reconstruct the structural body. There is also an effect that such troubles can be solved in advance.

Further, in claim 2 of the present application, the pH value of the soil S put into the void 1 is measured in advance, and the lower the pH value, the higher the proportion of the solidifying material in the soil / solidifying material mixed slurry SC. By doing so, even if soil with low pH value is weak in strength, FC
There is an effect that a structural body having high strength can be constructed.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a void forming step in a ground improvement method targeted by the present application.

FIG. 2 is an explanatory view of the next working process (formed body material charging process) from FIG.

FIG. 3 is an explanatory view of the next working step (construction body material stirring step) from FIG. 2.

FIG. 4 is a vertical cross-sectional view of an assembled body in a built state.

FIG. 5 is an explanatory diagram of a sample collecting step when the method for confirming the mixing ratio of the building material according to the embodiment of the present application is performed.

FIG. 6 is a flowchart showing a mixing ratio confirmation method according to the embodiment of the present application.

[Explanation of symbols]

1 is a void, 2 is a formed body, C is a solidifying material, S is a soil, Sa is a collapsed soil, W is water, SC is a soil / solidifying material mixed slurry,
SCa is a sample slurry.

Claims (2)

(57) [Claims] 1. A soil (1) having a predetermined opening area and a predetermined depth is formed by excavating and discharging soil in the ground, and the soil (S) previously excavated and discharged in the void (1) (S). ) And a solidifying material (C) such as cement and water (W) at predetermined ratios, respectively,
After mixing and stirring those materials in the void (1), the soil and solidifying material mixed slurry (SC) was mixed and stirred in the void (1) in the ground improvement method. Slurry soil / solidifying material mixed slurry (SC) to sample slurry (SCa)
Was collected, the flow value of the sample slurry (SCa) was measured, and the water content in the soil / solidifying material mixed slurry was inspected.
A method for confirming a mixing ratio of ground material in a ground improvement method, comprising measuring a specific gravity of the sample slurry (SCa) and inspecting a ratio of the solidifying material in the soil / solidifying material mixed slurry. 2. The method according to claim 1, wherein the pH value of the soil put into the void is measured, and the lower the pH value, the higher the proportion of the solidifying material in the soil / solidifying material mixed slurry. Method for confirming mixing ratio of building materials in ground improvement method.