JP6130952B1 - Sediment improvement equipment - Google Patents

Abstract

The present invention provides a method and an apparatus for improving earth and sand that can suppress the cost of improvement. The earth and sand S1 to be improved is brought into contact with the surface of a screen 21 using a wedge wire 22 and having a slit width L3 of 5 to 75 μm. The screen 21 vibrates at a frequency of 50 to 200 Hz. Furthermore, a suction force is exerted on the earth and sand S1 from the back side of the screen 21. [Selection] Figure 1

Description

The present invention relates to improvements apparatus of sediment, such as construction mud.

In construction work, such as excavation and civil engineering work, construction mud (construction sludge) with a very high water content is generated. This construction mud corresponds to the industrial waste of the Waste Management Law. Construction mud has a cone index of generally less than 200 kN / m ² and is very weak. Therefore, it cannot be reused as construction waste soil as it is. In order to reuse the construction mud, it is necessary to improve it to a quality that can be handled as construction generated soil, that is, a grade 4 improved soil (cone index 200 kN / m ² or more).

  In addition, construction mud may continue to be vibrated during transportation. In order to prevent this fluidization, it is necessary to improve the construction mud.

  Furthermore, in order to prevent liquefaction of the ground, the ground is being improved in various places. In improving the ground, it is effective to improve the earth and sand constituting the ground.

As described above, improvement of earth and sand, that is, chemical improvement of the properties of earth and sand is required in various situations. In order to improve the earth and sand, it is common to mix a solidifying material into the earth and sand. As the solidifying material, for example, cement, lime, water reducing material (paper powder, polymer water absorbing material, etc.) and the like are used. However, the use of a solidifying material increases the cost. The cost of the solidifying material is, for example, about 3000 yen / m ³ . Including the cost for transporting the solidified material and the cost for kneading, it becomes about 5000 yen / m ³ . In addition, if a solidified material is used, costs for securing and managing the stockyard of the solidified material, dust countermeasure costs, etc. are also required. Therefore, the total cost for improvement is about 6000 to 10,000 yen / m ³ . In addition, the amount of earth and sand is increased by about 5% due to the mixing of the solidifying material, which also causes an increase in processing costs.

  On the other hand, depending on the type of solidification material, the amount of mixing, etc., earth and sand may become waste. Moreover, when cement or lime is used as the solidifying material, alkali may be eluted from the improved soil. Furthermore, when cement is used as the solidifying material, hexavalent chromium may be eluted.

  In this regard, there is also a proposal for improving the solidification material and thereby solving the problem of alkali elution (see, for example, Patent Document 1). However, according to this proposal, the cost of the solidifying material is further increased.

Japanese Patent No. 3235019

The main object of the present invention is to provide is to provide a improvements device sediment which can suppress the cost of improvement.

  The mechanism of fluidization of earth and sand during transportation is the same as the mechanism of ground liquefaction during an earthquake. If the soil continues to receive vibration, the pressure of water (pore water) existing between the soil particles increases, and the shear stress (friction force between the soil particles) decreases. Moreover, the clay in earth and sand acts as a lubricant. Therefore, the earth and sand will fluidize if it continues to receive vibration. Then, if pore water and clay are removed from the earth and sand, fluidization and liquefaction of the earth and sand can be prevented without using a solidifying material, that is, while suppressing improvement costs. Moreover, if pore water and clay are removed from the earth and sand, the corn index rises and becomes higher than Type 4 improved soil, and can be handled as construction generated soil (similar to construction generated soil). The present invention has been conceived under such a premise. In addition, construction generated soil refers to earth and sand generated secondaryly in construction work and civil engineering work. Construction waste soil does not fall under industrial waste under the Waste Management Law.

  Means for solving the problems of the present invention are as follows.

(Aspect of Claim 1 )
A screen having a slit width of 5 to 75 μm using a wedge wire;
Vibration means for vibrating the screen at a frequency of 50 to 200 Hz;
Suction means for exerting a suction force on the earth and sand from the back side of the screen;
With
The earth and sand to be improved are configured to contact the surface of the screen,
The screen is a cylindrical strainer;
An upstream cylinder is provided on the upstream side of this strainer, and a sediment input port for introducing the unmodified soil into the upstream cylinder is provided.
A downstream cylinder is provided on the downstream side of the strainer, and a sediment discharge port for discharging the improved earth and sand is provided in the downstream cylinder,
The upstream cylindrical body and the downstream cylindrical body and the strainer are communicated with each other via an elastic body,
The upstream cylinder, the strainer, and the downstream cylinder are provided with screw blades for transporting earth and sand,
A cover body that covers the strainer is provided, and a slurry discharge port that discharges slurry to the cover body is provided.
The vibration means is configured to vibrate the cover body and vibrate the strainer by this vibration.
The suction means sucks the cover body through the slurry discharge port, and is configured to exert a suction force on the earth and sand by this suction.
An apparatus for improving earth and sand characterized by that .

According to the present invention, the improvements device sediment which can suppress the cost of improvement.

It is a schematic diagram of the earth and sand improvement apparatus of this embodiment. It is a schematic diagram of the screen of this embodiment. It is a modification structural example of the earth and sand improvement apparatus.

  Next, the form for implementing this invention is demonstrated. This embodiment is an example of the present invention. The present invention is not limited to this embodiment.

  As shown in FIG. 1, the earth and sand improving apparatus 1 of this embodiment includes an upstream cylinder 11 and a downstream cylinder 12, a strainer 20, a pair of elastic bodies 13, a cover body 14, a screw blade 15, and the screw blade 15. The drive source 16, the vibration means 17, and the suction means 18 are the main components. Hereinafter, it demonstrates in order.

(strainer)
The strainer 20 is formed, for example, by processing the screen 21 into a cylindrical shape. A wedge wire 22 is used for the screen 21. The wedge wire 22 is wound in a spiral shape, for example. This winding method is performed so that the wedge wires 22 adjacent to each other have a predetermined interval (interval L3). The slit of the screen 21 is formed with a predetermined interval.

  As shown in FIG. 2, the cross-sectional shape of the wedge wire 22 has an inverted triangular shape (also referred to as “wedge shape”). The upper side (wider side) of the wedge wire 22 corresponds to the surface side of the screen 21. The bottom side (narrower side) of the wedge wire 22 corresponds to the back side of the screen 21. Therefore, the slits of the screen 21 gradually spread from the front side toward the back side. In the strainer 20 of this embodiment, the inner peripheral surface corresponds to the front surface, and the outer peripheral surface corresponds to the back surface.

  A substance to be filtered (in this embodiment, earth and sand S1) passes through the strainer 20 and passes through the strainer 20 without passing through the screen 21, and a substance that passes through the screen 21 and reaches the outside of the strainer 20. And separated.

  The wire width L1 of the wedge wire 22 is preferably 5 to 75 μm, more preferably 15 to 40 μm. When the wire width L1 is too narrow, the processing (filtration) efficiency is deteriorated. Moreover, there is a possibility that the effect of exciting the screen 21 by the excitation means 17 described later cannot be obtained sufficiently. On the other hand, if the wire width L1 is too wide, the clay slurry S3 (details will be described later) may not be sufficiently removed. In order to eliminate this possibility, it is necessary to lengthen the strainer 20, and the improved apparatus 1 becomes larger.

  The wire thickness L2 of the wedge wire 22 is preferably 35 to 1000 μm, more preferably 500 to 750 μm. If the wire thickness L2 is too thin, the strength of the strainer 20 may be insufficient. On the other hand, there is no particular advantage if the wire thickness L2 is too thick.

  The interval L3 between the wedge wires 22 adjacent to each other, that is, the slit width L3 of the screen 21 is preferably 5 to 75 μm, more preferably 15 to 40 μm. If the slit width L3 is too narrow, the clay slurry S3 may not be sufficiently removed. On the other hand, if the slit width L3 is too wide, substances other than the clay slurry S3 may pass through.

  In general, clay is 5 μm or less, silt is 5 to 75 μm, fine sand is 75 to 250 μm, medium sand is 250 to 850 μm, coarse sand is 850 to 2000 μm, and gravel is 2 mm to 75 mm.

(Cylinder)
The upstream cylinder 11 is located on the upstream side (left side of the paper) of the strainer 20. The upstream cylinder 11 is cylindrical. That is, the upstream cylinder 11 has a substantially circular cross section. For example, the upstream cylinder 11 may have a substantially rectangular cross section. However, if the upstream cylindrical body 11 has a shape having a corner such as a substantially rectangular cross section, the corner S1 may be clogged with earth and sand S1 to be processed. If it is going to prevent clogging of this earth and sand S1, an apparatus will become complicated. Therefore, the upstream cylinder 11 preferably has a substantially circular cross section.

  The upper peripheral surface of the upstream side cylinder 11 is provided with a sediment input port 11 </ b> A through which unmodified soil (soil to be treated) S <b> 1 is charged. However, the earth and sand introduction port 11A is merely for introducing (supplying) the earth and sand S1 into the upstream cylinder 11. Therefore, for example, an upstream end portion (left end portion on the paper surface) of the upstream cylindrical body 11 may be opened, and the earth and sand S1 may be charged from the opening.

  The downstream cylinder 12 is located on the downstream side (the right side of the drawing) of the strainer 20. The downstream side cylinder 12 is cylindrical. That is, the downstream side cylinder 12 has a substantially circular cross section. The fact that the cross-sectional shape of the downstream cylinder 12 can be changed as appropriate, and the advantages and disadvantages of the change are the same as those of the upstream cylinder 11 described above.

  The lower peripheral surface of the downstream cylinder 12 is provided with a sediment discharge port 12A for discharging the improved soil (improved soil) S2. However, the earth and sand discharge port 12A is merely for discharging earth and sand S2 from the downstream side cylinder 12. Therefore, for example, the downstream end (the right end on the paper surface) of the downstream cylinder 12 is opened, and the earth and sand S2 can be discharged from the opening.

(A pair of elastic bodies)
An elastic body 13 is provided between the upstream cylinder 11 and the downstream cylinder 12 and the strainer 20. The elastic body 13 has a cylindrical shape and is configured such that the earth and sand S1 and S2 pass through the inside. The upstream cylinder 11 and the downstream cylinder 12 and the strainer 20 communicate with each other through the elastic body 13. Therefore, the earth and sand S1 in the upstream cylinder 11 passes from the upstream cylinder 11 through the elastic body 13 (through) into the strainer 20 and from the strainer 20 through the elastic body 13 (through). ) Transported (transferred) into the downstream cylinder 12.

  As will be described later, the strainer 20 is vibrated. However, since the elastic body 13 is interposed, the vibration of the strainer 20 is prevented from being transmitted (vibrated) to the upstream cylinder 11 or the downstream cylinder 12.

  In this regard, there is usually no problem even if the upstream cylinder 11 or the downstream cylinder 12 is vibrated. However, depending on the properties of the earth and sand S1, the vibration may cause the properties of the earth and sand S1 to change. If the property of the earth and sand S1 changes, the earth and sand S1 may not be smoothly transferred in the upstream cylinder 11 or the downstream cylinder 12. Moreover, if the property of the earth and sand S1 changes, the strainer 20 and the vibration means 17 may not be suitable for improving the earth and sand S1. The case where the strainer 20 is no longer suitable is, for example, a case where the slit width L3 is too narrow or too wide for the earth and sand S1 after the properties have changed. The case where the vibration means 17 is no longer suitable is, for example, a case where the frequency is too low or too high for the earth and sand S1 after the property has changed.

  The elastic body 13 can be made of rubber or the like, for example.

(Screw blade)
The screw blade 15 includes a central axis and a spiral blade spirally provided around the central axis as main components. The screw blade 15 rotates around the central axis.

  One end of the screw blade 15 is located in the upstream cylinder 11 and the other end is located in the downstream cylinder 12. That is, the screw blade 15 penetrates the upstream cylinder 11, the strainer 20, and the downstream cylinder 12.

  The screw blade 15 conveys the earth and sand S1 in the upstream cylinder 11 from the upstream cylinder 11 into the strainer 20 and from the strainer 20 into the downstream cylinder 12. However, the screw blades 15 are simply means for conveying the earth and sand S1. Therefore, if necessary, it can be changed to another conveying means.

(Drive source)
The drive source 16 is a means for rotating the screw blade 15 around the central axis. In the illustrated example, the drive source 16 is provided near the downstream end of the downstream cylindrical body 12. However, the drive source 16 may be provided in the vicinity of the upstream end of the upstream cylinder 11, for example.

  The drive source 16 is composed of, for example, a motor.

(Cover body)
The cover body 14 is provided so as to cover the strainer 20. The cover body 14 of this embodiment is cylindrical. That is, the cover body 14 of this embodiment has a substantially circular cross section. However, the cover body 14 can also have a substantially square cross section, for example.

  The cover body 14 is provided with a slurry outlet 14A for discharging the clay slurry S3. The slurry discharge port 14 </ b> A is provided on the lower peripheral surface of the cover body 14.

  The clay slurry S3 passing through the screen 21 from the inside of the strainer 20 and reaching the outside of the strainer 20 is temporarily stored in the cover body 14. The clay slurry S3 stored in the cover body 14 is discharged through the slurry discharge port 14A.

(Excitation means)
The vibration means 17 vibrates the cover body 14. The strainer 20 is vibrated by this vibration. The vibration means 17 consists of a vibrator etc., for example. The vibration means 17 of this embodiment is provided on the upper surface of the cover body 14.

  The vibration means 17 vibrates the screen 21 preferably at a frequency of 50 to 200 Hz, more preferably at a frequency of 150 to 170 Hz. If the frequency is too small, there is a possibility that pore water and clay in the soil S1 are not sufficiently separated from other soil particles. On the other hand, if the frequency is too high, the clay (clay particles) may not resonate and may not be sufficiently separated from other soil particles.

  As is clear from the above, one purpose of the vibration by the vibration means 17 is to fluidize the earth and sand S.

(Suction means)
The suction means 18 sucks the inside of the cover body 14 through the slurry discharge port 14A. By this suction, suction force is exerted on the earth and sand S1 in the strainer 20. The clay slurry S1 in the cover body 14 is discharged from the cover body 14 through the slurry discharge port 14A.

  The suction means 18 is composed of a mono pump or the like, for example.

  The suction force by the suction means 18 is not particularly limited. What is necessary is just to determine suitably according to the property of earth and sand S1. In the present embodiment, the screen 21 is vibrated so that pore water and clay are separated from other soil particles. Therefore, there is no need to increase the suction force, and there is no possibility that the earth and sand S1 will harden on the screen 21. Further, since the slits of the screen 21 are widened, there is no possibility that the earth and sand S1 is clogged with the slits. Of course, the vibration of the screen 21 itself also serves to prevent the sediment S1 from solidifying.

  The upstream cylinder 11, the strainer 20, and the downstream cylinder 12 of this embodiment are inclined. By having such an inclination, the fluidized clay and pore water can be easily discharged as the clay slurry S3.

  The inclination angle α of the upstream cylinder 11 or the like is preferably 10 to 45 ° (degrees), more preferably 15 to 30 °. If the inclination angle α is too small, there is no point in attaching the inclination. On the other hand, if the inclination angle α is too large, it is difficult to transport the earth and sand S1 inside the upstream cylinder 11 or the like.

(Improvement method)
Next, a method for improving the earth and sand S1 using the above improvement device 1 will be described.

  The earth and sand to be improved (the earth and sand before improvement) S1 is introduced into the upstream cylinder 11 from the earth and sand inlet 11A.

  The earth and sand S1 thrown into the upstream cylinder 11 is conveyed into the strainer 20 by the screw blades 15.

  The suction force from the suction means 18 reaches the earth and sand S1 conveyed into the strainer 20. Moreover, since the strainer 20 is vibrated, the earth and sand S1 continues to receive vibration. Due to this vibration, the earth and sand S1 is fluidized. In other words, clay and water (pore water) and other soil particles are separated. Therefore, the clay and water pass through the screen 21 as clayey slurry S3 by the suction force from the suction means 18, and reach the outside of the strainer 20 (inside the cover body 14).

  The time for separating clay and water (pore water) from other soil particles is, for example, 10 to 90 seconds, preferably 20 to 50 seconds. Therefore, the length of the strainer 20 may be designed so as to ensure this time (separation time).

The clay-like slurry S3 reaching the outside of the strainer 20 is further discharged through the slurry discharge port 14A . The discharged clayey slurry S3 can be solid-liquid separated by a filter or the like and reused.

  On the other hand, the soil particles that have not passed through the screen 21 are conveyed into the downstream cylinder 12 by the screw blades 15 as improved soil (soil after improvement) S2. The improved soil S2 conveyed into the downstream cylinder 12 is discharged through the earth and sand discharge port 12A.

  In this regard, the soil particles continue to receive vibrations on the surface (inner peripheral surface) of the screen 21 (strainer 20). Therefore, there is no possibility that the soil particles are clogged in the slit of the screen 21.

(Other forms)
In the above-described form, the screen 21 using the wedge wire 22 is processed into a cylindrical shape and used as the strainer 20. However, for example, as shown in FIG. 3 (1), the screen 21 using the wedge wire 22 may be flat. In this embodiment, the earth and sand S1 is continuously passed over the screen 21 (continuous method) or placed on the screen 21 (batch method).

In the embodiment described above, the inner circumferential surface of the strainer 20 to the surface of the screen 21, the outer circumferential surface of the strainer 20 corresponds to the rear surface of the screen 21. That is, the earth and sand S1 is configured to pass through the strainer 20. However, as shown in (2) of FIG. 3, a form in which the front surface and the back surface are reversed is also conceivable. That is, the outer peripheral surface of the strainer 20 corresponds to the surface of the screen 21, and the inner peripheral surface of the strainer 20 corresponds to the back surface of the screen 21. This form is used in a mode in which the strainer 20 is inserted into the earth and sand G, vibrated, and sucked, for example. According to this embodiment, the clay slurry S3 in the earth and sand G can be removed. That is, the earth and sand S1 can be improved as it is. In this respect, during the excavation of earth and sand (ground) G, the earth and sand G may become mud, and it may be difficult to continue the construction. However, if the earth and sand G are improved by the method of this embodiment, there is no possibility that it is difficult to continue the construction. Moreover, in this method, since clay is also removed from the earth and sand G, there is little possibility that the earth and sand G will become muddy due to rainfall or the like. Further, when the clay is removed, there is an advantage that radioactive substances such as cesium 137 can be removed along with the clay. From this form, it can be clearly understood that the main purpose of vibrating the screen 21 is not to “shake off” the substance to be separated.

  INDUSTRIAL APPLICABILITY The present invention can be used as an improvement method and improvement device for earth and sand such as construction mud. The earth and sand to be improved are not particularly limited. As earth and sand to be improved, for example, shield construction, promotion construction, tunnel construction, caisson construction, underground construction of buildings, river construction, dam construction, dredging construction, foundation construction, etc. The earth and sand (digging mud etc.) which generate | occur | produce with it can be illustrated.

The present invention cannot be used only when the construction mud is improved to a quality that can be handled as construction generated soil (type 4 improved soil or higher). For example, when the fourth type improved soil is improved to the third type improved soil (cone index 400 kN / m ² or more), the third type improved soil is improved to the second type improved soil (cone index 800 kN / m ² or more). In this case, it can also be used when the second type improved soil is improved to the first type improved soil.

DESCRIPTION OF SYMBOLS 1 Sediment improvement apparatus 11 Upstream side cylinder 11A Sediment insertion port 12 Downstream side cylinder 12A Sediment discharge port 13 Elastic body 14 Cover body 14A Slurry discharge port 15 Screw blade 16 Drive source 16
17 Vibrating means 18 Suction means 20 Strainer 21 Screen 22 Wedge wire S1 Sediment before improvement (Sediment subject to improvement)
S2 Sediment after improvement (improved soil)
S3 Clay slurry

Claims (1)

A screen having a slit width of 5 to 75 μm using a wedge wire;
Vibration means for vibrating the screen at a frequency of 50 to 200 Hz;
Suction means for exerting a suction force on the earth and sand from the back side of the screen;
With
The earth and sand to be improved are configured to contact the surface of the screen,
The screen is a cylindrical strainer;
An upstream cylinder is provided on the upstream side of this strainer, and a sediment input port for introducing the unmodified soil into the upstream cylinder is provided.
A downstream cylinder is provided on the downstream side of the strainer, and a sediment discharge port for discharging the improved earth and sand is provided in the downstream cylinder,
The upstream cylindrical body and the downstream cylindrical body and the strainer are communicated with each other via an elastic body,
The upstream cylinder, the strainer, and the downstream cylinder are provided with screw blades for transporting earth and sand,
A cover body that covers the strainer is provided, and a slurry discharge port that discharges slurry to the cover body is provided.
The vibration means is configured to vibrate the cover body and vibrate the strainer by this vibration.
The suction means sucks the cover body through the slurry discharge port, and is configured to exert a suction force on the earth and sand by this suction.
An apparatus for improving earth and sand characterized by that .

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