JP2002054133A - Recycling method for surplus liquid hardener - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recycling method for a surplus liquid hardener adopted in the soil cement mixing method, which is very easy and economical, contributes to prevention of clogging of pipes and a pump system by improving the fluidity of the liquid hardener without adding diluent water, and allows recycling of the surplus liquid by storing the surplus liquid until the following day. SOLUTION: The soil cement mixing method for use in constructing an underground wall, etc., is carried out by mixing the liquid hardener discharged from an auger head and in-site soil excavated by an auger with each other, and agitating the resultant mixture. The recycling method for the surplus liquid hardener is adopted in the soil cement mixing method, and comprised of the step of recovering the surplus mixed soil of the excavated in-site soil and the liquid hardener, which is discharged during excavation and agitation, the step of separating the recovered surplus mixed soil into the soil and the surplus liquid hardener, and the step of supplying the separated surplus liquid hardener to the auger head again. The recycling method for the surplus liquid hardener is characterized in that a hardening retardant is added to the liquid hardener.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a soil cement mixing method for, for example, construction of a water-stopping retaining wall, and more particularly, to recycling of a solidifying agent excess liquid generated at the time of applying the method and of solidifying agent liquid. The present invention relates to a method for recycling a solidifying agent excess liquid during soil cement mixing, characterized by improving fluidity and storing and reusing excess recycled liquid until the next day.

[0002]

2. Description of the Related Art In large-scale excavation work, in recent years, continuous walls have been generally formed by a soil-cement mixing method as a water stoppage retaining wall. The soil-cement mixing method is to create an underground wall by mixing and agitating the in-situ soil of the wall construction and the cement-based solidifying agent simultaneously with excavation, and thereby forming the underground wall uniformly. In general, it is necessary to inject about 50 to 90% of a cement-based suspension per unit volume of the soil to be constructed in order to secure the material, improve the insertability of the stress material, and reduce the load on the auger. Therefore, a muddy surplus liquid or solidifying agent mixed soil is generated in a form proportional to the injection amount of the cement-based solidifying agent liquid, and in many cases, this is naturally dried and then disposed of as industrial waste. I have.

Accordingly, the present inventor has proposed the above-mentioned Japanese Patent Application No. 2000-8.
No. 6836 proposes a "method for recycling excess liquid and a recycling plant". In this method, the amount of cement and bentonite in the excess liquid of the solidifying agent generated during construction of the soil cement mixing method is estimated, and the amount of cement and bentonite to be added to the recycled liquid is reduced based on the estimated value. The construction method is adopted.

[0004]

However, in the known method, it is necessary to treat excess solidifying agent liquid or mixed soil accompanying the construction of the soil cement mixing method as industrial waste. Countermeasures were extremely burdensome. On the other hand, in the method of recycling the excess solidifying agent solution proposed above, a large amount of cement-based solidifying agent solution must be injected to improve workability during construction. It was necessary to adjust the concentration of the solidifying agent in the separated recycle liquid in order to add dilution water for promotion, etc., and it was necessary to estimate the amount of cement and bentonite in the surplus liquid. The present invention can reduce such various burdens, is extremely simple and economical,
It provides a method of recycling excess solidifying agent in the soil cement mixing method, and further improves the fluidity of the solidifying agent liquid without adding dilution water, prevents clogging of piping and pump systems, and removes excess liquid. An object of the present invention is to provide a method for recycling a surplus liquid of a solidifying agent that can be stored and reused until the next day.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a soil cement mixing method for mixing and agitating a solidifying liquid discharged from an auger head and excavated soil excavated by an auger to construct an underground wall or the like. Recovering the excess mixed soil of the excavated in-situ soil and the solidifying agent liquid discharged during the excavation and stirring; separating the soil and excess solidifying agent liquid from the collected excess mixed soil; The method further comprises a step of supplying the excess solidifying agent surplus liquid to the auger head again, wherein a solidification retarding agent is added to the solidifying agent liquid. The recovered solidifying agent surplus liquid to which the solidification retarding agent is added is stored and reused as a solidifying agent liquid for excavation and mixing from the next day.

[0006]

The outline of the operation of the recycling method of the present invention is as follows. In an ordinary excavation process using a single-axis or multi-axis auger, the solidifying agent liquid is discharged from the auger head simultaneously with the excavation, and excavation and agitation proceed. In this case, the solidifying agent liquid used in the present invention uses an additive that delays solidification of the cement, in addition to the solidifying agent liquid component consisting of ordinary cement, bentonite and water. Next, the ex-situ soil excavated in the excavation and agitation step and the solidifying agent liquid are agitated and mixed, but most of the mixed soil in the initial stage of excavation is discharged from the excavation hole as surplus mixed soil. The stirring suction device installed in the self-propelled surplus liquid suction device sequentially sucks the discharged mixed soil and transfers it to the separation device by the subsequent squeeze pump. The separation device according to the present invention uses a cyclone and a mud screen in combination, whereby the excavated earth and sand and the excess solidifying agent liquid can be completely separated. Next, the excess solidifying agent liquid containing the separated additive is
It is sent to the automatic plant, which is the original means for adjusting the solidifying agent liquid, and is supplied again to the auger head of the auger as it is. Therefore, in the recycling method of the present invention, in principle, the excess of the solidifying agent liquid supplied at the beginning of one excavation step is collected and reused as it is. When a required amount of the solidifying agent liquid is adjusted in a predetermined one-day work process, the solidifying agent liquid is sequentially used in the excavation process, and the surplus is recovered and reused. Then, when the work by the soil cement mixing method for one day is completed, the excess solidifying agent liquid collected at that time is stored in a tank, and is used as it is in a similar construction process the next day.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flow chart according to a method for recycling excess liquid of a solidifying agent according to the present invention, and comprises a self-propelled excess liquid suction device 10, a sediment separator 20 and an automatic plant 30. The surplus liquid of the solidifying agent to which the solidification retarder added by such an apparatus is added is supplied to the auger 40 to perform the soil cement mixing method. The soil mixing method according to the present invention is used for various works such as construction of an underground wall, creation of a soil cement pile, and ground improvement. The auger 40 is of a normal type, and may be of a single-shaft or multi-shaft type.

Next, the flow of the solidifying agent excess liquid in the solidifying agent excess liquid recycling method will be described with reference to the flow chart shown in FIG. In the surplus liquid agitating suction device 11 of the self-propelled surplus liquid suction device 10, the solidifying agent surplus liquid sucked up by the rotating blades is supplied to the pipe P1, the squeeze pump 15, and the pipe P2.
After that, the liquid is sent to a separating unit having a built-in vibrating screen or the like in the mud screen 21 of the separating device 20, where the liquid is separated from solids such as gravels, earth and sand. At this time, the shower water for washing is sent from the water tank T1 to the mud screen 21 through the pipe P3, so that the liquid can be easily separated from fixed parts such as gravel, earth and sand. Need not use washing water.

The separated solidifying agent excess liquid is stored in a tank T2 of the separating device 20, while solids such as gravels, earth and sand are discharged to a vessel 24, and the solids collected in the vessel 24 are removed from a truck. It is usually transported as waste soil by V. In addition, the water from the water tank T1 is sent to the surplus liquid stirring and sucking device 11 of the self-propelled surplus liquid suction device 10 through the pipe P4 by a pump, and can be used for diluting the surplus liquid of the stirring and sucking device 11. It is not particularly necessary in the present invention.

The automatic plant 30 is provided with an additive storage tank 35 in addition to a mixer 31, an agitator 32, a vent silo 33, a cement silo 34, etc., which are known in the construction equipment of the soil cement mixing method. It is designed to feed additives. Here, to explain the additive which is one feature of the present invention, for example, a retarder called "Geo Tally" in trade name retains fluidity with respect to soil cement,
It has an effect such as a delay in curing speed. And
When the purpose is to delay the curing by about 1 to 7 days, the additive is added at a weight ratio of 2 to 3% for sandy soil and 2 to 6% for silt.

An excess liquid of the solidifying agent containing the additive accumulated in the tank T2 of the sediment separating apparatus 20 is pumped to the mixer 31 of the automatic plant 30 through a pipe P5 by a pump.
The water from the water tank T1 is also pumped to the mixer 31 of the automatic plant 30 through the pipe P6 by the water supply pump as necessary, similarly to the excess liquid of the solidifying agent. The mixer 31 and the agitator 32 are connected by a pipe. Further, cement is supplied to the mixer 31 from the cement silo 34 through a pipe P7 when necessary.

In the mixer 31 of the automatic plant 30, cement, bentonite, water and additives are added in the initial stage, and in the middle of the construction, the excess liquid and the cement milk to which the cement or the like is kneaded as necessary are mixed with the agitator 32. Through the pipe P8 to the excavating shaft 41 of the auger 40 by the grout pump and discharged from the excavating head at the lower end into the excavated ground to be used for ordinary ground improvement and creation of a soil cement pile. Things.

FIG. 2 shows an example of a surplus liquid agitating suction device 11 provided in the self-propelled surplus liquid suction device 10 shown in FIG. Interaction between the rotating blades 12 provided on the rotating shaft driven by the motor M and the fixed blades 13 fixed to the casing causes excess solidifying agent and earth and sand generated by excavation and stirring of the auger 40 shown in FIG. Is sucked up. The mixed sediment sucked up in this manner is passed through the connecting pipe P1 and the self-propelled surplus liquid suction device 10
Is supplied to a sediment separator 20 shown in FIG. The surplus liquid agitating / suctioning machine 11 is movable by being suspended from a boom 14 of a self-propelled trolley as shown in FIG. 1, and the squeeze pump 15 is also installed on the same self-propelled trolley.

FIG. 3 is a view for explaining the principle of the squeeze pump 15 installed on the truck of the self-propelled surplus liquid suction device. The structure of the squeeze pump 15 itself is publicly known, and a connection pipe P1 of the excess liquid stirring / suctioning machine 11 is connected to a suction port of a hose 17 disposed in a casing 16, and a discharge port of the hose 17 is A feed pump P2 to the earth and sand separation device 20 shown in FIG. 1 is connected to the outlet. Then, with the rotation of the pair of sliding shoes 19 provided on the rotor 18 that is driven to rotate by the motor, the earth and sand containing the excess liquid is reliably removed from the earth and sand separation device 2.
0 to the mud screen 21.

FIG. 4 is a view for explaining the principle of the sediment separating apparatus 20 shown in FIG. 1. The sediment separating apparatus 20 is constituted by a mud screen 21 and a cyclone 25, which are known per se. The mixed earth and sand containing the excess liquid from the self-propelled excess liquid suction device 10 is supplied to the mud screen 21. Although various configurations of the mud screen 21 itself are known, for example, two upper screens 22 are provided.
And a lower sieve 23 which is vibrated by a vibration motor 24 to quickly separate the sediment particles and the fluid. The solidifying agent, which is the surplus liquid separated in this way, is stored in the tank T2 in a muddy state containing fine particles.

Subsequently, the muddy excess solidifying agent liquid stored in the tank T2 is sent to the cyclone 25 through a pipe P10 by a pump, and the fine slurry and the coarse slurry, which are the excess solidifying agent excess liquid, are further removed. The surplus liquid that has been separated and reused is stored in a tank T3 provided in the earth and sand separation device 20, as shown in FIG. On the other hand, the coarse slurry separated by the cyclone 25 is supplied to the mud screen 21 again, and the mud portion is separated by the same operation as described above.
Sent to

FIG. 5 is a diagram showing the principle of a normal type of the cyclone 25. For example, a muddy excess solidifying agent supplied from a pipe P10 in FIG. The vortex is supplied to the upper portion of the main body, and is separated into an overflow, which is a fine slurry corresponding to the secondary rotating flow, and an underflow, which is a coarse slurry corresponding to the primary rotating flow, by the vortex generated in the main body. The excess liquid of the high-purity solidifying agent, which is the overflow separated in this way, is supplied from the upper outlet 27 to the pipe P as described above.
9 to tank T3. The excess liquid of the solidifying agent separated by such a process is substantially the same as the solidifying agent liquid adjusted in advance in the initial stage of the construction process. Is what you can do.

[0018]

According to the present invention, since all the solidifying agent liquid in the excess mixed soil generated in the initial stage of each successive excavation and mixing process is recovered and reused, the mixing to be treated as industrial waste is performed. An extremely efficient and economical soil-cement mixing method can be carried out with almost no residual soil and no solidifying agent liquid generated. In addition, by using a solidifying agent to which a solidification retarding agent is added, clogging of pipes and pumps can be prevented without adding extra water to the collected excess solidifying agent liquid. This is an efficient solidification agent surplus liquid recycling method that eliminates the need for liquid readjustment. Furthermore, by appropriately setting the amount of the additive which is a solidification retarder added to the solidifying agent, the collected excess solidifying agent liquid can be reused in the construction process on and after the next day, so that there is no waste of the solidifying agent. In addition, the present invention has a remarkable effect that the discharge of industrial waste can be prevented as much as possible.

[Brief description of the drawings]

FIG. 1 is a flow chart of a soil mixing method using a solidifying agent surplus liquid recycling method of the present invention.

FIG. 2 is a schematic explanatory view of a surplus liquid stirring suction device used in FIG.

FIG. 3 is a principle view of a squeeze pump.

FIG. 4 is a principle view of a sediment separation apparatus.

FIG. 5 is a diagram illustrating the principle of a cyclone.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Self-propelled surplus liquid suction machine 11 Excess liquid stirring suction machine 15 Squeeze pump 20 Sediment separator 21 Mud screen 25 Cyclone 30 Automatic plant 31 Mixer 32 Agitator 33 Vent silo 34 Cement silo 35 Additive storage tank 40 Auger

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Terao, 6-7 Nihonbashi Koamicho, Chuo-ku, Tokyo Inside Kawasho Jecos Co., Ltd. (72) Inventor Hajime Shimura 2-4-2 Nihonbashi Kayabacho, Chuo-ku, Tokyo No. 9 Inside Sanwa Kikai Co., Ltd. (72) Inventor Mamoru Hamano 1293 Tento-cho, Hanamigawa-ku, Chiba-shi, Chiba F-term in Chiba Plant Sanwa Kikai Co., Ltd.

Claims (2)

[Claims] 1. Mixing and agitation of a solidifying agent liquid discharged from an auger head and excavation site soil excavated by an auger,
In the soil cement mixing method for constructing underground walls, etc., a step of collecting surplus mixed soil of excavated in-situ soil and solidifying agent liquid discharged during excavation and stirring, and a step of collecting soil and surplus from the collected surplus mixed soil A step of separating the solidifying agent liquid from the solidifying agent liquid, and a step of supplying the separated solidifying agent excess liquid to the auger head again, wherein a solidification retarder is added to the solidifying agent liquid. Liquid recycling method. 2. The recovered solidifying agent surplus liquid to which the solidification retarding agent is added is stored and reused as a solidifying agent liquid for drilling and mixing from the next day.
The solidifying agent surplus liquid recycling method described in the above.