JP3260337B2 - Ground improvement device and ground improvement method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ground improvement apparatus and a ground improvement method for mixing and agitating an improvement material and soft soil while excavating a mixing stirrer into the ground.

[0002]

2. Description of the Related Art Conventionally, there have been known several types of ground improvement apparatuses provided with this type of mixing stirrer. For example, as shown in FIG. 15, a conventional ground improvement device 201 includes a backhoe 202 which is one of construction work machines and an arm 203 thereof.
And a mixing stirrer 204 attached to the apparatus. The mixing stirrer 204 is connected to the arm 203 via the connection part 207. The mixing stirrer 204 includes a support frame 212 extending downward from the connecting portion 207, and a plurality of guide wheels 213 attached to the tip of the support frame 212. A drive motor 214 is provided inside the support frame 212, and the drive motor 21
A drive wheel 216 is provided above 4. Drive motor 2
14 and a sprocket 2 attached to the rotating shaft of the drive wheel 216.
A drive chain 218 is wound around 17. The driving force of the driving motor 214 is transmitted to the driving wheels 216 by the driving chain 218. Drive wheel 216 and guide wheel 21
A stirring chain 219 is wound around 3 and the like. The stirring chain 219 is provided with a plurality of stirring blades 220. When the driving wheels 216 are driven, the stirring chains 21
9 rotates between the two wheels 216 and 213, and the stirring blade 220 operates. At a lower position of the mixing stirrer 204, a discharge nozzle 222 for discharging the improving material supplied from a improving material supply device (not shown) through a supply pipe (not shown) to the vicinity of the stirring blade 220 is provided.

Therefore, according to the ground improvement apparatus 201, the mixing stirrer 204 is operated vertically by pushing the mixing stirrer 204 perpendicularly to the ground surface 230, so that the mixing stirrer 2 is operated.
04 digs down into the ground 231. At this time, the improving material is discharged from the discharge nozzle 222 buried in the ground 231 to the vicinity of the stirring blade 220, so that the improving material and the soft soil in the ground are mixed and stirred by the stirring blade 220.
After that, after the lower end of the mixing stirrer 204 reaches the deepest part of the ground improvement surface, the mixing stirrer 204 is pulled up to the ground surface 230 to form a solidified columnar mixed treated soil, and the soft ground is improved. .

[0004]

By the way, in the conventional ground improvement apparatus 201, as shown in FIG. 16, by using the ground improvement apparatus 201, the ground improvement apparatus 201 is deeper than the first area A near the ground surface. The ground improvement may be performed only in the two regions B. In this case, the improving material is discharged from the discharge nozzle 222 when the lower end of the mixing and stirring machine 204 reaches the boundary surface Z between the first region A and the second region B. However, in this case, the improving material is mixed into the first region A where the ground improvement is not necessary through the stirring chain 219 or the like, and the soil in the first region A is unnecessarily solidified. There is a problem that it is.

[0005] In order to prevent the above-mentioned problems, a mixing stirrer 20 is used.
A method in which the improving material is discharged from the discharge nozzle 222 at the stage when the upper end portion of the No. 4 completely enters the second region B may be considered.
However, in this case, the improvement material does not completely spread near the boundary surface Z, and the ground improvement near the boundary surface Z may be insufficient.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to improve the ground only in a second area deeper than a first area close to the ground surface. By ejecting the improving material from each ejection port at the stage when completely enters the second area, the first and second
A ground improvement device and a ground improvement method which make it possible to improve the ground only in the second region by spreading the improvement material near the boundary surface of the region, and to prevent the improvement material from being mixed into the first region. It is in.

[0007]

According to a first aspect of the present invention, there is provided a ground improvement apparatus for discharging a modifying material, comprising the steps of: Drive wheels and induction together with a stirring chain for mixing and stirring
In a ground improvement device provided with a mixing stirrer that includes a stirring blade that circulates and runs along the wheel , the discharging means includes a lower discharge port provided at a lower position of the mixing stirrer and a lower discharge port. And at least one upper discharge port provided , wherein each of the lower discharge port and the upper discharge port
Consists of a plurality of discharge holes,
Supply pipe receiving the supply of water and distributing means provided in the supply pipe
And supplying the improving material supplied to the supply pipe through the distribution means.
To distribute to the upper discharge port and the lower discharge port.
It is intended to be.

[0008] According to the ground improvement apparatus having the above structure, when performing the ground improvement from immediately below the ground surface, after the mixing stirrer is completely buried in the ground, the lower discharge port provided at the lower position thereof; The improving material is discharged from each of the at least one upper discharge port provided above, and at the same time, the stirring blade is operated. At this time, the improving material discharged from the lower discharge port is mixed and stirred with the soft soil while spreading in the ground corresponding to the lower position of the mixing and stirring machine.
On the other hand, since the upper discharge port is located near the ground surface,
The improved material discharged from the discharge port is mixed and stirred with the soft soil while spreading near the ground surface. Also,
When improving the ground in the second area deeper than the first area near the ground surface, the mixing stirrer is located in the ground in the second area, and the upper end thereof is located at the boundary between the first area and the second area. After being positioned near the surface, the improving material is discharged from the lower and upper discharge ports, and at the same time, the stirring blade is operated. At this time, the improving material discharged from the lower discharge port is mixed and stirred with the soft soil while spreading in the ground corresponding to the lower position of the mixing and stirring machine. On the other hand, the improving material discharged from the upper discharge port is mixed and stirred while spreading near the boundary between the first and second regions. In addition, since the mixing stirrer operates in the ground in the second area,
The improving material does not mix in the ground of the first region. Change
In order to supply the improving material to multiple outlets,
One supply pipe is shared between the supply device and the distribution means
It becomes possible.

[0009] soil improvement apparatus according to claim 2 in order to solve the above problems, in the soil modifying apparatus according to claim 1, and a lower discharge pipe is communicated with the lower discharge port portion,
An upper discharge pipe which is communicated with the upper discharge port portion, characterized in that a compressed air supply means for supplying at all times the compressed air within the lower and upper discharge pipe.

[0010] According to the ground improvement apparatus having the above structure,
In addition to the operation of the ground improvement apparatus described in 1 , the compressed air supply means constantly supplies compressed air into each discharge pipe, so that the distribution pipe disconnects the communication with the supply pipe. There is no vacuum inside. Therefore, while the communication between the discharge pipes and the supply pipes is interrupted, the earth and the like do not flow backward to the corresponding discharge port.

According to a third aspect of the present invention, there is provided a ground improvement method for solving the above-mentioned problems, wherein the ground improvement method is performed by the ground improvement apparatus according to the first or second aspect, wherein the stirring blade is operated. By doing so, a first excavation step of excavating the upper end of the mixing stirrer to an improved ground surface having a predetermined depth,
After the upper end of the mixing stirrer reaches the improved ground surface, the stirrer blades are operated while discharging the improving material from the lower and upper discharge ports, thereby mixing and stirring the improved material and the soft soil and the lower end of the mixing stirrer. A second excavation step of excavating the part to a predetermined depth, and a rising step of elevating the upper end of the mixing agitator to the improved ground surface after the lower end of the mixing agitator reaches the predetermined depth, and thereafter, The second excavation step and the ascending step are repeated, and the ground improving layer is formed under the remaining untreated layer by displacing the mixing stirrer in the horizontal direction at each repetition.

According to the ground improvement method having the above structure, in addition to the operation of the ground improvement device according to the first or second aspect , in the first excavation step, the upper end of the mixing and stirring machine has a ground having a predetermined depth. After reaching the improved surface, in the second excavation step, the improved material discharged from each discharge port portion is mixed and stirred with the soft soil by the stirring blade, so that the improved material below the ground surface at a predetermined depth below the ground surface. The soft soil is improved into a column shape until the lower end of the mixing stirrer reaches a predetermined depth. Then, by raising the mixing stirrer in the raising step, the upper end of the mixing stirrer is returned to the improved ground surface. Thereafter, the second excavation step and the ascending step are repeated, and at each repetition, the mixing and stirrer is displaced in the horizontal direction, so that the column-improved soil is continuously continuous in the horizontal direction. A group of ground improvement layers is formed below the untreated layer.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment Hereinafter, a ground improvement apparatus and a ground improvement method according to a first embodiment of the present invention will be described in detail with reference to the drawings.

FIGS. 1 and 2 show a schematic configuration of a ground improvement apparatus according to the present embodiment. The ground improvement device 1 includes a backhoe 2 as one of construction work machines, an extension arm 4 attached to a tip of the arm 3, and a mixing stirrer 5 attached to a lower end of the extension arm 4.

The backhoe 2 includes a swing frame 6 provided to be swingable and a boom 7 provided to the swing frame 6.
And a cockpit 8 for operating the ground improvement device 1. The arm 3 is connected to an arm cylinder 9 provided on a boom 7. The boom 7 is moved up and down by a boom cylinder 10 provided on the turning frame 6. The inclination of the arm 3 with respect to the boom 7 is changed by driving the arm cylinder 9. The bucket cylinder 11 provided on the arm 3 is connected to the extension arm 4 via a link mechanism 12. When the bucket cylinder 11 is driven, the inclination of the extension arm 4 with respect to the arm 3 is changed. The rotating mechanism 13 provided between the arm 3 and the increasing arm 4 rotates the mixing stirrer 5 together with the increasing arm 4 about an axis perpendicular to the ground surface. Here, the cylinders 9 to 11 and the rotation mechanism 13 are appropriately driven, so that the boom 7,
The arm 3, the increasing arm 4, and the mixing stirrer 5 are moved.

An inclinometer 14 is attached to the extension arm 4. The inclinometer 14 is for measuring the verticality of the mixing and stirring machine 5, and the measurement result is sent as an electric signal to a display device 8 a provided in the cockpit 8.
a.

The mixing stirrer 5 includes a driving wheel 22, guide wheels 23 and 24, and an auxiliary wheel 2 provided on a support frame 21, respectively.
5 and 26 are provided. The drive wheels 22 are provided in a pair on the same drive shaft 27 in parallel. The guide wheels 23 and 24 and the auxiliary wheels 25 and 26 are provided in a pair in parallel with the drive wheels 22 in each row. Drive wheel 22 and guide wheel 2 in each row
Stirring chains 28 are wound around the wheels 3 and 24 and the auxiliary wheels 25 and 26, respectively. A plurality of stirring blades 29 are mounted on the outer circumference of each stirring chain 28 at a predetermined interval. In this embodiment, two sets of guide wheels 23 and 24 are provided side by side at the lower end of the mixing stirrer 5 and a plurality of stirring blades 29 are provided.
The agitation chains 28 including the above are run. Thereby, the shape of the lower end portion of the mixing and stirring machine 5, that is, the shape of the bottom portion with respect to the ground is a quadrangular shape.

A stirring chain 28 is provided above the support frame 21.
A plurality of spatulaes 31 are mounted on the circulation path of the stirring blade 29 and near the drive wheels 22. These spatula 31
Constitutes mud removing means for removing mud adhering to the stirring blade 29.

A tachometer 30 is provided on the support frame 21. The tachometer 30 measures the rotation speed of the drive wheel 22 per unit time, thereby obtaining the stirring chain 2.
8 is for measuring the orbiting speed per unit time, and hence the stirring speed of the soft soil by the stirring blade 29. The measurement result of the tachometer 30 is converted into an electric signal to the cockpit 8.
Is sent to the display device 8a, and is displayed on the display device 8a.

The support frame 21, the driving motor 32 of the hydraulic constituting the drive motion means is provided. This drive motor 32
Is supplied with hydraulic oil through a hydraulic pipe (not shown). The sprocket 33 fixed on the output shaft of the drive motor 32 is connected to the sprocket 34 fixed on the drive shaft 27.
To the drive chain 35.

A pressure gauge 36 is provided in the hydraulic piping of the drive motor 31. The pressure gauge 36 is connected to the drive motor 3
2 is for measuring the pressure of the hydraulic oil supplied to the pump 2. The pressure gauge 36 measures the ground reaction force at the bottom of the mixing stirrer 5 by measuring the oil pressure of the working oil as the stirring resistance that the stirring blade 29 receives from the ground.
The measurement result of the pressure gauge 36 is sent to the display device 8a of the cockpit 8 as an electric signal, and is displayed on the display device 8a.

The lower part of the mixing stirrer 5, that is, the two induction wheels 2
In the vicinity of 3, 24, there is provided a lower discharge nozzle 37A constituting a lower discharge port of the present invention for discharging soil improvement cement, water, air, and the like as an improving material. On the other hand, an upper discharge nozzle 37B constituting an upper discharge port of the present invention for discharging the improving material is provided at an upper position of the mixing and stirring machine 5, that is, in the vicinity of the drive wheel 22. As shown in FIG. 4, a supply pipe 38, a lower discharge pipe 39A, and an upper discharge pipe 39 are connected to these discharge nozzles 37A and 37B.
The improvement material is supplied through B.

Here, a discharge device including the discharge nozzles 37A and 37B provided for discharging the improving material in the mixing and stirring machine 5 will be described. FIG. 4 shows the discharge device 5.
0 shows a conceptual configuration. The discharge device 50 includes a supply pipe 38.
And a lower discharge pipe 39A and an upper discharge pipe 39B branched from the supply pipe 38, and a distribution as distribution means of the present invention provided at a connecting portion between the supply pipe 38 and the lower and upper discharge pipes 39A and 39B. Machine 40. An improvement material is supplied to the supply pipe 38 from an improvement material supply device (not shown). The lower discharge pipe 39A is for supplying an improving material to the lower discharge nozzle 37A. The upper discharge pipe 39B is
This is for supplying the improving material to the upper discharge nozzle 37B. The distributor 40 constituted by an on-off valve mechanism selectively connects the lower discharge pipe 39A or the upper discharge pipe 39B to the supply pipe 38.
Is to communicate with This distributor 40 is provided with the supply pipe 3
8 and the lower discharge pipe 39A, the communication between the upper discharge pipe 39B and the supply pipe 38 is interrupted, and when the supply pipe 38 and the upper discharge pipe 39B are connected, the lower discharge pipe 39A.
And the supply pipe 38 is interrupted. The lower discharge pipe 39A has a lower supply pipe 5 for supplying compressed air.
3A is connected, and an upper supply pipe 53B for supplying compressed air is connected to the upper discharge pipe 39B. These supply pipes 53A and 53B are connected to the compressed air supply device via the main supply pipe 52. These supply pipes 52, 5
3A and 53B constitute the compressed air supply means of the present invention.

According to the discharge device 50 having the above-described structure, the improvement material is supplied from the improvement material supply device to the lower and upper discharge nozzles 37A and 37B.
Until then, one supply pipe 38 can be shared. For this reason, each discharge nozzle 37
The arrangement of the pipes up to A and 37B can be simplified.

Further, according to the discharge device 50, the improving material supplied to the supply pipe 38 is selectively supplied to the lower discharge pipe 39A or the upper discharge pipe 39B via the distributor 40. That is, when the lower discharge pipe 39A communicates with the supply pipe 38 by the distributor 40, the communication between the upper discharge pipe 39B and the supply pipe 38 is cut off, and the improving material supplied to the supply pipe 38 is selectively supplied to the lower part. It is supplied only to the discharge pipe 39A and discharged from only the lower discharge nozzle 37A. On the contrary, the upper discharge pipe 39B is supplied by the distributor 40 to the supply pipe 38.
When the lower discharge pipe 39A and the supply pipe 3
8 is shut off, and the improving material supplied to the supply pipe 38 is selectively supplied only to the upper discharge pipe 39B and discharged only from the upper discharge nozzle 37B. In this embodiment, in the distributor 40, the lower discharge nozzle 37
The distribution ratio of the improving material supplied to A and the upper discharge nozzle 37B can be arbitrarily changed (for example, 5: 5, 7: 3, 10: 0, etc.). Therefore, each discharge nozzle 37A,
When the improving material is discharged from both of the nozzles 37B and the improving material is discharged from each of the discharge nozzles 37A and 37B,
The supply pressure of the improving material applied to the supply pipe 38 is equal to each discharge 3
7A and 37B are intensively added. For this reason,
Even when the earth and the like are clogged in each of the discharge nozzles 37A and 37B, all the supply power of the improving material is intensively and strongly applied to each of the discharge nozzles 37A and 37B. 37A and 37B can be forcibly excluded. As a result, each of the discharge nozzles 37A, 37A
7B can be prevented from being clogged with earth and sand, and the improving material can be smoothly discharged from each of the discharge nozzles 37A and 37B. For example, when the lower discharge nozzle 37A is almost clogged with earth and sand, the lower discharge pipe 39A and the supply pipe 38
Is communicated, the communication between the upper discharge pipe 39B and the supply pipe 38 is cut off. Thus, the improving material supplied to the supply pipe 38 is not supplied to the upper discharge pipe 39B at all, but is supplied intensively to only the lower discharge pipe 39A.
For this reason, the sediment or the like clogging the lower discharge nozzle 37 </ b> A, together with the improving material due to the supply pressure of the improving material, the nozzle 37 </ b> A.
A is discharged from A and is forcibly removed. As a result, clogging of the lower discharge nozzle 37A can be prevented, and smooth discharge of the improving material from the nozzle 37A can be ensured.

Here, when the discharge pipes 39A and 39B are disconnected from the supply pipe 38, the corresponding discharge nozzles 37A and 37B are opened to the outside.
Sediment and the like easily flow back into the nozzles 37A and 37B. However, in this embodiment, since the compressed air is supplied through the main supply pipe 52 and the supply pipes 53A and 53B to the discharge pipes 39A and 39B whose communication with the supply pipe 38 is cut off, Nozzles 37A, 37B
Backflow of earth and sand can be prevented. In this sense as well, it is possible to prevent the discharge nozzles 37A and 37B from being clogged with earth and sand, etc.
The smooth discharge of the improving material from the material can be secured.

Here, the spatula 31 provided in the mixing and stirring machine 5 will be described in detail. FIG. 5 shows an attached state of the spatula 31. The support frame 21 includes a support portion 21A adjacent to the upper end portion 43 of the mixing stirrer 5 and the support portion 21A.
And side surfaces 21B and 21C extending downward from both sides. A plurality of spats 31 are attached in parallel to the lower surface of the support portion 21A so as to protrude downward. Each spatula 31,
It is arranged corresponding to a pair of drive wheels 22 located below it. A plurality of stirring blades 29 are attached to the stirring chain 28 connected to each drive wheel 22 as described above. Each stirring blade 29 includes three cutter blades 29 </ b> A protruding in the radial direction of the drive wheel 22. These cutter blades 29A
Are arranged in the axial direction of the drive wheel 22, and a space between the cutter blades 29A is a stirring portion 29B. Each spatula 3
1 is fixed to the support portion 21A so as to pass through these stirring portions 29B and not to interfere with each cutter blade 29A. Therefore, each stirring blade 2 together with the stirring chain 28
9 is operated, the cutter blade 2 of each stirring blade 29 is operated.
When 9A passes between each spatula 31, each stirring unit 2
9B moves along the spatula 31. At this time, mud or the like adhering to the stirring section 29B is peeled off by each spatula 31 and removed. That is, the mud adhering to the stirring blades 29 is always removed by each of the spatulaes 31, and a decrease in the stirring function of the stirring blades 29 is suppressed. As a result, the stirring efficiency of the stirring blade 29 for stirring the soft soil and the improving material can be constantly maintained at a high value.

Next, the rotation mechanism 13 will be described in detail. FIG. 6 shows a plan view of the rotation mechanism 13. The rotation mechanism 13 includes a connecting portion 13B between the arm 3 and the extension arm 4.
And a fixing portion 13A provided below the connecting portion 13B.
And a rotating portion 13C rotatably provided below the fixed portion 13A. A fixed arm 13D protruding outward is attached to the fixed portion 13A. Rotating part 13C
Is mounted with a rotating arm 13E that protrudes outward corresponding to the fixed arm 13D. A proximal end of a hydraulic cylinder 13F is rotatably attached to a distal end of the fixed arm 13D. The hydraulic cylinder 13F is provided with a cylinder rod 13G that can be expanded and contracted by hydraulic pressure. The tip of the cylinder rod 13G is rotatably attached to the tip of the rotary arm 13E.

According to the rotation mechanism 13 having the above-described structure, the cylinder rod 13G of the hydraulic cylinder 13F extends in the direction of the arrow C, whereby the rotation unit 1 is rotated via the rotation arm 13E.
3C rotates in the direction of arrow E. By this rotation, the increasing arm 4 rotates, and the mixing / stirring device 5 rotates by a predetermined angle in the same direction. On the other hand, when the cylinder rod 13G of the hydraulic cylinder 13F contracts in the direction of arrow D, the rotating unit 13C rotates in the direction of arrow F via the rotating arm 13E. By this rotation, the increasing arm 4 rotates, and the mixing / stirring device 5 rotates by a predetermined angle in the same direction. Therefore, by operating the rotating mechanism 13 with the augmenting arm 4 arranged perpendicular to the ground surface, the mixing and agitating device 5 is rotated about its axis perpendicular to the ground surface 40 at the fixed position. become. Thereby, the direction of the mixing and stirring device 5 can be freely changed within a predetermined angle range at a fixed position. When it is desired to change only the direction of the mixing and stirring machine 5 at the same excavation position, the direction of the mixing and stirring machine 5 can be changed without moving the backhoe 2.

Next, the operation of the ground improvement apparatus 1 having the above configuration will be described. In order to operate the ground improvement device 1, FIG.
As shown in (1), the mixing stirrer 5 together with the increasing arm 4 is pushed up perpendicular to the ground surface 40. From this state, the operator of the cockpit 8 visually checks the measurement result sent from the inclinometer 14 on the display device 8a and checks the verticality of the mixer 5 while driving the stirring chain 28 to stir the ground surface 40. Stir with wings 29. Thereby, as shown in FIG. 2, the mixing and stirring machine 5 is excavated until the upper end portion 43 of the mixing and stirring machine 5 reaches the ground surface 40. As described above, after the mixing and stirring machine 4 is completely buried in the ground, the improving material is discharged from each of the lower discharge nozzle 37A provided at the lower position and the upper discharge nozzle 37B provided at the upper position.
At the same time, each stirring blade 29 is operated. At this time, the improved material discharged from the lower discharge nozzle 37A is mixed and stirred with the soft soil while spreading in the ground corresponding to the lower position of the mixing and stirring machine 5. On the other hand, since the upper discharge nozzle 37B is located near the ground surface 40 and in the vicinity of the driving wheel 22, the improved material discharged from the discharge nozzle 37B spreads near the ground surface 40 and becomes soft soil. It will be mixed and stirred.

Further, the operator of the cockpit 8 is operated by the inclinometer 14.
The vertical axis of the mixing stirrer 5 is confirmed by visually checking the measurement result sent from the display device 8a, and the hardness of the ground is confirmed by visually checking the measurement result sent from the pressure gauge 36 on the display device 8a. While observing the measurement result sent from 30 on the display device 8a and confirming and controlling the stirring speed by the stirring blade 29, the mixing stirrer 5 is dug into the ground 41. Thereby, the soft soil is mixed and stirred with the improving material along the vertical excavation track by the mixing and stirring machine 5, and the columnar improved treated soil is formed. In this case, the ground can be vertically improved while the hardness of the ground is confirmed and the stirring speed of the stirring blade 29 is controlled.

According to the ground improvement apparatus 1 having the above configuration, FIG.
As shown in FIG. 5, when improving the ground in the second area B, which is deeper than the first area A, which is closer to the ground surface 40, each of the discharge nozzles 3 until the upper end 43 of the mixer 5 reaches the second area B.
The mixing stirrer 5 is excavated without discharging the improving material from 7A and 37B. Then, the upper end 43 of the mixing stirrer 5
Is located near the boundary surface Z between the first region A and the second region B, the improving material is discharged from each of the discharge nozzles 37A and 37B, and at the same time, each stirring blade 29 is operated. At this time, the improving material discharged from the lower discharge nozzle 37A on the lower side is mixed and stirred with the soft soil while spreading over the ground corresponding to the lower end of the mixing and stirring machine 5. On the other hand, since the upper upper discharge nozzle 37B is located near the boundary surface Z, the improving material discharged from the discharge nozzle 37B is mixed and stirred while spreading near the boundary surface Z. At this time, since the mixing and stirring machine 5 does not touch the ground of the first area A but operates in the ground of the second area B, the improved material discharged from the upper discharge nozzle 37A is discharged from the first area A. A does not mix into the ground. As a result,
It is possible to selectively solidify only the ground in the second area B without solidifying the ground in the first area A.

According to the ground improvement apparatus 1 having the above-described configuration, the extension arm 4 is provided between the mixing stirrer 5 and the arm 3 of the backhoe 2. For this reason, the extension arm 4 is connected to the ground surface 40.
By operating the mixing stirrer 5 vertically with respect to, the mixing stirrer 5 can be lowered vertically into the ground, and the mixing stirrer 5 is lowered to a position deeper by the length of the increasing arm 4. It becomes possible. Therefore, the mixing stirrer 5 can act on the ground with verticality, and the ground can be improved to a deeper position.

According to the ground improvement apparatus 1 having the above-described configuration, the inclinometer 14 for measuring the verticality of the mixing and stirring machine 5 is attached to the augmenting arm 4, so that the operator of the cockpit 8 can check the measurement results of the inclinometer 14. By reading with the display device 8a, it is possible to know the verticality of the mixing and stirring machine 5. Therefore, it is not necessary to separately arrange personnel to measure the verticality of the mixing and stirring machine 5. In this sense, the workability of ground improvement can be improved.

According to the ground improvement apparatus 1 having the above configuration, the tachometer 30 for measuring the stirring speed of the stirring blade 29 is used.
Is provided, the operator of the cockpit 8 can read the measurement result of the tachometer 30 to know the stirring speed by the stirring blade 29. For this reason, it is possible to easily confirm whether the stirring speed of the stirring blade 29 is the set value.

According to the ground improvement apparatus 1 having the above-described structure, the pressure gauge 36 for measuring the pressure of the hydraulic oil supplied to the drive motor 32 is provided. By reading the measurement result, it becomes possible to easily know the ground reaction force at the bottom of the mixing and stirring machine 5. Therefore, the ground reaction force of the target ground can be measured in parallel with the ground improvement work without separately measuring the ground reaction force, and the ground improvement work can be performed while the operator checks the state of the target ground, The work efficiency can be improved.

Next, two ground improvement methods using the ground improvement apparatus 1 having the above configuration will be described.

[Soil Improvement Method 1] FIG. 7 shows a conceptual configuration of the soil improvement method 1. Here, a case will be described in which the portion of the second region B closer to the ground surface 40 than the first region A is ground improved. First, the excavation of the ground is advanced by the mixer 5 from the state of step 1 to the state of step 2 shown in FIG. That is, in the first excavation step, the respective stirring blades 29 are operated to excavate the upper end portion 43 of the mixing agitator 5 to the improved ground surface Z in the second region B located at a predetermined depth. Next, the mixing stirrer 5
In the second excavation step, the lower and upper discharge nozzles 37A, 37B
By operating the agitating blade 29 while discharging the improving material from the above, the improving material and the soft soil are mixed and stirred, and FIG.
As shown in Step 3 of FIG.
Is excavated to the deepest surface Y of the second region B located at a predetermined depth. Next, after the lower end portion 44 of the mixing and stirring machine 5 reaches the deepest surface Y, the upper end portion 43 of the mixing and stirring machine 5 is raised to the improved ground surface Z as shown in Step 2 of FIG. After that, the second excavation step and the ascending step are repeated, and the mixing and stirrer 5 is displaced in the horizontal direction at each repetition, so that the first unprocessed layer is formed.
The ground improvement layer is formed in the second region B below the region A, except for the region A. That is, as shown by the arrow S in FIG.
Mixing stirrer 5 until the upper end 43 of the
Is raised, and the mixing and stirring device 5 is moved laterally to be displaced. Thereafter, when the upper end portion 43 of the mixing stirrer 5 reaches the improved ground surface Z, the mixing stirrer 5 is lowered again until the lower end portion 44 of the mixing stirrer 5 reaches the deepest surface Y,
The mixing stirrer 5 is moved sideways to be displaced. By repeating this operation, the ground is improved only in the second region B.

According to the above ground improvement method 1, after the upper end portion 43 of the mixing and stirring machine 5 reaches the ground improvement surface Z in the first excavation step, the discharge nozzles 37A, 3
7B is mixed and agitated with the soft soil by each agitating blade 29, so that the soft soil in the second region B below the improved ground surface Z below the ground surface is mixed with the lower end 4 of the mixing agitator 5.
4 is solidified in a columnar shape until it reaches the deepest surface Y. And by raising the mixing stirrer 5 in the raising step,
The upper end 43 of the mixing stirrer 5 is arranged to return to the improved ground surface Z. Thereafter, the second excavation step and the ascending step are repeated, and the mixing and stirrer 5 is displaced in the horizontal direction each time the repetition is performed, so that the soil solidified in a columnar shape continues in the horizontal direction. As described above, the first
A group of ground improvement layers are formed in the second region B below the untreated layer in the region A. Here, when the mixing and stirring device 5 is moved as indicated by an arrow S in FIG. 7 and the upper end portion 43 of the mixing and stirring device 5 reaches the improved ground surface Z, the upper discharge nozzle 37B closes the vicinity of the ground surface Z. It is possible to spread the improving material to the rim. Therefore, the entire area of the second area B including the vicinity of the improved ground surface Z can be solidified by the improving material to improve the ground. That is, when improving the ground only in the second region B, which is deeper than the first region A near the ground surface 40, each of the discharge nozzles 37A, 3
7B, the first and second materials are discharged.
In this case, it is possible to selectively improve the ground only in the second region B by sufficiently spreading the improving material near the boundary surface Z between the regions A and B, and to mix the improving material into the first region A. Can be prevented.

Here, in the repetition of the second excavation step and the ascent stroke, as shown in FIG. 8, the turning frame 6 of the backhoe 2 is turned at a fixed position to turn the arm 3 or to bend and extend the arm 3. As a result, the mixing stirrer 5 is moved from the first plane area G to the second plane area H and displaced in the horizontal direction. At this time, the mixing mechanism 5 is rotated by the rotation mechanism 13, and the soil solidified in a columnar shape is continued while the side surface g of the first plane region G and the side surface h of the second plane region H are aligned with each other. it can.
Similarly, the second plane area H and the third plane area I, the third plane area I and the fourth plane area J, and the fourth plane area J and the fifth plane area J
The plane region K can be made continuous. That is, in this embodiment, the mixing and stirrer 5 is operated at one point to improve the ground of each unit plane area G to H, and the turning and bending of the arm 3 and the horizontal rotation of the mixing and stirrer 5 by the rotation mechanism 13 are performed. By combining and displacing the mixing stirrer 5 intermittently along a predetermined curved horizontal trajectory (FIG. 8 corresponds to a horizontal trajectory bent at a right angle), and by operating the mixing stirrer 5 at each displacement point, The ground is improved while a plurality of unit plane areas G to H are connected in the horizontal direction. Therefore, the arm 3 and the rotation mechanism 13
By operating the mixing stirrer 5 together, the ground improvement is performed while the backhoe 2 is stopped at a fixed position and a plurality of unit plane areas G to H are continuous in the horizontal direction along the curved horizontal trajectory. Become. As a result, the soil improved in a columnar shape occupying the unit plane areas G to H is arranged continuously in the horizontal direction, and a group of ground improvement layers is formed. As a result, since the backhoe 2 does not need to be moved frequently, the ground improvement along such a curved horizontal locus can be efficiently performed.

[Second Embodiment] Next, a ground improvement apparatus according to a second embodiment of the present invention will be described with reference to FIG.

FIG. 9 shows a schematic configuration of a ground improvement apparatus according to the present embodiment. This ground improvement device includes a mixing stirrer 111.
However, the configuration is different from that of the mixing stirrer 5 of the above embodiment in that the induction wheel 23 is omitted and only the induction wheel 24 is provided. The mixing stirrer 111 also has a drive motor 32 as a drive unit for driving the stirring chain 28 and the stirring blade 29.
Is provided. Similarly, the mixing stirrer 111 is provided with a tachometer 30 for measuring the stirring speed of the soft soil by the stirring blade 29. On the other hand, an improvement material supply device 112 as an improvement material supply device for supplying the improvement material to each of the discharge means and the outlet nozzles 37A and 37B has the same device 11
2 is provided with an improved material flow meter 113 for measuring the flow rate of the improved material supplied to each of the discharge nozzles 37A and 37B. The improving material supply device 112 supplies the improving material stored in the silo 114 to the discharge nozzles 37A and 37B through the supply pipe 38 and the discharge pipes 39A and 39B. The improvement material flow meter 113 is provided at a connection portion of the supply pipe 38 in the improvement material supply device 112. This flow meter 1
Reference numeral 13 includes a display 113a for displaying the measured flow rate of the improving material per unit time. The flow rate displayed on the display 113a can be read by an operator. The measurement result of the tachometer 30 is sent to the display device 8a of the cockpit 8 as an electric signal, and is displayed on the same device 8a. This ground improvement device includes an improvement material supply device 112.
Is further provided, and the measurement results of the tachometer 30 and the improvement material flow meter 112 are sent to the controller 115 as electric signals. Then, the controller 115 measures the value of the improved material flow rate measured by the improved material flow meter 113 and the measured value of the rotation speed meter 30 so that a constant improved material flow rate according to the difference in the stirring speed by the stirring blade 29 is obtained. The improvement material supply device 112 is controlled based on the value of the stirring speed to be performed.

Therefore, according to the ground improvement apparatus of the present embodiment, it is determined by the controller 115 based on the measurement result of the tachometer 30 that the predetermined stirring speed by the stirring blade 29 cannot be obtained depending on the condition of the target ground. In this case, the controller 115 controls the improving material supply device 112 so that the predetermined improving material flow rate according to the stirring speed at that time is obtained.
Control. Thus, a certain amount of the improving material according to the condition of the target ground is discharged from each of the discharge nozzles 37A and 37B. That is, by correlating the measurement result of the tachometer 30 with the measurement result of the improvement material flowmeter 113, a predetermined improvement material discharge amount is secured at a predetermined stirring speed. For this reason, when a predetermined stirring speed cannot be secured, the improving material supply device 112 is controlled to increase or decrease the amount of the improving material discharged from each of the discharge nozzles 37A and 37B. The amount can be secured, and the ground can be improved with optimal efficiency according to the condition of the target ground.

Note that the present invention is not limited to the above embodiments, and various modifications and improvements can be made without departing from the spirit of the invention. For example, the present invention is embodied as follows. You can also.

(1) In each of the above-described embodiments, as shown in FIG. 4, the lower discharge port and the upper discharge port are constituted by the lower discharge nozzle 37A and the upper discharge nozzle 37B, each of which has one large opening. . On the other hand, as shown in FIG. 10, a lower discharge port portion and an upper discharge port portion may be constituted by a lower discharge nozzle 37A and an upper discharge nozzle 37B comprising a plurality of smaller discharge holes 60A.

(2) In the first embodiment, two sets of guide wheels 23 and 24 are provided side by side at the lower end of the mixing stirrer 5 so that each stirring chain 28 including a plurality of stirring blades 29 runs. did. Thereby, the lower end portion of the mixing and stirring machine 5, that is, the shape of the bottom portion with respect to the ground was formed in a square shape. On the other hand, a set of guide wheels is provided at the lower end of the mixing stirrer so that a stirring chain including a plurality of stirring blades 29 is run, and the bottom of the mixing stirrer with respect to the ground has a wedge-shaped configuration. May be.

( 3 ) In the first embodiment, the ground improvement when the first area A and the second area B are both ground has been described. However, the ground improvement when the first area A is water. Can also be applied. In this case, the ground can be improved only in the second region B without discharging the improving material into the water.

( 4 ) To the ground improvement apparatus of the first embodiment, as shown in FIG. 14, a construction machine such as the backhoe 2 is provided with a lifting apparatus 71 including a lifting column 70, and the lifting column is provided. At the lower end of 70, the mixing stirrer 5 is attached. Then, the mixing stirrer 5 may be configured to be vertically movable with respect to the ground by vertically moving the lifting column 70 of the lifting device 71 vertically. In this case, it becomes possible to lower the mixing stirrer 5 to a deeper position while maintaining the verticality by the length of the lifting column 70.

[0049]

According to the ground improvement apparatus of the first aspect, when the ground is to be improved immediately below the ground surface, the mixing stirrer is completely buried in the ground and then the improving material is discharged from each discharge port. By doing so, it is possible to spread the improving material near the ground surface. In addition, when improving the ground only in the second region deeper than the first region immediately below the ground surface, the improving material is discharged from each discharge port when the upper end portion of the mixer / mixer completely enters the second region. This allows the improvement material to spread around the boundary surface between the first and second regions, thereby improving the ground only in the second region, and preventing the improvement material from being mixed into the first region. Also, the improvement material supply device
Simplification of the piping from the outlet to each outlet
it can.

According to the ground improvement device of the second aspect ,
In addition to the effect of the ground improvement device according to the first aspect , since compressed air is supplied to each discharge pipe, it is possible to prevent earth and sand from flowing back to each discharge port. Also in this sense, it is possible to prevent earth and sand from being clogged in each of the discharge ports, and to ensure a smooth discharge of the improving material from the discharge ports.

According to the ground improvement method of the third aspect ,
When improving the ground only in the second area deeper than the first area immediately below the ground surface, by discharging the improving material from each discharge port at the stage when the upper end of the mixing stirrer completely enters the second area, It is possible to improve the ground only in the second region by spreading the improving material near the boundary surface between the first and second regions.
Mixing of the improving material into the region can be prevented.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a ground improvement device according to a first embodiment.

FIG. 2 is a schematic configuration diagram showing the operation of the ground improvement apparatus.

FIG. 3 is a schematic configuration diagram showing an operation of the ground improvement apparatus.

FIG. 4 is a schematic configuration diagram of a discharge device provided in the mixing and stirring machine.

FIG. 5 is a diagram showing a configuration of a spatula provided in the mixing and stirring machine.

FIG. 6 is a schematic configuration diagram showing a rotation mechanism provided on the extension arm or the like.

FIG. 7 is a schematic view showing a ground improvement method 1;

FIG. 8 is a schematic view showing a ground improvement method 1;

FIG. 9 is a schematic configuration diagram showing a ground improvement device according to a second embodiment.

FIG. 10 is a view showing a modification of the discharge device according to another embodiment.

FIG. 11 is a schematic configuration diagram showing a ground improvement device according to another embodiment.

FIG. 12 is a schematic configuration diagram showing a ground improvement device according to another embodiment.

FIG. 13 is a schematic configuration diagram showing a ground improvement device according to another embodiment.

FIG. 14 is a schematic configuration diagram showing a ground improvement device according to another embodiment.

FIG. 15 is a schematic configuration diagram showing a conventional ground improvement device.

FIG. 16 is a schematic configuration diagram showing a conventional ground improvement device.

[Explanation of symbols]

Reference Signs List 1 ground improvement device 2 backhoe (construction work machine) 3 arm 4 augmenting arm 5 mixing stirrer 8 cockpit 13 rotation mechanism 14 inclinometer 22 drive wheel 23 guide wheel 24 guide wheel 28 stirring chain 29 stirring blade 30 rotation speedometer 31 spatula ( Mud removing means) 35 drive chain 36 manometer 37A lower discharge nozzle (lower discharge port) 37B upper discharge nozzle (upper discharge port) 38 supply pipe 39A lower discharge pipe 39B upper discharge pipe 40 distributor (distributor) 52 main Supply pipe 53A Lower supply pipe 53B Upper supply pipe (52, 53A, 53B: compressed air supply means) 113 Improved material flow meter 122 Stirrer blade 122A Stirrer blade 122B Stirrer blade 123 Mixing stirrer 124 Mixing stirrer

Continuation of the front page (56) References JP-A-5-280043 (JP, A) JP-A-10-68124 (JP, A) JP-A-11-124844 (JP, A) JP-A-10-88568 (JP, A) JP-A-10-102478 (JP, A) JP-A-11-324010 (JP, A) JP-A-9-296441 (JP, A) JP-A-9-67818 (JP, A) 4-247114 (JP, A) JP-A-54-5217 (JP, A) JP-A-60-87234 (JP, U) JP-A-53-65202 (JP, U) (58) Fields investigated (Int. (Cl. ⁷ , DB name) E02D 3/12 103 E02F 5/06

Claims (3)

(57) [Claims] 1. A discharge means for discharging the improving material, and a stirring chain for mixing and stirring the discharged improving material with the soft soil of the ground, orbiting along a drive wheel and an induction wheel,
In a ground improvement apparatus including a mixing stirrer including a stirring blade to be run , the discharge unit includes a lower discharge port provided at a lower position of the mixing stirrer, and at least a lower discharge port provided above the lower discharge port. One upper discharge port portion, and the lower portion
Each of the discharge port and the upper discharge port has a plurality of discharges.
A supply pipe comprising a hole and receiving the supply of the improving material from the improving material supply device
And a distributing means provided in the supply pipe.
The improving material supplied to the supply pipe is supplied to the upper part through the distribution means.
Distribution supply to the lower discharge port and the lower discharge port
An improved ground improvement device. 2. A soil modifying apparatus according to claim 1, and a lower discharge pipe is communicated with the lower discharge port portion, and an upper discharge pipe which is communicated with the upper discharge port portion, the lower and A ground improvement apparatus comprising: compressed air supply means for constantly supplying compressed air to an upper discharge pipe. 3. A soil improvement method carried out by the soil improvement device according to claim 1 or 2 , wherein the stirring blade is operated to improve an upper end portion of the mixing stirrer to a predetermined depth. A first excavation step of excavating to the ground surface, and after the upper end of the mixing stirrer reaches the improved ground surface,
By operating the stirring blade while discharging the improving material from the lower and upper discharge ports, the improving material and the soft soil are mixed and stirred, and the lower end of the mixing and stirring machine is excavated to a predetermined depth. A second excavation step, and a rising step of elevating the upper end of the mixing stirrer to the improved ground surface after the lower end of the mixing stirrer reaches a predetermined depth, and thereafter, the second excavation A soil improvement method comprising repeating a step and the ascending step, and displacing the mixing stirrer in the horizontal direction at each repetition to form a ground improvement layer under the untreated layer while leaving the untreated layer.