JPH07103548B2 - 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 an invention for improving the ground, and more particularly to a technology for improving the ground by using a mixed liquid of carbon dioxide gas and a cement liquid.

[0002]

2. Description of the Related Art Conventionally, there has been known a method of mixing cement-based liquid and carbon dioxide gas and injecting them into the ground, as disclosed in JP-A-53-108610 and JP-A-53-96212. When the cement-based liquid and carbon dioxide gas are mixed and injected into the ground in this way, the preferential permeability of the carbon dioxide gas, which is a gas, in the voids in the ground ensures the penetration of the cement-based liquid into the soil. It has the characteristics that even if the cement-based liquid is used alone, even soil that is difficult to penetrate can be satisfactorily penetrated, and that the cement-based liquid reacts with carbon dioxide gas and hardens quickly.

By the way, when carbon dioxide gas and cement-based liquid are mixed in a closed container, heat is generated at 50 ° C. to 60 ° C. When the heat is generated in this way, the viscosity of the cement-based liquid rises, and the amount of space between the soil particles is increased accordingly. There is a problem that the penetrating power becomes weak.
On the other hand, if the cement particles are coarse, they are caught between the soil particles and have a weak osmotic force. Therefore, considering the osmotic force, the smaller the cement particles are, the higher the osmotic force is. Also, the smaller the cement particles, the higher the strength. Therefore, in recent years, use of ultrafine particle cement has been performed. However, when the ultrafine cement, carbon dioxide and water are mixed and injected into the ground, the heat generated by the reaction between the ultrafine cement and carbon dioxide causes the viscosity to rise even higher than that of normal cement. Even though the cement-based liquid is satisfactorily permeated into the ground by utilizing the preferential permeability, there is a problem that the permeation force is weak.

Therefore, in view of this point, the applicant of the present invention has developed a method of injecting the carbon dioxide gas or the cement liquid in a cooled state when the cement liquid and the carbon dioxide gas are simultaneously injected into the ground. The application has already been completed, and this has been published as Japanese Patent Application Laid-Open No. 4-155008.
In this conventional example, the reaction between carbon dioxide and the cement-based liquid is suppressed to delay the heat generation, the viscosity is suppressed from increasing during the permeation, and the preferential preferential permeability of carbon dioxide can be utilized,
After the permeation, the temperature of the mixed liquid of carbon dioxide gas and the cement-based liquid rises, and the carbon dioxide gas and the cement-based liquid react with each other so that the cement-based liquid can be hardened quickly.

[0005]

However, in the conventional example disclosed in Japanese Unexamined Patent Publication No. 155008/1992 mentioned above, when the ground is improved, carbon dioxide gas or cement liquid is injected into the ground in a cooled state. Since the ground is simply broken down and the ground is not agitated, the soil around the injected ground is in a natural state, where carbon dioxide easily penetrates and places where carbon dioxide does not easily mix. As a result, the amount of cement-based liquid that permeates due to the prior priority permeability of carbon dioxide differs depending on where carbon dioxide gas easily permeates and where carbon dioxide gas does not permeate easily. There was a problem that the surroundings of the portion injected into the ground in this state could not be improved uniformly. Further, in the above-mentioned conventional example, it is made possible to facilitate the permeation of the cement-based liquid into the soil by utilizing the precedence preferential permeation of carbon dioxide while cooling and suppressing the increase in viscosity during permeation. However, compared with the case where only cement-based liquid is used, when the cement-based liquid is penetrated into the soil by utilizing the preferential preferential permeability of carbon dioxide gas, it is possible to penetrate far from the injection position. is there. However, the permeation amount of the cement-based liquid differs between the vicinity of the injection position and the position where the carbon dioxide gas has permeated (that is, the permeation amount of the cement-based liquid gradually decreases as the distance from the injection position increases). , There is a possibility that it is not possible to improve the ground uniformly around the part injected into the ground in the state where the carbon dioxide gas or the cement-based liquid is cooled, and even if you try to improve the ground only in the target area, The cement-based liquid permeates more than necessary due to the prior-permeability of carbon dioxide gas, which causes waste of the cement-based liquid and carbon dioxide gas, which causes a cost increase.

The present invention has been made in view of the above-mentioned problems of the prior art, and its object is to suppress the reaction between carbon dioxide gas and cement-based liquid to delay heat generation, It suppresses the increase of viscosity during infiltration, and utilizes the prioritized preferential permeability of carbon dioxide to evenly mix the mixture of carbon dioxide and cement-based liquid with the disintegrated soil. It is an object of the present invention to provide a ground improvement method capable of promoting the hardening of the liquid and the disintegrated soil to improve the ground, and further uniformly improving the ground only in a certain area to be improved.

[0007]

In order to solve the problems of the above-mentioned conventional examples and achieve the object of the present invention, the ground improvement method of the present invention has the following constitution.

That is, the ground 2 is crushed by a crushing machine 5 equipped with a stirring means 4, and a cement-based liquid such as cement milk or a mixed liquid mainly composed of cement milk and carbon dioxide gas are discharged from the vicinity of the tip of the crushing machine 5. The cooled carbon dioxide-containing cement-based mixed solution 1 in which the cooled carbon dioxide-containing cement-based mixed solution 1 is mixed into the crushed soil 3 in the crushing hole 8 and cooled by the stirring means 4 provided in the crusher 5 1 a and Kuzurekezu soil 3 mixture stirred to is characterized in that ground improvement.

Further, a cylindrical outer shell 6 in which a cooled carbon dioxide-containing cement mixture 1 prepared by mixing a cement liquid such as cement milk or a mixture mainly composed of cement milk with carbon dioxide is inserted into the ground 6 It is also preferable that the soil is improved by mixing and stirring the carbon dioxide gas-containing cement-based mixed solution 1 and the crushed soil 3 which are supplied into the crushed soil 3 in a portion surrounded by and are cooled by the stirring means 4.

It is also preferable that the cylindrical outer shell 6 is pulled out from the ground 2 after the carbon dioxide-containing cement-based mixed liquid 1 cooled by the stirring means 4 and the broken soil 3 are mixed and stirred.
Further, the carbon dioxide-containing cement-based mixed liquid 1 cooled by the stirring means 4 and the crushed soil 3 are mixed and stirred to improve the ground, and a cylindrical outer shell made of cast-in-place concrete is provided on the outer peripheral portion of the ground improving portion 15. It is also preferred to form the body 7.

Furthermore, it is also preferable to leave the cylindrical outer shell 6 in the ground 2 after mixing and stirring the carbon dioxide-containing cement-based mixed liquid 1 cooled by the stirring means 4 and the crushed soil 3.
In addition, a cylindrical outer shell body 7 made of cast-in-place concrete is formed around the ground 2 to be improved in advance, and the ground 2 in the pre-formed cylindrical outer shell body 7 made of cast-in-place concrete is crushed. In addition, the ground improvement method is characterized by mixing and stirring the carbon dioxide-containing cement-based mixed liquid cooled by the stirring means 4 and the crushed soil 3 to improve the ground.

[0012]

The cooled ground carbon dioxide-containing cement-based liquid mixture 1 obtained by mixing the cement-based liquid such as cement milk or a liquid mixture mainly composed of cement milk with carbon dioxide gas is ground to the ground 2 after the ground is destroyed. Carbon dioxide-containing cement-based cement-based cement-based mixture is prepared by mixing and stirring carbon dioxide-containing cement-based mixed solution 1 cooled by stirring means 4 and collapsed soil 3 which are supplied into collapsed soil 3 left inside. In reducing the viscosity of the mixed liquid 1 and facilitating the permeation of the cement-based liquid by the preferential permeation of carbon dioxide gas, the carbon dioxide gas in the collapse hole 8 reaches the ground 2 forming the peripheral wall of the collapse hole 8. The permeability of carbon dioxide gas between the collapsing soil 3 and the surrounding wall is significantly different, and the carbon dioxide gas that hits the surrounding wall tries to permeate into the collapsing soil 3 which is easier to penetrate than the surrounding wall, so that Containing cement mixture 1 The carbon dioxide gas that has been filled and has filled the collapsing holes 8 rises in the collapsing soil 3 left in the collapsing holes 8 to forcibly rise between the particles of the collapsing soil 3 and The cement-based liquid efficiently permeates the soil particles through which the gas has passed, and in this case, by stirring the carbon dioxide-containing cement-based mixed liquid 1 and the broken soil 3 with the stirring means 4, Mixing and stirring the carbon dioxide-containing cement-based mixed liquid 1 and the crushed soil 3 is performed, but in this case, since the carbon dioxide-containing cement-based mixed liquid 1 is cooled, the viscosity is lowered. Even when the broken soil 3 has a high viscosity, uniform mixing and stirring is possible. That is,
If the carbon dioxide-containing cementitious mixed solution 1 is not cooled, the viscosity of the mixed solution 1 becomes high, and if the crushed soil 3 has a high viscosity, it becomes difficult to uniformly mix and stir due to the viscosities of both.
By cooling the carbon dioxide-containing cement-based mixed liquid 1 when mixing the crushed soil 3 and the carbon dioxide-containing cement-based mixed liquid 1, uniform mixing and stirring becomes possible.

Then , the ground 2 is crushed by a crushing machine 5 equipped with a stirring means 4, and a cement-based liquid such as cement milk or a mixed liquid mainly composed of cement milk and carbon dioxide are discharged from the vicinity of the tip of the crushing machine 5. The cooled carbon dioxide-containing cement-based mixed liquid 1 mixed with and is supplied into the crushing hole 8, and the carbon dioxide-containing cement-based mixed liquid 1 and the crushed soil 3 cooled by the stirring means 4 provided in the crushing machine 5 are cooled. It is ground improvement by stirring and mixing the bets
Then, at the same time when the original ground is crushed, the crushed soil 3 and the carbon dioxide-containing cement-based mixed liquid 1 can be mixed and stirred, and the ground can be rapidly improved.

Further, the ground 2 is a cooled carbon dioxide-containing cement mixture 1 in which a cement liquid such as cement milk or a mixture mainly composed of cement milk is mixed with carbon dioxide.
The mixture is fed into the crushed soil 3 in the portion surrounded by the cylindrical outer shell 6 inserted therein, and the cement-based mixture 1 containing carbon dioxide gas cooled by the stirring means 4 and the crushed soil 3 are mixed and stirred. In the soil improvement, the carbon dioxide gas having the preferential prior permeability does not permeate outside the tubular outer shell 6, and therefore the carbon dioxide gas to be used is in the collapsed soil 3 surrounded by the tubular outer shell 6. And the cement-based liquid permeates between the soil particles of the disintegrated soil 3 to prevent carbon dioxide from permeating the surrounding soil unnecessarily and effectively preventing loss. It will be available. In this case, the stirring means 4
By mixing and stirring the carbon dioxide-containing cement-based mixed liquid 1 and the crushed soil 3 that have been cooled by, the cylindrical outer shell 6 is pulled out from the ground, whereby the ground can be accurately improved only in the target portion.

Further, the carbon dioxide-containing cement-based mixed liquid 1 cooled by the stirring means 4 and the broken soil 3 are mixed and stirred to improve the ground, and a cast-in-place concrete cylinder is provided on the outer peripheral portion of the ground improving portion 15. By forming the cylindrical outer shell body 7, it is possible to form a foundation in which the cylindrical outer shell body 7 and the ground improvement portion 15 in the cylindrical outer shell body 7 cooperate with each other.

Further, after mixing and stirring the carbon dioxide-containing cement-based mixed liquid 1 cooled with the stirring means 4 and the crushed soil 3, the tubular outer shell 6 is left in the ground 2 to serve also as a casing. The cylindrical outer shell 6 and the ground improvement portion 15 in the cylindrical outer shell 6 can form a cooperative foundation. Further, a cylindrical outer shell body 7 made of cast-in-place concrete is formed around the ground 2 to be improved in advance, and the soil in the tubular outer shell body 7 made of precast cast-in-place concrete is destroyed. Together with the stirring means 4
In the case of improving the ground by mixing and stirring the carbon dioxide-containing cement-based mixed solution cooled by the above and the crushed soil 3, the cylindrical outer shell 7 in which the carbon dioxide gas and the cement-based solution used in the ground improvement are formed in advance It is possible to use it effectively without penetrating into the ground 2 outside the ground and escaping, and moreover, the cylindrical outer shell 7
And the ground improvement portion 15 in the cylindrical outer shell body 7 can form a cooperative foundation.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the embodiments shown in the accompanying drawings. FIG. 1 shows a crushing machine 5 used in the present invention. A bit 1 is provided at the lower end of one or a plurality of rotation vertical axes 9.
0 is provided, and the rotating vertical axis 9 is provided with a stirring means 4. As the stirring means 4, in the embodiment, the wing portion 4 is used.
Although the a and the screw 4b are used as the stirring means 4, either one may be used, and the arrangement of these stirring means 4 can be arbitrarily selected. In the embodiment shown in the accompanying drawings, the plurality of rotation vertical axes 9 are adapted to rotate by transmitting the rotation of the rotation device 11 via the multi-axis device 12.
A jet port is provided at the lower end of the rotating vertical axis 9, and a cooled carbon dioxide-containing cement mixture 1 containing a mixture of a cement liquid such as cement milk or a mixture mainly composed of cement milk and carbon dioxide is used. It is designed to be discharged or ejected. The cooled carbon dioxide-containing cement-based mixed liquid 1 is, for example, a mixture of a cement-based liquid and dry ice. More specifically, cement, water, and other materials that are materials of the cement-based liquid, It is a mixture of granulated and sherbet-shaped dry ice and kneaded.

The ground 2 to be improved is ground by using the above-mentioned crushing machine 5, and the cooled carbonic acid jetted or discharged from the crushed soil 3 and the jet outlet provided near the tip of the crushing machine 5. The gas-containing cement-based mixed liquid 1 is mixed and stirred by the stirring means 4 to improve the ground. In this case, at the time when the cooled carbon dioxide-containing cement-based mixed liquid 1 is jetted or discharged from the jet outlet, the granular or sherbet-shaped dry ice becomes cold carbon dioxide gas, and the shavings in the shaving holes 8 are crushed. The soil particles in the soil 3 are preferentially permeated first, and then the cement-based liquid permeates. Then, even if cold carbon dioxide gas reaches the peripheral wall of the collapsing hole 8, the permeability of the carbon dioxide gas between the collapsing soil 3 in the collapsing hole 8 and the peripheral wall of the collapsing hole 8 is significantly different. The carbon dioxide gas that has collided with the peripheral wall of the drilled hole 8 tries to permeate into the collapsed soil 3 which is much easier to permeate than the peripheral wall,
As a result, the carbon dioxide-containing cement-based mixed liquid 1 is filled in the collapsing holes 8, and the carbon dioxide gas filled in the collapsing soil 3 is filled in the collapsing soil 3 left in the collapsing holes 8. As it rises, most of the cold carbon dioxide gas rises in the collapse hole 8 from the lower side to the upper side at a substantially uniform concentration.
The cement-based liquid efficiently permeates between the particles of the collapsed soil 3 left in the collapse holes 8 and the cold carbon dioxide gas passes through the soil particles. Here, when the carbon dioxide gas and the cement-based liquid are mixed, fine bubbles are formed,
These fine bubbles easily penetrate into the collapsed soil, and when the fine bubbles collide and are destroyed, the gas first enters between the soil particles, and then the cement-based liquid enters. In this way, the cement-based liquid is satisfactorily permeated between the soil particles of the crushed soil 3. Also,
The carbon dioxide gas is cooled as it has just changed from dry ice to gas, so it is suppressed that it reacts with the cement-based liquid during permeation, and the cement-based liquid is suppressed from increasing in viscosity due to heat generation. Does not prevent the soil from penetrating into the crushed soil, which is why
Even if ultrafine particle cement is used as the material of the cement-based liquid, it becomes possible to satisfactorily penetrate it. In this way, the carbon dioxide-containing cement-based mixed liquid 1 is allowed to permeate into the crushed soil 3 left in the crushed hole 8, but at the same time, the crushed soil 3 and the cold carbon dioxide-containing cement are mixed by the stirring means 4. Since the system mixture 1 is stirred, the crushed soil 3 in the crush hole 8 and the cold carbon dioxide-containing cement mixture 1 are mixed. In this case, if the carbon dioxide gas is not stirred, the carbon dioxide gas simply rises through the easily-passable gap in the collapsing soil 3 left in the collapsing hole 8.
The carbon dioxide gas that is going to rise is agitated by being agitated with, and the carbon dioxide gas evenly permeates the crushed soil 3 in the crushed holes 8, and in this case, the stirring is performed. As a result, the crushed soil 3 is finely sheared and made into small particles, and the bubbles are destroyed by stirring, so that carbon dioxide gas further penetrates between the particles of the crushed soil 3, and subsequently the cement-based liquid is added. Will penetrate and be mixed.
Then, by mixing and stirring the carbon dioxide-containing cement-based mixed solution 1 and the crushed soil 3 cooled by the stirring means 4, even when the crushed soil 3 has high viscosity, the cooled carbon dioxide-containing cement-based cement system is mixed. The viscosity of the mixed solution 1 is low, and as a result, compared to the case where both the crushed soil 3 and the mixed solution have high viscosity, uniform mixing and stirring are possible, and each part can improve the ground with uniform strength. However, in the present invention, when the temperature of the further cooled carbon dioxide-containing cement-based mixed liquid 1 rises, the cement-based liquid hardens quickly, and as a result, the carbon dioxide-containing cement once permeated into the disintegrated soil 3 There is no fear that the strength of the ground improvement portion 15 will be lowered by the system mixture 1 gradually permeating to the ground 2 side around the collapse hole 8 and escaping.
In this way, the ground of the broken soil 3 in the broken hole 8 is improved. In this case, it is possible to improve the ground corresponding to the collapse holes 8 by forming the collapse holes 8 independently, but the invention is not limited to this and the break holes 8 can be formed in the same manner as described above. Is continuously crushed to improve the ground to form a cliff wall, or the ground is improved in an area where a plurality of crush holes 8 are aggregated.

FIG. 2 shows another embodiment of the present invention. In this embodiment, a cylindrical outer shell in which a cooled carbon dioxide-containing cement mixture 1 prepared by mixing a cement liquid such as cement milk or a mixture mainly composed of cement milk with carbon dioxide was inserted into the ground. The soil-improved soil 3 in the portion surrounded by 6 is mixed and stirred with the carbon dioxide-containing cement-based mixed solution 1 and the collapsible soil 3 which are cooled by the stirring means 4 to improve the ground. That is, in this embodiment, a casing made of metal or reinforced concrete, which is the tubular outer shell 6, is attached to the crushing machine 5, and the tubular outer shell 6 is used when the ground 2 is crushed by the crushing machine 5. A casing made of a metal or reinforced concrete is inserted into the ground 2 at the same time, and the cooled carbon dioxide-containing cement-based mixed liquid 1 jetted or discharged from the jet port provided near the tip of the crusher 5 is stirred by the stirring means 4. The ground is improved by mixing and stirring. In this case, since the tubular outer shell 6 exists along the peripheral wall of the collapse hole 8, the cold carbon dioxide gas cannot move further to the side by the tubular outer shell 6, and therefore, all the carbon dioxide gas cannot be passed. The contained cement-based mixed liquid 1 will fill the lower part of the collapsing soil 3 in the cylindrical outer shell 6, and the carbon dioxide gas filled in the collapsing soil 3 will remain in the collapsing holes 8. As it rises in the soil 3, all of the cold carbon dioxide gas rises in the collapse hole 8 from the bottom to the top at a substantially uniform concentration, and the collapse soil left in the collapse hole 8 3 forcibly ascends between the particles, and the cement-based liquid efficiently permeates the soil particles through which the cold carbon dioxide gas has passed, and this is uniformly stirred by the stirring means 4. As a result, carbon dioxide does not unnecessarily escape to the surrounding ground, and all carbon dioxide and ces So that it is ground improvement of uniform intensity only area of interest by effectively using the door system solution.

By the way, the ground in the target area is improved as described above. After that, a cylindrical groove is formed in the outer peripheral portion of the ground improvement section 15 and the cast-in-place concrete is injected therein to form the cylindrical outer shell body 7 made of cast-in-place concrete. You may make it form the foundation 16 as shown in FIG. 3 with the cylindrical outer shell body 7 made from cast-in-place concrete formed in the outer peripheral part of the circumference. Here, the ground improvement portion 15 formed as described above is formed such that the lower end portion thereof reaches the inside of the supporting ground 2a, and the lower end portion of the cylindrical outer shell body 7 formed around it is also supported. Make it reach the ground 2a. In this case, the lower end portion of the cylindrical outer shell body 7 may form an enlarged portion 7a.
Then, the upper structure is formed on the foundation 16 constituted by the ground improvement portion 15 thus formed and the cylindrical outer shell body 7 made of cast-in-place concrete formed on the outer peripheral portion around the ground improvement portion 15.

By the way, in forming the ground improvement part 15, in the case where the cylindrical outer shell 6 is inserted and the ground of the collapsed soil 3 is improved in the cylindrical outer shell 6, the ground improvement part 15 is used.
There is a case where the tubular outer shell 6 is pulled out to the ground before being completely cured and the tubular outer shell 6 is reused, and a case where the tubular outer shell 6 is left as it is in the ground 2. In the case where the tubular outer shell 6 is left as it is in the ground 2, the tubular outer shell 6 and the ground improvement portion 15 in the inside constitute a foundation 16 on which the upper structure is formed. Good.

In the above embodiment, for example, after forming the ground improvement portion 15, the cylindrical outer shell 7 made of cast-in-place concrete is formed on the outer peripheral portion of the ground improvement portion 15, or the ground improvement portion 15 is formed. Although an example is shown in which the cylindrical outer shell 6 is simultaneously inserted into the ground 2 when forming, a cylindrical groove is first formed in the area where the ground improvement is used, and the cast-in-place concrete is injected therein. By doing so, a cylindrical outer shell body 7 made of cast-in-place concrete is formed, and then the soil in the portion surrounded by the cylindrical outer shell body 7 made of cast-in-place concrete is crushed, and the crushed soil and cooled carbon dioxide gas You may make it form the ground improvement part 15 by mixing and stirring the containing cement-based mixed liquid 1 and the crushed soil 3 by the stirring means 4. Also in this case,
The cooled carbon dioxide gas is the tubular outer shell body 7 that has been formed in advance.
It is prevented from penetrating into the surrounding ground 2 and is allowed to be used without wasting by moving from the lower side to the upper side in the cylindrical outer shell body 7 for ground improvement. In this case as well, the foundation 16 as shown in FIG. 3 is formed by the ground improvement section 15 and the cylindrical outer shell body 7 made of cast-in-place concrete formed on the outer periphery of the ground improvement section 15, and the upper structure is formed on the foundation 16. It can be formed.

Incidentally, in each of the above embodiments, the ground improvement section 1
The strength of No. 5 is designed to be higher than that of the supporting ground 2a. Further, in the above embodiment, an example in which the crushing machine 5 is provided with the opening for discharging or jetting the cooled carbon dioxide-containing cement-based mixed liquid 1 and the stirring means 4 is shown.
The carbon dioxide-containing cement-based mixed liquid 1 cooled by a supply means other than the above may be supplied, or the broken soil 3 broken by the breaker 5 may be cooled by a different supply means. The carbon dioxide gas-containing cement-based mixed liquid 1 may be supplied and mixed and stirred by the stirring means 4 different from the crusher 4.

As the cooled carbon dioxide-containing cement-based mixed liquid 1, cement, water, and other materials which are the materials of the cement-based liquid are mixed and mixed with dry ice in the form of granules or sherbet in the above embodiment. A kneaded product was used, but cement or a cement-based material mainly composed of cement, cooling water cooled by a cooling means, and carbon dioxide were mixed to form a cooled carbon dioxide-containing cement-based mixed liquid 1, You may make it supply this.

Further, cement or cement-based material mainly composed of cement, cooling water cooled by cooling means,
The cement-based mixed liquid 1 containing carbon dioxide gas cooled by mixing with dry ice may be formed and supplied. In this embodiment, the use of cooling water reduces the amount of dry ice used. The cost can be reduced.

[0026]

The present invention has the following features.
Have an effect.

That is, by a breaker equipped with a stirring means
Crush the ground, cement milk from near the tip of the crusher,
Cement-based liquid such as mixed liquid mainly composed of cement milk
Cement system containing cooled carbon dioxide mixed with carbon dioxide
Prepare the crusher by supplying the mixed liquid to the crushed soil in the crush hole.
Cement mixture containing carbon dioxide cooled by different stirring means
Since the soil is improved by mixing and stirring the liquid and the broken soil,
The viscosity of the gas-containing cement-based mixed liquid is reduced to reduce the viscosity of carbon dioxide gas.
Line preferential permeability makes it easier to penetrate cement liquid
Carbon dioxide on the ground forming the peripheral wall of the collapse hole
Even in the collapsed soil, carbon dioxide is more likely to permeate than the surrounding wall.
Of the carbon dioxide gas inside the collapse hole.
Carbon dioxide gas filled in the collapse hole due to the mento-based mixed liquid
Will rise up in the collapsed soil left in the collapsed hole and
Soil grains that have been forced to rise between particles and through which carbon dioxide has passed
The cement-based liquid will penetrate efficiently between the
In the case of
Mixing the mixed liquid with the disintegrated soil by stirring in stages
Stirring will be performed, especially carbon dioxide containing cement
Since the system mixture is cooled, the viscosity decreases, and
Even if the ground soil is highly viscous, uniform mixing and stirring is possible.
To do. As a result, according to the present invention, the viscosity is high.
Even soil can effectively use carbon dioxide and cement-based liquid without waste.
Efficiently and uniformly mix only certain areas to be improved.
There is an advantage that the ground can be improved by being mixed and mixed. Only
In addition, the ground was broken by a crusher equipped with a stirring means, and cooled carbon dioxide obtained by mixing carbon dioxide with a cement-based liquid such as cement milk or a mixed liquid mainly composed of cement milk from near the tip of the crusher. The gas-containing cement-based mixed solution is supplied into the crushing hole, and the carbon dioxide-containing cement-based mixed solution cooled by the stirring means provided in the crushing machine and the crushed soil are mixed and stirred to improve the ground. At the same time, it is possible to mix and agitate the crushed soil and the carbon dioxide-containing cement-based mixed solution at the same time, and to rapidly improve the ground.

Further, a cooled carbon dioxide-containing cement-based liquid mixture prepared by mixing a cement-based liquid such as cement milk or a liquid mixture mainly composed of cement milk with carbon dioxide is surrounded by a cylindrical outer shell inserted into the ground. In the one that improves the soil by mixing and stirring the carbon dioxide-containing cement-based mixed liquid cooled by the stirring means and the broken soil, the carbon dioxide gas having prior priority permeability is It does not permeate to the outside of the tubular shell, so even though carbon dioxide gas has prior priority permeability, it does not escape and permeate to the outside of the tubular shell and is surrounded by the tubular shell. All the carbon dioxide gas will preferentially permeate only in the broken soil, and then the cement-based liquid will permeate between the soil particles of the broken soil, and the carbon dioxide will permeate into the surrounding soil in vain. To prevent the loss It is capable of reducing the cost.

Further, in the case where the cylindrical outer shell is pulled out from the ground after mixing and stirring the carbon dioxide-containing cement-based mixed liquid cooled by the stirring means and the crushed soil, accurate ground improvement can be made only in the intended portion. The tubular outer shell can be reused. Further, the carbon dioxide-containing cement-based mixed liquid cooled by the stirring means and the broken soil are mixed and stirred to improve the ground, and a cylindrical outer shell body made of cast-in-place concrete is formed on the outer peripheral portion of the ground improved portion. As a result, it is possible to form a foundation in which the tubular outer shell body and the ground improvement portion in the tubular outer shell body cooperate with each other.

Further, after mixing and stirring the carbon dioxide-containing cement-based mixed liquid cooled by the stirring means and the crushed soil, the cylindrical outer shell is left in the ground to form a cylindrical outer shell which also serves as a casing. It is possible to form a foundation in cooperation with the ground improvement portion in the tubular outer shell. In addition, a cylindrical outer shell made of cast-in-place concrete is formed around the ground to be improved in advance, and the soil in the pre-formed cylindrical outer shell made of cast-in-place concrete is crushed, and stirring means is used. By mixing and agitating the carbon dioxide-containing cement-based mixed solution and the broken soil that have been cooled by, to improve the ground, the carbon dioxide used in the ground improvement, the cement-based liquid of the outside of the tubular shell formed in advance It is possible to use it effectively without penetrating into the ground and escaping, and also to form a foundation in which the tubular outer shell and the ground improvement portion in the tubular outer shell cooperate with each other.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, in which a cement-based mixed liquid containing carbon dioxide gas, which has been crushed by a crusher and cooled, is supplied and mixed and stirred.

[Fig. 2] Fig. 2 shows another embodiment of the present invention, in which a cement-based mixed liquid containing carbon dioxide gas, which has been crushed by a crusher and cooled in a cylindrical outer shell inserted in the ground, is supplied and mixed and stirred. FIG.

FIG. 3 is a cross-sectional view showing still another embodiment of the present invention in a state where a cylindrical outer shell is formed on the outer periphery of the ground improvement portion.

[Explanation of symbols]

 1 Cement-based mixed liquid containing carbon dioxide 2 Ground 3 Breaking soil 4 Stirring means 5 Breaking machine 6 Cylindrical outer shell 7 Cylindrical outer shell 15 Ground improvement section

Claims (6)

[Claims] 1. The ground is broken by a crushing machine equipped with a stirring means.
From the vicinity of the tip of the shaving and crushing machine, cement milk, cement
Cement-based liquid such as mixed liquid mainly composed of milk and carbon dioxide
A cooled cement-based mixture containing carbon dioxide mixed with
A stirring hand that is supplied to the crushing soil in the crushing hole and prepared for the crushing machine.
Cement mixture containing carbon dioxide gas cooled by stages and disintegration
A land characterized by mixing and stirring with soil to improve the ground
Board improvement method. 2. Mainly cement milk, cement milk
Cement-based liquid such as the mixed liquid and carbon dioxide were mixed
Insert cooled cement mixture containing carbon dioxide into the ground
Supplied into the collapsed soil in the part surrounded by the cylindrical outer shell
The cement mixture containing carbon dioxide gas cooled by the stirring means.
A special feature is to improve the ground by mixing and stirring the mixed liquid and the broken soil.
Ground improvement method to be collected. 3. A carbon dioxide gas-containing cell cooled by a stirring means.
After mixing and stirring the menthol-based mixed liquid and the crushed soil,
The shell according to claim 2, wherein the shell is pulled out from the ground.
Ground improvement method. 4. A carbon dioxide-containing cell cooled by a stirring means.
Ment type mixed liquid and crushed soil are mixed and stirred to improve the ground.
However, cast-in-place concrete is applied to the outer periphery of this ground improvement section.
Forming a cylindrical outer shell body of
The ground improvement method according to claim 2. 5. A cylindrical outer shell is left in the ground.
The ground improvement method according to claim 2. 6. The ground to be improved in advance
Form a cylindrical outer shell made of cast-in-place concrete,
This preformed cast-in-place concrete cylinder
The ground in the outer shell is destroyed and cooled by stirring means.
Mix the discarded carbon dioxide-containing cement-based mixed solution with the broken soil.
Ground improvement work characterized by performing mixed agitation to improve the ground
Law.