JP4927605B2 - Soil reforming plant and pipe backfilling method using the soil reforming plant - Google Patents

Description

  The present invention relates to a soil improvement plant for reusing soil generated at a construction site (so-called excavated soil) and a pipe backfilling method using the soil modification plant.

  When burying gas pipes, water pipes and other pipes on the road, excavated soil is carried out from the site and used for landfilling, and it is common to refill the pipes by procuring high-quality soil from another location. It is.

However, recently, landfills are decreasing, and landfills are becoming remote. Therefore, disposal of excavated soil has a problem of high transportation costs.
Therefore, in recent years, excavated soil is recycled and used at a construction site, and a soil quality improvement plant for that purpose has been proposed (see Patent Document 1).
JP 2000-33996 A (see FIG. 7)

In the soil improvement plant, a process of adding quick lime, mixing, and classifying with a sieve is required, and the apparatus is generally large.
However, in a site where gas pipes, water pipes and other pipes are buried on the road, for example, since the site site is narrow, a device that is as compact as possible is desired.
In this regard, in the apparatus of Patent Document 1, as shown in FIG. 7 of Patent Document 1, the kneading and mixing machine and the sieve are configured as separate apparatuses, and the entire plant is large.
For this reason, there is a problem that it is difficult to apply when the construction site is narrow, such as a gas pipe or water pipe backfill site buried underground in the road.

  The present invention has been made to solve such problems, and is a compact capable of regenerating excavated soil even in a narrow site near a backfill site such as a gas pipe or a water pipe or in a work site at a buried site. An object of the present invention is to provide a novel soil modification plant and a pipe backfilling method using the soil modification plant.

(1) A soil modification plant according to the present invention is a soil modification plant used in a pipe backfilling method, and a soil cutout device that cuts out the introduced soil in a fixed amount, and a soil improver in the quantitatively cut out soil. And a mixing and stirring classifying device for receiving and mixing earth and sand added with a soil conditioner, and mixing and classifying the earth and sand. Ri name is connected to so that,
The mixing and stirring classification device has a rotating cylinder that is rotationally driven, and is configured such that an upstream side of the rotating cylinder is a mixing and stirring unit and a downstream side is a classifying unit, and the mixing and stirring unit includes the rotating cylinder and Is provided with a central axis that is independently driven to rotate, and a stirring blade extending radially from the central axis,
A plurality of stirring blades are provided with a predetermined angle shifted around the rotation axis, and a stirring blade block is formed by collecting the plurality of stirring blades in the axial direction of the rotation shaft. the upstream end of the mixing and stirring unit and are located in the downstream end side of which is characterized in Rukoto.
The fact that the plurality of stirring blades are gathered in the axial direction of the rotating shaft means that the plurality of stirring blades are arranged within a range of 25% or less of the axial length of the mixing and stirring unit on the rotating shaft. . The stirring blade block refers to an aggregate of a plurality of stirring blades arranged as described above.
In the present invention, there are two cases: a case where all the stirring blades form a stirring blade block and a case where a stirring blade that does not form a stirring blade block is installed in addition to the stirring blade that forms the stirring blade block. Including.

(2) Further, in the above-described (1), the stirring blade is formed by connecting a plurality of rod-shaped bodies, and the connected rod-shaped body is configured to be rotatable within the rotation surface of the stirring blade at the connecting portion. It is characterized by being.

( 3 ) The pipe backfilling method according to the present invention is a pipe backfilling method in which pipes are buried using the soil reforming plant described in (1) or (2) above.
Dividing part or all of the construction section into three sections, in each section, the excavation process for excavating the ground, the pipe laying process for laying the pipe in the excavation process, and the place where the pipe was laid The backfilling process is performed sequentially,
The excavated soil excavated in one excavation process is used as an improved soil by the soil improvement plant, and the improved soil is used as backfill soil in another excavation area. is there.

  In the present invention, the earth and sand cutting device that cuts out the charged earth and sand in a fixed amount, the improver addition apparatus that adds a soil condition improver to the quantitatively cut and removed sand, and the earth and sand mixed with the earth and sand added with the soil condition improver A mixing and stirring classification device that performs stirring and classification, and each of these devices employs a configuration in which earth and sand are transported between the devices, and particularly, mixing and classification are performed by one device. As a result, the entire soil improvement plant can be made compact. As a result, the present invention can be applied even when the construction site is narrow, such as a gas pipe or water pipe backfill site buried underground in the road.

[Embodiment 1]
FIG. 1 is an explanatory diagram showing the overall configuration of a soil reforming plant 1 according to an embodiment of the present invention. The soil reforming plant 1 according to the present embodiment includes a soil cut-out device 3 that cuts out the soil that has been input in response to the input of excavated residual soil, and an improver addition device that adds a soil improver to the quantitatively cut-out soil 5 and a mixing and stirring classification device 7 that receives the earth and sand to which the soil quality improver is added and performs mixing and stirring and classification of the earth and sand. And the belt conveyor 9 which conveys soil is installed between the earth and sand cutting-out apparatus 3 and the mixing stirring and classifying apparatus 7, and the improving agent addition apparatus 5 can add a soil quality improving agent to the soil conveyed by the belt conveyor 9. Has been placed.
Hereinafter, each device will be described in detail.

(1) Earth and sand cutting device FIG. 2 is an explanatory view of the internal structure of the earth and sand cutting device 3, and FIG. 3 is an operation explanatory view.
The earth and sand cutting device 3 includes a hopper 11 (see FIG. 1) into which earth and sand are put, a left and right wall surface 13 that is disposed below and in parallel with a predetermined distance below the hopper 11, and between the left and right wall surfaces 13. A moving frame 15 that is installed and moves around, and a fixed bottom plate 17 that is installed below the moving frame 15 are provided.

The hopper 11 is a part for temporarily storing excavated soil, and has a function as a cushion tank by receiving the excavated soil. The upper portion of the hopper 11 is opened so that excavated soil can be input, and the lower portion of the hopper 11 is opened so that the excavated soil that has been input is dropped toward the bottom plate 17.
The left and right wall surfaces 13 provided at the lower part of the hopper 11 are arranged at the upper part of the moving frame 15 and guide excavated soil falling from the hopper 11 to the moving frame 15 side.

The moving frame body 15 has both side walls 21 formed by connecting a plurality of rectangular plate bodies 19 to a pair of chain conveyors that are moved around by a rotation driving motor 18 shown in FIG. The rectangular conveying plate 23 is disposed at a predetermined interval in the circumferential direction of the both side walls 21 at right angles.
The conveying plate 23 extends above the side walls 21 and pushes the excavated soil that has fallen into the movable frame 15 in the moving direction of the movable frame 15 so as to slide it at the height position. It is to be transported.

The bottom plate 17 is a plate body fixed below the moving frame body 15 and is provided in a range until the moving frame body 15 circulates and descends as shown in FIG.
The material of the bottom plate 17 is not particularly limited, and may be metal or plastic.

In the earth and sand cutting device 3 configured as described above, as shown in FIG. 3, the excavated soil 25 thrown into the hopper 11 falls on the bottom plate 17 in the moving frame 15, and the moving frame 15 is moved. By moving, the excavated soil is carried by the moving frame 15 so as to be worn out from the fixed bottom plate 17. At the exit, the upper part of the excavated soil is cut by the ceiling board 27 and is cut out in a fixed amount.
When the moving frame 15 moves to the tip of the circuit, since the bottom plate 17 disappears, the excavated soil falls downward, but since the excavated soil and the bottom plate 17 are cut off, the excavated soil adheres to the bottom plate 17. Easily fall without.

  Thus, according to the earth and sand cutting device 3 of the present embodiment, even if it is a viscous soil having a large adhesive force, which is said to be difficult to quantitatively cut out, it can be cut out quantitatively and smoothly. .

(2) Improving agent adding device As shown in FIG. 1, the improving agent adding device 5 is installed so as to straddle the conveying path of the belt conveyor 9, and excavated soil that moves quick lime, which is a soil quality improving agent, on the conveying path. To supply. The improver addition device 5 cuts the quick lime stored in the hopper 29 by the screw conveyor 31 in a fixed amount.
As described above, the excavated soil is quantitatively cut out by the earth and sand cutting device 3, and quick lime is quantitatively added to the quantitatively cut excavated soil, so that the quick lime is added to the excavated soil at a predetermined addition rate. Done.

(3) Mixing and stirring classifier FIG. 4 is an explanatory diagram of the mixing and stirring classifier 7, and FIG. 5 is a view taken along the line AA in FIG.
The mixing and stirring classification device 7 is a device that is disposed on the downstream side of the belt conveyor 9 and receives the excavated soil to which the soil conditioner is added, and performs mixed stirring and classification of the excavated soil.
As shown in FIG. 4, the mixing and stirring classifier 7 includes a hopper 33 serving as an input portion for excavated soil, and a substantially cylindrical outer shell 35, and the first motor 37 includes the outer shell 35. A rotating cylinder 39 that is rotationally driven is accommodated, and includes a rotating shaft 41 that penetrates the center of the rotating cylinder 39 over the entire length of the rotating cylinder 39, and a stirring blade 43 that is installed on the rotating shaft 41. Has been. The rotating shaft 41 is driven to rotate by the second motor 45.

  As shown in FIGS. 1, 4, and 5, the outer shell 35 of the mixing and stirring classifier 7 is installed on a stand 47. 1, 4, and 5, the rear end lower portion of the gantry 47 is installed on the ground via a foot portion 49 that is hinged to the gantry body. Therefore, the gantry 47 is moved up and down on the front end side thereof, and the rear end side thereof is rotated at the hinge connecting portion with the foot portion 49 so that the inclination angle can be freely changed.

In the example shown in FIG. 1, it is inclined at an angle of about 5 degrees toward the downstream side. The reason why the downstream side is located downward is to allow the excavated soil to naturally move downstream in the cylindrical body installed in the outer shell 35.
Note that the tilt angle of the gantry 47 can be arbitrarily set as described above. Therefore, when mixing and stirring for a long time is required, the tilt angle is reduced, and conversely, when the mixing and stirring time is short. The inclination angle may be increased.
The inclination angle is generally adjusted to around 5 degrees, but is not limited to this.

As shown in FIG. 4, a small conveyor 51 that conveys excavated soil classified by the rotating cylinder 39 to the downstream side is installed below the rotating cylinder 39. On the downstream side, a transport conveyor 53 for transporting to a truck or the like (not shown) is provided.
Further, as shown in FIG. 5, a chute 55 for receiving and discharging excavated soil oversized by classification is provided on the rear end side of the rotating cylinder 39.

FIG. 6 is an explanatory diagram of the rotating cylinder 39. As shown in FIG. 6, the rotary cylinder 39 has a mixing and stirring unit 57 on the upstream side where excavated soil is introduced, and a classification unit 59 on the downstream side of the mixing and stirring unit 57.
The mixing and stirring unit 57 is formed of a cylindrical body, and a plurality of stirring blades 43 are installed on a rotating shaft 41 disposed at the center of the cylindrical body.
As shown in FIG. 4, the cylindrical body is configured to rotate by transmitting the rotational force of the first motor 37 to the gear 61 provided on the outer peripheral portion of the cylindrical body. The number of rotations is not particularly limited, and the number of rotations may be set so that optimum mixing is obtained depending on the soil quality. However, it is usually several times to several tens of times / minute, and the rotation speed may be adjusted by adjusting the rotation speed of the first motor 37 with an inverter, for example.

As shown in FIG. 6, the agitation blades 43 are installed together on the upstream side and the downstream side. The number of the stirring blades 43 is set in consideration of the soil quality of the excavated soil and the driving torque of the second motor 45.
Further, as shown in FIG. 7 which is an arrow BB diagram in FIG. 6, each stirring blade 43 is disposed around the axis of the rotation shaft 41 by a predetermined angle, for example, 90 degrees. In FIG. 6, the stirring blade 43 orthogonal to the paper surface is omitted. That is, in this example, the four agitating blades 43 arranged so as to be shifted by 90 degrees around the axis of the rotating shaft 41 have two one agitating blade block, and these two agitating blade blocks serve as a mixing and agitating unit. 57 are arranged on the upstream end side and the downstream end side, respectively.
A method of fixing the stirring blade 43 to the rotating shaft 41 may be directly welded to the rotating shaft 41. However, it is preferable to fix the stirring blade 43 by bolting so that it can be easily replaced when damaged.

The rotating shaft 41 to which the stirring blade 43 is fixed is rotationally driven by the second motor 45, and the rotational speed thereof is, for example, about several times to several hundred times / minute, but the rotational speed is adjusted by the inverter to the second motor 45. It is preferable that adjustment is possible by adjusting the number of rotations.
The rotating direction of the stirring blades 43 may be the same direction as the rotating cylinder 39 or the opposite direction. However, by rotating in the same direction as the rotating cylinder 39, the rotation is driven by a small motor with a reduced torque. it can.

Here, the configuration of each stirring blade 43 will be described.
As shown in FIGS. 6 and 7, the stirring blade 43 is a rod-like body as a whole, and a base portion 43 a whose base end side is fixed to the rotating shaft 41, and can be rotated within the rotation plane with respect to the base portion 43 a. It is comprised from the front-end | tip part 43b attached to. As shown by the arrow in FIG. 7, the distal end portion 43 b can be rotated with respect to the base portion 43 a within the rotation surface of the stirring blade 43.
In this way, by configuring the stirring blade 43 from the base portion 43a and the tip portion 43b that can rotate with respect to the base portion 43a, the following operational effects can be obtained.

At the same time as the stirring blade 43 rotates, the distal end portion 43b and the base portion 43a are linearly formed by centrifugal force, and when used, the stirring blade 43 becomes a long stirring tool as a whole. Can be stirred and mixed.
And since the front-end | tip part 43b can be rotated with respect to the base 43a, even if a big lump like a gravel seems to be pinched | interposed into a cylindrical body inner surface and a stirring blade front-end | tip, the front-end | tip part 43b Since it bends, an excessive torque is not applied to the stirring blade 43, and the rotation of the stirring blade 43 does not stop. The gravel that is about to be sandwiched between the inner surface of the cylindrical body and the tip of the stirring blade is splashed by the stirring blade 43 and finely crushed, so that mixing and stirring can be performed efficiently.
Further, by making it easy to attach and detach the base portion 43a and the distal end portion 43b, replacement at the time of stopping, cleaning, and the like can be facilitated.

  As shown in FIG. 8, the rotating cylinder 39 may be provided with a flip-up plate 63 extending in the axial direction on the inner surface of the rotating cylinder 39. As shown in FIG. 8, the flip-up plate 63 has an action of jumping up the excavated soil accumulated in the lower part of the cylindrical cylindrical body and effectively mixing and stirring. In this example, four flip-up plates 63 are provided 90 ° apart from each other on the inner surface of the rotating cylinder, but the number is not particularly limited.

  FIG. 9 is a diagram for explaining the positional relationship between the stirring blade 43 and the flip-up plate 63. The state in which the stirring blade 43 and the jump-up plate 63 come to an overlapping position when viewed from the axial direction of the rotating cylinder 39 is rotated. The state seen from the axial orthogonal direction of the cylinder 39 is shown. As shown in FIG. 9, the flip-up plate 63 is arranged so that it does not overlap with the installation position of the stirring blade 43 in the axial direction of the rotating cylinder 39, that is, at the position where the stirring blade 43 is installed. It is preferable not to provide it. With such an arrangement, the tip of the stirring blade 43 and the flip-up plate 63 do not interfere with each other. Therefore, the length of the stirring blade 43 can be extended to the vicinity of the inner periphery of the rotating cylindrical body, and the excavated soil is mixed with the stirring blade 43. Can be prevented from slipping through the gap between the tip of the tube and the inner surface of the rotating cylinder 39.

The classifying unit 59 classifies the excavated soil stirred and mixed in the stirring and mixing unit into a predetermined size. Therefore, the classifying unit 59 is composed of a cylindrical net 65 made of a mesh of a predetermined mesh corresponding to the classifying size. The size of the mesh can be set to various sizes according to the classification standard determined for each construction site.
In this example, the classifying unit 59 is composed of the cylindrical mesh body 65. However, as long as it has a large number of holes, an expanded metal or the like may be used.

Since the classification unit 59 classifies the excavated soil, it may be clogged. Therefore, in order to prevent this, in the present embodiment, as shown in FIG. 6, air injection means 67 for injecting air from the outside to the inside of the classification unit 59 is provided.
The air injection means 67 includes an air compressor 69 for sending compressed air, a header 73 connected to the air compressor 69 via a hose 71, and a plurality of injection nozzles 75 provided on the header 73.

As shown in FIG. 6, the header 73 has substantially the same length as the cylindrical mesh body 65 of the classification unit 59, and is installed on the outer surface of the cylindrical mesh body 65 at a predetermined distance.
The position where the header 73 is installed is preferably a central portion in the height direction in the outer peripheral portion of the cylindrical mesh body 65, that is, a position rotated 90 degrees from the lowest position of the cylindrical mesh body 65. Further, it is more preferable to provide two at this position so as to face each other with the cylindrical net 65 interposed therebetween.

The compressed air is preferably sprayed constantly while the cylindrical mesh body 65 is operating, but may be intermittently performed.
The pressure of the compressed air is not particularly limited, but 3 to 5 kgf / cm ² (2.94 to 4.9 MPa) is preferable.

  By providing the air injection means 67, clogging of the cylindrical mesh body 65 can be greatly reduced, and thus the classification action can be maintained.

The operation of the mixing and stirring classifier 7 configured as described above will be described.
The excavated soil conveyed from the belt conveyor 9 is put into the hopper 33 of the mixing and stirring classifier 7. The inserted excavated soil is mixed and agitated while being spun upward by a rotating cylinder 39 as shown in FIG. Further, the excavated soil is crushed by the stirring blades 43 that rotate at a high speed in the rotating cylinder 39 and further stirred and mixed. That is, the excavated soil is simultaneously subjected to the mixing and stirring action by the flip-up by the rotation of the rotating cylinder 39 and the crushing and mixing and stirring actions by the stirring blade 43, thereby efficiently mixing and stirring.
In particular, in this embodiment, since the stirring blade block that collects and aggregates the stirring blades 43 is installed on the upstream end side of the mixing and stirring unit 57, the inserted excavated soil is finely crushed immediately after the addition, Mixing and stirring can be performed efficiently. Further, since the stirring blade block is also arranged on the downstream end side of the mixing and stirring unit 57, even if a situation occurs where the excavated soil becomes a mass in the middle of the mixing and stirring unit 57, the final stage of the mixing and stirring unit 57 Thus, crushing and mixing and stirring can be performed reliably.

The excavated soil mixed and stirred in the mixing and stirring unit 57 moves to the classification unit 59 on the downstream side of the rotating cylinder 39. In the classifying unit 59, the cylindrical mesh body 65 rotates, and classification is performed by the mesh of the mesh of the cylindrical mesh body 65. That is, the excavated soil finer than the mesh falls through the mesh of the cylindrical mesh body 65 and is sent to the small conveyor 51 and further conveyed to a truck (not shown) by the conveyor 53.
On the other hand, excavated soil that is coarser than the mesh moves to the downstream end of the cylindrical net 65 and is discharged from the open end via the chute 55.

  During operation of the rotating cylinder 39, compressed air is injected from the outside of the cylindrical mesh body 65 to the inside from the injection nozzle 75 of the air injection means 67. Accordingly, clogging of the cylindrical mesh body 65 is prevented, and continuous work can be performed without stopping the work due to clogging of the cylindrical mesh body 65.

As described above, according to the mixing and stirring classification device 7 of the present embodiment, since the mixing and stirring portion 57 and the classification portion 59 are configured integrally, the entire device is compact. For this reason, by using this mixing and stirring classifier 7, the entire soil reforming plant 1 becomes compact, and it can be used even in a construction site where there is no equipment installation space.
In addition, since the classification is performed immediately after mixing and stirring the excavated soil, the classification efficiency is also good.
The mixing and stirring unit 57 is devised in various ways as described above, and the mixing and stirring is efficiently performed as described above.

  Further, in the present embodiment, both the stirring and mixing and the classification can be efficiently performed although the stirring and mixing unit and the classifying unit 59 are configured by the single rotating cylinder 39. In the stirring and mixing unit, the rotational speed of the stirring blade 43 is an important factor that determines the stirring and mixing rate, whereas in the classification unit 59, the rotational speed of the cylindrical mesh body 65 is important to determine the classification efficiency. This is because the rotational speed of the rotating cylinder 39 can be determined from the viewpoint of the classification efficiency, and the rotational speed of the stirring blade 43 can be determined from the viewpoint of the stirring and mixing efficiency on the premise of this.

In the above-described embodiment, the driving of the rotary cylinder 39 and the driving of the stirring blade 43 are driven by separate driving sources such as the first motor 37 and the second motor 45, respectively. You may make it drive with a drive source.
In the above-described embodiment, the example in which the plurality of stirring blades 43 are gathered and arranged on the excavation soil input side has been described. However, they may be evenly arranged in the mixing stirring unit in the cylindrical rotating body.
In the above embodiment, the shape of the stirring blade 43 is shown by connecting a straight rod-like body so as to be rotatable in the middle, but it may be formed by connecting curved rod-like bodies. Moreover, you may make the connection part of the stirring blade 43 into two or more places. The rod-shaped body includes a flat plate-shaped body.
Furthermore, all the stirring blades 43 do not have to have the same length or structure, and the length may be changed. In that case, you may make it comprise the short stirring blade 43 from a single body instead of a connection structure.

Further, in the above-described embodiment, a single cylindrical type is shown as the header 73 constituting the air ejecting means 67. However, the header 73 may be curved so as to follow the cylindrical net body 65.
Alternatively, the header 73 may not be provided with a separate nozzle, and the header 73 itself may have a large number of holes.
Further, as a means for preventing clogging of the cylindrical mesh body 65, a mechanical cleaning tool such as a brush is provided on the outside of the cylindrical mesh body 65 in addition to the injection of compressed air. The cylindrical net body 65 may be cleaned.
For the same purpose, the cylindrical mesh body 65 may be vibrated, or an impact may be sometimes applied to the cylindrical mesh body 65 or it may be hit with another member.

[Embodiment 2]
The present embodiment relates to a pipe backfilling method in which, for example, gas pipe burying work for burying gas pipes under a road is performed using the soil reforming plant 1 shown in the first embodiment.
FIG. 10 is an explanatory diagram of the pipe backfilling method according to the present embodiment, and the relationship between FIG. 10 (a) and FIG. 10 (b) is that the construction progressed from the state of FIG. The state is shown in FIG.

In the pipe backfilling method according to the present embodiment, the work area where the gas pipe is buried is divided into, for example, three work areas, a first work area 77, a second work area 79, and a third work area 81.
In each work area, the process is divided into three processes: an excavation process for excavating the ground, a pipe laying process for installing a gas pipe in the excavated portion, and a backfilling process for backfilling the place where the pipe is laid. At that time, the process in each work area is shifted. That is, when the first work section 77 is in the backfilling process, the second work section 79 performs a pipe laying process, and the third work section 81 performs a drilling process using, for example, the power shovel 82.
In FIG. 10A, an installation area for the soil reforming plant 1 and the improved soil transfer truck 83 is provided on the right side of the third work area 81.

In FIG. 10A, the first work section 77 shows the backfilling process, the second work section 79 shows the pipe laying process, and the third work section 81 shows the excavation process.
Then, the excavated soil excavated in the excavation process of the third work area 81 is used as the backfill soil in the backfill process of the first work area 77 by improving the soil quality by the soil improvement plant shown in the first embodiment. For the shortage of the improved soil, the soil brought in from the outside may be used.

In FIG. 10B, the backfilling process of the first work area 77 is completed, the backfilling process is started in the second work area 79, the piping laying process is started in the third work area 81, and further the diagram of the third work area 81. The right next to the middle shows a state where the excavation process has been started as a new work area.
In this way, every time the backfilling process is completed, a new work section is provided, the excavation process is started in the work section, and the construction of all sections to be constructed is completed while sequentially setting new work sections.

As described above, according to the present embodiment, the construction target work area is divided into three work areas, and the processes performed in the respective work areas are shifted, so that the processes of each work area can be performed simultaneously, and the efficiency is improved. Construction progress is realized.
Further, since the excavated soil excavated in the excavation process in the third work area 81 is improved in soil quality in the soil improvement plant 1 and used in the backfill process in the first work area 77, a large amount of backfill soil is externally provided. Construction can be carried out without having to be carried in.

It is explanatory drawing which shows the whole structure of the soil reforming plant which concerns on Embodiment 1 of this invention. It is explanatory drawing of the internal structure of the earth and sand cutting device which comprises some soil reforming plants which concern on Embodiment 1 of this invention. It is operation | movement explanatory drawing of the earth and sand cutting device shown in FIG. It is explanatory drawing of the mixing and stirring classification apparatus which comprises a part of soil reforming plant which concerns on Embodiment 1 of this invention. It is an arrow AA diagram of FIG. It is explanatory drawing of the internal structure of the mixing and stirring classification apparatus shown in FIG. It is an arrow BB diagram of FIG. It is explanatory drawing of the other aspect of the mixing and stirring classification apparatus which comprises some soil reforming plants which concern on Embodiment 1 of this invention. It is explanatory drawing of the other aspect of the mixing and stirring classification apparatus which comprises some soil reforming plants which concern on Embodiment 1 of this invention. It is explanatory drawing of the pipe backfilling method which concerns on Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Soil reforming plant 3 Sediment cutting device 5 Improving agent addition device 7 Mixing and stirring classification device 9 Belt conveyor 39 Rotating cylinder 41 Rotating shaft 43 Stirring blade 43a Base 43b Tip portion 57 Mixing and stirring portion 59 Classification portion 63 Bounce plate 65 Cylinder Net 67 Air injection means 77 1st work area 79 2nd work area 81 3rd work area

Claims (3)

Soil reforming plant used for pipe backfilling method. Sediment cutting device that cuts out the deposited soil in a fixed amount, a modifier addition device that adds a soil improver to the quantitatively cut out soil, and a soil improver. and a mixing and stirring classifying device for mixing agitation and classification of sediment accept been sediment, each of these devices, Ri Na between the respective devices are connected to earth and sand is conveyed,
The mixing and stirring classification device has a rotating cylinder that is rotationally driven, and is configured such that an upstream side of the rotating cylinder is a mixing and stirring unit and a downstream side is a classifying unit, and the mixing and stirring unit includes the rotating cylinder and Is provided with a central axis that is independently driven to rotate, and a stirring blade extending radially from the central axis,
A plurality of stirring blades are provided with a predetermined angle shifted around the rotation axis, and a stirring blade block is formed by collecting the plurality of stirring blades in the axial direction of the rotation shaft. soil reforming plant characterized that you have placed upstream end and a downstream end of the mixing and stirring part of. 2. The soil improvement according to claim 1, wherein the stirring blade is formed by connecting a plurality of rod-shaped bodies, and the connected rod-shaped bodies are configured to be rotatable within a rotation surface of the stirring blade at a connecting portion. Quality plant. A pipe backfilling method in which pipes are buried using the soil reforming plant according to claim 1 or 2,
  Dividing part or all of the construction section into three sections, in each section, the excavation process for excavating the ground, the pipe laying process for laying the pipe in the excavation process, and the place where the pipe was laid The backfilling process is performed sequentially,
  Excavated soil excavated in one excavation process is used as an improved soil by the soil improvement plant, and the improved soil is used as backfill soil in a different work area from the excavation process. Back construction method.

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