JPH01163310A - Ground grouting work - Google Patents

Abstract

PURPOSE:To attain exact permeation and solidification of grout within a given range by a method in which a main component containing water glass is mixed with a hardener while continuously varying its proportions and injected into the ground by varying gel time. CONSTITUTION:Water glass or silica sol A prepared by adjusting the acidity or neutrality of the water glass by an acid liquid is supplied through a pipeline 4 and a control box 5 to an injection double tube 6 by a flow-regulating pump PA from a storage tank 1. At the same time, a hardener liquid BS of a compara tively short gel time and a hardener liquid BL of a comparatively long gel time are set into the tube 6 through a mixer 8 by flow-regulating pumps PBS and BBL from storage tanks 2 and 3 while controlling their discharge amounts continuously and in inverse proportion. The gel time of grout to be mixed together in the tip of the tube 6 can thus be continuously varied.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a ground injection method for strengthening the ground or stopping water.

"Prior art 1. Problems to be solved by the invention" In the conventional injection bead shape, the instantaneous injection was obtained by adding and mixing a certain amount of the curing agent B to the main component A, such as water glass or silica sol. Generally speaking, an injection solution adjusted to a certain gel time is injected into the ground, such as a loose setting method.

By the way, an injection liquid with a long Kel time (slow setting) has the advantage of ensuring a long penetration time, and even in ground with low permeability, the injection liquid can penetrate into areas far from the injection pipe and solidify. On the other hand, if there are areas where the injected liquid can easily penetrate, such as underground waterways, strata boundaries, or sludge layers around sheet pile walls, the injected liquid will continue to penetrate into these parts, and the underground It is easy to cause problems such as pollution, and most of the ground is heterogeneous, so the injected liquid injected from the injection pipe will concentrate and penetrate into areas with relatively good permeability.
There are drawbacks such as it being difficult to improve the ground uniformly.

On the other hand, since the injection liquid with a short gel time (instant setting) has a short penetration time, does it have the advantage of being able to solidify without flowing upstream even in groundwater or the boundaries of geological formations? There is a drawback that the permeation range of the liquid cannot be secured sufficiently, and it solidifies only in a very narrow area around the injection pipe.Also, the injection liquid tends to solidify locally as a homogel, causing problems such as ground upheaval. There are some drawbacks such as.

Therefore, conventionally, taking advantage of the mutual advantages of instant-setting and slow-setting injection liquids, the instant-setting injection liquid is first injected in the -step injection process, and the injection liquid is placed in the area near the injection tube where it tends to rise or the injection liquid is Is there also a known composite injection method in which the area around the sheet pile wall, which is prone to whitening, is consolidated, and then the injection liquid is changed to a loosely set injection liquid and injected into the surrounding ground far from the injection pipe? However, the above-mentioned problems caused by instant-setting and slow-setting injection solutions cannot be solved, but especially the problem of locally concentrated penetration of injection solutions with a long melt time cannot be solved.

"Means for Solving the Problems" In order to solve the above-mentioned conventional problems, the present invention continuously changes the composition of the curing agent in the injection liquid injected in the -step injection process, and from the start of injection. Show the gel time of the injected solution from long to the end 1
~ Or, by continuously changing from short to long, as the injection process progresses, the injection liquid sent to the ground can be concentrated in one direction, or a large amount can be poured into areas where it is easy to penetrate. This paper proposes a rational injection method that makes it possible to improve the ground evenly by ensuring that it infiltrates into the desired area without causing any upheaval, and solidifies in approximately the same distance as the infiltration distance.

"Embodiments" Hereinafter, embodiments of the present invention shown in the drawings will be explained.
In the storage tank 1, a main agent (liquid A) such as water glass or silica vine which has been treated with an acidic solution to make it acidic or neutral is stored, and in the storage tank 2, the mixing ratio of liquid A as a single curing agent is stored. Relatively short gel time when added and mixed (e.g.
A curing agent liquid (Bs liquid) formulated to harden with instant setting (in less than 30 seconds) is stored in storage tank 3, and when added to liquid A at a mixing ratio as a single curing agent, a relatively A curing agent liquid (BL liquid) that is cured with a long cure time (for example, slow setting for several minutes or more) is stored.

Liquid A is transferred from the storage tank 1 to the pipe line 4 by the flow rate adjustment pump PA.
It is fed under pressure through a management box 5 to an injection pipe 6 made of a two-ton pipe or the like.

B, liquid and BL liquid are transferred from the storage tanks 2 and 3 to the pipes 7s, 7t, while continuously increasing and decreasing the discharge amount of the phase car in an inversely proportional manner by the flow control pumps Pas+Pnt.
The curing agent liquid (Liquid B) flows into the mixer 8 through the pipe line 9, where it is merged and mixed to continuously change the composition of the components.
, via the management box 5 to the injection pipe 6.

The flow μ adjusting pump PA maintains the discharge amount constant by comparing and controlling the flow rate signal of liquid A from the flow meter IO and the setting value of the flow setting device 11.

Also,! R, the amount adjusting pump P8S+PRL continuously changes the discharge amount inversely proportionally by the variable reliability of the mixing ratio setting device 12, and B, the constant flow rate where the mixing ratio of the liquid and the BL liquid changes continuously relative to each other. A curing agent liquid (liquid B) is pumped with liquid A at a constant mixing ratio (for example, 1:1, 2:1).

The A liquid and the B liquid pumped into the injection tube 6 in this way are mixed together at the tip of the injection tube 6, etc., and the composition of the Bs liquid and the B14 liquid or the continuously changing B liquid changes from short to long. Alternatively, the liquid is sent to the ground as an injection liquid that changes over time from long to short gel time.

In other words, the amount of B liquid sent is IO! To explain the case of injecting at L/min, as shown in Fig. 2, B, liquid is injected at -
During the time from the start of the injection process to the end of the step, B increases continuously from 0 to 1O, and inversely proportional to this, B,
By concatenating and mixing the two while continuously reducing the liquid from 102 to 0C, the blending amount of the BL liquid gradually increases to 7. amount(
+1) Curing agent B or liquid A will be added and mixed,
As shown in FIG. 4, the injection solution obtained in this way is
At the beginning of the step injection, it is injected into the ground with a long gel time, and then gradually until the end of the injection, it is injected with a short gel time.

Therefore, this type of injection method is suitable for improving well-compacted, homogeneous ground with low permeability, such as a diluvial sand layer. The liquid is pushed out to a portion far from the injection tube 6 by the successive injection liquids whose penetration distance gradually becomes shorter, and solidifies at the penetration limit.

Then, as time passes, the gel time of the injected solution that is continuously injected becomes shorter and the penetration distance becomes shorter. It permeates evenly around the injection tube 6 and becomes clogged near the injection tube 6 when injection is completed.

Therefore, at the end of one step of injection, the injection liquid that has penetrated into the farthest part from the injection tube 6 and the injection liquid that has been injected near the injection tube solidify almost simultaneously, resulting in uniform improvement. The penetration range becomes an ideal shape that is almost circular.

In addition, contrary to the above, by continuously reducing the Bq solution from 10 to 100% and inversely increasing the BL solution from 0 to IO inversely, by combining the two, As the blended amount of BL liquid gradually increases, the blended amount of B5 liquid gradually decreases.It will be added to and mixed with the constant (10 sentences) curing agent B or A, thereby increasing the amount of the B5 liquid. As shown in FIG. 5, the injected liquid is injected into the ground with a short gel time at the beginning of the injection, and then is injected with a gradually longer gel time until the end of the injection.

Therefore, such injection 1-method is difficult to improve soil or complicated! f
If there is a layer (geological strata with different permeability or thin layers that allow the injected liquid to easily penetrate into the interface), or if there are structures such as manholes or steel sheet piles near the improved area. This is suitable for cases where the injected liquid easily penetrates into the boundary surface, and in such ground, the injected liquid with a short gel time at the beginning of injection will penetrate into the boundary surface and solidify immediately, making it difficult for the subsequent injected liquid. Since the IF prevents invasion, subsequent injection liquids that are continuously injected with gradually longer penetration distances penetrate into the areas that are easier to permeate one after another, and solidify in the order of shortest +I + nth gel time. become.

In this way, by continuously changing the improvement range for different injection resistances, starting with an injection solution with a short gel time or increasing gel time or a long injection solution, it is possible to improve the injection resistance from areas where it is easy to penetrate to areas where it is difficult to penetrate. It is possible to improve the ground reliably and uniformly by infiltrating the ground with the injection liquid in sequence.

As described above, in this invention, the gel time of the injection liquid is continuously changed, and as a result of sequentially injecting different injection liquids with different penetration distances, it is possible to reliably inject into the penetration range corresponding to the gel time and evenly. It can solidify and is extremely rational.

In addition, the relationship between the injection amount of the injection solution (27 minutes) and the mixing ratio of both solutions A and B (1:1) is shown in 3rd UA.

Some examples of liquid A, liquid 85, and liquid BL used in the present invention are shown in Table 1.

“Formulation Example-1” In this case, due to the relative increase/decrease of B9 liquid and BL liquid,
The injection solution can be continuously increased or decreased from 5 seconds to 10 minutes of gel time.

“Formulation Example-2” For example, injecting liquid containing Gel Time 4 is mixed into liquid A and liquid B.
1. It is used as a liquid, and is a combination of this BL liquid and BS liquid.

In this case, by relatively changing the blending ratio of Bs solution to BL solution using A solution by increasing or decreasing the ratio between θ and 1/3, the injection solution can be increased or decreased to a gel time of 5 seconds to 8 minutes. It can change continuously.

In contrast to this case, the Bs solution and the BL solution may be combined by using the A solution and the Bs solution as injection solutions with a short gel time.

The formulation example in E below is just an example, and if the gel time of A liquid and Bt liquid is longer than that of A liquid and Bs liquid, other various formulations may be used. Ru.

``Effects of the Invention'' As described below, according to the injection method of the present invention, the composition of the curing agent (Liquid B) is added to the main ingredient (Liquid A) whose main component is hydraulic lath (Liquid B) without continuously changing the composition. - Add and mix the injected liquid into the ground in one step of the injection process, and then inject the injected liquid into the ground from the start to the end of the injection process. The gel time of the liquid can be continuously changed from long to short or from short to long, allowing the injection liquid to reach the desired range without being concentrated in one direction or flowing in large amounts into areas where it is easy to penetrate. The only way to do this is to ensure that it infiltrates, solidifies in approximately the same distance as the infiltration distance, and improves the ground evenly.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing the injection device of the present invention, Fig. 2 is a diagram showing the blending relationship of the curing agent, and Fig. 3 is the relationship between the injection amount of the injection liquid and the mixing ratio of both liquids A and B. FIGS. 4 and 5 are llIr plane views showing the same implantation situation. l...A storage tank, 2...Bs liquid storage tank, 3...B3,
Liquid storage tank, 4. Pipe line, 5. Management box, 6. Injection pipe, 7s, 7L... Pipe line, 8. Mixer, 9. Pipe line, 10.. Flow meter, 11.・Flow rate setting device, 12...Mixing ratio setting device, PA, Pas, Pat,...Flow rate adjustment pump. Patent applicant Chi Takumi Co., Ltd. Representative Minoru Satoshi Figure 2 Figure 3 Figure 5 Figure 4

Claims (1)

[Claims] A curing agent (liquid B) is added and mixed to a main ingredient (liquid A) whose main component is water glass while continuously changing the composition of the ingredients, and the gel time is continuously changed in a one-step injection process. A ground injection method characterized by injecting liquid into the ground.