KR101038537B1 - The deep mixing apparatus to strengthen weak stratum and deep mixing process using that - Google Patents

Abstract

PURPOSE: A deep mixing apparatus for soft ground improvement and a deep mixing method using the same are provided to inject a mixture required for solidification directly without preprocessing work, to heighten mixing efficiency in the depths and to form an uniform and continuous high strength underground structure. CONSTITUTION: A deep mixing apparatus for soft ground improvement comprises: an input driving motor installed to the center of a 4-axis auger; an input shaft(140) connected to the input driving motor and arranged parallel to a connection rod(120); a mixing blade(148) fixed to the end of the input shaft to scatter dropping inputs in the radial direction; a screw feeder(142) formed in the appointed length on the top of the input shaft; a housing(144) sealing up the screw feeder and fixed with a bearing at the sealed state with the input shaft, and having a discharge port(146) to be symmetric in the diametric direction; a support(150) connected to a leader to fix the housing; and an input hopper fixed to the 4-axis auger and having an input pipe connected with the housing.

Description

DEEP MIXING APPARATUS TO STRENGTHEN WEAK STRATUM AND DEEP MIXING PROCESS USING THAT}

The present invention relates to a deep mixing treatment apparatus for improving the soft ground and a deep mixing treatment method using the same, and more particularly, when the soft ground is improved by adding a solidifying agent, even if the input is simply added without a separate pretreatment facility. The present invention relates to an in-depth mixing treatment device for improving the soft ground and a deep mixing treatment method using the same, in which an even and uniform mixing action is induced to increase the soft ground improvement efficiency and obtain sufficient degree of curing.

In general, Deep Cement Mixing (DCM) has been developed and developed by the Japan Institute of Transport and Port Research in 1976. In the mid-1970s, DLM (Deep Cement Mixing) was developed using solidifying agents such as quicklime, slaked lime and cement slurry. deep mixing method), slurry-based mechanical stirring mixing process, CDM (cement deep mixing), etc. have been put to practical use.

In addition, the Lime Column method was developed in Sweden at the same time as the DLM method, and this method is used in part by feeding quick lime powder into high pressure air and supplying it to the ground and stirring and mixing.

There are many kinds of such a deep mixing treatment method by the difference of the solidifying agent, the difference in the supply method of the solidifying agent, or the mixing method, and can be integrated into the mechanical mixing treatment method for convenience.

On the other hand, unlike the mechanical mixing treatment method, the injection mixing treatment method that has developed the chemical injection method is a method that expects the mixing of soil and hardener by jet by rotating the injection hole while spraying the cement slurry of high pressure.

The soft ground is being improved by such a method, and the deep mixing treatment apparatus is mentioned as an apparatus used at this time.

The deep mixing treatment device is well shown in Patent No. 0940802, digging ground using a four-axis auger (Auger) through the injection nozzle provided on the tip of these four-axis auger mixture (softener) , Stabilizers).

Therefore, since such a deep mixing apparatus is structurally digging, the mixture to be injected is mixed together, resulting in uneven mixing, and thus the desired hardness and strength are not obtained, and workability is also very poor.

Particularly, in the case of the registered patent, it is complicated to have a mixture manufacturing facility for improving the soft ground such as blast furnace slag storage tank, water tank, sand storage tank, lime storage tank, first, second and third mixers, mortar pump, jet pump, etc. It is a device used to improve the soft ground, such as the inconvenience of having to control each of them separately and controlling them at the exact time of input, as well as mixing inside the auger after the input, so that the required reaction cannot be maintained properly. Was very inefficient.

In addition, when the mixture is prepared through the first, second and third mixers, the complete mixture is prepared by first, second, and third pretreatment before the input, and is configured to be injected in the state where the mixture is made. The nozzle itself was inseparable because it was equipped with a stirring bit for digging at the bottom of the four-axis auger. Therefore, pretreatment facilities had to be required for this purpose. Occurred.

The present invention has been created in view of the above-mentioned problems in the prior art, and the four-axis in the clay layer (inorganic silt, organic silt, silt clay, silt soil, etc.) of the soft ground near the landfill area and the coast Auger agitator blades and a separate single-axis spray injection device are provided at the center to directly add the mixture required for solidification without any pretreatment, eliminating the need for separate facilities for pretreatment and increasing the efficiency of mixing and stirring in depth. The main object of the present invention is to provide a deep mixing treatment apparatus for improving the soft ground and a deep mixing processing method using the same, which can form a uniform and continuous high strength underground structure.

The present invention is a means for achieving the above object, a four-axis auger, a plurality of drive motors installed in the four-axis auger, the connecting rod of the internal hollow body connected to each of the drive motor, and the end of the connecting rod In the deep ground treatment apparatus for soft ground improvement comprising a drill bit and the injection port provided, and a leader for supporting the four-axis auger; An input drive motor installed at the center of the four-axis auger; An input shaft connected to the input driving motor and arranged in parallel with the connection rod, the input shaft being shorter with a step and a lower end of the connection rod; A mixing blade which is fixed to the lower end of the input shaft and scatters the input falling in the radial direction to be rotated; A screw feeder having a predetermined length formed at an upper end of the input shaft; A housing fixed to the screw shaft while being sealed with the feeding shaft, and having a discharge port symmetrically disposed at a lower outer circumferential surface thereof in a radial direction; A support connected to the leader to secure the housing; It is fixed on the four-axis auger, and provides a deep mixing treatment device for improving the soft ground, characterized in that it further comprises an input hopper having an inlet tube in oblique communication with the housing.

In this case, the hollow inside of the connecting rod is cement, and the inside of the housing is characterized in that the solidifying agent and the sand / gravel are individually introduced so as to have a weight ratio of 20 to 30:70 to 80.

In addition, the present invention provides a method for deep mixing the soft ground using the deep mixing treatment apparatus for improving the soft ground described above; Operating a driving motor and an input driving motor to rotate four connecting rods and an input shaft supported by the four-axis auger, and the four connecting rods dig into the ground and penetrate into the ground according to the rotation; When the penetration is completed to the desired depth, the cement is injected into the hollow inside of the connecting rod, and the weight ratio into the housing supported by the feeding shaft is 20 to 50%, blast furnace slag: 10 to 30%, Anhydrous gypsum: 5-20%, quicklime: 5-10%, calcined lime: 5-10%, fluidizing agent: 1-3%, metakaolin: 16-32%, polyester polyol: 2-5%, C ₁₂ A ₇ : 5 to 10%, isocyanate: 0.6 to 2.0%, sodium aluminate: 0.2 to 1.5%, polytyping: 0.2 to 0.5% of solidifying agent and sand / aggregate with a weight ratio of 20 to 30:70 to 80 Putting each individually; Softening characterized in that it comprises the step of drawing the connecting rod with the input step in the upward direction with the step of the first cement input, and stirring the evenly added solidifying agent and the sand / aggregate mixture evenly and uniformly dispersed with the input step. Provided is a deep mixing treatment method using a deep mixing treatment device for improving soil.

According to the present invention, even if the inputs including the solidifying agent in the depth is added without mixing, uniform mixing action is induced, so that the initial strength can be secured, and there is no need for a separate equipment for preparing the inputs required for mixing. Since it can be directly added in the mixed state, no large-scale equipment is required, so that the cost can be reduced, the equipment can be downsized and the efficiency can be improved, and workability can be improved.

1 is an exemplary view showing a deep mixing treatment apparatus for improving soft ground according to the present invention.
Figure 2 is an exemplary view showing a four-axis auger connection structure of the deep mixing treatment device for soft ground improvement according to the present invention.
FIG. 3 is a schematic plan view seen from points A, B, and C of FIG. 2.
Figure 4 is an enlarged view showing the main portion of the drive unit of the deep mixing treatment apparatus for improving soft ground according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment according to the present invention.

As shown in Figure 1, the deep mixing apparatus according to the present invention can be mounted on land equipment or offshore equipment.

At this time, the land equipment or the marine equipment is provided with a leader (L) (Lader) (L) for maintaining the vertical while supporting the four-axis auger (Auger) (100).

Therefore, the four-axis auger 100 is penetrated and pulled into the ground while lifting up and down along the leader (L).

In addition, a plurality of drive motors 110 are installed in the four-axis auger 100, and as shown in FIGS. 1 to 4, the connection rod 120 of the hollow body is rotated. Connected.

In addition, the connection rod 120 has a plurality of stirring blades 122 are fixed at intervals up and down at a portion of the length.

In addition, the drill bit 124 is installed at the lower end of the connecting rod 120, the injection hole 126 is provided in the center of the drill bit 124.

In addition, the connecting rod 120 is able to dig the ground while forming a substantially rectangular shape, as shown in Figure 3, each of the circles drawn by the stirring blade 122 is combined to form a large hole.

Meanwhile, an input driving motor 130 (see FIG. 4) is installed at the center of the four-axis auger 100, and an input shaft 140 is connected to the input driving motor 130 as shown in FIGS. 2 to 4. .

At this time, the screw feeder 142 is integrally formed at a portion of the input shaft 140, the mixing blade 148 is fixed at the lower end of the input shaft 140, and the screw feeder 142 is the housing 144. It is sealed by).

The housing 144 is firmly fixed by the support 150, and the support 150 is fixedly supported by the reader L.

In addition, the lower end of the housing 144 is fixed to the input shaft 140 in a sealed state, the outlet 146 is formed on the outer peripheral surface of the lower end of the housing 144 symmetrically in the radial direction.

Therefore, the input shaft 140 is rotatable while penetrating the center of the housing 144 in the longitudinal direction, at the same time discharged through the discharge port 146 after feeding the input injected into the housing 144 in the downward direction You can drop it.

In addition, the mixing blade 148 installed at the lower end of the input shaft 140, the mixing blade 148 provided at the lower end of the connecting rod 120 is more than the drill bit 124 with a step with the drill bit 124 It should be placed in a higher position whereby the mixing blade 148 rotates and disperses the input falling through the housing 144 to achieve a uniform and even mixing effect throughout the hole.

In addition, an input hopper 160 fixed to the 4-axis auger 100 and the reader L, as shown in FIG. 4, to input the input material into the housing 144, and the input hopper 160 from the input hopper 160. An inlet tube 162 extended inclined to communicate with the housing 144 is provided.

In this state, after the cement is put on the connection rod 120 may be discharged through the injection hole 126 provided in the center of the drill bit 124, the interior of the housing 144 through the injection hopper 160 The furnace may be added with a hardener, high pressure air, stone powder, sand, crushed powder or small aggregates.

Here, the solidifying agent in weight percent, Portland cement: 20-50%, blast furnace slag: 10-30%, anhydrous gypsum: 5-20%, quicklime: 5-10%, calcined lime: 5-10%, Glidants: 1 to 3% as base ingredients, metakaolin: 16 to 32%, polyester polyols: 2 to 5%, C ₁₂ A ₇ : 5 to 10%, isocyanates: 0.6 to 2.0% , Alumina soda: 0.2 ~ 1.5%, poly: It may comprise a 0.2 to 0.5%.

At this time, the basic components, such as portant cement, blast furnace slag, anhydrous gypsum, quicklime, calcined lime, glidant, etc., are conventional components already disclosed in many prior arts, and only a slight difference in composition ratio is a basic component of a solidifying agent. The fluidizing agent is for improving the mixing and fluidity of the soil and the solidifying agent, and usually lignin-based compounds, naphthalene-based compounds, melamine-based compounds, and polycarboxylic acid-based compounds may be used.

Particularly, in the present invention, since the solidifying agent is mixed and solidified by the Deep Cement Mixing (DCM) method, it must have a certain fluidity to improve workability. ~ 32%, polyester polyol: 2-5%, C ₁₂ A ₇ : 5-10%, isocyanate: 0.6-2.0%, sodium aluminate: 0.2-1.5%, polyper: 0.2-0.5% have.

In this case, metakaolin is added to fill the voids between the cement particles and the fine aggregate so that the hardened body can have a dense structure, and should be added to be limited to 16 to 32% by weight, if less than 16% by weight. If it becomes, the activity of transferring the calcium hydroxide produced by the hydration reaction to calcium silicate hydrate is difficult to express the durability and high strength, and if it exceeds 32% by weight, the fluidity of the solidifying agent is sharply dropped to make the construction difficult, so limited to the above range desirable.

And, polyester polyol (Polyester Polyol) is added to improve the flowability and flowability of the solidifying agent, when added in less than 2% by weight is the fluidity of the solidifying agent is lowered, when it exceeds 5% by weight, the fluidity is improved Since the fastness (fastness) and the compressive strength are lowered, it is preferable to limit the above range.

In addition, C ₁₂ A ₇ is a water-cooled amorphous mineral, for example, calcium aluminate-based amorphous material, added to the fastness, when added to less than 5% by weight can not lower the water content of the clay, the fastness is deteriorated, When it exceeds 10% by weight, the fluidity is lowered and the workability is inhibited, so it is particularly preferable to be limited to the above range.

Furthermore, isocyanate is added to react with the polyol to form unsaturated polyurethane bonds to improve adhesion, and when added below 0.6% by weight, the solidification is delayed because the reactivity with the polyester polyol is lowered and the adhesion is lowered. When the content exceeds 2.0% by weight, the reactivity is rapidly activated and the fluidity of the solidifying agent is inhibited, so it is preferably limited to the above range.

And, as described above, sodium aluminate (Sodium Aluminate) is a representative aluminum-based liquid quickener, when the addition of less than 0.2% by weight of cohesive force is lowered, the efficiency of fastening is lowered, if it exceeds 1.5% by weight of solidifying agent by excessive aggregation Since the fluidity | liquidity of is inhibited, it is preferable to limit to the said range.

In addition, poly putty is used to promote surface hardening and to prevent surface cracking. If the content is less than 0.2% by weight, the surface hardening effect is minimal, and if it exceeds 0.5% by weight, the fluidity of the solidifying agent is increased. Of course, since it inhibits fastness, it is preferable to limit to the said range.

The solidifying agent having a composition satisfying such reasons satisfies both sufficient fluidity and quickness at the same time, and therefore, is particularly suitable for soft grounds that simultaneously dig and solidify the ground in the deep mixing apparatus such as the present invention. It is preferable because it minimizes the elution of

In the present invention, it is most preferable to add the above-mentioned hardener and sand / aggregate at a weight ratio of 20 to 30:70 to 80 as an input to be input through the housing 144.

By using the deep mixing treatment apparatus according to the present invention having such a configuration it is possible to improve the soft ground by the following deep mixing treatment method.

For example, when the deep mixing treatment apparatus of the present invention is set on the ground to be constructed, the driving motor 110 and the input driving motor 130 are operated to connect the four connecting rods 120 and the input shafts supported by the four-axis augers 100. 140).

Then, the four connecting rods 120 are to dig the ground and penetrate into the ground.

In this process, the ground is dug as the stirring blades 122 provided on the four connecting rods 120 by the radius of the drawing, and the ground is dug, and finally they communicate with each other to form one large hole, wherein Mixing blade 148 of the input shaft 140 connected to the input drive motor 130 is to be introduced while digging the central portion.

In this way, when the penetration is made to the desired depth, the cement is introduced into the hollow interior of the connecting rod 120, the interior of the housing 144 supported by the input shaft 140 in the composition ratio described above The solidifying agent and the sand / gravel made of 20-30: 70-80 will be added in a weight ratio.

In other words, this process is different from the conventional method of inputting a completely mixed mixture through several pre-treatment steps, and thus separately inputting the prepared inputs without mixing, and thus, they are completely different methods and have significant differences.

Here, the input injected into the housing 144 is fed to the end of the housing 144 by the screw feeder 142 and then discharged through the discharge port 146, and the discharged input is immediately dropped, which rotates in the process. While colliding with the mixing blade 148, it is to be scattered in the radial direction.

Therefore, the scattered input is evenly and uniformly distributed throughout the large holes drilled by the drill bits 124, so that the soil dug during penetration with the cement introduced through the injection hole 126 is sufficiently and uniformly mixed. A robust and strong internal structure can be created, which makes it easy to obtain initial strength.

As such a process proceeds, the connecting rod 120 is pulled upward and then stirred.

Through this process, the present invention can achieve a more sufficient and efficient and uniform mixing ratio of the solid, the internal structure has a uniform and even rigidity as a whole to maximize the soft ground improvement effect.

In addition, since the solidifying agent used in the present invention is an environmentally friendly agent with little harmful substance elution, it can also help to prevent environmental pollution.

100: 4-axis auger 110: drive motor
120: connection rod 130: input drive motor
140: input shaft 150: support
160: Input Hopper

Claims (3)

A four-axis auger 100; A plurality of drive motors 110 installed in the four-axis auger 100; Connection rods 120 of the internal hollow bodies respectively connected to the driving motors 110; A drill bit 124 and an injection hole 126 provided at an end of the connecting rod 120; A reader (L) for supporting the four-axis auger (100); An input drive motor 130 installed at the center of the four-axis auger 100; An input shaft 140 connected to the input driving motor 130 and arranged in parallel with the connection rod 120, the input shaft 140 being shorter with a lower end of the connection rod 120; A mixing blade 148 which is fixed to the lower end of the input shaft 140 and scatters the input falling in the radial direction to be rotated; A screw feeder 142 having a predetermined length formed at an upper end of the input shaft 140; A housing 144 having a bearing fixed to the inlet shaft 140 while sealing the screw feeder 142 and having a discharge port 146 symmetrically in a radial direction on a lower outer peripheral surface thereof; A support (150) connected to the reader (L) to fix the housing (144); In the deep mixing treatment apparatus for soft ground improvement comprising a feed hopper (160) fixed on the 4-axis auger (100), the inlet hopper (162) in oblique communication with the housing (144);
Cement is introduced into the hollow inside of the connecting rod 120, and each of the solidifying agent and the sand / gravel is separately introduced into the housing 144 so as to have a weight ratio of 20 to 30:70 to 80. Deep mixing treatment device for improving soft ground.
delete In the method for deep mixing of the soft ground using the deep mixing treatment apparatus for improving soft ground according to claim 1;
The driving motor 110 and the input driving motor 130 are operated to rotate the four connecting rods 120 and the input shaft 140 supported by the four-axis auger 100, and according to the rotation, the four connecting rods. 120 digging the ground and intruding into the ground;
When the penetration to the desired depth is completed, the cement is injected into the hollow inside of the connection rod 120, and the port lance cement in a weight ratio into the housing 144 in which the feeding shaft 140 is supported: 20 to 50%. Blast furnace slag: 10-30%, anhydrous gypsum: 5-20%, quicklime: 5-10%, calcined lime: 5-10%, glidant: 1-3%, metakaolin: 16-32%, polyester polyol : 2 to 5%, C ₁₂ A ₇ : 5 to 10%, Isocyanate: 0.6 to 2.0%, Sodium aluminate: 0.2 to 1.5%, Polyperity: 0.2 to 0.5% 30 to 70:80 and a step of individually inputting a weight ratio of each;
With the step of the step of drawing the connecting rod 120 in the upward direction with the step of the first cement input, and then added to the solidified and sand / aggregate mixture added later and evenly dispersed in a uniformly dispersed state Deep mixing treatment method using a deep mixing treatment device for improving the soft ground.

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