JP7194635B2 - Gap filling method - Google Patents

Description

The present invention relates to a construction method for filling gaps formed in the ground.

Gaps formed in the ground, such as gaps formed by pulling out sheet piles or residual piles, underground cavities, gaps between mountains and structures, etc., are generally filled with fillers because there is a risk of collapse. It is

For example, in Patent Document 1, earth and sand 32 made of fluidized treated soil mixed with adjustment mud and solidifying material is fed from the ground into the space 31 through the space 31 and the opening 24 of the casing 20, and the space 31 is filled with earth and sand. 32 backfilling is disclosed. In addition, the code|symbol is a thing of patent document 1 description.

JP-A-2003-64680

However, there is a need to avoid cement solidifying agents and bentonites remaining in the ground after backfilling as in Patent Document 1, and to replace them with natural materials.

Therefore, there arises a technical problem to be solved in order to fill the gap formed in the ground without using the fluidized treated soil, and an object of the present invention is to solve this problem.

In order to achieve the above object, the method for filling gaps according to the present invention is a method for filling gaps formed in the ground, wherein microorganisms capable of producing calcium carbonate are dissolved in a solvent, and soil or water is added to a biowater solution. a step of mixing a granular material that is slag to obtain a filling sand ; a step of injecting the filling sand into the gap; and draining the bio-aqueous solution in the gap and precipitating the granular material in the gap. and filling with.

According to this configuration, the granular material accumulates in the gap and the gap can be filled back without using the fluidized soil, and the calcium carbonate generated by the microorganisms after the granular material has accumulated in the gap fills the granular material. Early product consolidation allows for early stabilization of the particulate material.

Further, in the gap filling method according to the present invention, the gap is a gap formed by pulling out an existing pile buried underground, and the filling sand is injected into the gap while pulling out the existing pile. Preferably, the bio-aqueous solution in the gap is drained and the gap is filled with the granular material.

According to this configuration, since the granular material is filled in the gap formed by pulling out the existing pile, the gap can be backfilled without using the fluidized soil.

The present invention can fill gaps formed in the ground without using fluidized soil.

4 is a flow chart showing the procedure of the gap filling method according to the first embodiment of the present invention. FIG. 2 is a schematic diagram showing a main part of the procedure shown in FIG. 1; 6 is a flow chart showing procedures of a gap filling method according to a second embodiment of the present invention. FIG. 4 is a schematic diagram showing a main part of the procedure shown in FIG. 3; The flowchart which shows the procedure of the filling construction method of the clearance gap which concerns on the 3rd Embodiment of this invention. FIG. 6 is a schematic diagram showing the main part of the procedure shown in FIG. 5;

An embodiment of the present invention will be described based on the drawings. In addition, hereinafter, when referring to the number, numerical value, amount, range, etc. of the constituent elements, unless otherwise specified or clearly limited to a specific number in principle, it is limited to the specific number It does not matter if the number is greater than or less than a certain number.

In addition, when referring to the shape or positional relationship of components, etc., unless otherwise specified or in principle clearly considered otherwise, etc. include.

In addition, the drawings may exaggerate characteristic parts by enlarging them in order to make the characteristics easier to understand. In addition, in cross-sectional views, hatching of some components may be omitted in order to facilitate understanding of the cross-sectional structure of the components.

In the present embodiment, expressions indicating directions such as up and down, left and right are not absolute, and are appropriate when each component is in the posture depicted in the drawing. In some cases, it should be changed and interpreted according to changes in posture.

FIG. 1 is a flow chart showing the procedure of the gap filling method according to the first embodiment of the present invention. In the gap filling method according to the present embodiment, a filling material is injected into a gap formed by pulling out an existing pile buried underground to backfill the gap.

First, an injection machine for injecting filling sand as a filling material is installed around the existing pile (S1). The injection machine is, for example, a three-point piling machine, a backhoe or boring equipment.

Next, the injection rod 1 is inserted into the ground 2 (S2). The injection rod 1 supplies filler material into the ground 2, and is inserted into the ground 2 in the vicinity of the existing pile 3, as shown in FIG. 2(a). The injection rod 1 is inserted so that its lower end reaches a gap 4 (to be described later) formed by pulling out the existing pile 3 .

Next, filling sand is created (S3). Specifically, first, a thickener and a solvent are mixed to produce an aqueous polymer solution, and a granular material is kneaded into the aqueous polymer solution to produce a filling sand. Aqueous polymer solutions and filler sands are produced, for example, using mixing plants.

The aqueous polymer solution contains a thickener and a solvent. The solvent dissolves the thickening agent, such as water and organic solvents.

Any thickener may be used as long as it can obtain a desired viscosity when dissolved in a solvent and is decomposed in the ground 2 to reduce the viscosity. By using a neutral water-soluble polymer as the thickener, the thickener reacts with metal ions in the ground 2 to form a metal complex. This decomposes the thickener.

Examples of the neutral water-soluble polymer used as a thickener include polyethylene oxide (manufactured by Meisei Chemical Industry Co., Ltd., trade name: Alcox) and polyethylene glycol having a molecular weight smaller than that of polyethylene oxide. is not limited to Polyethylene oxide exhibits good viscosity, stringiness and slipperiness. Polyethylene glycol can provide viscosity, but compared to polyethylene oxide, the stringiness and slipperiness are extremely low.

When polyethylene oxide is used as a thickening agent, the viscosity increases as the average molecular weight of the thickening agent increases if the concentration of polyethylene oxide in the aqueous polymer solution is the same. That is, a thickener with a high average molecular weight can obtain a desired viscosity even at a low concentration. For example, if the concentration of the thickening agent is 0.5 wt % and the average molecular weight of the thickening agent is 4,000,000, an aqueous polymer solution with a viscosity of 200 mPa·s can be obtained. Considering the discharge pressure of the pump, the friction of the injection rod 1, etc., which will be described later, the viscosity of the aqueous polymer solution measured using a Brookfield viscometer in accordance with JIS Z8803 is set to 100 to 50000 mPa·s. is preferred. In addition, "average molecular weight" means a number average molecular weight here.

The average molecular weight of the thickener is set to 50,000 or more. The average molecular weight of the thickener is preferably 300,000 or more. More preferably, the thickener has an average molecular weight of 2 million or more. As a result, a desired viscosity can be secured even with a low concentration of polyethylene oxide, so that an aqueous polymer solution can be obtained at low cost.

The particulate material to be kneaded into the aqueous polymer solution is a conventionally known material such as sand, soil containing silt or gravel, crushed stone, recycled crushed stone, glass sand, slag, and the like.

Next, the existing pile 3 is pulled out (S4). For example, the large-diameter flyer construction method, the PG construction method, and the like are known as the extraction construction method for the existing piles 3 .

The large-diameter flyer construction method is a construction method in which the existing pile 3 is pulled out by pulling up the wire wound around the existing pile 3 after excavating the periphery of the existing pile 3 with a casing to cut the edge.

In addition, the PG method is a method of excavating the casing to the tip of the pile so as to wrap the outer circumference of the existing pile 3, then chucking the existing pile with claws inside the casing, and pulling up the existing pile 3 while it is housed in the casing. be. A gap 4 is formed in the ground by pulling out the existing pile 3. - 特許庁Note that the steps S1 to S4 are not limited to this order, and the order may be changed appropriately.

Next, filling sand 5 is injected into the ground 2 (S5). As shown in FIG. 2(b), the filling sand 5 is injected via the injection rod 1 into the gap 4 formed as the existing pile 3 is pulled up. Injection of the filling sand 5 is performed by pumping using a pump (not shown). Any pump may be used as long as it can supply the filling sand 5 into the injection rod 1, and for example, a concrete pump can be considered, but the pump is not limited to this.

Thereafter, the pulling up of the existing pile 3 and the injection of the filling sand 5 are repeated, and as shown in FIG. can be filled and backfilled (S6).

As described above, the method for filling the gap according to the present embodiment ensures that the filling sand 5 accumulated in the gap 4 is decomposed while ensuring a suitable viscosity when the filling sand 5 is pumped by the viscosity of the aqueous polymer solution. In other words, since the filling sand 5 becomes plastic while being deposited in the gap 4, the gap 4 formed after the existing pile 3 is pulled out can be backfilled.

Next, a gap filling method according to a second embodiment of the present invention will be described. Note that the configuration according to the present embodiment is the same as that of the above-described first embodiment except for the configuration described below, and redundant description thereof will be omitted. FIG. 3 is a flow chart showing the procedure of the gap filling method according to the second embodiment of the present invention.

First, an injection machine for injecting filling sand as a filling material and a drainage machine such as a pump for sucking up circulating water (described later) from the ground are installed around the existing piles 3 (S10).

Next, the injection rod 1 and the drainage rod 6 are inserted into the ground 2 (S11). As shown in FIG. 4( a ), the injection rod 1 and the drainage rod 6 are inserted into the ground 2 near the existing pile 3 . The injection rod 1 is inserted so that its lower end reaches a gap 4 (to be described later) formed by pulling out the existing pile 3 . The drain rod 6 is inserted so that its lower end reaches a predetermined depth.

Next, filling sand is created (S12). Specifically, first, microorganisms are dissolved in a solvent to produce a bio-aqueous solution, and granular materials are mixed with the bio-aqueous solution to produce filler sand. The bio-aqueous solution is produced, for example, by dissolving 0.5 mol (about 5 kg in about 1000 L of solvent (water)) of microorganisms. A solvent is, for example, water. Note that the concentration of microorganisms in the biowater solution can be changed as appropriate.

Microorganisms are carbonates produced using urease-producing microorganisms isolated from soil. Microorganisms are particulates of limestone, such as calcite or dolomite, which are capable of producing, for example, calcium carbonate, and through their crystal growth and cation exchange reactions, the particulate matter is product-consolidated. It should be noted that the reaction time for product solidification becomes faster as the concentration of microorganisms in the bio-water solution increases. Also, the bio-aqueous solution has low viscosity and easily permeates.

Next, the existing pile 3 is pulled out (S13). A gap 4 is formed in the ground 2 by pulling out the existing pile 3 . Note that the steps S11 to S13 are not limited to this order, and the order may be changed appropriately.

Next, filling sand 7 is injected into the ground 2 (S14). As shown in FIG. 4(b), the filling sand 7 is injected via the injection rod 1 into the gap 4 formed as the existing pile 3 is pulled up.

Specifically, first, the filling sand 7 is fed into the gap 4 by a pump or the like (not shown). Since the bio-aqueous solution 8 has a low viscosity, the filling sand 7 cannot be pushed out using a pressure pump, so the bio-aqueous solution 8 is sent by compressed air.

Next, in the gap 4, the granular material 9 having a high specific gravity precipitates and accumulates. In addition, since the particulate material 9 deposited in the gap 4 is solidified by the microorganisms, the initial strength is developed early.

Next, the bio-aqueous solution 8 is drained outside (S15). Only the bio-aqueous solution 8 in the gap 4 is pumped up to a water tank (not shown) through the drain rod 6 so that the granular material 9 is continuously sent into the gap 4 without the bio-aqueous solution 8 in the gap 4 overflowing to the outside. The bio-water solution 8 pumped up is preferably configured to circulate between the gap 4 and the water tank by being sent into the ground 2 again after being mixed with the granular material 9 . As a result, the usage amount of the bio-aqueous solution 8 is reduced.

Thereafter, the pulling up of the existing piles 3 and the injection of the filling sand 7 are repeated, and as shown in FIG. can be filled and backfilled (S16).

As described above, the gap filling method according to the present embodiment deposits the granular material 9 in the gap 4 via the bio-aqueous solution 8, and then the granular material 9 is quickly solidified by microorganisms. , the gap 4 formed after the existing pile 3 is pulled out can be backfilled and the granular material 9 can be stabilized at an early stage.

Next, a gap filling method according to a third embodiment of the present invention will be described. Note that the configuration according to the present embodiment is the same as that of the above-described first embodiment except for the configuration described below, and redundant description thereof will be omitted. FIG. 5 is a flow chart showing the procedure of the gap filling method according to the third embodiment of the present invention.

First, an injection machine for injecting filling sand as a filling material is installed around the existing pile 3 (S20).

Next, the injection rod 1 is inserted into the ground 2 (S21). As shown in FIG. 6( a ), the injection rod 1 is inserted into the ground 2 near the existing pile 3 . The injection rod 1 is inserted so that its lower end reaches a gap 4 (to be described later) formed by pulling out the existing pile 3 .

Next, filling sand is created (S22). Specifically, first, a thickening agent and a solvent are mixed to produce an aqueous polymer solution, and the granular material is kneaded into the aqueous polymer solution to produce a filling sand.

Next, the existing pile 3 is pulled out (S23). A gap 4 is formed in the ground 2 by pulling out the existing pile 3 . Note that the steps S21 to S23 are not limited to this order, and the order may be changed appropriately.

Next, the filling sand 5 is injected into the ground (S24). As shown in FIG. 6(b), the filling sand 5 is injected via the injection rod 1 into the gap 4 formed as the existing pile 3 is pulled up. Injection of the filling sand 5 is performed by pumping using a pump (not shown).

Thereafter, the pulling up of the existing pile 3 and the injection of the filling sand 5 are repeated, and as shown in FIG. can be filled and backfilled (S25).

Next, a drilling machine such as a boring machine is installed around the existing piles 3 (S26).

Next, as shown in FIG. 6(d), a vertical hole is bored in the injection sand using a boring machine, and the bio-water solution 10 is injected into the ground through this vertical hole (S27).

Specifically, bio-aqueous solution 10 produced by dissolving microorganisms in a solvent is permeated into filling sand 5 deposited in gap 4 via water injection rod 11 . The bio-aqueous solution 10 is produced by dissolving, for example, 0.5 mol (about 5 kg in about 1000 L of solvent (water)) of microorganisms. A solvent is, for example, water. Note that the concentration of microorganisms in the bio-aqueous solution 10 can be changed as appropriate.

Microorganisms are carbonates produced using urease-producing microorganisms isolated from soil. Microorganisms are particulates of limestone, such as calcite or dolomite, which are capable of producing, for example, calcium carbonate, and through their crystal growth and cation exchange reactions, the particulate matter is product-consolidated. It should be noted that the reaction time for product solidification becomes faster as the concentration of microorganisms in the bio-aqueous solution 10 increases. Also, the bio-aqueous solution 10 has a low viscosity and easily permeates.

Therefore, the filling sand 5 deposited in the gap 4 is solidified as a product by the permeation of the bio-water solution 10, and the initial strength is developed at an early stage.

As described above, the gap filling method according to the present embodiment ensures a suitable viscosity when pumping the filling sand 5 with the viscosity of the aqueous polymer solution, while the filling sand 5 is deposited in the gap 4. In order to make it plastic, the gap 4 formed after the existing pile 3 is pulled out is backfilled, and the filling sand 5 is quickly solidified by the microorganisms of the bio-water solution 10, so that the gap 4 is backfilled. Sand can be stabilized early.

It should be noted that the present invention can be modified in various ways without departing from the spirit of the present invention, and it is a matter of course that the present invention extends to the modified ones.

The method for filling gaps according to the present invention is not limited to those applied to backfilling gaps formed by pulling out the existing piles described above, for example, when filling underground cavities, gaps between mountains and structures, etc. It is also applicable to

REFERENCE SIGNS LIST 1 ... Injection rod 2 ... Ground 3 ... Existing pile 4 ... Gap 5, 7 ... Filling sand 6 ... Drainage rod 8, 10 ... Bio-water solution 9 ... Granular material 11... water injection rod

Claims (2)

A filling method for a gap formed in the ground,
a step of mixing a granular material such as soil or slag with a bio-water solution in which microorganisms capable of producing calcium carbonate are dissolved in a solvent to obtain a filling sand ;
injecting the filling sand into the gap;
draining the bio-aqueous solution in the gap and filling the gap with the precipitated granular material;
A gap filling method comprising: The gap is a gap formed by pulling out an existing pile buried in the ground,
2. The gap according to claim 1 , wherein the filling sand is injected into the gap while pulling out the existing pile to drain the bio-water solution in the gap and to fill the gap with the granular material. filling method.

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