JPS605910A - Reuse of soil pile excessive liquid - Google Patents

Abstract

PURPOSE:To reuse excessive liquid to be generated during formation of soil piles by separating it from soil and sand by adding a cement admixture to delay the setting of cement in a proper mixing ratio to cement milk fo forming soil piles. CONSTITUTION:While excavating a pit 2 by an excavator 1, bentonite and cement milk are injected ino the pit 2 through a pump 3. Excessive liquid (a) to be generated during the formation of soil pile SP is sent to a separator 9 through a pump 10, where soil and sand separated are received by a waste soil tank 11 and the liquid containing cement component is supplied as a reusable liquid to a compounding tank 4. In the tank 4, the components of water, bentonite, cement, etc., are regulatively mixed and 0.4-1.0wt% an admixture to delay the setting of the cement is added to the mixture. The reusable liquid so reregulated is again used in the formation of soil piles.

Description

[Detailed Description of the Invention] The present invention is widely applied to the construction of earth retaining walls and water-stop walls because it is easy to construct, has low construction costs, and is a low-pollution construction method. In the soil pile construction method, soil deposits (which occur unavoidably during the soil pile construction process)
A method of reusing (recycling) the surplus liquid containing a mixture of soil, water, cement, and bentonite. , relates to a method for reusing the separated cement component-containing liquid for the construction of whole soil piles.

To explain in detail, it is soil pie! Methods for disposing of surplus liquid generated during cultivation include ■ Method of using a vacuum truck to dump it as industrial waste, @ Method of mixing a solidifying agent with the surplus liquid and solidifying it, and dumping it using a dump truck. A method of mixing a solidifying agent and solidifying it and reusing it as a landfill in a bay or site, separating the O surplus liquid into a liquid containing earth and sand components and a liquid containing cement components, and using the separated cement component-containing liquid. A method of reusing it as a material for creating soil piles is known, but method (■) requires that all of the surplus liquid generated in large quantities be disposed of as industrial waste, which has the disadvantage of incurring huge disposal costs. , θ further includes the material cost of solidifying agent, mixing processing cost, labor cost, and machine damage cost, which further increases the disposal cost.

Compared to these, O is the most rational and economical,
The method of the present invention relates to the method of O.

By the way, the conventional O method is a method of reusing the cement component-containing liquid separated from the earth and sand components as a soil pile construction material, but in this case, there are problems listed below and it is not practical.

■ The cement component in the excess liquid gels and its viscosity increases over time, making it impossible to pump up the liquid during the liquid recovery process. Also, if you add water to reduce the viscosity,
The amount of surplus liquid increases, and the processing cost increases accordingly.

■ The recycled components in the surplus liquid are water, cement, and bentonite excluding soil and sand, but when the soil and recycled components are separated, cement components adhere to the discharged soil (10 to 10% of the cement component). 096), and most of the cement components are wasted along with the earth and sand.

■ Considering the fact that the cement in the recycled liquid deteriorates and the pile strength decreases as a result, the effectiveness of recycled cement components is low, and therefore the effect of saving cement materials in soil pile construction in general is small.

In view of the above-mentioned circumstances, the present invention makes it possible to reuse the cement components in the surplus liquid as effectively as possible, thereby making it possible to expect a great saving effect on cement materials necessary for soil pile construction, and to treat the soil components. The purpose is to propose a method that can reduce costs.

The method for reusing soil pile surplus liquid according to the present invention, which was devised to achieve the above object, is based on Soil Pie! The present invention is characterized in that a cement mixture agent that retards the solidification of cement is added and mixed in advance into a cement mill for construction, and the effects of the present invention having such characteristics are as follows.

Since a cement admixture with a retarding effect is mixed in advance in the pouring process, the increase in viscosity due to gelation of the cement components in the excess liquid can be suppressed as much as possible.
This eliminates inconveniences such as not being able to pump up when collecting surplus liquid and increasing the amount of liquid due to the use of dilution water.

(2) For the same reason as above fil, for more than 1 day (8
Even if the surplus liquid after being left for 0 hours is reused, there is almost no problem with the strength of Soil Pie μ.

(3) Additionally, as mentioned in (1) above, by suppressing the gelation of cement components as much as possible, it becomes easier to efficiently separate surplus liquid into soil and cement component-containing liquid, and The residual rate of cement components is improved.

By combining the above +11 to (3), the effective cement components in the surplus liquid can be reused as effectively as possible, the amount of cement material required for soil pile construction can be significantly reduced, and at the same time, the generation of industrial waste can be reduced. The cost required for this process was significantly reduced, resulting in great economic effects.

Examples of the method of the present invention will be described in detail below based on the drawings.
fil is an excavator for creating soil piles, which excavates a vertical hole (2) underground, and excavates bentonite and cement milk injected into the vertical hole (2) via a pump (3). A soil pile (SP) is sequentially created by mixing and agitating the earth and sand accompanying the soil. (4
) is a mixing tank for cement milk, and a tank (51,
(61, (7), +81 to be supplied in an appropriate ratio), a cement admixture for delaying cement solidification, water, and bentonite are mixed and prepared, and then cement milk is pumped through the pump (3). (9) is configured to inject the surplus liquid (a) generated during the creation of the soil pipe (SP) and sent through the pump (IO) into the earth and sand. This is a separator that separates soil components into a liquid containing cement components, and the separated soil components are received in a waste soil tank (Uj) and dumped via a dump truck, while the soil components are separated into a liquid containing cement components. The liquid to be used is stored in the tank (I ring) and then transferred to the mixing tank (
4) and is configured to be reused for soil buy/1/(SP) creation. This reuse makes it possible to reduce the amount of cement used. The ring in the figure is a valve, and the cement admixtures mentioned above include lignin sulphonate, oxycarboxylate,
A material whose main component is magnesium fluoride is used.

The following are the results of experiments conducted by the applicant to demonstrate the effects of the method of the present invention, and in each experiment, a carboxylic acid-based retarder was used as the cement admixture.

(1) Effect on viscosity due to addition of cement admixture - As shown in the graph of Figure 2, when the admixture was added to 0.
If 8% by weight is added, the standing time will be 80 hours (h
It was clear that at level r), there was no problem with bong attachment.

[Old: Rate of adhesion of cement components to soil components due to addition of cement admixtures (residual rate of cement components in recycled liquid)
- As shown in the graph in Figure 8, although there are some differences depending on the size and particle size of the soil components,
．． If 8% by weight is added, the cement component and soil component can be separated well, and the residual rate of cement component in the reused liquid is 8%.
It was clear that we could expect about 0%.

I] Effect on quality (strength) of soil-by by reusing liquid containing cement admixture - Figure 4 (A)
As shown in the graph of (b), the admixture plays an important role in the final strength (-axial compressive strength) of the pile,
It was found that when 0.8 weight percent of the admixture was added, the product could be reused sufficiently even after 30 hours of standing time.

[Brief explanation of drawings]

The drawings show an embodiment of the method for reusing soil pile surplus liquid according to the present invention, and FIG. 1 is an overall system diagram, FIG. 2, and FIG.
Figures 4(a) and 4(b) are graphs showing the experimental results.

Claims (1)

[Claims] ■ Excess liquid generated during the creation of soil pie Iv (SP) is separated into earth and sand components and cement components, and the separated cement component-containing liquid is divided into soil/l/t<i/I/ ( SP
) is a method for reusing soil-by μ surplus liquid in the production of soil-by μ (SP), characterized in that a cement admixture for delaying the solidification of cement is added to the cement milk for creating soil-by μ (SP) in advance. How to reuse. (2) The method for recycling surplus soil-by μ liquid according to claim 0, wherein the addition rate of the cement admixture is 0.4 to 1.0 weight percent.