JP2012057356A - Manufacturing method of backfill material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a cost for backfill material and to alleviate an environmental burden.SOLUTION: A backfill material 27 is manufactured by mixing a sandy soil component with water, cement, and dispersant as additives. The backfill material can be manufactured by using as a raw material the sandy soil component of generated soil 24, which is generated by excavating the ground 21, and mixing it with the water, cement and dispersant. Thus, the manufacturing method can eliminate a need of procuring the backfill material from an external source and thereby reduce a cost for the backfill material. The manufacturing method can also reduce an amount of the generated soil to be disposed of as industrial waste and thereby alleviate an environmental burden.

Description

  The present invention relates to a method for manufacturing a backfill material.

  For example, as an example of a method for constructing a cast-in-place pile, a hole is formed by excavating the ground while supplying a stabilizing liquid (suspension of bentonite, thickener, polymer agent, dispersant, etc.). A construction method is known in which a pile is constructed by placing concrete through a tremy pipe inside, and then a backfill material is backfilled in the hole in the upper part of the pile (see, for example, Patent Document 1). .

  In such a construction method, the mixed liquid (muddy water) of the earth and sand (generated soil) and the stable liquid generated by excavating the ground is sucked up and collected by a muddy water pump, and predetermined treatment is performed by a muddy water treatment device installed on the ground. (After separating and removing solids from the generated soil, etc.), the reusable stabilizer is collected in the stabilizer storage tank, and the non-reusable stabilizer is discarded as waste. .

  Moreover, the solid content of the generated soil separated and removed from the muddy water is recovered from the muddy water treatment equipment, and a backfill material is produced by adding a solidifying material such as cement to the solid content of the generated soil. It is backfilled in the hole.

  In the case of the generated soil, if the strength as backfill material cannot be secured, procure fluidized soil that can develop strength from the outside, and then backfill it into the hole above the pile as backfill material. Yes.

JP-A-6-154863

  By the way, when the backfill material manufactured from the generated soil is used, sufficient fluidity may not be obtained due to the soil quality of the generated soil (for example, soil with a lot of sandy soil), and the backfill material is pumped. In addition, it becomes difficult to pump using a tremy tube. For this reason, the backfilling material must be put directly into the hole, the stable liquid in the hole becomes turbid due to the solid content of the backfilling material, and it takes a lot of work to process the recovered stable liquid, The stability liquid deteriorates early, and the number of times the stability liquid can be reused is greatly reduced.

  In addition, when fluidized soil is used as backfill material, sufficient fluidity can be ensured by adjusting the blending ratio, so the backfill material should be pumped using a pump and treme tube. However, there is no problem of turbidity of the stabilizing solution in the pores, but it is expensive to procure fluidized soil and costs to dispose of the generated soil as industrial waste. Will increase.

  The present invention has been made in view of the above-described conventional problems, and can reduce the cost required for the procurement of backfill material, and can also reduce the environmental burden. The purpose is to provide.

In order to solve the above problems, the present invention employs the following means.
That is, the present invention is characterized in that a backfill material is produced by adding water, cement, and a dispersant to sandy soil and mixing them.

  According to the method for producing a backfill material of the present invention, a backfill material can be produced using sandy soil as a raw material for the backfill material. Therefore, for example, it is possible to use the sandy soil of the solid content of the generated soil generated by excavating the ground when constructing the pile, and to manufacture the backfill material using this sandy soil as a raw material Therefore, when filling the hole in the upper part of the pile with the backfill material, it is not necessary to procure the fluidized soil from the outside as the backfill material. Moreover, since the amount of generated soil to be disposed of as industrial waste can be reduced, the environmental load can be reduced.

  In the present invention, the dispersant may be a polymer.

  According to the backfilling material of the present invention, the sandy soil particles can be uniformly dispersed throughout by the polymer dispersant.

  Furthermore, in the present invention, the sandy soil may have a particle size of 0.075 to 2.0 mm.

  According to the method for producing a backfill material of the present invention, a sandy soil having a particle size of 0.075 to 2.0 mm is used as a raw material, and water and cement are added thereto, and these are mixed together to form a sandy soil. It is possible to produce a backfilling material in which minute particles are uniformly dispersed throughout.

  Furthermore, in the present invention, the sandy soil may be contained in the generated soil generated by excavating the ground.

  According to the manufacturing method of the backfill material of the present invention, the sandy soil of the generated soil generated by excavating the ground can be effectively used as a raw material for the backfill material.

  As described above, according to the method for producing a backfill material of the present invention, a backfill material is obtained by using sandy soil as a raw material, adding water, cement, and a dispersant to this, and mixing them. Can be manufactured. Therefore, for example, when building a pile, it is possible to use the sandy soil content generated by excavating the ground, so when filling the hole in the upper part of the pile with backfill material, There is no need to procure fluidized soil from the outside as backfill material. Moreover, since the amount of generated soil to be disposed of as industrial waste can be reduced, the environmental load can be reduced.

It is the schematic which showed one Embodiment of the manufacturing method of the backfilling material by this invention. It is sectional drawing which showed the state which backfilled the backfilling material.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an embodiment of a method for producing a backfill material according to the present invention. The manufacturing method of the backfill material according to the present embodiment is effective for the construction of cast-in-place piles, and the sandy soil of the solid content constituting the generated soil generated by excavating the ground is used as a raw material. It is configured to produce a backfill material.

  When constructing a cast-in-place pile, as shown in FIG. 1, an excavator 1 (for example, a hydrophrase excavator) is used, and the excavator 1 is suspended from a winch wire of a crawler crane (not shown). The excavator 1 can be moved up and down via a wire by driving.

  A hydraulically driven rotary cutter 3 is rotatably provided at the lower end of the excavator 1. Further, the excavator 1 is provided with a hydraulic pipe that connects a hydraulic unit (not shown) including a hydraulic pump or the like installed on the ground and a drive source (hydraulic motor) of the rotary cutter 3, The rotary cutter 3 can be driven to rotate by supplying hydraulic pressure from the unit to the hydraulic motor through the hydraulic pipe.

  Further, the excavator 1 is provided with a discharge pipe having a plurality of discharge ports, and a stable liquid supply pipe that connects between the discharge pipe and a stable liquid supply device 6 installed on the ground. By supplying the stable liquid from the supply device 6 to the discharge pipe via the stable liquid supply pipe, the stable liquid can be discharged from each discharge port of the discharge pipe.

  Further, the excavator 1 includes a mud pump 4 for sucking up a mixed liquid (mud water 23) of the earth and sand (generated soil 24) and the stabilizing liquid 25 generated by excavating the ground 21 with the rotary cutter 3, and the mud water pump 4. A muddy water pipe 5 that guides the sucked muddy water 23 to the muddy water treatment device 12 on the ground is provided.

  Here, the stabilizing liquid 25 is a liquid composed of bentonite, a thickener, a polymer agent, a dispersing agent, and the like. By blending these at a blending ratio according to the soil quality of the ground 21, the ground 21 is blended. The property which maintains the stability of the inner wall of the formed hole 22 can be provided.

  Further, the generated soil 24 has different solid contents depending on the target ground 21, but is roughly divided into fine particles (clay: particle size 0.005mm, silt: particle size 0.075mm) and coarse particles (sand). : Particle size 0.075 to 2.0 mm, gravel: particle size 2.0 to 75 mm) and stone (stone: particle size 75 mm to 300 mm) ("Picture and soil engineering", page 10 , Classification by the particle size of soil particles, issue place: Ohm Co., Ltd., issued on June 28, 1999)

  In the present embodiment, sandy soil (particle size: 0.075 to 2.0 mm) in the solid content of the generated soil 24 is used as a raw material for the backfill material 27. Note that sandy soil as described above may not be obtained depending on the soil quality of the generated soil 24. In such a case, sandy soil having the same properties as described above may be procured from the outside.

  The stabilization liquid supply device 6 includes a stabilization liquid storage tank 7 that stores the stabilization liquid 25, and a stabilization liquid supply pump 8 that supplies the stabilization liquid 25 from the stabilization liquid storage tank 7 to the stabilization liquid supply pipe of the excavator 1. Yes. The stable liquid 25 sucked up by the muddy water pump 4 and separated from the solid content of the generated soil 24 by the muddy water treatment device 12 described later is collected and stored in the stable liquid storage tank 7.

  In the figure, 9 is a slurry pump for supplying the slurry-like solid content of the generated soil that has settled at the bottom of the stable liquid storage tank 7 to the second processing device 14 described later, and 10 in the figure is the stable liquid storage tank. 7 is a waste liquid pump that discharges the stable liquid deteriorated from 7 as waste liquid. The waste liquid discharged from the stable liquid storage tank 7 is supplied to the SMW plant 11 and used as an injection liquid for the soil cement wall. Alternatively, it is disposed of as waste liquid.

  The muddy water treatment device 12 includes a first treatment device 13 that separates the sandy soil of the generated soil 24 from the muddy water 23, and a second treatment device 14 that separates the viscous soil of the generated soil 24 from the muddy water 23. One or both of the first processing device 13 and the second processing device 14 are used according to the soil quality of the ground 21.

  The first treatment device 13 is, for example, a vibration sieve, and the muddy water 23 sucked up by the muddy water pump 4 is guided to the first treatment device 13 and the first treatment device 13 is driven. The sandy soil of the soil 24 is separated. The stabilizing liquid 25 that does not contain sandy soil is recovered from the first processing apparatus 13 and stored in the stabilizing liquid storage tank 7 of the stabilizing liquid supply apparatus 6.

  The second processing device 14 is, for example, a centrifuge (decanter), and the mud water 23 sucked up by the mud pump 4 is guided to the second processing device 14 and driven by the centrifugal force by driving the second processing device 14. The stable liquid 25 and the viscous soil of the generated soil 24 are separated into solid and liquid, and the viscous soil of the generated soil 24 contained in the muddy water 23 is separated. The stable liquid 25 that does not contain the viscous soil is recovered from the second processing apparatus 14 and stored in the stable liquid storage tank 7 of the stable liquid supply apparatus 6.

  In addition, when using both the 1st processing apparatus 13 and the 2nd processing apparatus 14, the sandy soil is isolate | separated from the mud water 23 with the 1st processing apparatus 13, and the mud water 23 which isolate | separated this sandy soil is used. The second treatment device 14 guides the viscous soil contained in the muddy water 23 in the second treatment device 14, and the second treatment device 14 supplies the stable liquid 25 that does not contain the sandy soil and the viscous soil. Are recovered and stored in the stable liquid storage tank 7 of the stable liquid supply device 6.

  The sandy soil separated from the stabilizing solution 25 by the first processing device 13 is collected from the first processing device 13 and supplied to the mixer 15 (such as a biaxial forced kneading mixer), and is mixed with the additive by the mixer 15. Thus, the backfill material 27 is manufactured.

  In this case, by using water, cement, and a dispersant (for example, a polymer, preferably a high-viscosity biodegradable polymer) as additives, these are added to the sandy soil, and these are mixed by the mixer 15. The backfill material 27 in which the particles of sandy soil are uniformly dispersed throughout is produced. The mixing ratio of the additive is adjusted so as to have a specific gravity, viscosity, wall-forming property, and fluidity suitable as the backfill material 27 of the target ground 21.

  Here, the biodegradable polymer is a polymer compound in which components are degraded over time due to the action of microorganisms and lose its function. For example, a biodegradable polymer is a semi-polymer that uses a natural polymer and cellulose as raw materials. Examples include synthetic polymers. However, the present invention is not limited to this, and any device having the same function may be used.

  The backfill material 27 manufactured by the mixer 15 is stored in the backfill material storage tank 16.

  Then, the excavator 1 having the above-described configuration is disposed at a predetermined position on the ground 21, and the excavator 1 is lowered by operating the winch of the crawler crane while the rotary cutter 3 is driven to rotate. Is drilled downward to form a hole 22 in the ground 21.

  At this time, the stabilizing liquid 25 is supplied from the stabilizing liquid supply device 6 to the stabilizing liquid supply pipe of the excavator 1, and the stabilizing liquid 25 is guided to the stabilizing liquid discharge pipe through the stabilizing liquid supply pipe. The earth and sand excavated by the rotary cutter 3 (the generated soil 24) and the stabilizing liquid 25 are mixed by discharging toward the ground 21.

  Then, after forming the hole 22 in the ground 21, the muddy water 23 is sucked up from the hole 22 by the muddy water pump 4 while operating the winch of the crawler crane to raise the excavator 1. It leads to the 1st processing apparatus 13 or the 2nd processing apparatus 14, and isolate | separates the sandy soil or the viscous soil of the generated soil 24 contained in the muddy water 23.

  And the stable liquid 25 which isolate | separated the sandy soil by the 1st processing apparatus 13 is collect | recovered in the stable liquid storage tank 7 of the stable liquid supply apparatus 6 from the 1st processing apparatus 13, and is made to store it. Alternatively, the stable liquid 25 from which the viscous soil has been separated by the second processing apparatus 14 is recovered from the second processing apparatus 14 and stored in the stable liquid storage tank 7 of the stable liquid supply apparatus 6. Alternatively, the stabilizing solution 25 from which the sandy soil has been separated by the first processing device 13 is guided from the first processing device 13 to the second processing device 14, and after the viscous soil has been separated by the second processing device 14, the second processing device. 14 is recovered and stored in the stable liquid storage tank 7 of the stable liquid supply device 6.

  Then, the sandy soil separated from the muddy water 23 by the first processing device 13 is recovered from the first processing device 13 and supplied to the mixer 15, and water, cement, and a dispersant (for example, a polymer, preferably A high-viscosity biodegradable polymer) is added and mixed with the mixer 15 to produce a backfill material 27 in which sandy soil particles are uniformly dispersed throughout.

  In parallel with the manufacturing work of the backfill material 27, a tremy tube (not shown) is inserted into the hole 22 formed in the ground 21, and the tremy tube is pulled through the hole 22 while pulling up the tremy tube. A pile 26 is constructed in the hole 22 by placing concrete in the hole 22. In this case, the hole 22 in the upper part of the pile 26 is filled with the stabilizing liquid 25 from the stabilizing liquid storage tank 7 of the stabilizing liquid supply device 6 and the inner wall of the hole 22 is stable. It is kept.

Then, the tremy pipe 17 is inserted into the hole 22 in which the pile 26 is constructed, the tip of the tremy pipe 17 is positioned at a position close to the upper end of the pile 26, and the pump 15 is operated to produce the mixer 15. The backfill material 27 is sequentially filled from the backfill material storage tank 16 into the hole 22 in the upper portion of the pile 26 through the tremy pipe 17 from the lower end to the upper end, and the whole in the hole 22 in the upper portion of the pile 26 is filled. Backfill with backfill material 27 (see FIG. 2).
In addition, you may comprise so that the backfill material 27 may be supplied to the tremy pipe | tube 17 by conveyance instead of the pumping pump 18. FIG.

  At this time, the stable liquid 25 overflowing from the hole 22 by filling the backfill material 27 into the hole 22 is sucked up by the stable liquid recovery pump 19 and is stabilized by the stable liquid supply device 6 through the stable liquid recovery pipe 20. It collects and stores in the liquid storage tank 7.

  In this way, a plurality of piles 26 can be constructed on the ground 21, and the hole 22 at the top of each pile 26 is filled with a backfill material 27 manufactured using the sandy soil of the generated soil 24 as a raw material. It will be possible to return.

  In the method of manufacturing the backfill material of the present embodiment configured as described above, the sandy soil and the viscous soil of the generated soil 24 are separated from the recovered mud water 23 and added to the sandy soil. By adding water, cement, and additives (for example, a polymer, preferably a high-viscosity biodegradable polymer) as an agent, and mixing this with a mixer 15, the particles of sandy soil are uniformly dispersed throughout. Since the backfill material 27 is manufactured and the backfill material 27 is backfilled in the hole 22 in the upper part of the pile 26, the generated soil 24 generated by excavating the ground 21 can be used effectively. It is possible to reduce the amount of generated soil 24 to be disposed as industrial waste, and to reduce the environmental load.

  Moreover, since the backfill material 27 having a predetermined strength can be manufactured by adjusting the mixing ratio of the additive added to the generated soil 24 (sandy soil), the strength of the generated soil 14 is insufficient. Therefore, it is not necessary to procure fluidized soil from outside.

  Furthermore, by adjusting the mixing ratio of the additive added to the generated soil 24 (sandy soil), the specific gravity, viscosity, wall-forming property, and fluidity are adjusted so as to correspond to the soil quality of the target ground 21. Since the adjusted backfill material 27 can be manufactured, the pumping using the pumping pump 18 and the tremy tube 17 becomes possible. Therefore, unlike the case where the backfill material 27 is directly put into the hole 22 at the top of the pile 26, the stabilizing liquid 25 is not turbid by the solid particles of the backfill material 27, and the inside of the hole 22 Thus, it is possible to reduce the time required for processing the recovered stable liquid 25, to prevent the stable liquid 25 from deteriorating at an early stage, and to increase the number of times the recovered stable liquid 25 is reused.

  In the above description, the backfill material 27 is manufactured using sandy soil as a raw material. However, the backfill material 27 may be manufactured using sandy soil mixed with some clay. In the above description, the sandy soil of the generated soil generated by excavating the ground 21 is used as the raw material, but the backfill material 27 is manufactured using the sandy soil procured from outside as the raw material. May be.

  In the above description, since the stabilizing liquid used for the construction of the cast-in-place pile is supplied to the SMW plant 11 at the same site as the construction site of the cast-in-place pile, it can be used as an injection liquid when constructing the soil cement wall. It is not necessary to treat the stabilizing liquid as a waste liquid, and the processing cost of the stabilizing liquid can be reduced and the environmental load can be reduced.

DESCRIPTION OF SYMBOLS 1 Excavator 3 Rotary cutter 4 Mud pump 5 Mud pipe 6 Stabilizing liquid supply device 7 Stabilizing liquid storage tank 8 Stabilizing liquid supply pump 9 Slurry pump 10 Waste liquid pump 11 SMW plant 12 Mud water processing apparatus 13 1st processing apparatus 14 2nd processing apparatus DESCRIPTION OF SYMBOLS 15 Mixer 16 Backfill material storage tank 17 Tremy pipe 18 Pressure feed pump 19 Stabilization liquid collection pump 20 Stabilization liquid collection pipe 21 Ground 22 Hole 23 Muddy water 24 Soil 25 Stabilization liquid 26 Pile 27 Backfill

Claims (4)

  A method for producing a backfill material, characterized in that a backfill material is produced by adding water, cement, and a dispersant to sandy soil and mixing them.   The method for producing a backfill material according to claim 1, wherein the dispersant is a polymer.   The method for producing a backfilling material according to claim 1 or 2, wherein the sandy soil has a particle size of 0.075 to 2.0 mm.   The method for producing a backfilling material according to any one of claims 1 to 3, wherein the sandy soil is contained in the generated soil generated by excavating the ground.

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