JP4689556B2 - Ground consolidation method using plastic gel injection material - Google Patents

Description

The present invention relates to a ground consolidation method in which consolidation materials having different permeability are used in combination. As a consolidation material having poor permeability, a silica-based non-curable powder, and a calcium-based powder-hardening expression material , if necessary. fluidity plastic gel injection material for a material selected from fluidity adjusting agent to be added as an active ingredient over time is injected into the coarse portion and the gap portion in the ground, or plastic-like gel by applying dewatering Fill the voids of the ground into the gaps in the ground, or constrict the ground by forming while expanding into the ground, and further strengthen the ground by combining the injection of the ground consolidation material with better permeability It relates to ground strengthening methods.

  As a method of strengthening the ground by injecting a solidified material into the target ground such as soft ground, conventionally, a quick setting injection material or cement bentonite is injected as a primary injection as follows, and a slow injection as a secondary injection. A method for injecting a binding material is known.

(1) Since cement-based injecting material is used as an instantaneous injecting material, its strength develops quickly. Therefore, when the secondary injecting material is injected from the same injection hole after the primary injecting material is injected, the injection of the secondary injecting material is obstructed. To do.
Further, when cement bentonite is used as a primary injection material, it takes 1 day or more for waiting for hardening, and there is a problem that the construction period becomes long.

(2) In the construction method in which primary injection and secondary injection are performed using a double tube rod having two injection liquid channels, first, the primary injection material A liquid (main agent) and B liquid (instantaneous reaction reagent) After joining and injecting through two flow paths at the tip of the injection tube, the injection process is complicated because it is switched to the mixed liquid of the secondary injection material A liquid (main agent) and C liquid (relaxation reaction agent).

  Also, when the groundwater pressure is high or the water level fluctuates, such as tunnels, shafts, revetments, etc., or there is a groundwater flow, there is often a method of injecting an injectable material with good permeability after filling rough parts or voids with instantaneous grouting. However, the instant setting grout solidifies only large voids and rough parts in the ground, whether they are suspension type or solution type, and only solidifies the surface of the soil particles in the coarse voids. It is. That is, since there is no fluidity, only the surface of the rough portion is filled thinly, and a thick consolidated layer cannot be formed.

  By the way, under the condition that the groundwater level fluctuates like backfilling of the revetment, the groundwater flows back and forth between the sea and land, or the groundwater moves continuously for a long time due to water pressure like a tunnel or a shaft. The above-mentioned solidified product due to the instant grouting is damaged or deteriorated by the movement of groundwater, and loses its water-stopping consolidation effect within a relatively short period of time. Because such a ground has a small specific surface area, the surface area of the soil particles (surface area per unit volume) adhered to each other by the instantaneous grouting is small, and the thickness of the solidified body is easily reduced. This is because the gelled product is pushed away to the free space side by water pressure or water flow and easily loses the consolidation effect.

(3) When the instantaneous setting injection material is a solution type in the primary injection, the strength and strength are so weak that rough portions and voids that can penetrate the instantaneous setting grout are filled only with the gel of the weak solution, so It will be pushed out easily. In addition, when the instantaneous setting injection material is of a suspension type, the chemical solution is solidified with high strength around the discharge port and the injection tube, so that the penetration of the secondary injection is inhibited.

(4) In the case of the double pipe double packer method, cement bentonite (hereinafter referred to as CB) is usually used for the primary injection, but CB takes one day for the consolidation time, and the secondary injection must be injected after that. The process takes time. Moreover, since CB has no gelation time, it is easy to deviate and the restraining effect is insufficient, and when groundwater is flowing, there is a problem that it flows out before consolidation. In addition, a method has been proposed in which the ground is strengthened by filling or pressing a large amount of plastic grout. However, since it does not penetrate between small soil particles, it is difficult to improve the entire ground.

JP-A-6-108449 JP 2002-294686A

  Therefore, the present invention aims to form an improved ground integrated with the use of consolidation materials having different fluidity, and is characterized by using a plastic gel injection material as the consolidation material with poor permeability. To do.

  In addition, fly ash, slag, incinerated ash, clay, earth-generated sand and silica sand, etc., which are industrial by-products as plastic gel injection material, are blended so that the predetermined flow characteristics can be obtained, or Clay, bentonite, silt, thickener, peptizer, foam material, etc. to expand debris by increasing fluidity or water retention and solidifying in the ground In addition to this, a small amount of cement or calcium-based hardened material such as lime, gypsum and slag and water are blended at a predetermined ratio, and pressed into the ground under the prescribed conditions, then lump in the ground. The object is to build a solid solid body or plastic mass to reinforce the ground.

In order to solve the above-mentioned problems of the present invention, according to the ground consolidation method of the present invention, it is a ground consolidation method of injecting into the ground in combination with different consolidation materials, and the one with poor permeability A fluid plastic gel injection material is used as the consolidation material . This plastic gel injection material loses its fluidity with time or due to dehydration and forms a lump of the injection material itself in the ground. The following components (1), (2), (4), or (1 ), (2), (3) and (4) as active ingredients.
(1) Silica-based non-curable powder (F material)
(2) Calcium-based powder hardening material (C material)
(3) Fluidity adjusting material (A material)
(4) Water (W material)

The present invention is a silica-based non-curable powder body as a permeable poor caking material, and is an active ingredient material selected from fluidity adjusting agent to be added as necessary and the calcium-based powdery productive material A lump of fluidized plastic gel injection material injected into rough or voids in the ground, and with the passage of time or from pressure-dehydrating plastic gel that has reduced fluidity. Is formed while filling the voids in the ground, or expanding in the ground, pushing the particles to the periphery, forming a lump of plastic gel consolidated body itself in the ground, restraining the ground, The ground will be strengthened together with the injection of the ground consolidation material with better permeability.

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

  In order to strengthen the ground, the present invention is different from mere filling of the plastic gel with a void, and press-fits the plastic gel into the ground to constrain the ground so as to infiltrate the soil particles with a highly permeable injection solution. It is possible to improve the ground by integrating the ground. For this purpose, a plastic gel having fluidity is important. The plastic gel according to the present invention will be described below.

  In order to obtain such a restraining effect, the plastic injection material does not penetrate between the soil particles and does not deviate from the injection range, and is formed in a lump in a weak portion or a large gap in a predetermined holding area. In addition, it is necessary to enlarge the lumps while maintaining the lumps to create a tightly constrained ground.

  Therefore, as a result of various studies, the present inventor completed the present invention by focusing on the characteristics of the fluid plastic grout and solving the above problems.

In the present invention, the plastic gel refers to a grout that exhibits a plastic shape after blending. The time when the plasticity is exhibited after blending is referred to as gelation time, but the plastic gel flows if force is applied after gelation. That is, it has a plastic holding time. As time passes, or it becomes non-plastic by dehydration, it has the feature that it does not flow even when solidified and applied with force. That is, since it has fluidity even in a gel state, it is expressed as “fluid plastic gel injection material ” in the present invention. In addition, in the present application, a plastic gel injection material, a fluid plastic grout, a fluid plastic grout, a plastic grout, a plastic grout, a fluid plastic gel, a plastic gel, a plastic injection material, and the like are also described. .

(1) Fluidity of fluid plastic grout decreases not only with time but also with dehydration. Moreover, while it is pressed into the ground, it is gel-like, but has fluidity. When the injection is stopped, the fluidity is lost, and when the injection pressure is applied again, the preceding gel flows again and repeats this. be able to. The plastic gel pressed into the ground becomes a lump in the gap or weak part of the ground while maintaining a long flow holding time to fill the large gap, or push the soil particles to the periphery, and the lump in the ground It is formed and fluidity is reduced with time or by pressure dehydration, eventually becomes non-plastic and hardens, strengthening the ground.

(2) Since plastic grout flows when force is applied in the form of a gel, it fills only large voids in the ground and does not enter between fine soil particles.

(3) If the plastic grout is not dehydrated, its strength will be moderate, but if it is dehydrated by pressurization, it will become non-flowable due to the reduced water powder contrast, and can rapidly develop strength.

(4) If pressure is applied to the plastic grout due to the water permeability of the ground, it will dehydrate and lose its fluidity, become a non-plastic gel, and will not flow even if force is applied. In addition, if the injection pressure is applied to the gel filled in the large gap, even if it remains in the form of a fluid gel (plastic holding time), it will not flow above or below the groundwater flow or the groundwater level. Resist and harden over time to lose fluidity (become non-plastic).

(5) Plastic grout can be injected in one-pack type, 1.5-shot, or 2-shot, and can maintain fluidity for a long time in the flow path from the ground to the discharge port of the injection pipe. Yes (because it is not dehydrated in the injection tube and has a long plastic hold time).

As described above, in the ground consolidation method using the consolidation material having different permeability in the present invention, the sealing effect of filling the void around the injection tube with the consolidation material having the lower permeability, the rough portion around the injection tube As a plastic gel injection material for the purpose of obtaining the effect of preventing the injection when the secondary injection material deviates during the injection, or the effect as the primary injection material for press-fitting into the weak part and strengthening (1) Silica-based non-curable powder (F material), (2) Calcium-based powder cured material (C material), (3) Fluidity adjusting material (A material) and (4) Water ( W material), or (1) and (2) and (4) effectively applied to obtain, the large voids under the enhanced and basic weak portion reinforced with stuffing, or the suction prevention portion of the revetment or the like by using To enlarge and enlarge the mass of plastic gel for occlusion and reinforcement, While press spread can also serve as strengthening of the weak part of.

In this case, it is possible to use a single injection tube with a poorly permeable solidified material and a highly permeable solidified material, but it is also possible to inject each from separate injection tubes. .

To spread the soil particles in the ground, expand the bulk gel without deviating into the ground and strengthen the ground, and to integrate and strengthen the ground by penetration between soil particles with excellent permeability The plastic gel according to the present invention that can be made comprises (1), (2), (3), (4) or (1), (2), and (4) .

  The flowable plastic gel does not fill the gaps in the fine sand, but fills the entire large gaps with the gel. Further, the gel is flowed as it is by press-fitting with an injection pressure, and the filling range is expanded to form a filling layer of thick gel. Furthermore, if it press-fits and spin-dry | dehydrates, or fluidity will fall with time, or it will become nonplastic and harden | cure. For this reason, the space | gap and rough part around an injection pipe are filled, and the injection | pouring object ground is restrained in a short time.

  In addition, if a sheet such as a revetment breaks due to such characteristics and is sucked out and injected from the injection hole in the backfill where a large gap is formed, the plastic grout does not deviate as it is in the free space direction. Is in a gel form (plastic gel) but keeps its plastic state until it loses fluidity (has plastic retention time), so the pressure of the volcanic lava just loses its fluidity gradually as the temperature drops. While adding to the wall, the same phenomenon occurs when the consolidation range is expanded while standing in the wall, expanding the massive gel into the large gap created in the seaside stone and in the backfill The suction part is totally filled and solidified over a wide area. For this reason, the consolidated portion is not destroyed even by the rise and fall of the seawater level and the flow of water.

In addition, if the caking material with better permeability is injected into the backfill soil side, all the voids that can be penetrated by groundwater will consolidate, preventing the backfill soil from being sucked out completely and permanently. It becomes possible. The same is true for tunnels and shafts. That is, the shortcoming of the instantaneous water stop effect of the instantaneous setting grout can be solved.

Further, the fluidity plastic grout that have more features, the use of high injection material permeability deviation to occur easily implanted outside hitting the injected into the ground, in particular the prevention of deviation of the ground surface very The inventors have found that it is effective.

1) Application to the double pipe injection method The double pipe injection method uses a double pipe rod having a plurality of flow channels to drill holes to a predetermined position, and then fills the gap around the injection pipe with the instantaneous grouting. After filling the rough part of the injection stage, a slow grout is injected to consolidate the thin part. In this case, the quick setting grout is prepared by feeding the main agent A liquid and the quick setting reagent B liquid from different flow paths, joining them at the tip and injecting the quick setting grout, and then the liquid A and the slow setting reaction. Agent C solution is mixed or merged and switched to slow grouting injection. In this method, the injection stage is moved from the bottom to the top while switching the above alternately.

  By the way, if a plastic grout is injected instead of the instantaneous setting grout, a double pipe injection method can be performed very simply and effectively.

(1) One pipe line of the double tube rod is used as a primary injection material and a plastic gel liquid supply line, and one pipe line is used as a slow-binding secondary injection material. First, when the plastic gel is press-fitted, the drilling space is filled with the plastic gel around a predetermined injection stage around the injection tube. In addition, the plastic gel is press-fitted around a rough portion or a weak portion. And the vicinity of the discharge port of the double tube is dehydrated to become a non-plastic gel. In the space where pressure is not easily transmitted, the plastic gel state is maintained. Thereafter, the injected secondary injection material breaks the gel and is injected into fine portions where the plastic gel does not enter.

(2) When the injection tube is pulled up to the next injection stage, since the inside of the injection tube is not dehydrated, it remains plastic in the plastic grout liquid flow path. The injection material is dehydrated and hardened in the vicinity of the injection tube outlet, but it is pushed out by the press-fitting of the plastic gel in the subsequent tube, and the plastic gel pushes the still fluid plastic gel around the injection tube. To be filled.

(3) Since a packer is formed around the tube due to the dehydration of the plastic gel due to the injection pressure, the secondary injection material injected thereafter can be injected into the ground details at the injection stage without deviating upward. it can.

(4) Since the plastic grout used as the primary injection material can maintain fluidity for several hours in the injection pipe flow path, the primary injection and the secondary injection can be performed by feeding the liquid from the respective injection pipe flow paths together with the secondary injection material. What is necessary is just to inject | pour alternately, it is excellent in workability | operativity and an injection | pouring process is shortened.

  In this way, the primary injection plastic grout fills the rough voids in the ground or, if the ground is weak, spreads with a gel to form a massive solid body and strengthens it, so that the secondary injection material is finely divided. By penetrating, a great improvement effect is obtained. Further, when a deviation from the ground surface occurs in the secondary injection material, the plastic gel is fed immediately to easily block the deviation path of the secondary injection material and prevent the deviation.

2) Application to the double packer method (multi-packer method) The fluid plastic grout can be used as a seal grout or a primary injection material for the double packer method. In the case of a plastic grout, unlike the CB, since there is no need to wait for the seal grout or the primary injecting material to cure, the secondary injecting material can be immediately injected, so the process can be shortened.

  In the conventional double packer method, CB is injected around the injection tube and in the primary injection. However, CB takes time to consolidate, and it is necessary to wait for solidification for about one day before performing secondary injection. In addition, since it does not have a gelling function itself, if it deviates to the ground surface, the effect of restraining the ground is lost, and the secondary injection material tends to deviate from the ground surface or out of the injection area as described above.

  On the other hand, the fluid plastic grout itself has fluidity, but dehydrates while being injected into the ground, and is filled to a portion where the fluidity is lowered and easily deviates to restrain the ground. In addition, it rapidly cures by dehydration, and since it is a gel, it is difficult to cause breathing, and no gap is formed between the solidified product of the plastic gel and the ground, so that it has an excellent restraining effect on the secondary injection material. CB, on the other hand, does not gel and solidify the entire injected solution evenly, but solids settle and solidify, so the secondary injection material has little restraining effect.

  In addition, using the multipacker injection pipes of Examples 6 and 7, the flowable plastic grout is injected from one of the two injection liquid channels of the injection inner pipe at each predetermined injection stage, and the primary injection is performed. If the process of performing coarse filling injection of the gap around the outer tube and the rough part in the injection stage and then performing osmotic injection with a long gelation time as a secondary injection from one channel is performed while moving to each injection stage Since there is no need to perform sealing grouting with a normal CB and waiting for curing, the process can be greatly shortened. In addition, if a deviation from the secondary injection material from one pipe line to the ground surface occurs, the flowable plastic grout is immediately injected from the other injection flow path to easily prevent the deviation and restrain the ground. I can do it.

  In recent years, in the liquefaction prevention injection method, the interval between injection holes (2 to 4 m) is increased, and an injection solution with a long gelation time of 1 to 10 hours is continuously fed for several hours to 10 hours or more. A method of forming a large-diameter solid body is used, but in this case, naturally the injection solution with a long gelation time tends to deviate outside the ground surface or the injection range, and if it begins to deviate, the injection effect is expected at all. It becomes impossible.

By the way, as soon as the osmotic infusion solution begins to deviate, if plastic grout is injected from one of the pipes, the infusion solution rapidly flows through the ground along the deviating route and dehydrates rapidly. Since it loses and fills the departure path and develops strength, an excellent deviation prevention effect is produced in that it penetrates and solidifies into a predetermined injection region without deviating even if the osmotic injection solution is injected immediately thereafter.

The fluid plastic gel according to the present invention (consolidated material with poor permeability ) has fluidity until the injection solution is injected into the ground, maintains fluidity in the ground, and does not penetrate between soil particles. Since it has the effects of cavity filling, formation of massive consolidated bodies, and growth to menstruation, it is effective to give a restraining effect to the ground to be improved with a consolidated material having better permeability. The inventor found that a silica-based non-curable powder, a calcium-based curing material, and a mixture of water, or a silica-based non-curable granular material, a calcium-based curing material, a fluidity-adjusting material, and a water mixture in the ground. We focused on strengthening the ground by forming a lump in the ground, expanding the gelled mass while maintaining fluidity in the process of dehydration, and decreasing as the dehydration progresses. And, as an indicator of the above flow characteristics of the injected liquid in the ground, (1) Flow (table flow and / or cylinder flow) showing fluidity and slump value (2) Gelation time by plastic gel (3) Plastic state Retention time (4) Focused on the solidification time to become non-plastic.

Of these, the gelation time is the time when the table flow is 20 cm after blending, and the plasticity retention time is the time after gelation that does not flow even when external force is applied, that is, the penetration resistance value is 0.01 MN / m ² . It was set as the curing time as the time up to the point in time. We paid attention to the fact that these are greatly influenced by the change of water powder ratio due to the phenomenon of press-fitting dehydration in the ground.

  In addition, since the strength is low if the amount of the hardening developing material is small, it is greatly expanded into a lump without being split injected while maintaining fluidity in the soil, and a lump solid body is formed by the injecting material itself. I found it.

  In this case, since the strength of the cured product is relatively low, a high-strength pile such as a cement consolidated body is not formed in the ground after construction. For this reason, we focused on the fact that vibrations caused by earthquakes are less likely to break due to stress concentration and can be integrated with the surrounding ground.

As a result of various studies to solve the above problems, the present inventor has found the following.
1) Silica-based non-curable powders, especially silica powders that have undergone incineration processes such as slag, fly ash, and incineration ash, react with a small amount of Ca composition such as cement and lime, and undergo a porazonization reaction. At the initial stage, Ca is adsorbed on the surface to cause an electrochemical reaction, and it becomes a binder, resulting in a pseudo fluidity drop. Further, when the water powder ratio decreases with dehydration, a plastic gel is formed. Further, it solidifies through a non-plasticized gelled product.

  Such a phenomenon is accelerated by dehydration in the ground, and the effect of the present invention is sufficiently obtained if the formed lump is stronger than the surrounding ground. In addition, the flow characteristics can be specified by flow or slump without adding a hardening-expressing material, or the moisture content can be specified by the water / powder ratio to penetrate between soil particles in the ground. A lump is formed in the ground without diffusing into the shape, and the lump is expanded by continuing the press-fitting. The present invention has found that as long as the dehydrated mass in the ground maintains the same strength as the surrounding compressed ground or higher strength, it serves to strengthen the ground.

2) The table flow, slump, and cylinder flow show the fluidity of the injection solution in which the hardening agent is added to the silica-based powder, the table flow is in the range of 15 cm to 25 cm, and the slump is in the range of 10 cm to 28 cm. The flow is about 10 to 26 cm, the table flow is about 20 cm, the slump is about 21 cm, and the cylinder flow is about 15 cm. It becomes a plastic gel and the water powder ratio decreases with time or dehydration. And the slump goes down.

Water powder ratio of silica-based non-self-hardening powdery material and consisting of a calcium-based productive material powder powdery material, by adjust the productive material ratio of the total powder, in the ground of the ground grout Adjusting the plastic flow characteristics and expansion of the plastic gelled product in the ground, and further promoting the gelling time and plastic holding time until reaching the plastic gel, an accelerator or retarder, fluidizing agent, The workability and the size of the plastic gel can be adjusted by using additives such as a peptizer and a foam material. If the water powder ratio is too small, or if the ratio of the cured material is too large, the expansion of the massive gel in the ground is inhibited by dehydration, so that ratio is important.

  In particular, if the ratio of hardened material is large, it becomes too strong due to dehydration in the ground, which not only prevents the gel from spreading, but is similar to the fact that a large concrete body has been created in the surrounding soil, and the entire ground is integrated. This prevents the earthquake resistance of the improved ground because it causes local stress and breaks during an earthquake.

  In addition, the fluid injection solution made of silica-based powder that forms a lump by dehydration in the ground is made of not only the above-mentioned artificial powder material but also excavated earth and sand, etc., and clay and thickeners. Or water retaining material is added to make the fluidized soil a predetermined flow characteristic, that is, a table flow or slump value, and adjusted to show a predetermined water-powder ratio, and dehydrated and the flow is reduced to 20 cm or less. It becomes a gel, and the surrounding ground becomes denser by injecting so that it does not penetrate between the soil particles and does not deviate from the cracks, so that the predetermined ground can be improved. Needless to say, the strength increases if a curing material is further added as the material.

3) Workability suitable for kneading and pumping of the ground injection material and press-fitting into the ground is 12 cm or more, preferably 15 cm or more and 30 cm or less in the table flow, slump 5 cm or more, preferably 10 cm or more and 28 cm or less, cylinder It is larger than 8 cm in the flow, preferably about 10 cm or more and 26 cm or less. The determination of the water / powder ratio that governs slump and flow has a major impact on workability and the formation and expansion of lumps in the soil. It is possible to accurately determine the fluidity that changes sequentially with time, manage the water powder ratio and the cured material ratio by flow, and quickly adjust the blending and water powder ratio to make a massive plastic gel in the ground Is important to form and expand.

4) When an additive is added, the gel time for forming a plastic gel according to the amount added can be adjusted. By adding water glass or aluminum sulfate salt as an accelerator, the flow can be easily reduced or the gelation time can be shortened. Further, the slump can be reduced from around 20 cm to 10 cm or less. Also, by forming a plastic gel together with dehydration in the ground, and continuing the press-fitting for a longer time for the gel to remain in a plastic state, the bulk gel grows and forms a large bulk gel in the ground. It can be changed into a cured product through a non-plastic gel.

  In this case, a small flow or low slump plastic grout can be obtained by combining and mixing silica-based powders with a mixture of calcium-based curing agent as solution A and solution silica such as water glass or aluminum salt as solution B. Can be injected. However, it is possible to inject plastic grout with a low flow value and low slump in the case of cavity filling, but in the case of press-fitting to the ground, fluidity is lost rapidly due to dehydration that occurs in the ground. It becomes difficult to compress the surrounding ground by expanding For this reason, it is necessary that the table flow of the merged liquid is 12 cm or more, the slump is larger than 5 cm, and the flow through the cylinder is larger than 8 cm at the time when it is injected into the ground from the injection tube discharge port even if the combined injection is performed.

5) On-site generated soil such as clay and earth and sand can be added as aggregate. Aggregate not only serves as an extender, but also serves to adjust consolidation strength and fluidity. Generally, the strength decreases as the ratio of aggregate in the powder increases, and the fluidity decreases as the particle size of the aggregate increases.

  Clay such as bentonite, clay in the soil generated in the field, fine particles such as silt and loam, polymer agents, thickeners, etc. are excellent as water retention and thickeners, and dewatering of press-fitted materials that have been pressed into the ground It acts as a binder with a pseudo-bonding property by acting as a binder for the powdery substance, and forms a lump gel without being separated and dispersed, and helps to enlarge it.

6) Addition of aluminum salt such as aluminum sulfate or water glass (including water containing acidic water glass obtained by mixing water glass and acid shall be regarded as water glass in the present invention). Decrease, increase viscosity. In order to grow a massive gel by forming a plastic gel in the ground without causing the ground injection material to split into veins in the ground, the hardened material expression ratio, water body ratio, aluminum ratio, flow value, slump It is important to select and apply the range of values and the silica concentration from the silica solution.

7) Even though cement suspension suspension grout is very viscous, if it is made plastic, the resistance to press-fitting from the injection port of the injection tube that opens into the ground and the liquid feed tube up to the injection port There is a problem that the liquid feeding resistance is extremely large and the liquid feeding pipe and the pump are easily clogged. For this reason, if a thin composition is used to facilitate liquid feeding, it becomes a vein in the ground. For this reason, in the technology of the prior application, like the backfill injection, a cement-based suspension with good fluidity and a plastic material are mixed at the time before being sent to the injection pipe, and instantly plasticized into the ground. A method for press-fitting to a slump of less than 5 cm has been proposed.

  However, the cementitious plastic grout that has become plastic in front of the injection tube immediately becomes strong due to dehydration in the ground, so it is difficult to grow into a large block gel and requires a large injection pressure. It becomes impossible to inject or it destroys the ground and deviates.

  As a result of research, the present inventor has found the following necessary conditions for the press-fit material not to deviate by splitting in the ground and grow into a large lump gel, and the mechanism of formation and expansion of the lump gel.

1. The ground injection material is fluid until it is injected into the ground, but after it is injected into the ground, it should not break off by splitting the ground.

2. The ground injection material reaches the plastic gel before being injected into the ground, or is injected into the ground and reduced in fluidity by pressure dehydration to form a lump of plastic gel. Thing.

3. The lump retains its plastic shape in the ground, and the lump is expanded by a plastic gel that is subsequently pressed into the lump, thereby expanding the lump. As a result of being expanded at the outer peripheral part of the massive body, it is further dehydrated to become non-plastic and loses its fluidity, and with time, a solidified band is formed from the outer peripheral part to form a large massive consolidated body. It reduces the voids in the earth and sand, spreads them, and pre-sets them statically.

4). Since the inside of the lump has a plastic shape, if there is further injection of the ground injection material, some solidification zones on the outer periphery of the lump will be broken, and the plastic gel will be pushed to the periphery to dehydrate it. It becomes non-plastic and the solidification zone expands. When the solidification zone becomes harder than a certain level, it becomes difficult to break it with normal pump pressure, and press-fit becomes impossible. The time becomes the size of the lump solidified product.

  As a result of the research, the inventor found that the flow of fluid even after being pressed into the ground from the tip of the injection pipe installed in the ground without causing resistance pressure in the liquid feeding pipe during pumping or clogging in the pump. By press-fitting the ground injection material that has a property and exhibits a plastic shape even when dehydrated, a plastic gel having a plastic holding time (a time when it is pressurized to be in a fluid state) is formed in the ground. Further, the present inventors have found that a massive body grows and completed the present invention.

  For example, as shown in Table 1, blending 1 with the same cured product ratio of 18.50% and water-powder ratio of 35%, and blending 2 with a water-powder ratio of 30% will result in a plastic gel after blending. The gel times require 480 minutes and 300 minutes, respectively. When the water powder ratio is 25%, the gelation time is 2 minutes. This means that at the time of compounding, when the injected material that has not reached the plastic state before being injected into the ground is mixed in the ground, the water body ratio is reduced from 35% to 30% (dehydration rate of about 15%) and further 25% ( As the dehydration rate is reduced to 30%, the gel time is reduced to 2 minutes, forming a plastic gel and forming a lump.

  In addition, since the plastic holding time is 7.5 hours at the time of gelation, the bulk gel expands, the breathing is small, the viscosity increases, it is difficult to diffuse, and the solidified product has high strength. Such characteristics have not been known so far.

  That is, the flowable injection material does not reach gelation until the water powder ratio is dehydrated from 35% to 25% after being pressed into the ground, and becomes 25% (dehydration rate of about 30%) for 2 minutes. Later, a plastic gel was formed, and the plastic holding time at that time was 7.5 hours. As the press-fitting continued, the gel-like gel was greatly formed, and as the dehydration or curing phenomenon progressed, It tells that it becomes a non-flowable gel and solidifies.

  Therefore, even if it does not exhibit plasticity at the time of injection, it can become plastic by dehydration in the ground. In the injection of such fluid injection solution, even if the compounding solution is injected as a single solution, the powder injection solution is set as A solution, and the gelation promoting material such as aluminum and water glass is set as B solution. Alternatively, the liquid A can be applied to any plastic gel and the liquid B can be used as a gelation accelerator such as water glass regardless of the means.

As a result of the above research by the present inventor, the plastic gel injection material (consolidated material with poor permeability) is press-fitted as follows to form a large lump in the ground and increase the strength, Furthermore, by introducing a binder with better permeability, a reliable ground improvement method that can be designed by integrating the ground has become possible.

1. The infusion solution itself has fluidity by the pump, but the one injected into the ground is split into veins so that it does not penetrate and solidify. This is because the gap between the soil particles in the area of the aggregate is reduced, and the density of the ground between the injection holes around the aggregate is increased only after the aggregates are formed by the gelled material within the range of the injection holes. It is because it can be expected with certainty.

2. The material injected into the ground is prevented from penetrating between the soil particles, and the soil particles on the ground between the plurality of injection holes are pushed away by a lump. This is because if the injection solution penetrates between the soil particles, the ground between the multiple injection holes cannot be compressed, and the increase in density due to the compression of the ground in the range of the injection holes cannot be expected with certainty. is there.

3. The gel press-fitted into the ground forms a consolidated body in a lump shape and grows into a large-diameter consolidated lump. To do this, do (1)-(5).

(1) A mixture of non-curable silica-based powder and water as the injection material is larger than 5 cm slump, and / or the table flow is 12 cm or more and / or the flow through the cylinder is larger than 8 cm, or further within the slump of 28 cm. And / or using a fluid ground injection material having a table flow of less than 30 cm and / or a cylinder flow of less than 28 cm, or a ground injection material mixed with a calcium-based powdered hardening material, and using this in the ground The soil particles are pushed to the periphery by expanding the lump made of the injection material itself that is formed by press-fitting into the water and dewatering, and the lump is formed in the ground to strengthen the ground.

(2) The ground injection material can reach a table flow of 20 cm or less by dehydration. Here, the time when the table flow becomes 20 cm is regarded as the time when the plastic gel is formed.

(3) As the dehydration proceeds, the ground injection material passes through a plastic gel and becomes non-plastic and solidifies.

(4) The ground injection material is curable fluidized soil or non-hardened fluidized soil, which loses fluidity due to dehydration and reaches a flow of 20 cm or less, and exhibits strength equal to or higher than the surrounding ground. The formulation is as follows.

(5) The ground injecting material is blended to become a plastic gel when the water powder ratio is within 30%, and if it continues to be pressed into the ground, it becomes a plastic gel and a massive solid body is formed.

The following conditions are preferable in order that the lump by a plastic gel grows large in the ground and becomes a consolidated body.
[Curing expression ratio C / (F + C) × 100 (%)]:
1 to 50% by weight, preferably 1 to 40% by weight, more preferably 1 to 20% by weight
[Water powder ratio W / (F + C) × 100 (%)]:
20 to 200% by weight, preferably 20 to 100% by weight, more preferably 20 to 50% by weight
[Aluminum ratio Aluminum salt / (F + C) × 100 (%)]:
0.01 to 0.52% in terms of Al ₂ O ₃
[Water glass]:
0 to 7.0% by weight based on silica
[Slump (cm)]:
Slump at the time of injection is 5 cm or more, preferably 5 to 28 cm, more preferably 10 to 28 cm.
[Flow (cm)]:
The table flow at the time of injection is 12 cm or more and less than 30 cm, preferably 15 to 28 cm.
Cylinder flow during injection is 8 cm to less than 28 cm, preferably about 10 to 26 cm
〔breathing〕:
10% or less, preferably 5% or less
Under the above conditions, further, a plastic gel or a blend in which the water / powders ratio is reduced by 30% or less and the plastic flow, that is, the table flow is 20 cm or less is used.

  In order to shorten the time until the plastic gel is exhibited, it can be adjusted by adding water glass or aluminum salt. That is, they act as gelation accelerators. When acidic water glass obtained by mixing water glass and acid such as sulfuric acid to remove alkali of water glass is used, a gel is formed very quickly. In the present invention, acidic water glass is also treated as water glass. In this case, the gelation time can be adjusted by using sodium bicarbonate or sodium carbonate in combination. A gel retarder such as lignin sulfonate can also be used.

As a representative example of the flowable plastic gel used in the present invention, a powdery hardening material made of cement, slaked lime, slag or gypsum added to the non-curable silica-based powder constituting the suspension is used. Less than 50% by weight, preferably 1 to 40% by weight, more preferably 1 to 20% by weight, and the water powder ratio is 20 to 200% by weight, preferably 20 to 100% by weight.

When adding a gelation accelerator, the aluminum ratio is 0.1 to 3.0% by weight (in terms of Al ₂ O ₃₎ with respect to the total amount of the powder contained in the injection material, that is, the main material and the curing material. 0.01 to 0.52%) By mixing, the table flow is 12 or more and less than 30 cm, preferably 15 to 28 cm, gel time is within 3 minutes to several hundred minutes, plastic holding time is several hours to 10 hours or more, breathing The rate is within 10%, preferably within 5%, the slump is greater than 5 cm and not more than 28 cm, preferably 10 to 28 cm, and the flow through the cylinder is greater than 8 cm and less than 28 cm, preferably about 10 to 26 cm.

  Due to these characteristics of the present invention, addition of silica such as water glass or acidic water glass as a gelation accelerator can greatly reduce gel time and plastic holding time, and also breathing and slumping. Furthermore, the flow becomes smaller. The ground injection material of the present invention is pressed into the ground to become a plastic gel, pushes the soil particles to the periphery, grows into a large solid aggregate in the ground, and can strengthen the ground.

As described above, the flowable plastic gel used in the present invention uses a suspension obtained by adding less calcium-based curing agent to non-curable silica-based powder , but it is combined with the type of granular material used. And by blending at a specific blending ratio, a desired infusion material exhibiting fluidity and consolidation characteristics is press-fitted into the ground according to the purpose, and an injection hole is created by forming a massive solid body in the ground. It is possible to push the soil particles of the ground surrounded by the surroundings and strengthen the ground.

To consolidate the bulk during ground, although it flow by pressurizing, between soil particles a plastic grout to form a plastic gel so as not to Wari裂without penetration, and veins, table A plastic grout having a flow range of 12 cm to less than 30 cm, preferably 15 to 28 cm, slump greater than 5 cm, preferably 10 to 28 cm, and cylinder flow greater than 8 cm and less than 28 cm, preferably 10 to 26 cm. Preferably there is.

  In addition, considering the formation of a plastic gel in the ground by dehydration under pressure, the plastic gel before injection or the water-to-powder ratio is reduced by 30% or less, and the plastic gel (almost in the table flow) 20 cm or less) is preferable. If the flow value or slump is below this level, it will be difficult to grow a solid aggregate of plastic gel in the ground, and if it exceeds this value, it will be split and injected into veins and cracks before it can be dehydrated to form a lump. Hateful.

The flowable plastic gel of the present invention is
(1) Silica-based non-curable powder (F material),
(2) Calcium-based powdery hardening material (C material),
(3) Fluidity adjusting material (A material),
(4) Water (W material)
Of these, (1) and (2) and (4) or (1), (2), (3) and (4) are used.
By mixing with the type and combination of the materials used and the specific mixing ratio, the desired injection material exhibiting flow characteristics and consolidation characteristics according to the purpose is pressed into the ground to fill the gap around the injection pipe. Alternatively, by creating a massive solid body in the ground, the soil particles surrounded by the injection hole can be pushed to the periphery to strengthen the ground.

  In order to consolidate in the ground, it is a ground injection material that forms a plastic gel that can flow by pressurization but does not penetrate between soil particles and does not split into veins. It is a ground injection material showing a range of 12 cm or more and less than 30 cm, preferably 15 cm to 28 cm, slump greater than 5 cm, preferably 10 to 28 cm, and cylinder flow greater than 8 cm and less than 28 cm, preferably 10 to 26 cm. It is preferable. In addition, in consideration of the formation of a plastic gel by pressure dehydration in the ground, it is a plastic gel before injection, or the water-to-powder ratio is reduced within 30%, and the plastic gel (almost in the table flow) 20 cm) is preferable.

  If the flow value or slump is below this level, it will be difficult to grow a lump of plastic gel in the ground, and if it exceeds this value, it will be split or injected into a vein or crack before dehydration. Therefore, it is difficult to form a lump or seal-like consolidation.

The following can be mentioned as a method for adjusting the flow characteristics and consolidation characteristics of the flowable plastic gel.
(1) Silica-based non-curable powder (F material)
As silica-based non-curable powder (F material) in the present invention, non-curable silica-based powder as a main material of the granular material, in-situ generated soil such as incineration ash, clay, earth and sand, and silica sand 1 Species or multiple species may be mentioned.

(2) Calcium-based powdery hardening material (C material),
As a calcium type powdery hardening expression material (C material) in this invention, any one or several groups of cement, lime, gypsum, and slag are mentioned. However, when the non-curable silica is slag, slag as a curing material is excluded. In the above, the slag may be a general product such as a normal 4000 (cm ² / g) brane, or may be an ultrafine particle slag such as 6000 to 15000 (cm ² / g) brane.

(3) Curing agent ratio, water powder ratio Curing material ratio is C / (F + C) × 100 [%], and water powder ratio is W / (F + C) × 100 [%]. There, F, C, W is Ru weight der respectively. Hardening Expression material ratio less than 50% by weight, preferably 1 to 40 wt%, excellent effect in more preferably 1 to 20 wt%, and 1 to 10% by weight of the formulation.

In addition, when mixing gypsum, or gypsum and cement, lime, slag, or a group (G) of water and water (W) as a hardening developing material, use a gypsum ratio and a mixture of gypsum, The gypsum ratio and the mixture ratio of gypsum are G / (F + G) × 100 (%) , and the water powder ratio is W / (F + G) × 100 (%) . G represents weight. The gypsum ratio and the mixture ratio of gypsum are 1 to 40% by weight, preferably 1 to 20% by weight, and the water powder ratio is 20 to 70% by weight.

  The ratio of the cured material is less than 50% by weight, preferably 1 to 40% by weight, more preferably 1 to 20% by weight, and even 1 to 10% by weight has a very excellent effect. When the hardening expression material is 0, it is necessary that the slump and the flow satisfy the above conditions, and the lump that is dehydrated and press-fitted into the ground has the same or higher strength than the surrounding ground.

  In this case, the composition and water / powder ratio can be selected by filling the injection material in a mold with porous stone or paper on the top and bottom and pressurizing it with a cylinder at a pressure equivalent to the assumed injection pressure. It is possible to set the strength of the specimen to be equal to or greater than the strength corresponding to the average soil density of the surrounding soil after injection. Of course, the composition can be similarly set when a small amount of the curing material is added.

  The water powder ratio is 20 to 200%, preferably 20 to 100%. However, when the non-curable silica is slag, the water powder ratio is more preferably 30 to 80%.

  When gypsum or a gypsum mixture is used, the gypsum ratio and the gypsum mixture ratio are 1 to 40% by weight, preferably 1 to 20% by weight, and the water powder ratio is 20 to 70% by weight. When such a compounded liquid is mixed, it remains as it is if the water powder ratio is small, and when the water powder ratio is large, it becomes a lump sooner or later by dehydrating in the ground.

The plastic gel flows when force is applied, but stops flowing when it stops. The gel time for forming a plastic gel is when the table flow is approximately 20 cm. The aqueous powder ratio, soil flow, the plastic gel even when water powder ratio By pressing圧脱water fluidity plastic gel injection material ground in the addition of neat or additive exhibiting slump greater Can be formed inside.

  The lump formed in the ground needs to be enlarged over a wide range as much as possible to form a large lump consolidated body while having a low fluidity. For this purpose, the flow, slump, and water powder ratio (or gypsum ratio, gypsum mixture ratio) are important, and further, the ratio of hardening expression and the additive are also important.

  If the ratio of the cured material is excessive, the characteristics of the mortar grout mainly composed of cement, etc. will be strong, the water will separate and the breathing will increase, it will be difficult to become a plastic gel, and it will not be a plastic gel by dehydration. It becomes a non-plastic gel and solidifies in a short time to form a high strength consolidated body. For this reason, it splits and deviates or solidifies and becomes impossible to inject.

  Mass solidification that has a cured material ratio of less than 50%, preferably 1 to 40%, more preferably 1 to 20%, most preferably 1 to 15%, and has grown greatly through a plastic gel in the ground Things are formed. In particular, when the ratio of cured material is 1 to 20%, or 1 to 10%, the strength is low, the plastic gel retention time in the ground is long, and it is easy to expand, and the improved ground is even. It integrates with the surrounding ground that has increased in strength and density, and has excellent earthquake resistance.

(4) Fluidity modifier (A material)
a) Aluminum salt Further, in the present invention, a silica-based powder, a hard suspension composed of one or a plurality of cement, lime, gypsum, and slag as a hardening developing material, and water express plasticity. In order to adjust time, an aluminum salt such as aluminum sulfate or polyaluminum chloride can also be included as a fluidity adjusting agent.

In this case, preferably, the ratio of cured material is 2 wt% or more and less than 50 wt%, the water powder ratio is 20 to 60 wt%, and the aluminum ratio is 2.0 wt% or less, preferably 0.1 to 1.0 wt%. %, And a blended grout of 0.01 to 0.35% by weight in terms of Al ₂ O ₃ . Here, the aluminum ratio is aluminum material / (F + C) × 100 [%]. Aluminum material represents weight.

  In the above, the aluminum salt or water glass as a gelling accelerator as a fluidity adjusting agent may be mixed with a silica-based powder, a hardening expression material and press-fitted into the ground with a pump, or in an injection tube, Alternatively, it may be mixed and mixed near the injection tube, or in the process of injecting a mixture of silica-based powder, curing agent and gelation accelerator, a gelation accelerator may be further mixed and injected. You may do it.

b) Foaming agent, foaming agent A foaming agent or a foaming agent can be added as a fluidity adjusting agent to increase fluidity and reduce the weight. For example, by adding bentonite as a clay, and further polymer thickeners such as polyvinyl alcohol, carboxymethylcellulose (CMC), methylcellulose, etc., dispersibility in water is suppressed, precipitation is reduced, and workability is improved. It serves as an improvement effect or as a water-retaining material and as a binder of the above-mentioned powder material, which is the main material, and forms a fluid having a structure that is difficult to disperse while maintaining fluidity in the form of a pseudo gel. As a result, the dehydration in the ground is reduced and the expansion of the blockiness is promoted.

  The injection material used for the secondary injection material in the present invention may be cement bentonite or a water glass-based injection material using a solution-type silica consolidation material, but naturally, a consolidation material with excellent durability is preferable, An injection material mainly composed of a water-soluble silica compound obtained from glass by dealkalization treatment with an ion exchange resin or an ion exchange membrane or neutralization treatment with an acid is preferred.

  As an injection material mainly composed of such a water-soluble silica compound, a colloidal silica injection material (an injection material in which a curing agent such as an inorganic salt is added to colloidal silica to be gelled), an active silica injection material (active A pH adjusting material and an injection material in which an inorganic salt is added to gel if necessary, and a silica sol-based injection material (weak alkaline to neutral, acidic) are preferable.

  In the case of a colloidal silica-based injection material, the durability becomes better when the pH of the solidified body is lowered by adding a small amount of acids. On the other hand, in the case of acidic silica sol, or colloidal silica or activated silica, the gelation time may be greatly shortened due to the influence of the pH of the weak alkaline suspension injection material. It is desirable to use a material containing a metal sequestering agent.

  Examples of such compounds include phosphoric acid, phosphoric acid 1 soda, phosphoric acid 2 soda, phosphoric acid 3 soda, pyrophosphoric acid soda, acidic pyrophosphoric acid soda, tripolyphosphoric acid soda, tetrapolyphosphoric acid soda, hexametaphosphoric acid soda, and acidic metaphosphoric acid soda. .

  The gelation time of the solution-type silica consolidated material may be instantaneously set when the target ground is very rough and the injection amount of the primary injection material is small. In this case, a gelation time of one day or longer can be used. This gelation time corresponds to the gelation time in soil, and varies greatly depending on the type of solution-type silica consolidated material. For example, even if the active silica-based injecting material has a long gelation time of about several days as a blended liquid unit, when it is injected into the ground, the gelation time can be within one day due to contact with soil.

  When using the consolidated material of the present invention, the injection ratio varies depending on the condition of the ground to be injected, but the ratio of solution-type silica consolidated material 1 to 5 (volume ratio) to the plastic grout 1 is set. Is preferred.

  The plastic grout in the present invention not only fills the voids, but can also expand the voids or weak areas. At that time, it becomes non-plastic with dehydration and finally solidifies.

  After such a process, for the first time, filling with a packer effect around the injection pipe or filling of the suction part of the revetment and subsequent penetration of the permeable grout between soil particles, or the deviation flow path at the time of deviation of the permeable grout Filling becomes possible. This is possible by using a flowable plastic grout. The flowable plastic grout used in the present invention will be described in detail in the following examples.

Materials used
(1) Fly ash Coal ash discharged from thermal power plants: FA, silica-based non-curing powder,
Density 1.9 to 2.3 g / cm ³ , particle size distribution 0.1 mm or less is 90% or more
(2) Cement Ordinary Portland cement: PC, hardened material
(3) Sulfuric acid band Aluminum sulfate, Al ₂ O ₃ = 17.2%, gelation accelerator
(4) Water glass
JIS No. 3 water glass, SiO ₂ = 29.0%, Na ₂ O = 9.0%, molar ratio 3.3, gelation accelerator
(5) Slaked lime Industrial calcium hydroxide, gelation accelerator and curing agent
(6) Slag Slag 8000 Blaine value, curing material and silica-based non-curable powder
(7) Gypsum Hemihydrate gypsum, hardening material
(8) Incineration ash Incineration ash discharged from waste incinerators, silica-based non-curable powders Density 2.5-2.7 g / cm ³
(9) Bentonite water retention and thickening material
(10) Foaming agent Pre-foaming air generating agent

Formulation Examples 1-3
Mix fly ash, cement and water. The blending amount of fly ash and cement was similarly changed only in the blending amount of water. Table 1 below shows the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 1 to 3 thus obtained.

  In Table 1, the gelation time refers to the time until the plastic gel is formed after blending, and the time when the table flow becomes approximately 20 cm is defined as the gel time (gelation time). The plastic holding time refers to the time during which a gel-like state is maintained if it is stationary, but is in a state of flowing when a force is applied. As shown in Formulation Example 3, as the water powder ratio decreases, the blended solution immediately becomes plastic. Therefore, immediately after blending as in blending examples 1 and 2, a fluid suspension is dehydrated in the process of being poured into the ground, and the plastic gel shown in blending example 3 is obtained.

  As shown in Table 1, Formulation 1 with the same cured material ratio of 8.05% and a water powder ratio of 35% and Formulation 2 with a water powder ratio of 30% gelated until a plastic gel was formed after blending. The time takes 480 minutes and 300 minutes, respectively. When the water powder ratio is 25%, the gelation time is 2 minutes. This means that at the time of blending, when the injection material that has not reached the plastic state before being injected into the ground is mixed in the ground, the water body ratio is 35% to 30% by dehydration (dehydration rate is about 15%) and further 25 % (Dehydration rate 30%), the gel time is reduced to 2 minutes, forming a plastic gel and forming a lump. Moreover, since the plastic holding time is 7.5 hours at the time of gelation, the bulk gel expands, the breathing is small, the viscosity increases, it is difficult to diffuse, and the solidified product has high strength.

  Such characteristics have not been known so far. That is, the flowable injection material does not reach gelation until the water powder ratio is dehydrated from 35% to 25% after being pressed into the ground, and is 25% (dehydration rate is about 30%). Later, a plastic gel was formed, and the plastic retention time at that time was 7.5 hours. As the press-fitting continued, the gel remained large, and as the dehydration or curing proceeded, It becomes a non-flowable gel and tells it to solidify.

  Therefore, even if it does not exhibit plasticity at the time of injection, it can become plastic by dehydration in the ground. In the injection of such fluid injection solution, even if the compounding solution is injected as a single solution, the powder injection solution is A solution, the gelation promoting material such as aluminum, water glass, etc. is B solution, and it is going to be combined injection Alternatively, the liquid A can be applied to any plastic gel and the liquid B can be used as a gelation accelerator such as water glass regardless of the means.

Formulation Examples 4-6
Mix fly ash, cement and water. The amount of water was changed in the same manner as that of fly ash and cement. Table 2 below shows the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 4 to 6 thus obtained.

  From Table 2, when the ratio of the cured material is increased, the breathing rate is increased, the plastic holding time is shortened, and the initial viscosity is also increased. Therefore, high pressure is required for pressure feeding, and powder and water cannot be evenly fed, and clogging easily occurs in the injection tube. Alternatively, even if a gelling agent is added, the water-to-powder ratio decreases rapidly due to dehydration, and split veins are easily injected. Therefore, the ratio of cured material is less than 50%, preferably 1 to 20%, more preferably 1 to 15%, and most preferably 1 to 10%. In the present invention, blast furnace cement, alumina cement, early-strength cement, slag cement, or any other cement can be used without using Portland or cement.

Formulation Examples 7 and 8
A sulfate band was added to Formulation Examples 1 and 2 in Table 1 to promote gelation. Here, to promote gelation means to shorten the time until the plasticity is exhibited after blending or to reduce the flow. Table 3 below shows the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 7 and 8 thus obtained.

  From Table 3, by adding a sulfuric acid band, the gel time is shortened, but the plastic holding time is not so much reduced, and the breathing rate is also reduced. Although it is possible to immediately gel in the blending of fly ash, cement, and water as shown in Formulation Example 3 in Table 1, it is more efficient to use a gelling regulator in consideration of workability in the field. However, since the sulfuric acid band has the property of reducing the strength expression, the addition amount is within 2.0%, preferably within 1.0% with respect to the powder.

Factors and conditions for plastic grout (1) Ratio of hardened material: fly ash, that is, fly ash, and cement content relative to cement content: cement (hardened material) weight / {fly ash (silica type) Non-hardening powder) weight + cement (curing material) weight} × 100 [%]

  Cement is a material that develops hardening and can also be called fly ash plasticizer. When fly ash is mixed with cement, it causes a pozzolanic reaction to obtain consolidated strength. However, as the ratio of the cured material is increased, the characteristics as a plastic grout deteriorate. That is, since the precipitated and increased breathing and the precipitated are difficult to flow and hardly become a plastic gel, the ratio of the cured material is less than 50%, but the preferred range is not adding a sulfate band (gelling accelerator). In the case, it is 1 to 20%, preferably 1 to 15%, more preferably 1 to 10%. Moreover, when adding a sulfuric acid band, it is 2 to 40%, Preferably it is 2 to 20%.

(2) Water-powder ratio Water content with respect to the powder in the grout: water weight / {fly ash (silica-based non-curable powder) weight + cement (curing material) weight} × 100 [%]

  When this value is small, it tends to be plastic. That is, the time for forming a plastic gel after blending is shortened, and the flow value is decreased. However, if the water powder ratio is too small, workability is impaired, so the range is 20 to 200%, preferably 20 to 100%, more preferably 20 to 50% (weight ratio).

  However, when water glass is used as an accelerator, the water powder ratio can be increased. In addition, since the properties of the grout differ depending on the mixing conditions, environment, and materials, the measurement of the breathing rate, flow value, and strength described later is important.

(3) Addition amount of sulfate band Addition amount of sulfate band to powder in grout: sulfate band weight / {fly ash (silica-based non-curable powder) weight + cement (hardening material) weight} × 100 [% ]

  The sulfuric acid band is a gelation accelerator, and when added to the fluid state of fly ash and cement, it promotes gelation and accelerates the time to become a plastic gel. However, since the sulfuric acid band also has an effect of reducing the consolidation strength, its addition amount is 2.0% or less, preferably 0.1 to 1.0%.

(4) Gel time Here, it does not mean chemical gelation that is solidified like that found in common water glass grouts, but it loses its fluidity due to its own weight after compounding, and plastic that flows when force is applied. The physical gelation time until it becomes a gel is expressed as gel time. Unlike a grout made from a common water glass, it cannot show a clear gelation time. Therefore, when the value became 20 cm or less using the table flow, it was not regarded as gelation, and this was defined as gel time.

(5) Plasticity retention time Asphalt penetration test method Static penetration resistance was measured using a penetration cone with a total mass of 230 g, tip angle of 15 degrees, and 36 mm according to JIS K 2530-1961. When it exceeded 0.01 MN / m ² , it became a non-plastic gel and was regarded as consolidated or cured, and the time from gelation to consolidation was defined as the plastic retention time.

(6) Breathing rate After blending, mix the grout thoroughly, then put the grout into a 200 ml graduated cylinder and seal it statically. After 1 hour, measure the amount of breathing water (superior liquid). Ask. (Breathing water volume / measuring cylinder capacity) x 100 [%]

  Here, the breathing rate after 1 hour is shown. When the composition has a breathing rate of 10% or more after the lapse of 1 hour, the injected solution is easily separated and easily injected in the form of veins or cracks. Thereafter, the breathing rate further increases as time passes. Therefore, the blending rate after 1 hour is preferably 10% or less, preferably 5% or less. FIG. 1 shows the relationship between the water powder ratio and the breathing rate according to the presence or absence of the sulfuric acid band in Tables 1 and 3.

(7) Flow value Based on a flow test (JIS R 5201 table flow), the grout was subjected to 15 drop motions in 15 seconds, and the spread was measured. About 18-19 cm is said to be suitable as the plastic grout, but in the present invention, the fluidity due to its own weight disappeared when the flow value became 20 cm or less, and the gel time was used. The flowable injecting material in the present invention is used in such a composition that the water-to-powder ratio is lowered by pressure dehydration by pouring into the ground and the table flow reaches 20 cm or less.

The flow by the cylinder is to measure the spread of the grout when a cylinder having a height of 8 cm and a diameter of 8 cm is filled with the grout and the cylinder is removed. An appropriate range in that case is approximately 8 to 18 cm, and approximately 15 to 22 cm when a drop motion of 15 times similar to the table flow is given after removing the cylinder. Since it can be measured more easily than the above table flow, it is often used in the field. However, since it is simple, an artificial error may occur. FIG. 12 shows an approximate relationship between the table flow and the cylinder flow.
In such a blend, even if the water powder ratio is large, the water powder ratio becomes 20% or less in the ground due to dehydration and solidifies from a plastic gel through a non-plastic gel.

(8) Initial viscosity The viscosity of the liquid mixture immediately after mixing was measured using a B-type viscosity type. Immediately after mixing, measurement was possible due to the fluidity, but when gelled, it becomes 100,000 cps or more, and measurement is impossible. FIG. 2 shows the relationship between the water powder ratio and the viscosity depending on the presence or absence of the sulfate band in Tables 1 and 3.

(9) After blending the uniaxial compressive strength, the fully mixed grout was put into a mold having a diameter of 5 cm and a height of 10 cm, cured for one day in a stationary state, and the uniaxial compressive strength was measured. FIG. 3 shows the relationship between the water powder ratio and the uniaxial compressive strength according to the presence or absence of the sulfuric acid band in Tables 1 and 3. According to FIG. 3, the strength is reduced by the addition of the sulfuric acid band. In addition, when the water powder ratio is large, the time until consolidation is prolonged, so that the strength development is slower than that when the water powder ratio is small.

Formulation Examples 9-11
Mix water glass into a suspension of fly ash, cement, slaked lime, and water. Table 4 below shows the preparation conditions and physical property values of the ground injection materials of Formulation Examples 9 to 11 thus obtained.

(1) Addition amount of slaked lime Addition amount of slaked lime to powder in grout Addition amount of slaked lime / {weight of fly ash (silica-based non-hardening powder) + weight of cement (hardening agent)} x 100 [%]

  Slaked lime is a gelling accelerator, and when mixed with fly ash like cement, it causes a polazone reaction. However, consolidation strength is not as good as cement. Here, in order to make it plastic, it was used as a gelation accelerator for having the retention time. The range is preferably 3 to 15%, although it depends on the amount of cement added.

(2) Silica concentration SiO ₂ amount in grout: SiO ₂ % of water glass × (water glass weight / grouting weight) [%]
According to the experiment by the present applicant, the silica concentration is 0.2 to 7.0% in order to plasticize or solidify the grout, depending on the blending ratio of other materials. However, when a low molar ratio water glass having a molar ratio of No. 3 water glass or less is used, 3.0 to 7.0% is preferable. Of course, a high molar ratio water glass or powdered water glass can also be used. An acidic water glass obtained by mixing water glass and acid can also be used as a gelation accelerator. This case is also expressed as water glass in the present invention.

(3) Characteristics and comparison The characteristics of the formulation shown in Table 4 are that gel time can be easily prepared, and the plasticity retention time is slightly short, but the expression of early strength is remarkable. Therefore, it is suitable when importance is placed on the expression of early strength. The gel time of A liquid can be shortened by using plastic grout as A liquid and water glass aqueous solution as B liquid. Further, by mixing the grout well after gelation, the expression of the early strength decreases, but the plastic holding time can be lengthened. Therefore, it is suitable for ground improvement in which the injection body is expanded by injecting the mixture well-mixed after gelation for the purpose of requiring long-time injection or repeated injection at the injection point once injected by interval injection.

Formulation Examples 12 and 13
A fly ash, cement, water, and a gelling accelerator were blended, and the gelling accelerator was further added to the above blending example 7 which became plasticized with time and solidified, thereby speeding up the gel time. A sulfuric acid band aqueous solution and an aqueous solution obtained by diluting water glass with water were added to Formulation Example 7 having fluidity before gelation. The blending ratio was 20 for the grout of blending example 7 and 1 for the aqueous plasticizer solution. Tables 5 and 6 below show the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 12 and 13 thus obtained.

(1) Characteristics and Comparison of Formulation Examples 12 and 13 When an aqueous solution obtained by diluting water glass with water is added to Formulation Example 7 which is a plastic grout, the gel time becomes extremely short, and the plastic retention time also becomes short. Strength development becomes remarkable. Therefore, it is suitable when importance is placed on early strength development. Further, when the liquid A is a plastic grout and the liquid B is a water glass aqueous solution, it is easy to form a block gel by the mixed injection tube of the liquid A and the liquid B.

Formulation Example 14
Bentonite as a thickener was mixed with fly ash and cement. The preparation conditions and physical property values of the ground injection material of Formulation Example 14 are shown in Table 7 below.

Formulation Example 15
Fine aggregate (mountain sand) was mixed with fly ash and cement. The preparation conditions and physical property values of the ground injection material of Formulation Example 15 are shown in Table 8 below.

Formulation Example 16
Fly ash and cement were mixed with muddy water. The preparation conditions and physical property values of the ground injection material of the blending example 16 are shown in Table 9 below.

(1) Water powder ratio Water content to powder in grout: water weight / (fly ash weight + cement weight + bentonite weight, fine aggregate weight, clay weight) × 100 [%]
Here, bentonite and fine aggregates were used as a gelation modifier for powders other than fly ash and cement. Moreover, the muddy water containing clay was used as mixed water. These gelation modifiers were considered as powders in the grout.

(2) Characteristics and Comparison of Formulation Example 14 Addition of bentonite as a thickener increases the viscosity of the grout, so that it becomes more plastic than when only the same amount of cement is used. However, when the addition amount of cement is reduced by adding bentonite, the consolidation strength is lowered. Therefore, the flowability can be adjusted by setting the PC addition amount to 3% or more and using bentonite as a thickener. The ratio of cured material is less than 50%, preferably 1 to 20%, and the water powder ratio is preferably 20 to 150%.

(3) Characteristics and Comparison of Formulation Example 15 Fine aggregate (mountain sand) can be mixed with fly ash and cement as an extender, but if there are many fine aggregates, the breathing rate tends to increase. The amount of fine aggregate added is preferably 80% or less. Further, the curing developing material ratio is less than 50%, preferably 1 to 20%, and the water powder ratio is preferably 20 to 150%.

(4) Characteristics and Comparison of Formulation Example 16 Mixture of fly ash and cement with muddy water is thickened by clay contained in the muddy water, and improves fluidity and water retention. There is an effect as a material or a water retaining material, and it is effective in expanding the plastic gel in the soil. Therefore, the properties of the grout can be adjusted by the content of clay contained in the muddy water. It is preferable that the ratio of cured material is less than 50% and the water powder ratio is 20 to 150%.

Formulation Examples 17 and 18
As an air generating agent, a prefoaming foaming agent and a post foaming aluminum powder were mixed with fly ash and cement mortar. The blending examples 17 and 18 are shown in Table 10 and Table 11. The air generating agent has the effect of improving fluidity in addition to reducing the density of the consolidated body.

(1) Fluidity modifier: foaming agent addition amount When the foaming agent content in the grout is the foaming agent weight / (cement weight) × 100 [%], the foaming agent addition amount is 0. From 0.5 to 1.5% (weight ratio of cement) is preferred.

(2) Fluidity modifier: Aluminum powder addition amount Aluminum powder reacts with alkalis such as cement to generate hydrogen gas (foaming). When the aluminum powder content relative to the powder contained in the grout is aluminum ratio: aluminum powder weight / powder body weight × 100 [%], an aluminum ratio of about 0.01% is effective.

(3) Characteristics and Comparison of Formulation Examples 17 and 18 The air generating agent has an effect of improving fluidity in addition to reducing the density of the consolidated body.

Formulation Examples 19 and 20
Incinerated ash and volcanic ash were used as the silica-based non-curable powder that is the main material of the injection material of the present invention. Incineration ash was blended with fly ash in a one-to-one amount, and volcanic ash was blended with fly ash in a one-to-three amount. Tables 12 and 13 below show the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 19 and 20 obtained as described above.

(1) Water-powder ratio Water content with respect to the powder in the grout: water weight / (fly ash, incineration ash, volcanic ash, (silica non-curable powder) weight + cement weight) x 100 [%]
Here, incinerated ash and volcanic ash were used as non-curable powders other than the cured material and fly ash. In addition, on-site generated soil or silica sand can be used.

(2) Characteristics and Comparison of Formulation Examples 19 and 20 When comparing Formulation Example 19 in Table 12 and Formulation Example 3 in Table 1, the blending example 19 in which incinerated ash is mixed has a reduced breathing rate and a flow value of It has become smaller. Moreover, the same result was obtained even if the combination example 20 of Table 13 and the combination example 1 of Table 1 were compared. When incinerated ash and volcanic ash are mixed, it is considered that the fluidity tends to be lost and the strength development tends to be lower than that of fly ash alone. However, since the plastic holding time is long, the fluidity and the consolidation strength can be adjusted by mixing this with a gelation modifier. The ratio of cured material is less than 50%, preferably 1 to 20%, and the water powder ratio is preferably 20 to 150%.

Formulation Example 24
Slag is used as a silica-based non-curable powder that is the main material of the injection material of the present invention, and is mixed with cement and water. Table 14 below shows the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 21 and 22 thus obtained.

(1) Water-powder ratio Water content with respect to the powder in the grout: water weight / (slag (silica-based non-curable powder) weight + cement weight) × 100 [%]

(2) Characteristics and Comparison of Formulation Examples 21 and 22 When comparing the case of using fly ash and the case of using slag as the main material, the slag has a better reaction with cement and is compared with Formulation Example 2. Then, the ratio of the cured material is the same, and the gel time is fast and the strength development is remarkable despite the fact that the water powder ratio is doubled. It is also possible to add a gelling regulator to this. However, since the development of strength is rapid even when only slag, cement, and water are blended, it is considered that when an accelerator is used as the gelation modifier, curing is promoted and the plastic holding time is shortened. The ratio of cured material is preferably less than 50%, more preferably 1 to 20%, and the water powder ratio is preferably 20 to 150%, more preferably 30 to 80%.

Formulation Examples 23, 24, 25
Slaked lime, slag, and gypsum were used as the curing agent and mixed with fly ash and water. Tables 15, 16, and 17 below show the adjustment conditions and physical property values of the ground injection materials of Formulation Examples 23, 24, and 25 thus obtained.

(1) Curing manifestation material ratio Curing manifestation material content to powder content in grout: Curing manifestation material weight / (fly ash (silica non-curable powder) weight + curing manifestation material weight) × 100 [%]
Since slaked lime, slag, and gypsum were used as the hardening developing materials, the weight of the hardening developing material means the slaked lime addition amount, the slag addition amount, and the gypsum addition amount.

(2) Characteristics and Comparison of Formulation Example 23 When slaked lime is used as a hardening developing material, a pozzolanic reaction occurs when added to fly ash as with cement, but this reaction is very slow, but it becomes plastic. Consolidation takes time, and it takes several weeks to obtain sufficient consolidation strength. Therefore, slaked lime is more effective as a thickening material than a hardening developing material. Therefore, it is thought that the outstanding effect can be anticipated by using together with a cement like the blending examples 9, 10, and 11 or mixing with a gelling accelerator.

(3) Characteristics and Comparison of Formulation Example 24 When slag is used as a hardening developing material, it gels slightly faster than cement and the plastic holding time becomes longer, but the result is similar to cement. Therefore, it is possible to adjust the gelation time and fluidity by mixing the gelation modifier, but in the case of slag than when mixing the same amount of cement, the strength expression is delayed, so the gel has the effect of reducing the strength. It is not preferable to mix a large amount of the chemical adjusting agent.

(4) Characteristics and Comparison of Formulation Example 25 When gypsum is used as a curing agent, gypsum tends to be plastic because it reacts quickly,
Since the development of strength is fast, the plastic holding time is extremely short. Therefore, it is preferable to adjust the gelation time by using a retarder or the like. Alternatively, if it is desired to increase the strength quickly, an accelerator can be used.

  A field injection experiment was conducted on the formation of a massive solid body (spherical solid body), which is a feature of the present invention. The composition liquid used is the composition shown in Table 18, and the target ground is sandy ground having an N value of 7, a relative density of 40%, and a fine particle content of less than 20%. As comparative examples, Comparative Examples 1 and 3 of a conventional water glass suspension type instantaneous setting compound (hereinafter referred to as an instantaneous setting method) are instantaneous setting (gelation time 10 seconds, no plastic holding time). LW (gelation time 1 minute, no plasticity retention time), Comparative Example 4 is a cement-based injection material (gelation time several seconds, no plasticity retention time). The formulations of Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4 are shown in Table 19, Table 20, Table 21, and Table 22, respectively. Examples using the formulation example of Example 1 are shown in Table 18. A to F are also shown for the mixing of the mixture, the formation of the plastic gel, and the press-fitting situation. The consolidation status in the excavation survey is shown in I-VI.

  From Table 18, in the case of press-fitting according to Category A, a silica-based non-curable powder, a calcium-based powder-curing material, a suspension made of water and a plastic gel, or a gelling modifier are mixed and used as a plastic gel. When press-fitting until it becomes impossible to press at the set pressure, a substantially spherical solid body formed of a plastic gel is formed. The growth of the gel-like lump forms a lump having a large plastic-retaining time and a high water / powder ratio and a high ratio of the cured substance.

  In the press-fitting according to section B, after mixing, the injection starts before becoming a plastic gel, reaches the plastic gel during the injection process, and press-fits until it becomes impossible to inject at the set pressure, and the shape becomes indefinite. However, a massive solid body was formed within the injection target range. This is because the liquid mixture with sufficient fluidity in the initial stage of press-fitting is pressed in the direction where the press-fitting resistance of the ground is small and weak, and the fluidity decreases with dehydration, and the plasticized injection material is pressed in and the mass is expanded. It seems to have solidified. In this case, even if it is not a spherical body, it is compacted around a weak portion, so that the improvement effect can be sufficiently obtained.

  In the press-fitting according to section C, after mixing, the plastic gel does not reach until the press-fitting of the stage is completed, but the pressure increases with the press-fitting time, and finally the injection amount becomes zero and the injection becomes impossible. In the investigation of the drilling results, the fluidity is large at the beginning of the injection, so some parts are split and injected to the outside of the handling range, but the fluidity is lost due to dehydration in the ground, and a plastic gel is formed within the handling range. At the same time, massive gel grows and the effect of compressing and strengthening the surrounding ground is obtained.

  In the injection by section D, it is a normal water glass grout with no gelling liquid plastic state retention time, and the pressure increases with gelation, but if it is further injected, it splits into a pulse shape and deviates outside the range of responsibility. Consolidate into a shape. For this reason, there is almost no effect of increasing the density of the target ground.

  The injection according to the section E is a compounded liquid that does not exhibit a general plastic state, and does not show an increase in pressure while maintaining the initial pressure during injection, and deviates outside the injection target range and hardly improves.

  In the press-fitting according to section F, dehydration occurs immediately outside the discharge port as soon as it is discharged from the injection tube discharge port to the ground at the time of injection into the ground injection, and the injection material inside the discharge port becomes It was found that the dehydration of the injection material in the injection tube reached the upper part in the injection tube when it was dehydrated and further pressurized, and finally the entire injection tube solidified and became unable to be injected.

  This is also the reason why when a plastic grout with little fluidity is injected into the ground, no matter how much the pump pressure is raised, the injection becomes impossible and no crack injection occurs.

  In sections A, B, and C, the volume of the consolidated body and the injection amount were measured in the excavation survey after injection, and the dehydration amount was within about 30%. From this, it was found that if the injection material in the above flow range was pressurized and dehydrated until it could not be injected and pressed into the ground casting, a solid gel that could not flow with a dehydration rate within about 30% was formed in the ground casting. .

  From various field injection experiments including these phenomena, it is found that the compounded solution at the time of injecting the injection solution has reached a plastic gel at the time of injection, or even if it is not a plastic gel at that time, during injection. If the composition is set so that it reaches the plastic gel before it is injected into the ground, or the plastic gel is formed during the injection by dehydration within 30% of the compounded liquid, it will lump in the ground It was found that a gel was formed.

Example 2 is an example of the improvement effect in the ground where the N value is 10 or less. For example, in the case of compounding example 3, for 5 minutes after mixing, the discharge rate is 5 l / min per minute, the initial pressure is 1.0 MN / m ² , the maximum diameter pressure is 3.0 MN / m ² , and the injection speed becomes zero. It became impossible. As a result of the excavation investigation in which the total injection amount was 50 l, it was found that a massive gel of approximately 35 l (dehydration rate 30%) was formed.

  The improvement effect of the plastic press-in method is the press-fit of plastic gel whose fluidity decreases in the ground, so it is intended for loose ground that can be press-fitted with pump pressure, and usually has an N value of 15 or less, most preferably It is a soft ground with an N value of 10 or less. However, in order to prevent liquefaction and strengthen the foundation, it is necessary to further improve the ground having an N value of 15 or more, or 20 or more. Under such ground conditions and purposes, the present inventor has found that the method according to the sections B and C of Experiment 2 is extremely effective in several field injection tests.

In such a ground, when compound 3 is injected as in section A, the injection pressure increases to 3 MN / m ² within 2 minutes from 1MN / m ² after the injection, making it difficult to press-fit. after 3 hours mixing, were injected at an initial pressure 0.1 mN / m ² per minute discharge rate 5l / min, the total maximum pressure 2.0 mN / m ² becomes more 5 minutes after 1.0 MN / m ² as a limit pressure Press-fitting was performed so that the injection volume was 50 l. Some cracks were observed in the leading part of the same solidified body, and a large solidified body having a large thickness centered on the crack on the center side was formed.

  From this, the injection of the state of the plastic gel at the time of injection is that the plastic gel grows and expands in the ground even if the N value is within 15, but if the N value of the ground becomes 15 or more, the plastic gel continues to be pressed in as the plastic gel. It becomes difficult. However, by injecting into the ground a compounded liquid that is not a plastic gel in the initial stage of injection, even if the ground has a large N value of 15 or more, it splits while forming a crack like a vein, and when it becomes a dehydrated plastic gel, the fluidity is It lowers and becomes a gel in the crack, and the massive gel expands around the gel and grows into a large massive gel. Although it is not this spherical body, the density of the surrounding ground can be increased within the range of handling and the strength of the ground can be increased.

  These results indicate that the ground density is sufficient to inject the plastic gel by injecting the plastic gel by injecting cracks after injecting a solution type grout with good fluidity at the beginning of the injection. It was found to be an extremely effective means for ground improvement requiring high ground or ground improvement.

A conventional cement grout or LW grout only deviates in a pulse shape, but a plastic gel press-in method is performed by press-fitting an injection material that reaches the plastic gel or a plastic gel-type injection material on the way. It has been found that the scope of application has been dramatically expanded.
Field injection experiment

Explanation of consolidation status in the above Shape of consolidated body in excavation survey I Formation of large solid aggregates of approximately spherical shape with a diameter of 30 to 70 cm
II The shape is not spherical but irregular, but formed into a solid aggregate with a diameter of 20-50cm
III Some of the tip part was pulsated to the outside of the injection range.
IV Deviation outside the range of pulse injection with a thickness of 1-10cm V Deviation outside the range of pulse injection with a thickness of 1-5cm
VI Only the size of the injection hole

  As a result of the study by the test construction shown in FIG. 4 in the present invention, it was found that the ground strengthening effect was obtained by the injection design as follows.

In FIG. 4, the injection interval is 0.5 to 3.0 m. The improvement rate is 5 to 40%. Here it corresponds to the cross-sectional area of the conversion to consolidated mass and improved rate allocation improvement area 1 m ² per 1 injection hole, the improvement ratio 5-40% means 0.05~0.4m ^2. In addition, this improvement rate is calculated from the reduction amount of the gap in the receiving area per hole from the N value of the improvement target ground and the improvement target N value, and the reduction amount corresponds to the area to be replaced by the gelled product. Is calculated from

  Table 23 shows design examples effective as ground reinforcement in the present invention. This is based on the experimental example performed on the sand ground in Example 2, the injection arrangement is a square arrangement shown in FIG. 4 (b), the injection interval is 1 m, 2 m, and the improvement rate is 5%, 10%, 15% and 20%.

  FIG. 5 shows a method of using a double tube rod having a plurality of flow paths, injecting plastic gel from the flow path for primary injection, and using solution-type silica grout for secondary injection from the other flow path.

  In the present invention, the secondary injection material only needs to have better permeability than the primary injection material, and can be penetrated depending on the ground condition. For example, in addition to the solution-type silica grout, a cement grout that does not exhibit a suspension-type plasticity or an ultrafine cement grout may be used. Moreover, although it is a plastic grout, the thing of higher permeability than a primary injection material should just be.

(1) Chemical solution Formulation 2 of the example was used as the primary injection material, and solution-type non-alkaline silica grout was used as the secondary injection material. This solution-type non-alkaline silica grout is based on active silica (SiO ₂ concentration 4 wt%) obtained by dealkalizing water glass by ion exchange, and a predetermined silica concentration of 6% by water glass and acid (phosphoric acid). And acidic silica solution adjusted to pH 4.0. Here, you may use the acidic silica solution which consists of acidic silica sol obtained by adding water glass and an acid as a secondary injection material, and removing the alkali of water glass.

  In FIG. 5, after drilling to a predetermined depth, a plastic gel is injected as a primary injection material into the gap around the injection tube and the rough portion of the ground. Subsequently, solution type silica grout is injected as a secondary injection material, penetrates into the fine voids of the ground, and strengthens the ground. The injection tube was pulled up and the next step was repeated in the same manner.

One month later, when excavated, it was injected into a columnar shape, and the strength of the solidified body (sand gel) of the silica solution was measured and found to be 0.4 MN / m ² . Further, when the solidified body of the plastic gel was measured, it was 1.23 MN / m ² .

  From the results, the plastic gel of the primary injection material injected into the ground has a water powder ratio of 30% and a gel time of 300 minutes when blended in the mixer. Since the state retention time is also 11 hours, the fluidity can be maintained for a long time and the liquid can be fed from the pump. However, the water is injected into the ground, consolidated in the ground by the subsequent injection material, and dehydrated. The powder ratio decreases, and gelation occurs through Formulation Example 3. Therefore, the plastic gel injected into the ground shortens the gel time and the plastic retention time, and the caking strength increases due to a decrease in the water-powder ratio, which is higher than the experimental strength of the plastic gel. The consolidation strength is lower than the water powder ratio. Moreover, by using a solution-type silica grout as a secondary injection material, details in the ground are injected.

  In actual construction, depending on the characteristics of the ground and the expected strength, the combination of primary injection and secondary injection is not limited to the combination of plastic grout for primary injection and solution-type grout for secondary injection, as shown above. A plastic grout or a suspension grout in which slag, cement bentonite or the like is blended in the secondary injection may be used.

  Moreover, when there are many rough voids in the ground and the ground is strongly improved, a plastic grout can be used for the primary injection, and a plastic grout having higher fluidity than the primary injection can be used for the secondary injection. At this time, in order to adjust the fluidity of the primary injection material and the secondary injection material, aluminum sulfate, water glass, slag, bentonite, gypsum, etc. are used as the fluidity adjusting agent, and the gelation time and plasticity retention time are adjusted. By doing so, the permeability to the ground can be changed. In the above, the plastic gel may be mixed in the injection pipe path of the primary injection after combining the blending example 2 as the A liquid and the fluidity adjusting agent as the B liquid.

  The injection method is shown in a superimposed manner by pressing into the ground, pushing the soil particles around and solidifying them in a lump while pushing the surrounding soil and strengthening the ground. In injecting such a plastic injection material, the initial injection pressure is lowered to increase the injection pressure step by step while dehydrating the preceding injection, or first, a plastic grout having a high fluidity is injected, followed by By press-fitting a plastic grout having low fluidity, a thick solidified layer that can withstand water flow and water pressure can be formed by pushing the plastic grout having high fluidity into a fine gap.

Alternatively, it is injected while intermittently pressurizing by repeatedly injecting and interrupting, thereby spreading the soil particles to the periphery while preventing deviation due to interpenetration of the soiled gel particles and cracking of the ground, and the density of the ground It may be consolidated while increasing. Alternatively, a plastic grout having low fluidity can be pressed into a sheet pile or a breakage part of the revetment while being gradually pushed in, and then solidified through dehydration and non-plasticization. (Fig. 6 (a), (b), (c))
In addition, this injection is performed by simultaneous injection from a plurality of injection points, switching injection to another injection point, that is, a continuous injection method as shown in FIG. 6B, and a transition from one injection point to another injection point. The injection is performed by the interval injection method in which the injection is performed again after returning to the injection, or a combination of these methods.

  Furthermore, the ground injection material according to the present invention can be injected from a plurality of injection points to constrain the ground between the injection points, and the ground density between the injection pipes can be increased to consolidate the ground. In order to expect such an effect, it is desirable to install a plurality of injection pipes on the ground at intervals of 0.5 m or more and 3 m or less. On this, the permeable injecting material can be injected from the same injection hole or from another injection hole, and the whole injection can be performed.

The above-described injection is performed using, for example, the following injection pipes (a), (b), and (c).
(A) An injection tube having a drilled portion or a discharge port at the tip.
(B) Injection is performed using an injection tube having a plurality of discharge ports in the axial direction.
(C) An injection tube having at least one bag packer in the outer tube.

  If an excessive amount of plastic gel is formed in the ground at the same time in order to greatly improve the strength of soft ground, etc., the ground surface will be raised, the ground will be destroyed in the lateral direction, and the There is a tendency that the strength of the ground does not improve as set. For this reason, it is desirable to take advantage of the characteristics of the ground injecting material, injecting at a low discharge amount at the initial stage of injection, gradually increasing the injection pressure and continuing to press fit within a predetermined injection pressure range to increase the injection amount. The strength of the ground before the injection (N value, etc.), the injection depth (upload pressure), the injection pressure, the injection amount, and the area of the area per injection can be obtained.

  Or, more accurately, if the ground displacement is taken into account. In addition, fluidity is present during the injection, and when the injection is stopped, the fluidity stops and gelation or pressure dehydration occurs, and a pseudo-solid state appears. Injected at intervals of 2), it is repeatedly injected to make it solidify, and the injected ground is consolidated without destroying it, and the removed water is dispersed among the surrounding soil particles, compacting and dehydrating the ground side It is also effective to increase the consolidated diameter of the gelled product or to inject these grouts with a certain time lag (time difference).

  For example, in the vertical injection, the interval method is repeated, injection is performed, and the ground injection material is pressed into the ground injection material previously injected, and the ground is By repeatedly pressing the ground injection material without splitting, the side of the ground is consolidated and dewatered, and the ground is strengthened.

  Alternatively, a predetermined number of holes are formed in a predetermined area of the ground, and the ground injection material is injected into the ground injection material at a single location through a predetermined time lag for each hole. In order to avoid this, it is possible to divide the design injection amount into several parts.

  In this way, the plastic grout of each drilling hole is injected by the interval method for each soil layer or each stage at a predetermined time lag, and the plastic grout injected in advance consolidates the surrounding ground, or by itself, or In addition, when the injection solution is dehydrated, the ground injection material to be injected into the predetermined number of drilling holes by the repeated injection is repeated for each soil layer or stage with respect to the ground of each drilling hole. Similarly, it is possible to perform consolidation dehydration on the side, increase the strength, suppress the displacement as a whole, and enhance the strength of the ground in the predetermined area.

  For example, an injection tube with a discharge port at the tip is inserted to a predetermined depth, and the step of lifting the injection tube is stepped up so that the discharge port is positioned within the range of the plastic gel before becoming non-plastic gel. The mass of the gel-like gel is enlarged and press-fitted.

  Furthermore, the bag body is set in an area near the ground surface in the injection tube to be inserted into the drilling hole, the suspension type grout is press-fitted inside, the bag is inflated to the periphery, and the surrounding ground is consolidated. The ground surface is improved without departing from the plastic injection material, and the ground injection material is press-fitted from the lower side of the bag body, so that the plastic gel does not get over the hardened body of the bag and is restrained by the bag body. Due to the effect, there is no displacement of the ground uplift and the like, and the strength due to the ground dewatering action can be achieved as a whole and the strength improvement can be achieved over the entire region.

  In this case, it is preferable that the installation area of the bag body be within a depth close to the ground surface, for example, within a 3 m range (particularly, a 1.5 m range). This is because even in a plastic gel, this region tends to deviate to the ground surface. For the same reason, it is possible to equalize the compression of the ground surface and prevent the ground surface from being raised by installing injection holes densely in a region close to the ground surface. This is because, in a region close to the ground surface, for example, within 3 m (especially within 1.5 m), if a large amount of injection is performed from a single injection hole, the earth surface tends to deviate because there is little earth covering, and ground uplift It is easy to wake up.

  Therefore, in this region, the vicinity of the ground surface can be uniformly strengthened by making the injection hole denser than the region having a large depth and reducing the injection amount per one. In addition, the ground improvement on the ground surface is likely to cause a ground uplift due to a low overlay pressure, and the ground uplift reaches a diameter of several m on the ground surface. Therefore, instead of shifting the injection hole to be injected into the adjacent injection hole, the injection hole is transferred to the injection hole outside the influence range of the ground uplift, and the injection of the adjacent injection hole is performed when the ground uplift has subsided. Is desirable.

  In the area close to the ground surface, the injection step is shifted from the upper part to the lower part, the ground injection material is press-fitted to compress the ground near the ground surface, and then the injection pipe is inserted to the bottom of the improved ground. By shifting the injection step upward from the injection, the ground bulge on the ground surface is reduced, or the upper restraint effect allows a reliable improvement below it.

  In addition, in order to eliminate soil moisture in the injection of this ground injection material into the ground, drainage material for drainage is also provided, and intermittent drainage effect (injection is suspended) It is possible to promote the side consolidation dehydration effect of the ground by dehydrating during the operation, or to accelerate the dehydration of the plastic injection material (application of this drain material is suitable for the strengthening of the soil of the cohesive soil layer) ).

  Alternatively, drainage pipes are installed to remove groundwater and increase the speed of consolidation. By providing a water inlet in addition to the outlet on the side of the pipe, the drain effect can be achieved by sucking in excess water or soil water from the inlet through the inlet while pressing the inlet from the outlet.

  Furthermore, in order to measure changes in the ground uplift, etc., a sensor such as a laser measures the change in real time and grasps the amount of compression of the ground, or responds immediately when the change causes an abnormal design. The injection of plastic grout is adjusted, or the injection volume and injection depth are changed via the controller of the injection apparatus, or the specific gravity of the injection liquid, the injection volume, and the interval time are automatically switched. It is possible to move to another stage before the predetermined displacement is exceeded and to improve the ground strength by compaction dehydration as designed, and the above ground displacement measurement is the measurement of ground uplift on the ground surface In addition, a measuring rod with a strain gauge can be set in the ground to detect changes in the ground part in the measuring direction, and a pore water pressure gauge is installed in the ground to understand the consolidation dehydration status. I can do it.

  In this invention, when the ground injection material is pressed into the soft ground at a low speed from the injection tube, the flowable plastic gel expands the range of the bulk gel while the injection pressure is applied. In the part, the water content of the grout is reduced by dehydration to the surrounding soil particles due to the injection pressure, the fluidity is lost, and the plastic gel is changed to the non-plastic gel. In this way, the density of soil between the injection holes is increased, the strength of the ground is increased, and the ground is strengthened. The injection hole interval is effectively 0.5 to 3.0 m depending on the quality, the target improvement degree, and the size of the soil cover.

  Next, the present invention will be described with reference to FIG. In this case, as shown in FIG. 6A, the rod injection tube is used to sequentially inject from the bottom to the top or from the top to the bottom. Alternatively, a double pipe double packer injection outer pipe may be installed to inject from the inner pipe through a plurality of discharge ports. In this case, it is preferable for enlarging the gelled product to move the stage so that the discharge port is located in a range in which the plastic gel in the ground is in a state before becoming the non-plastic gel.

  FIGS. 6 (b) and 6 (c) show the basic mode of the interval method, in which a predetermined soft ground 3 and a predetermined number of holes 4 are formed in a lateral direction with a predetermined pitch in the same manner as a conventional mode. Forming at a depth, inserting the injection tube 9 into the drilling hole 4, while converting the suspension type plastic grout from the injection device (not shown) on the ground to a predetermined stage of the injection tube 9 by a predetermined time lag, The injection is performed continuously, and is repeated through a predetermined step-up or step-down, and the injection is repeated for each zone of the ground 3 in a chasing manner. In this case, an injection tube rod may be used as the injection tube, or injection may be performed by inserting the injection inner tube into the outer injection tube and moving the injection stage.

  In this case, the injection in each cycle is performed at a low pressure so as not to deviate in the initial stage of the injection, and is performed while draining the ground 3 or dehydrating the injected liquid, and after a predetermined timing. When the pumping is stopped, the fluidity is lost and solidified with time as described above, and the ground injection material to be injected later pushes the plastic gel formed in advance from the inside to the side, and the upper ground direction Injected in a laterally polymerized manner without deviating from the above, consolidating and dehydrating the lateral ground, and dehydrating the external part of the injection site to cure with a hardened plastic gel A band is formed, and the plastic gelled material by the ground injection material for post-injection overlaps to increase into a large lump.

  In this case, a predetermined number of holes 4 are formed at predetermined intervals in the horizontal direction in a predetermined area of the ground 3, and injection pipes 9 are individually inserted into the respective holes, and the valve 5 and the pump are set at a predetermined time lag. Then, the ground injection material is formed in parallel in the horizontal direction by shifting the injection timing for the drilling hole 4 through the computer through a predetermined program by the controller 6 having a computer. For the drilled holes 4, the entire ground is consolidated in the lateral ground of the adjacent holes 4 by injecting the ground injection material by the interval method with a predetermined time lag through the valve 5 and the controller 6. As a result, the strength of the ground can be improved over the entire area.

  That is, when a large amount of the main soil injection material is pressed into the improved ground at once through the injection hole, the surrounding soil is destroyed before the sufficient range is compacted or the ground is raised. However, when the total injection volume is divided and press-fitted at intervals, because it is plastic, the flow stops due to interruption of the injection and is held in that position, and the surrounding soil is dehydrated and the plastic grout is dehydrated. Thus, the size of the solidified body by the massive plastic gel grows sequentially, and the columnar solidified body and the composite ground having an increased density sandwiched between the columnar solidified bodies are obtained.

  Of course, in this mode, by taking a predetermined interval method, it is possible to return to the initial drilling hole 4 after making a round of all the drilling holes 4 at a predetermined timing. In the injection of the board injection material, the formed mass of the plastic gel is solidified and maintains a compacted state with respect to the ground 3. In other words, when a large amount of the main soil injection material is pressed into a predetermined area at once through the injection hole, the improved ground will be destroyed before the surrounding soil is compacted to a sufficient extent. When it is pressed in at intervals, the flow is stopped by the interruption of pouring because it is plastic, and it is held at that position, and the surrounding soil is given time for consolidation dehydration and time for dehydration of the plastic gel, and then the bulk plasticity The size of the consolidated body due to the gel grows, and a composite ground of a columnar consolidated body and an increased density region sandwiched between the columnar consolidated body is obtained.

  For this reason, the injection pressure produces a consolidation action in the lateral direction rather than acting on the ground uplift. In addition, due to the function of the plastic gel injected at a predetermined time lag in the axial direction upward of the drilling hole 4, the displacement is more likely to occur in the horizontal direction than in the vertical direction, and therefore, the upward protrusion of the ground 3 can be avoided.

  7 and 8 show that a plastic gel of a primary injection material is injected into a flow path, and a solution type silica grout or suspension type grout as a secondary injection material from the other flow path, or a gelling time and a plasticity holding time. It is possible to inject a plastic grout that is longer than the primary injection. The plastic gel of the primary injection material coarsely packs the gap around the outer injection tube and the rough portion of the injection stage, and the secondary injection material penetrates into fine portions in the ground. By providing the outer sleeve rubber sleeve at an interval, it is possible to inject gradually from a deep part to a shallow part.

  Also, when the secondary injection material deviates and creates an escape route to the upper part, conventionally, in order to wait for the secondary injection material to consolidate, the injection was stopped for about a day, and the secondary injection material in the escape route solidified. After that, the injection was resumed, but in the present invention, by switching to the plastic gel of the primary injection material and injecting it, it was possible to easily block the escape path and prevent the deviation of the secondary injection, and waited for the primary injection material to solidify. Even if it is not, it can be injected again, the process can be shortened, and the secondary injection material can be reliably infiltrated into the ground.

  In FIG. 7, after the primary injection of the plastic grout, the injection inner tube is pulled up while repeating the secondary injection of the permeable silica grout. Further, when the secondary injection material deviates to the ground surface during the injection, if the primary injection material is injected, the deviation flow path of the secondary injection material can be blocked to prevent the deviation.

  In FIG. 8, the injection of the secondary injection material after the injection of the primary injection material is repeated while pulling up the injection stage. Alternatively, if the secondary injection deviates to the ground surface during the injection, the primary injection material is injected to close the deviation flow path of the secondary injection material.

Method of injecting while changing the fluidity As a method of injecting according to the ground conditions while changing the fluidity of the fluid plastic gel, after injecting a plastic gel with low fluidity, Although the fluidity of the previously injected plastic gel is lowered by the press-fitting, the fluidity comes out by the press-fitting of the subsequent injection material, and can be press-fitted into a fine part in the ground.

  Also, by sending a plastic gel with high fluidity first and then sending a plastic gel with low fluidity, the plastic gel injected earlier is press-fitted into a fine gap, expanding the press-fitting range and press-fitting. By dehydrating, the fluidity is lowered, so that the deviation of the plastic gel having high fluidity can be prevented.

  In the method using the injection device of FIG. 9, components (1) and (2) and (4), or (1) and (4), or (2) and (4) are injected from one tube. By injecting (2) or (3) from one tube and mixing in the tube, the fluidity can be adjusted and the plastic gel can be injected. Moreover, fluidity | liquidity can also be adjusted by mixing (3) with the liquid mixture of any flow path.

  Furthermore, using the injection device of FIG. 9, the plastic gel can be injected as liquid A from one tube, and liquid B can be injected from the other tube, mixed in the tube, and injected. It is possible to adjust the gelation time and fluidity retention time and to inject the plastic gel by adjusting the feeding amount of the liquid A and the liquid B and changing the blending ratio.

  In the above, the plastic gel is fed from one flow path and injected into the ground, and the permeable grout is injected from the other flow path at the same time or with a time difference, thereby having different permeability. The injection material can be used in combination.

Injecting the injection material according to the injection area In addition to injecting the primary injection and the secondary injection in the same ground as shown above, injecting the plastic gel and the secondary injection material into the adjacent ground area With this, an effective effect can be obtained.

  In the existing revetment as shown in FIG. 10 and FIG. 11, the tide level tidal causes a suction phenomenon of the back of the revetment from the deficient portion of the suction prevention, resulting in the subsidence and inclination of the revetment and further the depression of the road surface. .

  At this time, in the repair work of the defective part, the secondary injection is performed by injecting plastic gel as a primary injection material into the defective part of the sheet, and then blocking the sheet defective part roughly to intensify the details of the ground. It is possible to prevent dilution of the material by surrounding water such as seawater, and to prevent a decrease in the concentration of the injected drug solution by conventional fluidized water.

  At this time, the plastic gel used for the primary injection material is dehydrated under pressure in the ground using a quick setting compound, and rapidly solidifies, so that only the rough part and the surface of the stone are consolidated. It easily breaks up and down, and even if it is hardened with osmotic silica liquid by backfilling, its strength is weak.

  However, by using a flowable plastic grout, it is possible to gradually expand the range of the bulk gel during the plastic holding time and accompany dehydration. Because of solidification through non-plasticity due to the shortening of the length and the decrease in the plastic holding time, the voids can be filled firmly.

  In the present invention, when a solidifying material having different permeability is used in combination and injected into the ground, and when the ground is consolidated, a silica-based non-curable powder (F material) and Calcium-based powder hardening material (C material), fluidity adjusting material (A material), and fluid plastic gel injection containing water (W material) as an active ingredient in addition to the F material, C material, and A material. Since the material is used and loses fluidity over time or due to dehydration, a mass of the injected material itself is formed in the ground, so that the soil particles fill the voids in the ground or expand in the ground. It is intended to constrain the ground by pushing to the periphery and to strengthen the ground by using a ground-solidifying material with better permeability, and is highly likely to be used in the field of civil engineering and construction.

It is a graph showing the difference of the breathing rate by the presence or absence of a sulfuric acid band. It is a graph showing the difference of the initial viscosity by the presence or absence of a sulfuric acid band. It is a graph showing the difference in strength expression by the presence or absence of a sulfate band. It is a ground reinforcement model diagram by plastic grout press-fitting, (A) is a column cross-sectional view showing the arrangement of consolidated bodies by plastic grout in the area to be improved, (B) and (C) are plan views and plastic injection material FIG. (B) is a square layout, and (C) is a triangular layout. In a double pipe compound injection construction method, it is explanatory drawing of the construction method which uses a plastic gel for primary injection, and uses a solution type non-alkaline silica grout for secondary injection. (A) is a cross-sectional view of a mode of pull-up injection from the bottom to the top with a rod injection tube of plastic gel drilled adjacent to the ground in a predetermined area, (b) is adjacent to the ground in the predetermined area It is a cross-sectional view showing an example in which an outer injection tube is installed and a plastic gel is press-fitted from the injection inner tube, and is a cross-sectional view of an embodiment according to the interval method while switching the valve 5 from one pump. c) is a cross-sectional view showing the effect of reinforcing the tensile strength of the injection tube with the high density body of the ground by solid, forming a solidified body with a plastic gel at intervals between the predetermined installation of the injection tube with tensile strength. is there. In the double pipe double packer method, the composition 1 of the example of the plastic gel is used as the primary injection material, and the secondary injection material is an explanatory diagram of the method using the solution type non-alkaline silica grout shown in Table 1. It is explanatory drawing of the construction method which injects through an external rubber sleeve. It is explanatory drawing of the construction method which changes the fluidity | liquidity of a plastic gel using a double pipe double packer. In the method of injecting plastic gel and secondary injection into the backfill soil along the waterproof sheet, an explanatory diagram of the method of injecting the plastic gel around the damaged part of the waterproof sheet and waterproofing, then performing the secondary injection It is. In the method of injecting plastic gel and secondary injection into the backfill soil in the dampening prevention sheet deficient part of the revetment, injecting the plastic gel around the damaged part of the waterproof sheet and waterproofing, then secondary injection It is explanatory drawing of. It is a graph showing the relationship between a table flow and a cylinder flow.

Explanation of symbols

3 Ground 4 Drilling 5 Valve 6 Controller 7 Computer 8 Rubber sleeve (check valve)
9 Injection tube

Claims (16)

It is a ground consolidation method of injecting into the ground in combination with a consolidation material with different permeability, as a consolidation material with poor permeability among the consolidation materials with different permeability,
(1) Silica-based non-curable powder (F material)
(2) Calcium-based powder hardening material (C material)
(3) Fluidity adjusting material (A material)
(4) Water (W material)
Among them, (1) and (2) and (4) or (1) and (2) and (3) and (4) are included as active ingredients,
The table flow during press-fitting is 12 cm or more and less than 30 cm, and / or the slump is greater than 5 cm and less than 28 cm, and / or the flow through the cylinder is greater than 8 cm and less than 28 cm, and is plastic before or during press-fitting into the ground Using a flowable plastic gel injection material that reaches the gel, try to infiltrate between soil particles with a solidified material with better permeability, that is, an injection material with better fluidity and permeability than the flowable plastic gel injection material. integrated soil, permeability of bad caking material, i.e. to densify constrain surrounding ground to form a bulk solid sintered by variable塑状gel by the flowable plastic gel grout A characteristic ground consolidation method. According to claim 1, wherein the plastic-like gel injection material, Ri optimum plasticized gel within percent dehydration rate 30, in soil lost its fluidity by dehydration to form a bulk body, surrounding ground which is equal to or more than the Ground consolidation method that is an injection material that develops strength . The ground consolidation method according to claim 1 or 2, wherein the interval between the injection holes is 0.5 m to 3 m and the ground density between the injection holes is increased to strengthen the ground. In any one of claims 1 to 3, the silica-based non-hardening powdery material (F material) fly ash, slag, ash, one of the powdery material and / or clay or sand through the firing process Ground consolidation method as an active ingredient. The ground consolidation method according to any one of claims 1 to 4, wherein the calcium-based powdery hardening material (C material) is one or more selected from the group consisting of cement, lime, gypsum, and slag.
However, slag is excluded from a hardening expression material, when a non-hardening powdery body is slag. The ground consolidation method according to any one of claims 1 to 5, wherein the plastic gel injection material is 1 to 40 weight percent in the ratio of the cured material.
However, hardening expression material ratio = C / (F + C) × 100 (%), and F and C both indicate weight. The ground consolidation method according to claim 6, wherein the plastic gel injection material is less than 1 to 20 weight percent of the ratio of the cured material. The ground consolidation method according to any one of claims 1 to 7, wherein the plastic gel injection material has a water body ratio of 20 to 200 weight percent.
However, the water body ratio = W / (F + C) × 100 (%), and F, C, and W all indicate weight. The plastic gel injection material according to any one of claims 1 to 8, wherein the plastic gel injection material is a flow of a gelation accelerator, a gelation retarder, a thickener, a water retention material, a peptizer, a foaming agent, or a fluidizing material. ground consolidation method comprising the additive of either sex adjustment member. In Claim 9 , the fluidization adjusting material is mixed with the plastic gel injection material in advance and press-fitted into the ground, or the injection of the plastic gel injection material and the combined injection of the plastic gel injection material and the fluidity adjustment material are performed. Ground consolidation method that is used together and injected into the ground. The plastic gel injection material according to any one of claims 1 to 10, wherein the plastic gel injection material contains aluminum salt as an additive in an aluminum ratio of 0.1 to 3.0 weight percent, or water glass or a mixture of water glass and acid is silica. Is a ground consolidation method containing 0.2 to 7.0 weight percent in terms of concentration SiO ₂ .
However, the aluminum ratio = aluminum salt / (F + C) × 100 (%), where the aluminum salt represents weight. According to claim 9, clay fluidity adjusting agent, silt, polymeric thickeners, soil consolidation method comprising any of the water-absorbing resin. In any 1 paragraph of Claims 1-12, an injection pipe with a plurality of injection passages is installed in the ground, and the fluid plastic gel (consolidation material with poor permeability) is introduced from one injection passage. ) was injected, the air gap and the injection pipe rough areas around the periphery injection tube and stuffing in bulk consolidation body by plastic gel, injected into the soil caking material the better permeability of the other flow path A ground consolidation method that integrates the ground by interparticle penetration . In any 1 paragraph of Claims 1-12, the injection pipe which consists of an injection outer pipe and an injection inner pipe is installed in the ground, and the fluid plastic gel is rough around the injection pipe or around the injection pipe from the injection inner pipe. A ground consolidation method in which it is injected into a part to form a massive consolidated body of plastic gel . In any one of claims 1 to 14, of the permeability of different caking material, permeability good towards caking material is ground a suspension type grout or silica-based solution type grout caking Law. In any one of Claims 1-12, the hardening expression material added to slag is less than 50 weight% in the powdery raw material to be used, and a water powder contrast is 20 to 200 weight%, and the case where a gelling accelerator is added Is a table flow of 12 cm or more and less than 30 cm by mixing an aluminum salt with an aluminum ratio of 0.1 to 3.0% by weight with respect to the total amount of powder contained in the pouring material, gel time is within 3 minutes to several hundred minutes, The ground characterized in that the plastic holding time is from several hours to 10 hours or more, the breathing rate is within 10%, the slump is greater than 5 cm and less than 28 cm, and the flow through the cylinder is greater than 8 cm and less than 28 cm. Consolidation method.

Images