JP4488403B2 - Waste mud recycling method and equipment for ground improvement method - Google Patents

Description

  The present invention relates to a method and an apparatus for reusing waste mud generated in ground improvement work.

  Ground improvement works are roughly classified into three methods: continuous wall method, mechanical stirring method, and high-pressure injection method. However, in any construction method, the waste mud generated by the ground improvement work is actually treated as industrial waste. Specifically, the waste mud is treated with a vacuum vehicle, and since it contains cement, it is left to solidify for a few days, or it is solidified by adding various solidifying materials, or using water-absorbing materials. In many cases, the water content of the mud is reduced and then dumped to a waste disposal site. There is also an example of discarding after adding the flocculant. All of these conventional methods are based on the premise that the sludge is dumped into the disposal site as industrial waste. Therefore, in recent years, the disposal site has become saturated in several years, The establishment of a new disposal site has become difficult due to opposition from residents who are concerned about adverse effects. Considering such a situation, the reduction and reuse of waste mud in the ground improvement method is indispensable now in the 21st century.

  From this point of view, various technologies for reducing and reusing waste mud have been proposed, and most of them contain particles contained in the waste as much as possible in order to reuse them as water. After removing and reducing the particle size of the residual particles as small as possible (for example, particle size of 75 μm or less), it is injected into the ground as it is or mixed with a solidified material (for example, see Patent Document 1). .

However, no matter how much particles are removed, there is a limit, and the more accuracy is required, the more complicated, excessive, and low-efficiency equipment for reuse becomes, and it is difficult to secure construction space. Or increase the construction cost.
Japanese Patent Laid-Open No. 11-152741

  Therefore, a problem to be solved by the present invention is to provide a waste mud recycling technique that enables processing with simple, space-saving and high efficiency.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
By passing the waste mud discharged by the ground improvement work through a plurality of screening devices and cyclone separators with different sieve hole diameters, particles with a particle size of more than 4.5 mm are removed from the waste mud, A reuse liquid production step for obtaining a reuse liquid in which the content of particles having a particle diameter of 4.5 mm or less is 5% by weight or less;
The reusable liquid has a series of proximal end inner pipes, a pressure reservoir, a distal end inner pipe, and an injection nozzle,
The cross-sectional area (S) of the pressure reservoir, the cross-sectional area (S1) of the proximal-side inner pipe, and the cross-sectional area (S2) of the distal-end inner pipe satisfy the relationship of the following formula:
S>S1> S2
The distal end side inner tube is bent at a right angle from the outlet portion of the pressure reservoir toward the outer tube of the monitor;
The spray nozzle extends linearly to the distal end side inner pipe and is provided on the outer peripheral surface of the monitor;
Supplied to a monitor in which the nozzle diameter of the spray nozzle is 4.5 mm or more, the tensile strength of the portion forming the inner surface is 370 N / mm ² or more, the proof stress is 305 N / mm ² or more, and the Rockwell hardness is 40 or more. A feeding step to
An injection step of injecting the reuse liquid at a pressure of 1 MPa or more from the injection nozzle of the monitor into the ground.
Reuse method of waste mud in ground improvement method characterized by this.

<Invention of Claim 2>
By passing the waste mud discharged by the ground improvement work through a plurality of screening devices and cyclone separators with different sieve hole diameters, particles with a particle size of more than 4.5 mm are removed from the waste mud, A reuse liquid production step for obtaining a reuse liquid in which the content of particles having a particle diameter of 4.5 mm or less is 5% by weight or less;
An improved liquid production step for obtaining an improved liquid obtained by mixing water with the reuse liquid;
The improvement liquid has a series of proximal end side inner pipes, a pressure reservoir, a distal end side inner pipe, and an injection nozzle,
The cross-sectional area (S) of the pressure reservoir, the cross-sectional area (S1) of the proximal-side inner pipe, and the cross-sectional area (S2) of the distal-end inner pipe satisfy the relationship of the following formula:
S>S1> S2
The distal end side inner tube is bent at a right angle from the outlet portion of the pressure reservoir toward the outer tube of the monitor;
The spray nozzle extends linearly to the distal end side inner pipe and is provided on the outer peripheral surface of the monitor;
Supplied to a monitor in which the nozzle diameter of the spray nozzle is 4.5 mm or more, the tensile strength of the portion forming the inner surface is 370 N / mm ² or more, the proof stress is 305 N / mm ² or more, and the Rockwell hardness is 40 or more. A feeding step to
An injection step of injecting the improved liquid from the injection nozzle of the monitor at a pressure of 1 MPa or more to the ground.
Reuse method of waste mud in ground improvement method characterized by this.

<Invention of Claim 3>
In the reuse liquid production step, the waste mud discharged by the ground improvement work is passed through a plurality of screening devices and cyclone separators having different sieve hole diameters, so that the particle size of 4.5 mm or more from the waste mud. After removing the particles and setting the content of particles having a particle size of 4.5 mm or less contained in the waste mud to 5% by weight or less, the viscosity is adjusted by at least one of a soil dispersant, a cement water reducing agent, an AE agent, and citric acid. The reuse method of waste mud in the ground improvement construction method according to claim 1 or 2 performed by adding one kind.

<Invention of Claim 4>
By passing the waste mud discharged by the ground improvement work through a plurality of screening devices and cyclone separators with different sieve hole diameters, particles with a particle size of more than 4.5 mm are removed from the waste mud, A recycle liquid production means for obtaining a recycle liquid having a content of particles having a particle diameter of 4.5 mm or less contained in an amount of 5 wt% or less;
A series of proximal inner pipes for supplying the recycle liquid, a pressure reservoir, a distal inner pipe, and an injection nozzle;
The cross-sectional area (S) of the pressure reservoir, the cross-sectional area (S1) of the proximal-side inner pipe, and the cross-sectional area (S2) of the distal-end inner pipe satisfy the relationship of the following formula:
S>S1> S2
The distal end side inner tube is bent at a right angle from the outlet portion of the pressure reservoir toward the outer tube of the monitor;
The spray nozzle extends linearly to the distal end side inner pipe and is provided on the outer peripheral surface of the monitor;
Supply means in which the nozzle diameter of the spray nozzle is 4.5 mm or more, the tensile strength of the portion forming the inner surface is 370 N / mm ² or more, the proof stress is 305 N / mm ² or more, and the Rockwell hardness is 40 or more; ,
An injection means for injecting the reuse liquid, the improvement liquid or water from the injection nozzle of the supply means to the ground at a pressure of 1 MPa or more;
Wastewater reuse equipment in the ground improvement method characterized by this.

<Invention of Claim 5>
By passing the waste mud discharged by the ground improvement work through a plurality of screening devices and cyclone separators with different sieve hole diameters, particles with a particle size of more than 4.5 mm are removed from the waste mud, Solid-liquid separation means for containing 5% by weight or less of particles having a particle size of 4.5 mm or less , viscosity measurement means for measuring the viscosity of the liquid treated by the solid-liquid separation means, and viscosity measured by the viscosity measurement means From the viscosity adjusting means for adding a viscosity adjusting agent to the liquid treated by the solid-liquid separation means and obtaining a recycled liquid whose viscosity is adjusted. A recycle liquid production means for obtaining a recycle liquid,
An improved liquid production means for obtaining an improved liquid by mixing water with the reuse liquid;
A series of proximal inner pipes for supplying the improved liquid, a pressure reservoir, a distal inner pipe, and an injection nozzle;
The cross-sectional area (S) of the pressure reservoir, the cross-sectional area (S1) of the proximal-side inner pipe, and the cross-sectional area (S2) of the distal-end inner pipe satisfy the relationship of the following formula:
S>S1> S2
The distal end side inner tube is bent at a right angle from the outlet portion of the pressure reservoir toward the outer tube of the monitor;
The spray nozzle extends linearly to the distal end side inner pipe and is provided on the outer peripheral surface of the monitor;
Supply means in which the nozzle diameter of the spray nozzle is 4.5 mm or more, the tensile strength of the portion forming the inner surface is 370 N / mm ² or more, the proof stress is 305 N / mm ² or more, and the Rockwell hardness is 40 or more; ,
An injection means for injecting the improvement liquid from the injection nozzle of the supply means at a pressure of 1 MPa or more to the ground.
Wastewater reuse equipment in the ground improvement method characterized by this.

<Invention of Claim 6>
The inlet diameter of the pressure reservoir is 15 to 35 mm, the pipe diameter of the pressure reservoir is 50 to 85 mm, the pipe length of the pressure reservoir is 20 to 85 mm, and the pressure reservoir The facility for reusing mud in the ground improvement method according to claim 4 or 5, wherein the diameter of the outlet of the ground is 80% or less of the diameter of the inlet.

  The present invention is based on the premise that particles cannot be removed from the conventional idea of removing particles as much as possible, and even in such a case, the recycled liquid is surely put in the ground. It is characterized in that the strength and the diameter of the reusable liquid spray nozzle are determined so that they can be supplied. Therefore, according to the present invention, it is possible to use simple and space-saving equipment while reducing the possibility of nozzle clogging and equipment wear, and it is not necessary to place importance on removal efficiency. The use liquid can be manufactured.

  In the present invention, it is desirable to adjust the reuse liquid to a viscosity corresponding to the supply pressure into the ground. In this case, the supply of the reuse liquid into the ground can be made more reliable. Other details will be described later.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 shows a facility outline of a ground improvement method to which the present invention is applied. Reference numeral 1 denotes a water storage tank, and reference numeral 2 denotes a solidification material storage silo such as cement. These injection materials are introduced into the improved liquid production apparatus 3 by a pump (not shown) as required. In the improved liquid production apparatus 3, water and a solidifying material are mixed to produce an improved liquid, and the produced improved liquid is sent out by the injection pump P2 via the pressure feed hose 32 and supplied to the injection pipe 10 inserted in the ground. Further, it is supplied into the ground G through the injection pipe 10.

  Further, in a certain ground improvement method, prior to or together with the supply of the improvement liquid into the ground G, water is injected to the planned ground improvement portion through the injection pipe 10 inserted into the ground G, May cut or relax. The illustrated form assumes this case, and the stored water in the water storage tank 1 can be directly supplied to the injection pipe 10 via the pumping hose 31 by the pump P1.

Furthermore, in the ground improvement method, in order to increase the cutting ability when injecting water into the ground improvement planned part and injecting water into the ground improvement planned part in order to increase the improved diameter There is also a method of injecting water and high-pressure air. The illustrated form assumes this case, and high-pressure air from the compressor C can be supplied to the injection pipe 10 via the air hose 33.

  In such ground improvement methods, mud is discharged from the hole opening with the supply of drilling water, cutting water or relaxation water into the ground G, or with the supply of the improvement liquid into the ground. For this reason, usually, a mud pit 41 is provided at the hole, and the mud discharged here is collected.

  In the present invention, the recovered sludge is reused. For this reason, in the illustrated form, the mud in the mud pit 41 is sucked by the suction pump P <b> 3 and supplied to the reuse liquid manufacturing apparatus 4. An example of the reuse liquid production apparatus 4 is shown in FIG. The waste mud is put into the waste mud storage tank 4A and temporarily stored, and then supplied to the solid-liquid separation means 4S by a pump to remove particles with a particle size of more than 4.5 mm and dry residual particles. The amount of recycled liquid is 5% by weight or less. The removed solid content is disposed of in the same manner as before.

  The solid-liquid separation means 4S is not particularly limited as long as the reusable liquid can be produced, but from the viewpoint of installation area and cost, the screening device 4B such as a vibration sieve having a sieve hole diameter of 4 mm to 0.088 mm is used for 1-4. It is preferable that the first stage is equipped with the cyclone type separation device 4C in the latter stage, and after removing the coarse particles to some extent in the first stage 4B, the latter stage 4C is used to finish and remove the fine particles.

The recycle liquid obtained by solid-liquid separation may be used as it is, but depending on the content of silt or clay, the viscosity becomes high and there is a risk of injecting the injection nozzle. Therefore, in such a case, it is preferable to adjust the viscosity by temporarily storing the reuse liquid in the adjustment tank 4D as illustrated. Specifically, when a viscosity measuring means 4E such as a B-type viscometer is provided in the adjustment tank 4D, it is determined whether or not the viscosity measured by the viscosity measuring means 4E is a predetermined value or more. Viscosity can be adjusted by adding one or a plurality of viscosity modifiers such as a soil dispersant, a cement water reducing agent, an AE agent, and citric acid to the liquid in the adjustment tank 4D. Preferably provided 撹拌device for adjusting tank 4D. As the soil dispersant, a polycarboxylic acid-based one can be used publicly, and as a water reducing agent for cement, an AE water reducing agent and a high performance AE water reducing agent (including a delay type) are used in addition to a normal water reducing agent. be able to.

  Specifically, when the reuse liquid is injected into the ground G at a low pressure of 1 to 10 MPa when the reuse liquid is used, the reuse liquid is 20 to 20 so that the P funnel flow value is less than 20 seconds. When spraying into the ground at a high pressure of 50 MPa, it is preferable to adjust the viscosity so that the P funnel flow value is less than 15 seconds. In this case, when a B-type viscometer is used as the viscosity measuring means, it can be dealt with by converting the measured value into a P funnel flow value. The correlation graph for this conversion is shown in FIG. The P funnel flow value (seconds) in the present invention means a value measured according to a mortar fluidity test (P funnel method) according to the Japan Society of Civil Engineers standards.

In the present invention, the reused liquid thus obtained is used as part or all of the water used for ground improvement as it is or after being mixed with other materials, and then the nozzle diameter is 4.5 mm or more to form the inner surface. It is fed into the ground at a pressure of 1 MPa or more through a nozzle having a tensile strength of 370 N / mm ² or more, a proof stress of 305 N / mm ² or more, and a Rockwell hardness of 40 or more. A suitable nozzle inner diameter is 4.5 to 10 mm. In the case of a carbon steel pipe for machine structure (STKM), STKM13B or higher (that is, 13C, 14A, etc.) corresponds to this.

Hereinafter, a specific example of an injection tube will be described. FIG. 3 shows an example of a portion having an injection nozzle attached to the tip of the injection tube, that is, a portion generally called a monitor, and is a three-channel tube constituted by a triple tube. The injection pipe 10 has three flow paths at the base end: a drilled water WO and a flow path 11 for improved liquid M at the center, a flow path 12 for high-pressure water W in the middle, and a flow path 13 for compressed air A on the outside. Has a road. Inner tube portions 20, 21, 22 and a distal end body 23 are provided on the distal end side of the proximal end portion. Moreover, the injection tube 10 is a self-drilling type, and a drilling bit 14 is attached to the tip thereof. The drill bit 14 is formed with a discharge hole for discharging the drill water WO sent through the drill water WO channel 11.

Moreover, high pressure water injection nozzles 15, 15 that inject only high pressure water W are attached to the inner pipe portion 20, and are communicated with the high pressure water flow paths 12, 12. At the same position in the vertical direction of the injection pipe 10, Two places are provided at opposite positions. The injection directions of the high-pressure water W are all horizontal. The water injection nozzle 15 in the illustrated example is composed of an outer shell member that constitutes an attachment portion for the injection pipe, and an inner surface constituent member having a reduced inner diameter (nozzle diameter) on the distal end side with respect to the proximal end side. In such a double structure, the inner diameter of the inner surface component member is 4.5 mm or more, and the inner surface member has a tensile strength of 370 N / mm ² or more and a proof stress of 305 N / mm. The nozzle of the present invention can be formed by using a material having ² or more and Rockwell hardness of 40 or more.

Further, below the position of the injection pipe 10 where the high pressure water injection nozzles 15 and 15 are provided, the improvement liquid injection nozzles 16 and 16 for high pressure injection of the improvement liquid M and the compressed air A are provided on the two sides. Yes. As shown in an enlarged view in FIG. 3, the improved liquid injection nozzle 16 is composed of a core nozzle 16A for injecting the improved liquid M and an surrounding nozzle 16B that surrounds the periphery of the core nozzle 16A and injects compressed air A. Each of which is in communication with the improvement liquid flow path 11 or the compressed air flow path 13 (Note that the communication between the compressed air flow path 13 and the surrounding nozzle 16B is orthogonal to the compressed air flow path 13) It is communicated via the flow path 13A). The improved liquid jet nozzles 16 are provided at two different positions in the vertical direction of the injection tube 10 and at opposite positions. Regarding the injection direction of the improvement liquid M and the compressed air A, the upper improvement liquid injection nozzle 16 is obliquely downward, and the lower improvement liquid injection nozzle 16 is horizontal. When the reuse liquid is used as the improvement liquid as in the present embodiment, the diameter of the core nozzle (improvement liquid injection nozzle) 16A is 4.5 mm or more, and the whole core nozzle 16A has a tensile strength of 370 N / mm. The nozzle of the present invention can be formed by forming with a material of ² or more, proof stress of 305 N / mm ² or more, and Rockwell hardness of 40 or more.

The switching of the flow path direction in which the drilling water WO is sent from the drilling water and improvement liquid channel 11 to the drilling water discharge hole (not shown) or the improvement liquid M is sent to the improvement liquid injection nozzle 16 is performed at the tip of the injection pipe 10. The switching valve 17 is built in. The switching valve 17 includes a valve seat 17A and a ball 17B thrown toward the valve seat 17A. When supplying the drilling water WO , the ball 17B is not introduced, and the drilling water WO is sent to the drilling water discharge hole through the flow path 18 passing through the valve seat 17A. When supplying the improved liquid M, the flow path 18 is sealed by introducing the ball 17B, and the improved liquid M is sent to the improved liquid injection nozzle 16.

In order to improve the ground G using the injection pipe 10, as shown in FIG. 1, first, the drilling water WO is supplied from a discharge hole (not shown) at the tip of the injection pipe 10 using a drilling device 40 such as a boring machine. While discharging, the ground is drilled until the tip of the injection tube 10 reaches the ground improvement planned lower limit position, and the injection tube 10 is arranged at a predetermined position. Then, when pulling up the injection tube 10 while rotating around the axis, only the high-pressure water W is injected from the water injection nozzle 15, and the improved liquid M is supplied from the improved liquid injection nozzle 16 provided at a position lower than this to the compressed air. An improved body is created in the ground G by performing high-pressure injection while being accompanied. And the waste mud discharged | emitted by the creation process to the waste mud pit 41 is collect | recovered by the pump P3 as above-mentioned, is supplied to the reuse liquid manufacturing apparatus 4, and will be reused.

  The application target of the present invention is not limited to this injection pipe example, and any nozzle of any construction method can be used as long as the reuse liquid is sent out to the ground. Of course, it is applicable.

  Thus, instead of pursuing the removal of particles to the utmost limit, the particle size of 4.5 mm or less is stopped at a level containing 5 wt% or less (dry content), and the diameter, strength, and injection pressure of the injection nozzle for the reuse liquid are controlled. By using a specific range, even with simple and space-saving equipment, the possibility of nozzle clogging and wear is reduced, and the supply to the ground can be made reliably, and there is no need to place importance on removal efficiency. This makes it possible to produce a reusable liquid with efficiency.

(Other)
(A) Examples of the ground improvement method to which the present invention can be applied include a continuous wall method, a mechanical stirring method, and a high-pressure jet method. In the present invention, waste mud by any of these methods can be used, and any method can be reused. Moreover, in this invention, after processing the sludge collect | recovered in a certain construction location by this invention, it can also be reused in another construction location. Therefore, for example, the waste mud collected by a certain kind of ground improvement method can be used as a reuse liquid according to the present invention and then used by another kind of ground improvement method.

(B) Further, the reuse liquid of the present invention can be reused only for cutting (or relaxation) of a hole or a ground improvement scheduled portion without mixing with other materials such as a solidified material. In addition, since the reusable liquid of the present invention contains particles having a remarkably large particle size as compared with the conventional one, if this is used for cutting the ground improvement planned portion, the cutting ability is increased, although it is slight. There is a side effect.

(C) In a ground improvement method in which a recycle liquid is mixed with a solidifying material to produce an improvement liquid, a cement quantitative measurement device for measuring the cement content of the recycle liquid is used, for example, from the recycle liquid production apparatus 4 Until the improvement liquid production apparatus 3, more specifically, it is provided in the adjustment tank 4D in FIG. 2 and the like, and based on the measurement result, the insufficient cement with respect to the design value set in advance in the improvement liquid production apparatus 3 is provided. It is also preferable to be configured to supply to the reuse liquid. In addition, the code | symbol 4F in FIG. 2 has shown the cement quantitative measurement apparatus. As the cement quantitative measurement device 4F, a type based on the quantitative determination of Ca ions can be used.

(D) In the present invention, as long as at least the nozzle portion has a specific diameter and strength, the configuration of the pressure feed line up to that point is not limited. The specific inner diameter similar to that of the nozzle of the present invention is also applied to a portion that may be clogged or worn, such as a bent portion, a curved portion, or a reduced diameter portion other than the nozzle (a portion where the inner diameter of the tube is reduced). It is preferable to have strength. Of course, the entire pressure feed line can have a specific inner diameter and strength similar to those of the nozzle of the present invention.

FIG. 4 shows an example of a monitor having a bent portion and a reduced diameter portion. The monitor 50 includes a fluid ejection nozzle 53 formed on the outer peripheral surface of the distal end portion, and a supply pipe that is in the monitor and supplies fluid to the ejection nozzle 53. The injection nozzle 53 has a flow path formed in a tapered shape. Characteristically, a base end side inner tube 52b extends from the base end side to the vicinity of the injection nozzle 53 in the outer tube 52a forming the outer surface of the monitor 50, and this base end side inner tube 52b. The cylindrical tank part which makes the pressure reservoir part 54 is connected to the front-end | tip of the outer pipe 52a along the longitudinal direction, and the front-end | tip of this reservoir part 54 and the injection nozzle 53 extend in the direction orthogonal to the outer pipe | tube longitudinal direction. It is connected via the side inner pipe 52c. That is, the proximal end side inner tube 52b forms an upstream portion with respect to the pressure reservoir portion 54, and the distal end side inner tube 52c forms a downstream portion.

In the illustrated example, the pressure reservoir 54 has a larger area S in the cross section perpendicular to the fluid flow direction than the proximal and distal inner pipes 52b and 52c, and temporarily stores the fluid. As a result, the rectifying action is exhibited and the stabilizing action of the supply pressure to the injection nozzle 53 side is exhibited. Therefore, the pressure reservoir 54 mentioned here does not include a portion where the conduit 2 is simply bent. The pressure reservoir 54, for example, the area of the cross section perpendicular to the fluid flow direction in the pressure reservoir 54 (outer tube longitudinal direction) and S, and the length of the fluid flow direction of the pressure reservoir 54 is L, the proximal end When the area of the cross section perpendicular to the fluid flow direction (outer pipe longitudinal direction) in the side inner pipe 52b is S1, and the area of the cross section perpendicular to the fluid flow direction in the distal end side inner pipe 52c is S2,
S>S1> S2
It can be formed by determining S, S1 and S2 according to the diameter of the monitor 1 so as to satisfy the relationship.

Thus, when injecting the fluid, the fluid such as water supplied from the pump (not shown) through the proximal end side inner pipe 52b is temporarily stored in the pressure reservoir 54, and after rectification and pressure stabilization are achieved, It is injected from the injection nozzle 53 through the distal end side inner pipe 52c. As a result, the injection force can be increased by about 1.5 times or more compared with the case where the pressure reservoir 54 is not provided.

  Particularly preferably, as shown in the figure, an outlet to the tip side inner pipe 52c is formed at the tip of the pressure reservoir 54 far from the injection nozzle 53, and the tip side inner pipe 52c is perpendicular to the outlet part. After being bent, the linearly extending in the transverse direction of the monitor 50 is formed so as to reach the injection nozzle 53. Further, the injection nozzle 53 is formed so as to reach the outside of the insertion axis with a linear internal pipe line coaxially connected to the linear part of the distal end side inner pipe 52c. As a result, it is possible to secure the maximum linear portion on the side of the injection nozzle 53 in the flow path portion from the pressure reservoir 54 to the injection nozzle 53, and the fluid delivered from the pressure reservoir 54 is maximally vigorous. Therefore, the injection power can be remarkably increased. In other words, this part becomes an increasing part. However, when the length of the linear energizing portion exceeds a certain level, for example, about 80 mm shown in a preferred dimension example described later, the injection force enhancing effect is saturated. This is presumably because the pressure reservoir 54 is too far from the injection nozzle 53, and the effectiveness of the rectifying and stabilizing action is reduced by the length of the distal end side inner pipe 52c and cannot be fully exhibited. Therefore, the length of the pipe line is not simply increased by using the distal side inner pipe 52c as a curved pipe.

Further, in addition to the shape of the distal end side inner tube 52c and the nozzle, the injection force can be increased by about four times or more compared with the conventional case by satisfying the following dimensional conditions.
The inlet from the proximal end inner pipe 52b in the pressure reservoir 54 and the pipe diameter d1: 15 to 35 mm of the proximal end inner pipe 52b.
Pipe diameter φ2 of the pressure reservoir 54: 50 to 85 mm
Pipe length L of the pressure reservoir 54: 20 to 85 mm
Outflow port to the tip side inner pipe 52c in the pressure reservoir 54 and the pipe diameter d2 of the tip side inner pipe: 12 to 28 mm (and ≦ 0.8 × d1)
Sum x of the pipe length of the straight portion in the front end side inner pipe 52c and the pipe length in the injection nozzle: 50 to 80 mm
Diameter d3 of the injection nozzle 53: 4.5 to 6 mm

Incidentally, the monitor assumed in this dimension example has an inner diameter φ1 of about 110 mm. Therefore, for a monitor outside this range, a dimension appropriately scaled down or scaled up according to the inner diameter of the monitor can be suitably applied. That is, the above dimension example is expressed as a numerical value (mm / φ1 (mm)) per 1 mm of the monitor inner diameter, and each dimension value can be obtained by multiplying the monitor inner diameter by these coefficients.
d1 = 0.14 to 0.32
φ2 = 0.45-0.77
L = 0.18-0.77
d2 = 0.11 to 0.25 (and ≦ 0.8 × d1)
x = 0.45-0.73
d3 = 0.04 ~0.05
In the monitor thus configured, the outlet to the front end side inner tube 52c in the pressure reservoir 54 is a reduced diameter portion similar to the nozzle 53, and the front end side inner tube 52c has a bent portion. These parts are more likely to be clogged or worn than other parts. Therefore, in such a case, it is desirable that not only the nozzle 53 but also the reduced diameter portion and the bent portion have the specific strength and inner diameter of the present invention.

  Two types of nozzles made of STKM13B carbon steel pipes for mechanical structures are available, with diameters of φ4.5 mm and φ3.1 mm, and sand content of 4.5 mm or less is 0% by weight, 2% by weight, 4% by weight And 4 types of test water containing 6% by weight (all dry contents) were prepared, and an injection test was conducted under the condition of controlling the discharge pressure to 30 MPa, and the relationship between the discharge pressure and the amount of sand content was examined. The P funnel float values of the test water were all less than 10 seconds. The test results are shown in FIGS. From this result, when the content of residual particles in the recycle liquid is 5% by weight or less, stable discharge is possible, while in the case of 6% by weight, the nozzle is blocked in about 15 minutes from the start of injection. .

  There are 6 types of nozzles, STKM-13A, B, and C, 2 types, φ4.5mm and φ3.1mm, and 5% by weight of sand less than 4.5mm. Test water with a P funnel float value of less than 10 seconds was prepared, and an injection test was conducted under the condition of controlling the discharge pressure to 30 MPa, and the relationship between the nozzle material and the damage time was examined. The test results are shown in FIG. 7 and FIG. From this result, it was found that the same level of durability as that of the conventional nozzle can be secured if the nozzle is STKM-13B or higher.

  Two types of nozzles made of STKM13B mechanical structure carbon steel pipes, φ4.5 mm and φ3.1 mm, are prepared according to the diameter, and test water containing 5% by weight (dry content) of sand less than 4.5 mm 4 types of P funnel float values of 8 seconds, 10 seconds, 15 seconds, and 20 seconds are prepared, and an injection test is performed under the condition that the discharge pressure is controlled to 3 MPa, and the discharge pressure and viscosity (P funnel float value) I investigated the relationship. The test results are shown in FIG. 9 and FIG. From this result, it was found that the nozzle clogging can be prevented by setting the P funnel float value to less than 20 seconds when performing low pressure injection.

  Two types of nozzles made of STKM13B mechanical structure carbon steel pipes, φ4.5 mm and φ3.1 mm, are prepared according to the diameter, and test water containing 5% by weight (dry content) of sand less than 4.5 mm Are prepared in three types with a P funnel float value of 8 seconds, 10 seconds, and 15 seconds, and an injection test is conducted under the condition that the discharge pressure is controlled to 30 MPa, and the relationship between the discharge pressure and viscosity (P funnel float value) Examined. The test results are shown in FIG. 11 and FIG. From this result, it was found that when the high pressure injection is performed, the nozzle clogging can be prevented by setting the P funnel float value to less than 15 seconds.

  For example, waste mud discharged in various ground improvement works such as a continuous wall method, a mechanical stirring method, and a high-pressure injection method can be reused with simple equipment.

It is a block diagram showing an example of ground improvement equipment to which the present invention is applied. It is a block diagram of the example of a reuse liquid manufacturing apparatus. It is a longitudinal cross-sectional view of a monitor example. It is a schematic diagram of another example of a monitor. 2 is a graph showing test results of Example 1. FIG. 2 is a graph showing test results of Example 1. FIG. 6 is a graph showing the test results of Example 2. 6 is a graph showing the test results of Example 2. 6 is a graph showing the test results of Example 3. 6 is a graph showing the test results of Example 3. 6 is a graph showing the test results of Example 4. 6 is a graph showing the test results of Example 4. It is a graph which shows the correlation with a B-type viscosity and a P funnel flow value.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Water storage tank, 2 ... Solidification material storage silo, 3 ... Improvement liquid manufacturing apparatus, 4 ... Reuse liquid manufacturing apparatus, 10 ... Injection pipe.

Claims (6)

By passing the waste mud discharged by the ground improvement work through a plurality of screening devices and cyclone separators with different sieve hole diameters, particles with a particle size of more than 4.5 mm are removed from the waste mud, A reuse liquid production step for obtaining a reuse liquid in which the content of particles having a particle diameter of 4.5 mm or less is 5% by weight or less;
The reusable liquid has a series of proximal end inner pipes, a pressure reservoir, a distal end inner pipe, and an injection nozzle,
The cross-sectional area (S) of the pressure reservoir, the cross-sectional area (S1) of the proximal-side inner pipe, and the cross-sectional area (S2) of the distal-end inner pipe satisfy the relationship of the following formula:
S>S1> S2
The distal end side inner tube is bent at a right angle from the outlet portion of the pressure reservoir toward the outer tube of the monitor;
The spray nozzle extends linearly to the distal end side inner pipe and is provided on the outer peripheral surface of the monitor;
Nozzle diameter of the injection nozzle is equal to or greater than 4.5 mm, the tensile strength of the portion forming the inner surface 370N / mm ² or more, proof stress supplied to the nozzle 305N / mm ² or more and a Rockwell hardness of 40 or more A feeding step to
An injection step of injecting the reuse liquid at a pressure of 1 MPa or more from the injection nozzle of the monitor into the ground.
Reuse method of waste mud in ground improvement method characterized by this. By passing the waste mud discharged by the ground improvement work through a plurality of screening devices and cyclone separators with different sieve hole diameters, particles with a particle size of more than 4.5 mm are removed from the waste mud, A reuse liquid production step for obtaining a reuse liquid in which the content of particles having a particle diameter of 4.5 mm or less is 5% by weight or less;
  An improved liquid production step for obtaining an improved liquid obtained by mixing water with the reuse liquid;
  The improvement liquid has a series of proximal end side inner pipes, a pressure reservoir, a distal end side inner pipe, and an injection nozzle,
  The cross-sectional area (S) of the pressure reservoir, the cross-sectional area (S1) of the proximal-side inner pipe, and the cross-sectional area (S2) of the distal-end inner pipe satisfy the relationship of the following formula:
    S> S1> S2
  The distal end side inner tube is bent at a right angle from the outlet portion of the pressure reservoir toward the outer tube of the monitor;
  The spray nozzle extends linearly to the distal end side inner pipe and is provided on the outer peripheral surface of the monitor;
  The nozzle diameter of the injection nozzle is 4.5 mm or more, and the tensile strength of the portion forming the inner surface is 370 N / mm ² As described above, the yield strength is 305 N / mm ² A supply step for supplying to a nozzle having a Rockwell hardness of 40 or more,
  An injection step of injecting the improved liquid from the injection nozzle of the monitor at a pressure of 1 MPa or more to the ground.
  Reuse method of waste mud in ground improvement method characterized by this. In the reuse liquid production step, the waste mud discharged by the ground improvement work is passed through a plurality of screening devices and cyclone separators having different sieve hole diameters, so that the particle size of 4.5 mm or more from the waste mud. After removing the particles and setting the content of particles having a particle size of 4.5 mm or less contained in the waste mud to 5% by weight or less, the viscosity is adjusted by at least one of a soil dispersant, a cement water reducing agent, an AE agent, and citric acid. The reuse method of waste mud in the ground improvement construction method according to claim 1 or 2 performed by adding one kind.   By passing the waste mud discharged by the ground improvement work through a plurality of screening devices and cyclone separators with different sieve hole diameters, particles with a particle size of more than 4.5 mm are removed from the waste mud, A recycle liquid production means for obtaining a recycle liquid having a content of particles having a particle diameter of 4.5 mm or less contained in an amount of 5% by weight or less;
  A series of proximal inner pipes for supplying the recycle liquid, a pressure reservoir, a distal inner pipe, and an injection nozzle;
  The cross-sectional area (S) of the pressure reservoir, the cross-sectional area (S1) of the proximal-side inner pipe, and the cross-sectional area (S2) of the distal-end inner pipe satisfy the relationship of the following formula:
    S> S1> S2
  The distal end side inner tube is bent at a right angle from the outlet portion of the pressure reservoir toward the outer tube of the monitor;
  The spray nozzle extends linearly to the distal end side inner pipe and is provided on the outer peripheral surface of the monitor;
  The nozzle diameter of the injection nozzle is 4.5 mm or more, and the tensile strength of the portion forming the inner surface is 370 N / mm ² As described above, the yield strength is 305 N / mm ² And a supply means having a Rockwell hardness of 40 or more,
  An injection means for injecting the reused liquid from the injection nozzle of the supply means to the ground with a pressure of 1 MPa or more;
Wastewater reuse equipment in the ground improvement method characterized by this. By passing the waste mud discharged by the ground improvement work through a plurality of screening devices and cyclone separators with different sieve hole diameters, particles with a particle size of more than 4.5 mm are removed from the waste mud, Solid-liquid separation means for containing 5% by weight or less of particles having a particle size of 4.5 mm or less , viscosity measurement means for measuring the viscosity of the liquid treated by the solid-liquid separation means, and viscosity measured by the viscosity measurement means From the viscosity adjusting means for adding a viscosity adjusting agent to the liquid treated by the solid-liquid separation means and obtaining a recycled liquid whose viscosity is adjusted. A recycle liquid production means for obtaining a recycle liquid,
An improved liquid production means for obtaining an improved liquid by mixing water with the reuse liquid;
A series of proximal inner pipes for supplying the improved liquid, a pressure reservoir, a distal inner pipe, and an injection nozzle;
The cross-sectional area (S) of the pressure reservoir, the cross-sectional area (S1) of the proximal-side inner pipe, and the cross-sectional area (S2) of the distal-end inner pipe satisfy the relationship of the following formula:
S>S1> S2
The distal end side inner tube is bent at a right angle from the outlet portion of the pressure reservoir toward the outer tube of the monitor;
The spray nozzle extends linearly to the distal end side inner pipe and is provided on the outer peripheral surface of the monitor;
Supply means in which the nozzle diameter of the spray nozzle is 4.5 mm or more, the tensile strength of the portion forming the inner surface is 370 N / mm ² or more, the proof stress is 305 N / mm ² or more, and the Rockwell hardness is 40 or more; ,
An injection means for injecting the improvement liquid from the injection nozzle of the supply means at a pressure of 1 MPa or more to the ground.
Wastewater reuse equipment in the ground improvement method characterized by this.   The inlet diameter of the pressure reservoir is 15 to 35 mm, the pipe diameter of the pressure reservoir is 50 to 85 mm, the pipe length of the pressure reservoir is 20 to 85 mm, and the pressure reservoir The facility for reusing mud in the ground improvement method according to claim 4 or 5, wherein the diameter of the outlet of the ground is 80% or less of the diameter of the inlet.

Images