JPH11172718A - Fluidization process method and improved soil therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluidization process method whereby a good filling property is obtained, no cavities are left behind, and the total balance of physical properties such as flowability, material separation resistance, strength, and the like can be achieved, so that stable construction work is made possible, and to provide improved soil from which fluidization process soil for use in the method can easily be prepared simply when mixed with water and a hydraulic hardener such as cement, and which provides a high rate of utilizing surplus soil, etc., while enabling a device to be made smaller and providing excellent operability. SOLUTION: In a fluidization process method in which backfilling or filling work involved in civil engineering work is carried out by pouring fluidization process soil, a clod of earth is mixed with 10 to 300 kg/m<3> of quick lime or a soil improver composed chiefly of quick lime to obtain the fluidization process soil. Improved soil obtained by crushing the clod into finer grains and making the grains almost equal in grain size is mixed with water and a hydraulic hardener and fluidized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved method of a fluidization treatment method for backfilling, backfilling or filling in civil engineering construction work, and an improved soil used therefor.

[0002]

2. Description of the Related Art Conventionally, in the construction method of backfilling, backfilling or filling of earth and sand in civil engineering construction work, as earth and sand for construction,
Excavation soil generated at the construction site For example, construction method using excavated soil,
When the generated residual soil is poor, a construction method is known in which high-quality earth and sand is used instead, or an improved soil obtained by mixing a soil improving material such as a solidified material with the remaining soil is used. This construction method requires compaction and compaction.However, in the case of backfilling for laying and repair of buried pipes such as water pipes and underground railways such as water and sewer pipes, gas pipes and communication cables, compaction It is necessary to control the pressure of the buried pipe to such an extent that there is no danger of damage to the buried pipe. This tends to cause problems such as land subsidence and sinking. In such a case, excessive stress is likely to be generated in the buried pipe or the like, which may lead to breakage. The same occurs in backfilling methods such as retaining walls and abutments.

On the other hand, in order to solve such a problem,
Various fluidization treatment methods have been proposed. In this method, the treated soil is given a fluidity to improve the filling property. For such a fluidized treated soil, for example, water and a solidified material are mixed with earth and sand by reciprocating rotary stirring. What was obtained by stirring (Japanese Patent Application Laid-Open No. 63-233115), that obtained by mixing a hydraulic hardening material and water into excavated soil and fluidized (Japanese Patent Application Laid-Open No. 1-312118), mixing earth and sand with water Fast-fluidized fluidized soil consisting of a mixture of muddy water and solidified material obtained by the above method (Japanese Patent Application Laid-Open No. Hei 6-344328),
There is a mixture of muddy water containing fine-grained soil such as silt and bentonite (Japanese Patent Laid-Open No. 7-82884). In such a construction method, the fluidized soil is increased by at least the amount of water or muddy water, compared to the generated residual soil, the soil mixed with the solidified material, and the earth and sand (hereinafter sometimes referred to as residual soil, etc.). , The utilization rate of the residual soil decreases, and the preparation of the treated soil requires a larger device.Especially, when the construction site is narrow, the work becomes difficult or the space for installing the device cannot be taken. There is a problem that the operation becomes complicated, such as preparing the treated soil with an apparatus provided at an appropriate place in a wider space and transporting the treated soil to a construction site, resulting in an increase in cost.

[0004]

SUMMARY OF THE INVENTION Under such circumstances, the present invention provides a good balance of physical properties such as fluidity, material separation resistance, strength, etc., with good filling properties and no voids. Just by mixing with a fluidized treatment method that enables stable construction, and a hydraulic hardening material such as water and cement, the fluidized treated soil used in the method can be easily prepared, and the utilization rate of residual soil The purpose of the present invention is to provide an improved soil which has a high performance, can make the apparatus smaller, and has excellent workability.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies on the fluidization treatment method having the above-mentioned good characteristics and the improved soil used therein, and as a result, the soil mass was obtained without using an adjusting material such as muddy water. In addition to mixing and mixing a specific soil improvement material in a specific ratio to crush and crush the earth mass,
The one with the same grain size will be the desired improved soil,
The present inventor has found that a fluidization treatment method using a fluidized soil prepared using the same is suitable for the purpose, and has completed the present invention based on this finding.

That is, according to the present invention, in a fluidization treatment method in which backfilling, backfilling, or filling of civil engineering construction work is performed by pouring fluidized treated soil, quicklime or quicklime is used as a fluidized treated soil for an earth mass. Mixing and mixing 10 to 300 kg / m ^{3 of the} main soil improvement material, crushing the soil mass to make it finer, and mixing and mixing water and hydraulic hardening material with the improved soil having the same particle size. A fluidization treatment method characterized by using a liquefied material, and a method for improving the soil mass by using quicklime or quicklime as a main component for the soil mass.
The purpose of the present invention is to provide an improved soil obtained by mixing and mixing 0 to 300 kg / m ³ to break up and crush the earthen lump and to make the grain size uniform.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION There is no particular limitation on the mass of soil used in the preparation of improved soil in the present invention. For example, silty soil, cohesive soil, sandy cohesive soil, gravel cohesive soil, loam, volcanic ash cohesive soil, Sandy soil, gravel, etc. are used, and the remaining soil and high quality soil are also used.

[0008] There is no particular limitation on the quick lime added to the soil mass, but one usually obtained by firing limestone is used.

[0009] Instead of quicklime, a soil improving material mainly containing quicklime is used. Cement, gypsum, slag, and the like can be given as auxiliary materials of the soil improvement material, and the auxiliary material is blended in a ratio of less than 50% by weight, preferably 40% by weight or less based on the total amount of the soil improvement material.

The mixing ratio of quicklime or a soil improving material mainly composed of quicklime (hereinafter referred to as quicklime improving material) to the earth mass varies depending on the purpose of use and the type of the earth mass, but it is usually 10 to 300 kg / m ³ , preferably 10 to 300 kg / m ³ . Is 20-200kg
/ M ³ . If the ratio is too small, the effect of the present invention will not be sufficiently exhibited, and if it is too large, the effect will not be improved for the amount, and it will be economically disadvantageous, which is not preferable.

It is presumed that when quicklime is blended into a soil mass, it absorbs water in the soil mass and causes a digestion reaction, and the product causes an action such as ion exchange, so that the soil mass is smoothly broken up. .

The crushing of the earthen lump is promoted by subjecting it to a mixing treatment with the quicklime blended therein. It is preferable to use a mixing disintegrator for the mixing treatment. There is no particular limitation on the mixing and crushing machine. For example, a drum mixer, a single-shaft or twin-shaft paddle mixer, a ribbon mixer, a double-roll crusher, an impact crusher, or a combination thereof may be used. It has a supply port for the improved material-incorporated soil mass, a discharge port for the crushed soil at the lower part, and a swingable swinging swing by centrifugal force in a trapezoidal box-shaped casing that has a tapered divergent shape from the upper end to the lower end. First and second drive rotors in which the blades are divided in the axial direction and in the axial direction are arranged in parallel on the left and right, respectively, and a third drive rotor having the same shape as the above is provided by the two drive rotors. It is preferable that the drive rotor is disposed below the intermediate position. The casing of the mixing and crushing machine has the above-mentioned shape, so that it is possible to prevent the sediment on the side wall of the lumps dispersed by the impact effect of the swingable blade. Particularly effective soil ingots using this mixing and crushing machine are, in general, construction soil containing various contaminants such as concrete ash, ascon gala, and gravels, crushed stone washing cake, shield mud, and defective soil such as sedimentary soil such as dams.

Next, the mixing and crushing machine will be described in more detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing an internal structure of one example of a mixing and disintegrating machine, FIG. 2 is a side view of a drive rotor, and FIG. 3 is a front view thereof.
Reference numeral 1 denotes a box-shaped main body (casing) having, at an upper end thereof, a supply port 2 for a soil mass in which a raw lime-based improving material is mixed, and a lower end (bottom) for discharging a wide crushed soil with the entire surface of the casing open. 3 are provided.

The casing 1 has a trapezoidal shape extending from the upper end to the discharge port at the lower end, and has a shape capable of preventing soil from adhering to the inner surface of the main casing.
Further, a shielding plate 4 having a V-shaped cross section is provided on the inner surface of the upper end of the casing from the vicinity of the lower end of the supply port 2 so as to prevent the supply material from escaping outward and to rotate by the rotation of the drive rotor. It has a shape that blocks dust that flies along with the generated updraft and does not go out of the mixer.

Next, in FIGS. 2 and 3, reference numeral 11 denotes a driving rotor shaft which is driven to rotate. The outer periphery of the shaft 11 is axially divided into four blade shafts 13 fixed by blades 12, respectively. The plurality of blades 14 are swingably mounted. The blades 14 are indicated by solid lines when the rotor is rotating, and by broken lines when the rotor is stopped.

As shown in FIG. 1, the driving rotor has a total of 3
The first rotor 21 and the second rotor 22 in the upper stage are mounted symmetrically with respect to the center of the supply port and rotate inward (the first rotor rotates clockwise and the second rotor rotates counterclockwise). The lower third rotor 23 is provided below an intermediate position between the upper first rotor and the second rotor. This third rotor may be either clockwise or counterclockwise.

The earth mass and the quicklime improving material are mixed in a predetermined ratio in advance, and this mixture is charged into a mixing and crushing machine.
It is important that the throwing position is dropped to the middle of the blades of the first drive rotor so as not to pass between the blades of the first and second drive rotors arranged in parallel. This can be easily performed by adopting a structure in which the position of the belt conveyor head can be adjusted according to the belt speed of the supply conveyor.

By introducing the mixture of the earth mass and the quicklime-based improving material into such a position, the mixing and crushing effect of the blades of the first, second and third drive rotors is repeated three times. The quicklime-based improving material is sufficiently uniformly adhered to the surface of the soil mass by the blades of the drive rotor, and further adhered to the new surface of the earthen mass as the soil mass is crushed. The improvement material adhering to the surface of the mass has the effect of flour, and the crushed mass does not become a large mass again.

The first rotor, the second rotor, and the third rotor may be replaced by 790 rpm, for example, if desired.
600 rpm for the second rotor and 900 rpm for the third rotor
Can be set to different rotational speeds. In this way, turbulence is generated in the box-shaped casing, and the finely dispersed soil mass is introduced into a state in which the supplied soil improvement material is dispersed in the form of a mist, and the two come into contact with each other.
Even more homogeneous mixing takes place.

Thus, the improved soil of the present invention can be obtained in a homogenous mixed state in which the soil mass is finely crushed and the grain size is uniform. The improved soil of the present invention is preferably classified using a sieve or the like, whereby the grain size of the improved soil can be further uniformed.

In the fluidization treatment method of the present invention, the improved soil is mixed with water and a hydraulic hardening material, mixed and fluidized, and used as the fluidized treatment soil. As the hydraulic solidifying material, for example, Portland cement, blast furnace cement,
Cement such as fly ash cement, cement-based solidifying material, blast furnace slag fine powder, and the like are included. In this fluidized soil, water and a hydraulically solidifying material are used in an appropriate amount with respect to the improved soil in accordance with required strength, fluidity under construction conditions, and the like, and preferably 30 to 200 kg / m ³ and 1 kg.
Each is blended at a ratio in the range of 00 to 500 kg / m ³ . In this fluidized soil, an additive usually used for fluidized soil, such as a foaming agent, a dispersant, and a fluidizing agent, is blended, as necessary, within a range not to impair the purpose of the present invention. Is also good.

In the fluidization treatment method of the present invention, the fluidized soil is poured into a backfilling, backfilling or filling work site in civil engineering construction work, and is hardened and solidified.

[0023]

Next, the present invention will be described in more detail by way of examples, which should not be construed as limiting the present invention.

Comparative Examples 1 to 5 Construction-derived soil composed of cohesive soil mixed with gravel in Yokohama was collected five times at the same location. 1 to No. 5 was used as it was for comparison.

Examples 1 to 5 The same construction excavated soil as used in the comparative example was
The collected soil was blended with quicklime at a rate of 50 kg / m ³ in each of the collected soils, finely divided by a crushing mixer as shown in FIG. 6
-No. 10 was prepared.

Test Example Comparative soil No. 1 to No. 5 and the improved soil No. 5 of the present invention.
6-No. Cement, water, and a foaming agent were added to each of the raw material soils of No. 10 in the amounts shown in Table 1 to prepare fluidized treated soils. The physical properties of the soils were flow value, unit volume weight, breathing rate, uniaxial compression. I sought strength. Table 2 shows the results.
In addition, the flow value of the fluidized soil immediately after preparation is as follows:
According to the flow test based on JIS R 5201, the breathing rate was determined by JS for the fluidized soil immediately after preparation.
Each was determined by a breathing test based on CE-1986. The unconfined compressive strength was determined by preparing a columnar sample having a diameter of 50 mm and a height of 100 mm using the fluidized soil.
After curing in a constant-temperature room at 0 ° C. and a humidity of 80% for 28 days in a constant-temperature room, it was determined by a uniaxial compression test based on JISA 1216.

[0027]

[Table 1]

[0028]

[Table 2]

From this, the comparative improved soil No. 1 to No.
The fluidized soil prepared using No. 5 is the same as the material soil No. 5 even though the material soil is the same.
1 to No. 1 The physical properties of the fluidized soil vary widely among the five, and the physical properties are not stable, and when the flow value is increased, the breathing rate is deteriorated, the uniaxial compressive strength is reduced, and the breathing rate is improved. Then, the flow value and the uniaxial compressive strength decrease, and when the uniaxial compressive strength is increased, the flow value decreases and the breathing rate deteriorates. 6-No. No. 10 for the fluidized treated soil prepared using 6
Or No. It can be seen that the fluidized soil shows stable physical properties with almost no variation among the 10 fluidized soils, and has an excellent balance between the physical properties.

[0030]

According to the fluidization treatment method of the present invention, in backfilling, backfilling or filling work of civil engineering construction work,
Good filling properties, no cavities remain, good balance of overall physical properties such as fluidity, material separation resistance, strength, etc., and stable construction results can be obtained. In addition, the improved soil of the present invention has a high utilization rate of residual soil and the like, can reduce the size of the apparatus, is finely crushed, has a uniform particle size, has excellent workability, and is a hydraulically hardened material such as water and cement. The fluidized soil used in the fluidization method can be easily prepared only by mixing the fluidized soil. In addition, the use of a mixing crusher allows the quicklime-based improving material to be efficiently and homogeneously mixed with the soil mass, particularly the remaining soil, crushed stone washed cake, shield mud, sedimentary soil such as dams, etc. Remarkable effects such as more efficient crushing and more uniform particle size are exhibited.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an internal structure of an example of a mixing crusher.

FIG. 2 is a side view of a driving rotor of one example of the mixing and crushing machine.

FIG. 3 is a front view of the drive rotor of FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casing 2 Raw material supply port 3 Reformed soil discharge port 11 Drive rotor shaft 14 Blade 21 First rotor 22 Second rotor 23 Third rotor

[Procedure amendment]

[Submission date] February 10, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction contents]

In the fluidization treatment method of the present invention, the improved soil is mixed with water and a hydraulic hardening material, mixed and fluidized, and used as the fluidized treatment soil. As the hydraulic solidifying material, for example, Portland cement, blast furnace cement,
Cement such as fly ash cement, cement-based solidifying material, blast furnace slag fine powder, and the like are included. In this fluidized soil, water and a hydraulically solidifying material are used in an appropriate amount depending on the required strength, fluidity under construction conditions, and the like, and preferably 100 to 500 kg / m ³ and 30 to 200 k.
g / m ³ . In this fluidized soil, an additive usually used for fluidized soil, such as a foaming agent, a dispersant, and a fluidizing agent, is blended, as necessary, within a range not to impair the purpose of the present invention. Is also good.

Claims (3)

[Claims] 1. A fluidization treatment method in which backfilling, backfilling or filling of a civil engineering construction work is performed by pouring a fluidized treated soil, wherein the fluidized treated soil is mainly composed of quicklime or quicklime. 10-300 improvement material
kg / m ³ blended and mixed to disintegrate and crush the earthen lump, and to mix and fluidize the water and hydraulic hardening material to the improved soil with uniform particle size. And fluidization treatment method. 2. An improved soil in which quick lime or a soil improving material mainly composed of quick lime is blended with 10 to 300 kg / m ³ and mixed with a soil mass to crush the soil mass to make it finer and to have uniform grain sizes. 3. The improved soil according to claim 2, wherein the crushing of the soil mass is performed by using a mixing crusher.