JP6371024B1 - Method of injecting quick-setting hardened grout - Google Patents

Abstract

Using a pumping device equipped with a delay timer, time adjustment of liquid A and liquid B at different discharge speeds is performed by proportional injection, and both liquids are merged at the tip of a double tube or liquid B in advance. Provided is a method of injecting an instantaneous setting curable grout capable of being injected. SOLUTION: Liquid B is mixed with liquid A at a ratio of 130 to 200 L with respect to 1 m 3 of liquid A, the gelation time is within 25 seconds, and the uniaxial compressive strength after 3 hours is 1.5 N / mm 2 or more. In the method of injecting instant setting hardened grout, a delay timer using a pumping device in which the pumping capacity of the pumping pump, the inner diameter of the pumping hose, and the cross-sectional area of the double pipe are smaller in the liquid B than in the liquid A By delaying the start of the operation of the pump of the A liquid from the start of the operation of the pump of the B liquid, the time for the liquid A and the liquid B to reach the tip of the double tube is made simultaneous. Adjust to, and inject a quick-setting hardened grout. [Selection] Figure 1

Description

  The present invention relates to a method for injecting instantaneous hardened grouting for injecting instantaneous hardened grouting as ground injection or cavity filling injection, and a pumping device for instantaneous hardened grouting to be used therefor.

  Immediate hardening hardening grout is injected into soft ground, river embankments, earth structures such as ponds, rocks, etc. It is divided into grout injection for water (hereinafter referred to as ground injection) and grout injection (hereinafter referred to as cavity filling injection) for filling subsurface cavities such as roads and railways.

  Since the ground injection and the cavity filling injection have different application purposes and different requirements, the items are described separately.

[Ground injection]
First, the prior art of the chemical | medical solution (henceforth grout) which combined the cement and water glass of the ground injection regarding this invention is described. In Patent Document 1, water glass and a grout containing about 0.01 to 0.4 cement of water glass undiluted solution are separately pumped, merged as close as possible to the tip of the injection tube, and immediately injected and consolidated. An injection method using water glass and cement is disclosed (refer to the claims of Patent Document 1).

The injection method described in Patent Document 1 is a method in which a small amount of cement (60 to 70 kg per 1 m ³ ) is added to water glass, and the gelation time (hereinafter referred to as gel time) is 10 to 20 minutes. It was intended to penetrate into. However, it was never put into practical use.

  As a practical application, for example, in Non-Patent Document 1, as a liquid A, a total of 500 L obtained by adding water to No. 3 water glass 200-250 L, and as a liquid B, a total of water added to 200-250 kg of cement A water glass suspension grout mixed with 500 L is disclosed (see pages 13, 26, 40, 77, etc. of Non-Patent Document 1).

The water glass suspension grout described in Non-Patent Document 1 is a grout having a long gel time of about 1 minute, generally called LW, and a homogel strength of about 3 N / mm ² (age 28 days). In addition, it was used for the purpose of stopping water and strengthening the ground as infiltration of large gaps such as gravel layers and splitting (veiling) injection into viscous soil layers.

  In addition, when injecting grout into sandy soil, if the content of silt and clay is 10% or more, even if it is solution type grout, it cannot be infiltrated between soil particles and injected in a split shape (split the ground layer). To inject while).

  This water glass suspension grout is used as a ground pouring method, water glass is used as liquid A, cement is used as a curing agent (liquid B) for gelling water glass, and the main component is water glass. It is a grout that has been put into practical use from the same technical idea as in Patent Document 1.

  However, LW is based on the principle that liquid A and liquid B are injected in equal amounts, the gel time is short and cannot be instantly set, and the rising strength after gel (early strength development) is very high. There was a difficulty of being weak. For this reason, the plastic solidification after gelation and the subsequent rising strength are very weak, and even after gelation, it is pressed into the distance by an infusion pump (a constant amount discharge regardless of the infusion pressure) and remains within the limited range. I couldn't.

  Thereafter, an instantaneous setting method was developed, and an instantaneous setting grout in which a gelation accelerator such as lime was added to LW was produced, but the rising strength after gelation was not improved so much and LW was not significantly different. The reason is that the rising strength immediately after gelation is entirely governed by the gelation strength of water glass, and it takes a long time (about 5 to 8 hours) for the cement to start hardening.

  As described above, in the conventional technique, since the rising strength after gelation cannot be increased, there is a great difficulty in that the injection cannot be performed in a limited range. For this reason, at present, LW is hardly used.

[Cavity filling injection]
Next, the prior art of cavity filling injection relating to the present invention will be described. Patent Document 2 filed in 1979 discloses a plastic grout using thixotropic gel based on a completely new concept as a cavity filling (backfill) injection method (Patent Document 2 Patent Request) Refer to the scope of In addition, the plastic grout here has a strength enough to be self-supporting in a stationary state, but a consolidation strength (mayonnaise) that can be easily fluidized when pressurized (added with injection pressure). Is a grout.

  Unlike the above-described LW, the plastic grout described in Patent Document 2 is a so-called main agent (liquid A), and a small amount of water glass (liquid B) is added at a high concentration as a hardener that gels a large amount of cement. The principle is to use the proportional injection method.

Patent Document 3 includes a liquid A which is a cement suspension and a liquid B which is a water glass aqueous solution, and the water glass concentration in 1 L of the liquid B is 20% by weight or more based on SiO _2. A grout material is disclosed, characterized by mixing both AB liquids in such a ratio that the amount of SiO _{2 in} the liquid is about 3.5 to 9 g with respect to 100 cc of the volume of the mixed liquid of A and B. (Refer to claim 1 etc. of claim of patent document 3). The grout material described in Patent Document 3 is intended to shorten the gel time by adding a small amount of a high-concentration B liquid to the A liquid.

Then, Patent Document 4, consists of a liquid B is A liquid and water glass solution is cement suspension, water glass concentration in solution B 1L is in the range of about 160~320g in an amount of SiO ₂ The ratio AB both liquids are mixed so that the amount of SiO ₂ derived from B liquid is about 0.6 to 3.5 g with respect to 100 cc of the volume of B liquid and the volume of water in A liquid. A grout injection method characterized by injecting a grout material is disclosed (see claims of Patent Document 4). The grout injection method described in Patent Document 4 has an advantage that early strength can be obtained, and has a property superior to that of LW in which A liquid and B liquid are mixed and injected in equal amounts. .

Further, Patent Document 5 discloses, as Examples 16 to 21, a grout material containing 200 to 400 kg of cement per 1 m ³ of grout and S / W × 100 ÷ √C of 0.19 to 0.46. Yes. Here, S is the weight of SiO _{2 in} the water glass, W is the remaining capacity excluding SiO ₂ and Na ₂ O in the water glass, and C is the weight of the cement (the claim of the patent document 5) Item 1, Table 4, etc.). The grouting material described in Patent Document 5 is capable of obtaining a higher strength than the grouting material used in the grouting method described in Patent Document 4.

  However, although the grouting material and the grouting method described in Patent Document 5 are excellent in the expression of early strength, they have not been put into practical use until now. The reason is that a large amount of cement is required to extremely enhance early curing, and the amount of water glass as a curing agent must be increased accordingly. Then, the gel time is short and the plastic holding time (injectable time) after the gel becomes extremely short, deviating from the practical range where grout injection can be performed, and the grout injection work cannot be performed. Because there was a problem.

  In order to solve this problem, it is necessary to ensure a practical gel time capable of injection filling up to the filling range where the grout material should be injected together with the development of early strength. However, it is possible to extend the pot life by adding a retarding agent to the cement milk (liquid A), which is the main ingredient, but the problem of the retarding effect disappearing if water glass is added to this. There is. For this reason, at present, even if any additive is added, it has been impossible to solve the trade-off between the expression of early strength and the securing of practical gel time.

As a means for solving this problem, the present invention injects an instantaneous setting hardened grout having a uniaxial compressive strength of 1.5 N / mm ² or more after 3 hours within a gelation time of 25 seconds beyond a limited range. Proposed injection method that can be.

  In addition, the plastic grout using patent documents 2 to 4 is widely used as a back-filling material for shield tunnels (approximately 100%), and its construction method is described in non-patent document 1 (non-patent document). (Refer to P77 of Literature 1).

  That is, in the shield tunnel, the B liquid (water glass) is injected by a proportional injection method of 0.07 to 0.1 volume part with respect to 1 volume part of the liquid A (main component cement). Although the pump discharge volume, the size of the pumping pipe, and the discharge speed differ greatly, the arrival of liquid A and liquid B at the injection point (the grout hole in the segment before the shield machine) is manually checked and communicated with the plant. This is because even the proportional injection can be injected without any problem.

  However, since the conventional quick setting hardened grout is proportional injection of B liquid (water glass) with respect to A liquid (cement milk), the discharge speed of A liquid and B liquid differs greatly. is there. In addition, since both the above-described ground injection and cavity filling injection are performed by installing a double pipe below the surface of the earth, there is a problem that the discharge speed of the liquid A and the liquid B cannot be easily visually confirmed on the ground. It was.

  As a method of visually confirming the discharge speeds of the liquid A and liquid B, the pump of the liquid A is pumped when the liquid A reaches the tip of the injection hose by manually turning the pump ON / OFF at the tip of the injection hose. Can be considered, and when the liquid B arrives later, it is connected to a double pipe and injected. However, this method has a big problem that it is very complicated and the work efficiency is poor.

  The ground injection of the present invention is intended to inject into a limited range by shortening the injection possible time (gel time + plasticity holding time) as compared with cavity filling injection.

Japanese Patent Publication No. 36-24122 Japanese Patent Application Laid-Open No. 08-239255 Japanese Patent Publication No. 02-4634 Japanese Patent Publication No. 02-43790 JP 2000-290651 A

Goshiro Miki and Kazuo Shimoda, “Plastic grout injection method”, Nikkan Kogyo Kogyo Shimbun, July 20, 2001, p26, 40, 77

  Therefore, the present invention has been devised to solve the above-mentioned problems, and the object of the present invention is to use a pumping device equipped with a delay timer, and a liquid A having different discharge rates by proportional injection and A method for injecting instantaneous hardened grout capable of adjusting the time of the B liquid and simultaneously injecting both liquids at the tip of the double tube or by bringing the B liquid in advance, and a pumping device for the instantaneous hardened grout used therefor Is to provide.

In the method of injecting an instantaneous setting hardened grout according to the first invention, a liquid B of water glass having a volume of SiO ₂ of 24% or more is added to a liquid A of cement milk containing 500 to 1000 kg of cement per 1 m ^3. In a method of injecting an instantaneous setting cured grout that is mixed at a ratio of 130 to 200 L with respect to 1 m ^{3 of} liquid and gelation time is within 25 seconds, and uniaxial compressive strength after 3 hours becomes 1.5 N / mm ² or more. The liquid B is more pumped than the liquid A using a pumping device having a smaller pump discharge capacity of the pressure pump, the inner diameter of the pressure feed hose, and the cross-sectional area in the double pipe, and the pressure pump of the liquid A by a delay timer. Is delayed from the start of the operation of the pump for pumping the B liquid, and adjusted so that the time for the liquid A and the liquid B to reach the tip of the double pipe is the same, so Features injecting grout To.

According to the first aspect of the present invention, it is easy to manage the construction without manpower, and the instantaneous setting hardened grout can be injected into a limited range of the ground. For this reason, it is possible to strengthen the ground by forming a ground compaction or a strong grout consolidated body at low cost.
Also, the pump is turned on and off manually by the tip of the injection hose. When the liquid A reaches the tip of the injection hose, the pump of the liquid A is stopped, and when the liquid B reaches later There is no need to do this by connecting to the tube. Therefore, the work efficiency is very good, the number of workers can be greatly reduced, and the construction cost of the grout injection work can be greatly reduced.

It is a structure explanatory view showing typically the composition of the pumping device concerning the embodiment of the present invention. It is a figure which shows the pump automatic operation panel of a pumping apparatus same as the above, (a) is the front view seen from the outside, (b) is an internal block diagram which opens an opening-and-closing door and shows the internal structure of an operation panel.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an instantaneous curing grouting pump according to an embodiment of the present invention and an instantaneous curing grouting method using the same will be described in detail with reference to the drawings.

<Principle of gelation / hardening of quick setting hardened grout>
First, the gelation / curing principle of the instantaneous setting cured grout used in the method for injecting the instantaneous setting cured grout according to the embodiment of the present invention will be described. The method of injecting the instantaneous setting hardened grout according to the present embodiment is a two-component injection method in which cement milk is used as the A solution and the water glass solution is used as the B solution. Such a two-component grout becomes a sol when the liquid A and the liquid B are mixed, the viscosity increases with the passage of time, the fluidity is lost, and the gel is formed. The time from mixing the two liquids to gelation is the gel time.

  The gelled grout gradually increases in strength after gelation and reaches curing through a plastic consolidated region (plastic holding time). This plastic consolidated region is a cement-type grout (cement milk) and must pass through before any grout is cured (see p. 26 of Non-Patent Document 1, FIG. 3.1).

  Therefore, the time during which the two-component grout can be injected is the sum of the gel time and the plastic holding time (hereinafter referred to as plastic time). Accordingly, a grout having a sufficient plastic time (for example, 10 to 20 minutes) is particularly referred to as a plastic grout.

However, when plastic grout is made into an extreme wrinkle formulation, for example, an instantaneous setting hardened grout with a uniaxial compressive strength of 1.5 N / mm ² or more after 3 hours, the plastic time becomes extremely short, within 10 seconds. End up. For this reason, the time for which the conventional quick-setting hardened grout can be injected has been limited to about 35 seconds even when the plastic time and the gel time are combined.

  Specifically, when the instantaneous setting grouting is injected and filled at 30 L / min, the amount that can be injected in 25 seconds is 12.5 L. If such a quick-setting hardened grout is used for ground injection, it can be injected in a limited range and can be prevented from running away to an unnecessary distance.

  On the other hand, when the instantaneous setting hardened grout is used for filling the cavity, the cavity area is wide and a large amount is required per one place. For this reason, if the injection is continued even after the injectable time has elapsed, the grout is hardened and the pressure rises. For example, in the case of injection into a cavity under the road surface, a board bulge is caused.

  Therefore, when using the quick setting hard grout for cavity filling injection, it is performed in an injection form that can be injected far away by the injection method described in Japanese Patent Application No. 2017-109712 (unpublished) filed by the present inventor.

  In addition, the injection method of the ground injection and the cavity filling injection is not particularly distinguished, and any of the injection methods according to the purpose such as the case of injecting far away by ground injection or the case of filling a small cavity is appropriately used. Just inject.

<Instantaneous hardened grout>
Next, the instantaneous setting hardening grout used for the injection method of the instant setting hardening grout which concerns on this embodiment is demonstrated. The basic formulation of the instantaneous setting cured grout used in the method for injecting the instantaneous setting cured grout according to the present embodiment aims to have a uniaxial compressive strength of 1.5 N / mm ² or more after 3 hours. As a result, the gelation time of the instant hardenable grouting is inevitably within 25 seconds.

Specifically, cement milk obtained by dissolving cement prepared in a range of 500 to 1000 kg per m ³ in water is used for the liquid A as the main agent. The cement to be used is not particularly limited, but ordinary portland cement, blast furnace cement, early-strength cement and the like are preferable.

  Moreover, you may add the additive which may be added to a normal grout material to A liquid. For example, as additives, slag, fly ash, lime, dispersant (retarding agent), foaming agent, primary minerals such as fine powdered limestone and rock, clay minerals such as bentonite, fillers, and the like can be used.

The B water glass has a SiO ₂ capacity of 24% or more, preferably 30 to 35%, and the molar ratio (SiO ₂ / Na ₂ O) is preferably 3.0 to 4.0. This B liquid is adjusted and mixed within the range of the ratio of 130-200L with respect to 1 m < ³ > of A liquid. For example, 30% concentration water glass refers to water glass containing 300 g of SiO _{2 in} 1 L of solution.

<Pressure feeding device>
Next, with reference to FIG. 1, an instantaneous curing grouting pumping device according to an embodiment of the present invention will be described. FIG. 1 is a configuration explanatory view schematically showing the configuration of the instantaneous curing grouting pump according to the embodiment of the present invention.

  As shown in FIG. 1, the instantaneous curing grouting pump 10 according to an embodiment of the present invention includes two water storage tanks 1, 1 for storing the A liquid and B liquid of the above-mentioned instantaneous curing grouting, respectively. ', Two pumping pumps 3, 3' for pumping them, a pumping hose (pressure hose 4, 4 ') connecting them, a double pipe rod 5 embedded in the ground, and pumps 3, 3 It is composed of an automatic pump operation panel 20 that automatically controls'. This pumping device 10 is a device that divides the above-mentioned instantaneous setting hardened grout into A liquid (cement milk) and B liquid (water glass) and injects them into the ground or fills the cavity.

  The pumping device 10 according to this embodiment is different from the conventional pumping device in the pump automatic operation panel 20 and other configurations are the same as those in the prior art. Therefore, the pump automatic operation panel 20 is mainly used. Will be described.

As described above, the pressure feeding device 10 according to the present embodiment has an extremely high volume ratio of the two liquids that are adjusted and mixed within the range of the ratio of the B liquid 130 to 200 L with respect to the A liquid 1 m ³ . The principle (premise) is to perform proportional mixing in different states.

  For this reason, as described above, the conventional pumping apparatus has a problem that a time difference occurs until the tip of the double tube rod 5 is reached due to the difference in the discharge speed between the liquid A and the liquid B. In the pumping apparatus 10 according to the present embodiment, this problem is solved by a delay timer described later of the pump automatic operation panel 20.

(Pressure pump)
The pressure feeding device 10 includes a water storage tank 1 storing A liquid and a suction hose 2 (pressure hose) connected to the A liquid pressure feeding pump 3, a water storage tank 1 ′ storing the B liquid, and a suction hose 2. Two pumps, “a pump 3 for pumping B liquid pressure” connected via “(pressure hose)”, are provided.

  The pressure pump 3 ′ for feeding the B liquid pressure is smaller than the discharge capacity of the pressure pump 3 for feeding the A liquid pressure. Specifically, when the discharge capacity of the pressure feed pump 3 for A liquid pressure feed is 15 L / min, the discharge capacity of the pressure feed pump 3 ′ for B liquid pressure feed is 2.0 to 3.0 L / min. Of course, it is needless to say that the pump capacities of the two pumps may be any as long as the discharge capacities can be adjusted within the above range.

  In the conventional pumping apparatus, normally, the capacity of the two pumps used is one that discharges the same amount per fixed time regardless of the level of the pumping (injection) pressure.

(Pressure hose)
The pressure feeding hose used in the pressure feeding device 10 is a pressure resistance connecting the suction hoses 2, 2 'connecting the water storage tanks 1, 1' and the pressure feeding pumps 3, 3 ', and the pressure feeding pumps 3, 3' and the double tube rod 5. It consists of hoses 4 and 4 '.

  In these suction hoses 2 and 2 ′, the hose connecting the water storage tank 1 storing the A liquid and the pressure feeding pump 3 for A liquid pressure feeding is the suction hose 2, and the water storage tanks 1 ′ and B storing the B liquid. A hose connecting the pressure-feeding pump 3 ′ for pressure-feeding is the suction hose 2 ′.

  On the other hand, the pressure-resistant hoses 4 and 4 ′ are pressure-resistant hoses 4 that connect the pressure-feed pump 3 for liquid A pressure-feeding and the outer tube 6 of the double tube rod 5, which will be described later. A hose connecting 'and an inner tube 7 to be described later of the double tube rod 5 is a pressure hose 4'.

  The size of the pumping hose used in such a pumping apparatus 10 is ideally a cross-sectional area corresponding to the ratio of the pumping capacity per unit time of the A liquid and the B liquid. However, at present, the mixing ratio is not always the same, and a pressure feeding hose having a cross-sectional area corresponding to the ratio of the liquid A and the liquid B is not used. That is, in the conventional pumping device, taking into account that the pumping ratio (discharge amount) of the B liquid to the A liquid changes, the cross-sectional area of the pumping hose is a cross-sectional area corresponding to the ratio of the A liquid and the B liquid. It can be said that there is no entity.

As a conventional example, if the pressure feeding pump for liquid A pressure feeding is about 10 L to 30 L / min, the pressure feeding hose (pressure hose 4) is generally cut to 1/2 inch (φ12.7 mm). Those having an area of 126.6 mm ² ) are used.

Here, for example, when the discharge amount of A liquid per hour is 15 L / min, the discharge amount of B liquid needs to be at least 2 L / min. When the discharge amount is 15 L / min using a 1/2 inch pressure feed hose (pressure hose 4), the pressure is 1.97 m / sec. Therefore, in order to set the discharge amount of the liquid B at 2 L / min, it is necessary to make the cross-sectional area of the pressure feed hose (pressure hose 4 ′) very thin below 16.9 mm ² . However, such a very thin pressure hose does not exist in the current commercial standard products.

In addition, the liquid B (water glass solution) is commercially available considering that the viscosity is high and the resistance pressure increases when the cross-sectional area decreases, and that the hose length is generally about 40 to 100 m. The standard product that can be selected is a 3/8 inch (φ9.525 mm, sectional area 70.8 mm ² ) pressure hose (pressure hose 4 ′).

  In other words, the discharge speed when a 3/8 inch pressure hose (pressure hose 4 ') is used for pumping the B liquid is 0.47 m / sec, compared with the discharge speed of the A liquid pumping 1.97 m / sec. It turns out to be very slow.

(Double pipe)
The double pipe rod 5 is a pipe material made of a rod-like double pipe having an outer diameter of 40.5 mm in which an inner pipe 7 is piped in an outer pipe 6. This double tube rod 5 is used by being inserted into a borehole drilled (excavated) in the ground or the like, and the A liquid and B liquid of the above-mentioned instantaneous hardened grout are divided into an outer tube 6 and an inner tube 7. It has a function as an injection tube that injects and joins at the tip 5a.

In the double tube rod 5 according to this embodiment, the cross-sectional area of the outer tube 6 that pumps the A liquid is 650 mm ² , and the cross-sectional area of the inner tube 7 that pumps the B liquid is 78.5 mm ^2. Yes. Therefore, the cross-sectional area of the inner tube 7 is smaller than the cross-sectional area of the outer tube 6.

  However, even if the cross-sectional area of the inner tube 7 is smaller than the cross-sectional area of the outer tube 6, as described above, the mixing ratio of the liquid A and the liquid B of the quick setting hardened grout is extremely different. The discharge speed of B liquid (pumping speed) will become slow from the difference in the discharge quantity of liquid and B liquid (pressure feed amount per time).

  That is, even when the instantaneous hardened grout is separately pumped using the double tube rod 5 in which the cross-sectional area of the inner tube 7 is smaller than the cross-sectional area of the outer tube 6, as described above, There is a problem that the liquid A reaches the tip 5a of the double tube rod 5 earlier than the liquid B.

  Specifically, when the discharge amount of the pressure pump 3 for liquid A pressure feeding is 15 L / min, the length of the pressure hose 4 is 40 m, and the length of the outer tube 6 (double tube rod 5) is 10 m, A The arrival time of the liquid at the tip 5a is about 20 seconds + 26 seconds = 46 seconds.

  On the other hand, when the discharge amount of the pump B 3 ′ for pumping the B liquid is 2 L / min, the length of the pressure hose 4 ′ is 40 m, and the length of the inner pipe 7 (double pipe rod 5) is 10 m, The arrival time at the tip 5a is approximately 85 seconds + 24 seconds = 109 seconds.

  For this reason, when the pumping device 10 according to the present embodiment is simply used to simultaneously drive and pump the pumping pump 3 for liquid A and the pumping pump 3 'for pumping B, the tip of the liquid B The arrival time to the part 5a is delayed about 60 seconds (1 minute) from the liquid A. Therefore, it is necessary to check the difference in the arrival time of the two liquids to the tip 5a and to operate the pressure feeding pump 3 for liquid A pressure feeding with a delay of about 60 seconds (1 minute).

  However, in actual sites, it is extremely cumbersome and causes human error to check the time difference between the two liquids reaching the tip 5a and to manually operate the two pumps 3 and 3 'with a time difference. There was a problem that it was easy work and construction management was difficult.

  Of course, the double pipe according to the present invention is not limited to the structure, shape, size (cross-sectional area), etc. of the double pipe rod 5 described above. In short, the double pipe according to the present invention is inserted into the borehole of the ground 8 and is installed under the ground surface 8a so that the liquids A and B of the instantaneous setting hardened grout can be joined and mixed at the tip. Any pipe material having a heavy pipe structure may be used.

  Moreover, when using a triple tube for the pumping of the quick setting hardened grout, two flow paths are used, and the cross-sectional area is smaller on the inner side than on the outer side.

(Pump automatic operation panel)
Next, an automatic pump operation panel 20 which is a characteristic part of the pressure feeding device 10 according to the embodiment will be described with reference to FIG. 2A and 2B are diagrams showing the automatic pump operation panel 20 of the pressure feeding device 10, wherein FIG. 2A is a front view seen from the outside, and FIG. 2B is an internal configuration diagram showing an internal configuration of the operation panel with the lid opened. .

  As shown in FIG. 2 (a), on the front side of the open / close door of the pump automatic operation panel 20, a main power lamp 20a that displays whether or not the main power is energized, and the above-described pump for pumping B liquid pressure. B hydraulic pump operation lamp 20b indicating whether or not 3 'is operating, and A hydraulic pump operating lamp 20c indicating whether or not the above-described A hydraulic pump 3 is operating. Etc. are provided.

  In addition, on the front side of the open / close door of the pump automatic operation panel 20, there are also provided an operation button 20d for starting the operation of the pressure pumps 3, 3 ', a stop button 20e for stopping the operation of the pressure pumps 3, 3', and the like. ing.

  As shown in FIG. 2B, the automatic pump operation panel 20 includes a breaker 21 for turning on / off the main power source, a B hydraulic pressure pump switch 22 electrically connected to the breaker 21, It is mainly composed of an A liquid pressure pump switch 23 electrically connected to the breaker 21, a delay timer 24, and the like.

  The breaker 21 is a magnet switch having the function of a breaker that cuts off the power supply from the power source in order to prevent leakage when a current of a certain level or more flows through the automatic pump operation panel 20.

  The B liquid pressure pump switch 22 is electrically connected to the above-described B liquid pressure pump 3 ′ and operates the pressure pump 3 ′ depending on whether or not the B liquid pressure pump 3 ′ is energized. Or it is a magnet switch which stops.

  The A liquid pressure pump switch 23 is electrically connected to the above-described A liquid pressure pump 3 via a delay timer 24, and determines whether or not the A liquid pressure pump 3 is energized. This is a magnet switch for operating or stopping 3 '.

  The delay timer 24 has an extremely different mixing ratio between the liquid A and the liquid B in the instantaneous setting grouting, and therefore the liquid B discharge speed (pressure feed) due to the difference in the liquid A and B liquid discharge (pressure feed per hour). This is a timer for solving the above-mentioned problem that the (speed) becomes slow.

  Specifically, the delay timer 24 has a function of delaying the operation start time of the A liquid pressure feed pump 3 for a set time from the operation start time of the B liquid pressure feed pump 3 '. As will be described later, the delay timer 24 functions so that the liquid A and the liquid B reach the tip 5a of the double tube rod 5 at the same time, or the liquid B precedes the liquid A.

  As described above, the delay time until the start of the operation of the pressure pump 3 set in the delay timer 24 is the difference in the discharge amount between the pressure pump 3 and the pressure pump 3 ′, the difference in inner diameter between the pressure hose 4 and the pressure hose 4 ′, and Calculation is made based on the length, the cross-sectional area of the outer tube 6 and the inner tube 7 of the double tube rod 5, the length thereof, and the like.

<Operation procedure of the pressure feeding device>
Next, using FIG. 1 and FIG. 2, the operation procedure of the above-described pumping device 10 by the pump automatic operation panel 20 will be described.

When the operation button 20d shown in FIG. 2A is pressed, the B liquid pressure feed pump switch 22 and the A liquid delay timer 24 are turned on. Then, the pressure feed pump 3 for A liquid pressure feed does not operate until a predetermined time elapses due to the action of the delay timer, and the pressure feed pump 3 operates when the set time elapses (see FIG. 1).

  On the other hand, when the operation is stopped, when the stop button 20e shown in FIG. 2A is pressed, both the B liquid pressure pump switch 22 and the A liquid pressure pump switch 23 are turned OFF, and the pressure pump 3 and All of the pumping pumps 3 ′ are stopped immediately, and all operations of the pumping apparatus 10 can be stopped (see FIG. 1).

  Thus, according to the pumping device 10 according to the present embodiment, the pumping device 10 can be operated or stopped only by pressing the operation button 20d or the stop button 20e of the pump automatic operation panel 20. For this reason, as described in the background art, the pump is manually turned on and off at the tip of the injection hose, and when the liquid A reaches the tip of the injection hose, the liquid A pump is stopped. It is not necessary to connect to the double pipe and inject at the time of reaching. Therefore, not only the construction management is easy, but the work efficiency is very good, and the number of workers can be greatly reduced, so that the construction cost of the grout injection work can be greatly reduced.

<Injection method>
Next, a method for injecting an instantaneous setting cured grout according to an embodiment of the present invention will be described. As described above, the ground injection and the cavity filling injection are described separately because the injection forms are different. Further, the case of injecting using the above-described pumping device 10 will be described as an example.

[Ground injection]
First, ground injection will be described. The purpose of ground injection is to inject instantaneous hardened grout into a limited area of the ground. For this reason, the liquid A and the liquid B are simultaneously merged and mixed from the distal end portion 5a of the double tube rod 5 of the pressure feeding device 10 to form a ground compaction or a strong grout consolidated body, thereby strengthening the ground. . Typically, the following three methods can be mentioned.

  (1) As shown in FIG. 1, the double tube rod 5 of the pressure feeding device 10 is installed under the ground surface 8 a of the ground 8. Then, the setting of the delay timer 24 of the pump automatic operation panel 20 is set so that the liquid A and the liquid B reach the tip 5a at the same time, and the terminating hardened grout is injected in a split shape (pulse shape) to consolidate the grout. Form the body.

  (2) The double tube rod 5 is rotated at a fixed position (same depth) to form a disk-shaped grout consolidated body.

  (3) The double tube rod 5 is pulled up while rotating to form a grout consolidated body in a spiral shape.

  What is characteristic among the above methods is that (3) a grout consolidated body is formed in a spiral shape.

  In addition, by adjusting the size and discharge amount of the injection hole at the tip 5a of the double tube rod 5, directivity can be given to the grout with a forced pressure higher than the ground injection pressure.

  Furthermore, it is also possible to create a columnar grout consolidated body by pulling up the double tube rod 5 continuously into the space (atmosphere and accumulated water) generated under the ground surface 8a.

[Cavity filling injection]
Next, the cavity filling injection will be described. As described above, the cavity filling injection has a problem that since the gel time and the plasticity time of the quick setting hard grout are short and the rising strength is very large, the injectable range is limited and the filling cannot be performed far away.

  Therefore, in the method of injecting the instantaneous setting hardened grout according to the present embodiment, in order to ensure a sufficient grout injection time, the B liquid is preceded from the tip portion 5a of the double tube rod 5 and injected into the grout solidified body. A tract is formed and an instantaneous hardened grout is injected. The inflow channel is formed in the grout solidified body by bringing the B liquid into contact with the instantaneous setting hardened grout in which the A liquid and the B liquid are merged and mixed, and the gelation is delayed.

  Specifically, the setting of the delay timer 24 of the pump automatic operation panel 20 is set so that the liquid B reaches the tip 5a earlier than the liquid A, and the liquid A and the liquid B are injected after the liquid B is pre-injected. A grout in a state of joining the tip portion 5a is injected. Thereby, a flow path is formed in the portion where the liquid B is pre-injected, and it is possible to inject the instantaneous setting hardened grout to a further distance.

  Further, in order to fill and inject the instantaneous setting hardened grout far away, the above-mentioned A liquid pressure feed pump switch 23 temporarily stops the A liquid pressure feed pump 3 to inject only B liquid, and then the switch 23 It is preferable to repeat the operation of the pressure pump 3 for liquid A pressure.

  The injection form in which the liquid B is preceded and then mixed and mixed with the liquid A is described in detail in Japanese Patent Application No. 2017-109712 (unpublished) filed separately by the present inventor. In addition, the cavity filling injection fills forward from the tip of the double tube.

  As described above, if the method for injecting an instantaneous setting hard grout according to the embodiment of the present invention is applied to ground injection, it is easy to perform construction management and does not require manual labor. A hardened grout can be injected. For this reason, it is possible to strengthen the ground by forming a ground compaction or a strong grout consolidated body at low cost.

  In addition, if the method of injecting the instantaneous setting hard grout according to the embodiment of the present invention is applied to the cavity filling injection, the operation can be easily managed without manpower, and the portion where the gel time is easily delayed is used as the route. The hardened grout can be injected and filled in a wider range to be cured early. Therefore, it is possible to achieve both the early strength that was difficult in the past and secure a practical gel time, and it is possible to repair and reinforce by filling grout in a wide area.

[Effect confirmation experiment]
Next, examples and comparative examples will be given, and physical properties of the quick setting cured grout will be evaluated by tests such as gel time measurement, plastic time measurement, and uniaxial compressive strength test described later to verify the effect of the present invention. Each test was conducted at a liquid temperature of 20 ° C. First, the test method of each test will be described.

(1. Measurement of gel time)
The gel time is measured by placing a predetermined solution A in a 5 x 30 cm plastic bag, adding solution B with the top of the plastic bag closed by hand, releasing the hand and simultaneously shaking it up and down and stirring. The time until loss of fluidity was defined as gel time.

(2. Measurement of plastic time)
The measurement of the plastic time is very short and the measuring instrument cannot be used. Therefore, the plastic time is defined as the time during which the grout after the gel time measurement is not fluidized even if the grout is pressed by hand.

(3. Uniaxial compressive strength test)
The uniaxial compressive strength test was conducted according to JIS R 5201 (cement physical test method). Specifically, the grout is adjusted by the same method as the measurement of gel time, put into a 4 × 4 × 16 cm triple frame before gelation, and wet-cured at 20 ° C. for 0.3 hours, 1 hour, 3 hours. The mold was removed after each curing period (hour) of 28 days, and the uniaxial compressive strength was measured.

  Next, various test results will be described by giving examples of the instantaneous setting cured grout. The cement used to produce the instant setting hardened grout according to the example is cement obtained by mixing ordinary Portland cement as cement A, blast furnace cement B type as cement B, and 3 parts by weight of ordinary Portland cement and 7 parts by weight of slag as cement C. Three types of cement were used.

  Bentonite was used as an additive. As the bentonite, Super Clay (registered trademark) manufactured by Hojun Co., Ltd., an American clay mineral, was used.

The water glass, the molar ratio as waterglass _{A (SiO 2 / Na 2 O} ) of 30% strength aqueous glass SiO ₂ capacity of 3.1, the molar ratio as water glass _{B (SiO 2 / Na 2 O} ) 3 types of water glass having a SiO ₂ capacity of 30% and a water glass C of 40% of SiO _{2 with} a molar ratio (SiO ₂ / Na ₂ O) of 3.0. Using. The water glass having a capacity of 30% refers to a water glass containing 300 g of SiO _{2 in} 1 L of the solution. The viscosity of the water glass A is about 20 cpm (20 times the water).

  In the manner described above, a predetermined amount of liquid A and liquid B are mixed to produce an instantaneous setting cured grout, and measurement results obtained by performing each test such as gel time measurement, plastic time measurement, and uniaxial compressive strength test are shown in Table 1. Show.

From Table 1, it is necessary that the cement weight contained in the liquid A is 500 kg or more per 1 m ^{3 in} order to set the uniaxial compressive strength after 3 hours of the quick setting hardened grout to 1.5 N / mm ² or more. I understand. The upper limit of the cement weight was set to 1,000 kg or less that can be pumped. However, when the cement weight is 800 kg or more, an adhesive such as bentonite is not used together.

And from Table 1, it was confirmed that the water glass to be mixed as the B liquid is a proper amount of 130 to 200 L of water glass having a capacity of SiO _{2 and} a concentration of 30% with respect to 1 m ^{3 of} the A liquid. .

Moreover, as shown in Table 1, the gel time is 3 to 25 seconds and the plastic time is 7 seconds in the blending of the instantaneous setting cured grout with the uniaxial compressive strength after 3 hours being 1.5 N / mm ² or more. Became within. It can be seen that this is shorter than the conventional quick setting cured grout shown as Comparative Example 5.

Furthermore, from Table 1, the rising strength after the plasticizing time measured in Examples 4, 6, 9, and 10 is 0.26, 0.20, 0.31, and 1.06 N / mm ² after 0.3 hours. It was 2.05, 4.09, 2.11, 5.77 N / mm ² at 3.0 hours, and it was found that the resin was rapidly cured. Further, Example 11 shows a very high value of 6.90 N / mm ^{2 in} 3 hours and 32.00 N / mm ² or more in 28 days, although the rising strength is inferior because of less cement and more slag.

From this, since the instantaneous setting hardened grout having a uniaxial compressive strength of 1.5 N / mm ² or more after 3 hours hardens rapidly, the hardened grout is split and a new quick setting hard grout is injected. Because it cannot be used, it is most suitable for ground injection for the purpose of limited range.

On the other hand, in the water glass suspension grout (LW) shown as Comparative Example 5, as shown in Table 1, the rising strength after the lapse of plastic time is 0.01 N / mm ² in 0.3 hours, 0.02 N / mm ² at 1.0 hours, was 0.04 N / mm ² at 3.0 hours, extremely it can be seen rising strength is weak.

  The water glass suspension grout (LW) according to Comparative Example 5 is mixed with 500 L of liquid A obtained by adding a gelation accelerator to 400 kg of cement and 500 L of B liquid obtained by adding 300 L of water to 200 L of water glass C solution. It is a thing.

  Thus, if it is the water glass system suspension grout (LW) which concerns on the comparative example 5, since the rising intensity | strength after hardening is weak, even if it inject | pours a new grout further after gelatinization, already injected gel It is possible to easily enter a new grout by splitting the broken grout.

(Confirmation experiment of gel time delay effect)
Next, in order to confirm the effect of delaying the gel time by the method of injecting the instantaneous setting cured grout according to the present invention, the instantaneous setting cured grout according to Example 4 described above is prepared, and the instantaneous setting cured grout for the B liquid is prepared. Examples 10 to 14 in which only the mixing ratio was changed were prepared. Table 2 summarizes the measured gel times of the quick setting cured grouts according to Examples 10 to 14 and 4 below.

Here, the instantaneous setting hardened grout according to Example 4 was obtained by adding 160 L of water glass 160L with a volume of SiO ₂ of B ₂ : molar ratio 4.0 to cement milk containing 600 kg of cement per 1 m ^{3 of} liquid A. It is added. Moreover, the B liquid shown in Table 2 is a 30% water glass of SiO ₂ having a molar ratio of 4.0.

  As shown in Table 2, when the instant setting curable grout according to Example 4 is mixed with the B liquid at a ratio of 20%, the gel time becomes very long as 1170 seconds, and the mixing ratio of the instantaneous setting curable grout is sequentially changed. As it increases, the gel time decreases. However, since the delay effect of the gel time is exhibited until the B liquid reaches 0%, it can be said that the delay effect of the gel time by the prior injection of the B liquid has been confirmed in this experiment. Therefore, it can be considered that the injection path of the instantaneous hardening grouting can be secured by injecting the liquid B in advance, as in the method of injecting the instantaneous hardening grouting according to the present invention.

In short, even in the case of injecting a quick setting hardening grout having a gelation time within 25 seconds and a uniaxial compressive strength after 3 hours of 1.5 N / mm ² or more, the quick setting hardening according to the present invention. Like the method of injecting grout, a new quick setting hardened grout can be injected forward by injecting the B liquid in advance before injecting the grout. This is because gelation is delayed while contacting and mixing along the flow path of the injected B liquid. Therefore, according to the method of injecting a fast-curing cured grout according to the present invention, it is possible to achieve both the development of early strength and the securing of a practical gel time, which has been difficult in the past, and repair by filling grout over a wide area, Reinforcement is possible.

  As described above, the method for injecting an instantaneous setting cured grout according to the embodiment of the present invention and the pumping device for the instantaneous setting cured grout used therefor have been described in detail. However, the above-described or illustrated embodiments implement the present invention. It is only what showed one embodiment actualized in doing. Therefore, the technical scope of the present invention should not be limitedly interpreted by these.

10: Pressure feeding device 1, 1 ': Water tank 2, 2': Suction hose (pressure feeding hose)
3, 3 ': Pressure pump 4, 4': Pressure hose (pressure hose)
5: Double tube rod (double tube)
6: Outer pipe (double pipe)
7: Inner pipe (double pipe)
8: Ground 8a: Ground surface

Claims (1)

Mix B liquid of water glass with a capacity of 24% or more in SiO ₂ capacity at a ratio of 130 to 200 L with respect to 1 m ^{3 of} liquid A to cement liquid A containing 500 to 1000 kg of cement per m ^3. A method for injecting a fast-curing cured grout in which the gelation time is within 25 seconds and the uniaxial compressive strength after 3 hours is 1.5 N / mm ² or more,
Using the pumping device with the pumping capacity of the pumping pump, the inner diameter of the pumping hose, and the cross-sectional area of the double pipe smaller than the liquid A,
By delaying the start of operation of the pressure pump of the A liquid by the delay timer from the start of operation of the pressure pump of the B liquid, the time when the liquid A and the liquid B reach the tip of the double pipe is simultaneously A method for injecting an instantaneous hardening grouting, characterized in that the injection of the instantaneous hardening grouting is performed.

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