JPS6248010B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a deep mixing treatment method for strengthening soft ground by applying cement-based and other ground improvement agents into soft ground such as on the seabed while stirring and mixing. This relates to a mixing processing machine.

When performing construction using a conventional deep mixing machine,
Cement milk is added either when the treatment machine penetrates into the target ground or when it is pulled out after penetration from the improver discharge port provided at the upper or lower part of the stirring blade in the excavation and stirring mechanism at the lower end of the treatment machine. In order to strengthen the ground, the soil improvement agent was discharged and stirred and mixed into the soil.

One of the objects of this invention is to make it possible to discharge a soil improvement agent both when the treatment machine penetrates into the target ground and when it is pulled out after penetration, so that the soil improvement agent such as cement milk can be used more easily than in the conventional case. An object of the present invention is to provide a new deep mixing treatment machine that enables stirring and kneading into the ground in a uniform manner.

Next, when implementing the deep mixing treatment method, the deepest part of the soft ground into which the treatment machine is penetrated to apply the improvement agent is the boundary between the soft ground and the strong ground, and is hard due to soil texture. For example, 1-2
The treatment machine is moved up and down several times over a height range of 500 m, and during this time the improver is continuously discharged and applied and the soil is stirred to ensure that the improver reaches the deepest part of the soft ground. Conventional practice has been to achieve a consistent agitated mixing application. Also, even if the soil at the top of the soft ground is very soft like floating mud, the treatment machine can be repeatedly moved up and down while continuously discharging the improving agent and stirring the soil in the same way as described above. This is often carried out at the top of soft ground. In such cases, according to the conventional deep treatment machine, the improving agent is discharged and applied from one improving agent discharge port, resulting in low working efficiency and a long working time.

Another object of the present invention is to apply the improving agent into the soil at a high rate when the treatment machine is moved up and down several times to sufficiently stir and mix the improving agent in the deepest part of soft ground. An object of the present invention is to provide a new deep mixing processing machine that improves work efficiency and shortens work time.

To explain the configuration of the deep mixing processing machine according to the present invention with regard to the illustrated embodiments, first, in the first embodiment shown in FIGS. 1-5,
1 is a driving pipe, and a plurality of transmission shafts 3 are rotatably supported on this driving pipe 1 via an appropriate number of bearings 2. A hollow stirring shaft 5 equipped with a lower digging/stirring blade 4A and an appropriate number of upper stirring blades 4B is connected to the lower end of each transmission shaft 3 by a coupling 6. A drive section 7 equipped with a hydraulic or electric motor and a speed reducer as necessary is provided at the upper end of the processing machine, and each transmission shaft 3 is connected to the drive section 7 by a coupling 8. , so that it can receive rotational drive. In addition, as shown in FIGS. 1 and 2, a hollow improving agent injection tube 9 is provided along the casting pipe 1, and this improving agent injection tube 9 is particularly supported on the casting pipe 1 so that it can slide up and down. A hydraulic cylinder 10 is provided near the upper end of the casting pipe 1 for sliding the improving agent injection pipe 9 up and down. A improver feed pipe 11 made of a rubber hose is connected to the upper end of the improver injection pipe 9. A lower improver discharge port 12 is formed at the lower end of each stirring shaft 5, and a improver injection pipe 9 is formed at the lower end of each stirring shaft 5.
The lower end portion is inserted into a valve case 13 that is fixed to the pouring pipe 1 along the pouring pipe 1, and is fixed to the lower surface of the valve case 13 and placed on an extension of the improving agent injection pipe 9. An upper improver discharge port 15 is formed at the lower end of the improver discharge pipe 14 provided. A swivel device 16 is provided at the upper end of each stirring shaft 5.
The inner and outer parts are connected by a connecting pipe 17 made of a rubber hose.

The lower end of the slidable improver injection pipe 9 and the valve case 13 constitute a multi-stage switching valve 18 as described below. That is, as shown in FIG. 3, a pipe connection portion 13a, only one of which is shown in FIG. 3, is formed in the middle of the valve case 13, and each swivel device 1
Each of the connecting pipes 17 connected to the valve case 13 is connected to the pipe connecting part 13 which is opened into the valve case 13.
Connecting to the valve case 13 with a,
It has been done. In addition, the above-mentioned improver discharge pipe 14 is constructed by joining the flange 14a formed at the upper end of the discharge pipe 14 to the flange 13b formed at the lower end of the valve case 13 via a seal ring 19, and then
Both flanges 13b and 14a are connected to the valve case 13 by a connector 20, and a protrusion 21 that protrudes into the valve case 13 is integrally formed on the upper surface of the flange 14a. A suitable number of radial communication holes 21a are formed in this protrusion 21 to communicate the inside of the valve case 13 to the inside of the improver discharge pipe 14, and the protrusion 2
A circular groove is formed on the upper surface of the housing 1, and a sealing plate 22 made of rubber or the like is fitted into the groove. Further, on the inner circumferential surface of the valve case 13, an annular protrusion 13c is integrally formed on the inner surface side of the pipe connecting portion 13a, and another annular protrusion 13d is integrally formed at an appropriate distance below the annular protrusion 13c. A valve case 1 is formed and has an insertion port for the improving agent injection pipe 9.
3 Seal rings 23, 24, 2 made of rubber or the like are provided on the inner surface of the top wall, the upper and lower surfaces of the annular projection 13c, and the upper surface of the other annular projection 13d, respectively.
5 and 26 are attached by baking or the like. At the lower end of the improver injection pipe 9 facing into the valve case 13, there is a third valve whose upper surface is in close contact with the seal rings 23 and 25, respectively, when the injection pipe 9 is slid upward to the maximum extent as shown in FIG. 3a. As shown in Fig. c, when the injection tube 9 is slid downward to the maximum extent, upper and lower annular convex portions 9a and 9b are integrally formed on the outer peripheral surface of the seal rings 24 and 26, respectively, so that the lower surfaces of the seal rings 24 and 26 come into close contact with each other. There is also an upper and lower communication hole 9c
and 9d, when the injection tube 9 is slid upward to the maximum extent as shown in FIG. Further, as shown in FIG. 3b, when the injection tube 9 is slid to the intermediate position between FIG. 3a and FIG. As shown, the upper and lower communication holes 9c and 9d are arranged so that when the injection tube 9 is slid downward to the maximum, the upper communication hole 9c communicates with the inside of the pipe connection part 13a. be. Furthermore, as shown in FIG. 3c, when the injection tube 9 is slid downward to the maximum extent, the lower end of the injection tube 9 comes into pressure contact with the seal plate 22, and the lower end of the injection tube 9 It is arranged and provided at a position where it will be closed.

Since the multi-stage switching valve 18 has the above structure, when the improver injection pipe 9 is slid upward to the maximum extent as shown in FIG. The soil improvement agent that comes out is trapped in the case 13 between the seal rings 23 and 24, and the soil improvement agent that comes out into the valve case 13 from the lower end of the injection pipe 9 is sent from the communication hole 21a of the protrusion 21 to the improvement agent discharge pipe. 14. In addition, as shown in FIG. 3b, when the soil improvement agent injection pipe 9 is slid to the intermediate position between FIGS. flows out and flows into the stirring shaft 5 through the connection pipe 17 and the swivel device 16, and the soil improvement agent that comes out into the valve case 13 from the lower end of the injection pipe 9 flows through the communication hole 21a of the protrusion 21. The improving agent is caused to flow into the improving agent discharge pipe 14 from there. Further, as shown in FIG. 3c, when the improving agent injection tube 9 is slid downward to the maximum extent, the pipe connecting portion 13d is connected to the upper communication hole 9c.
The soil improving agent flows out into the agitating shaft 5 through the connecting pipe 17 and the swivel device 16, and the soil improving agent exits into the valve case 13 from the lower communicating hole 9d. Seal ring 2
5 and 26 within the case 13, and the lower end of the injection pipe 9 is sealed by the seal plate 22, so that the soil improvement agent does not flow into the improvement agent discharge pipe 14. That is, the illustrated multistage switching valve 1
8 allows the soil improvement agent to flow only into the improvement agent discharge pipe 14 through the upper improvement agent discharge port 15 at the lower end of the discharge pipe 14.
The improver is discharged only from the stirring shaft 4, and the improver is discharged only from the lower improving agent outlet 12 at the lower end of the stirring shaft 4. It is configured so that it can be selectively discharged from both the improver discharge port 15 and the lower improver discharge port 12. Switching the multi-stage switching valve 18 between the three operating states as described above is performed by selectively vertically sliding the improver injection pipe 9 using the hydraulic cylinder 10, as described above. The hydraulic cylinder 10 is equipped with a limit switch mechanism 27 as shown in FIG.
The limit switch mechanism 27 detects that the improving agent injection pipe 9 has reached the position shown in FIGS. 3a, b, or c, and stops driving the hydraulic cylinder 10.

The lower improver discharge port 12 at the lower end of each stirring shaft 5 may be simply opened, but the discharge port 1
When the soil conditioner from 2 is not discharged, the soil is stirred by the stirring shaft 5.
In order to prevent it from getting inside, it may be equipped with the following check valve mechanism. That is,
As shown in FIGS. 4 and 5, a substantially hemispherical sealing member 28a is provided on the upper surface of the conical head 28 disposed at the lower end of each stirring shaft 5, and the lower end portion of the hollow portion of the stirring shaft 5 is slightly closed. As shown in FIG.
The valve seat 29 is formed in such a way that the valve seat 29 can be brought into close contact with the valve seat 29 in a state in which the valve seat 29 faces slightly into the hollow portion. Then, on a suitable number of mounting plates 30 welded and protruding from the outer periphery of the head 28,
Upright pins 31 are fixed, and the pins 31 are inserted into the same number of support cylinders 32 that are welded and protruded from the outer periphery of the lower end of the stirring shaft 5, and the spring bearing ring 33 on the upper surface of the support cylinder 32 and the pins 31 are inserted. Nut 34 screwed into the upper end
A compression spring 36 is disposed on each pin 31 between the other spring bearing rings 35 which are prevented from coming out, and the compression spring 36 moves and biases the head 28 upward via the pin 31, thereby sealing. Part 2
8a is brought into close contact with the valve seat 29 to close the improving agent discharge port 12 at the lower end of the stirring shaft 5 when the improving agent is not being discharged. With this configuration, when the ground improvement agent is caused to flow into the stirring shaft 5 as described above, the sealing member 28a is pushed by the supply pressure of the improvement agent, and the head 28 is displaced downward against the force of the spring 36. The lower improving agent discharge port 12 is opened. The sealing force by the compression spring 36 is
Adjustment can be made by turning the nut 34 and moving it up and down on the pin 31.

Since the deep mixing processing machine according to the first embodiment illustrated in FIGS. 1-5 is configured as described above, this processing machine may be
When carrying out the deep mixing treatment method to strengthen soft ground such as on the seabed by suspending it from a crane of a work boat, the same construction can be carried out in the following manner. That is, FIG. 6 shows an example of such a construction mode, and in the case shown in FIG. Processing is carried out while constantly rotating 4A and 4B, but first, the improver feed pipe 11
A soil conditioner such as cement milk is fed from the bottom conditioner outlet 12 at the end of the stirring shaft 5, with the multi-stage switching valve 18 switched to the state shown in FIG. 3c.
While discharging the ground improvement agent from the base, the treatment machine is driven and penetrated into the target ground from the surface of the target soft ground as shown in FIG. 6a to the depth reaching the stable ground shown in FIG. 6b. At this time, the soil improvement agent is discharged and supplied into the ground over the entire depth of the pile formed by the penetration of the treatment machine. Next, as shown in FIGS. 6b and 6c, the upper improver discharge port 15 at the end of the improver discharge pipe 14 is in the deepest penetration state shown in FIG. 6b.
By a distance l ₁ approximately corresponding to the height position where is located,
With the flow of soil improvement agent from the improvement agent feed pipe 11 stopped, the processor is pulled out and brought to the state shown in FIG. 6c. Next, as shown in FIG. 6c, the soil improving agent is fed from the improving agent feeding pipe 11 and is discharged from the lower improving agent outlet 12 at the end of the stirring shaft 5. While re-penetrating the processing machine by the previous pulling distance l ₁ ,
bring about the state shown in At this time, the ground improvement agent was discharged and supplied twice to the distance l ₁ of the deepest part of the pile. From the state shown in FIG. 6d, the multistage switching valve 18 is now switched to the state shown in FIG. 3a, and the soil improvement agent is continued to be fed from the improvement agent feed pipe 11.
While discharging the soil improvement agent from the upper improvement agent discharge port 15 at the end of the improvement agent discharge pipe 14 as shown in FIG. 6e, the treatment machine is pulled out, and as shown in _FIG. Perform the extraction only. This pulling out is performed until the upper improving agent discharge port 15 at the end of the improving agent discharge pipe 14 reaches the surface level of the target ground, as shown in FIG. 6 f, and from the state shown in FIG.
By discharging the improver from the upper improver discharge port 15 while the drawing is being carried out to the state shown in _FIG . Next, the multi-stage switching valve 18 is switched from the state shown in FIG. 3a to the state shown in FIG.
Stopping the improving agent discharge from 5 and Fig. 6g.
While discharging the improving agent from the lower improving agent outlet 12 as shown in FIG.
The processor pulls out the distance l ₃ . At this time, with the second discharge and supply of the soil improvement agent from the lower improvement agent discharge port 12, the soil improvement agent is also discharged and supplied twice to the range of the illustrated distance _l3 . Next, the supply of the ground improvement agent from the improvement agent supply pipe 11 is stopped, and as shown in FIG. 6h, both the upper and lower improvement agent discharge ports 1
With the improver discharge from ports 2 and 15 stopped, re-penetration into the processor is carried out by the distance _l3 described above. Thereafter, the processor is again pulled out a distance l ₃ while the improver discharge is stopped, and the state shown in FIG. 6i is reached, completing one cycle of deep mixing treatment.

When carrying out the soil improvement treatment as described above, the soil improvement agent is discharged twice over the entire depth of the pile as described above, and the blade
Stirring and mixing are repeated multiple times over the entire depth of the pile using A and 4B rotations, and a high proportion of the ground improvement agent such as cement milk is supplied into the target ground and stirred and kneaded into the ground extremely uniformly. .

Then, the multistage switching valve 18 described above switches this to the state shown in FIG. 3b, so that
Since the soil improvement agent is configured to be able to be discharged from both the upper improvement agent discharge port 15 at the end of the improvement agent discharge pipe 14 and the lower improvement agent discharge port 12 at the end of the stirring shaft 5, the deep mixing according to the present invention In addition to being usable in the manner shown in FIG. 6 and described above, the processor can also be used in the following manner.

In other words, Figure 12 shows the construction mode in which the treatment machine is repeatedly moved up and down in the deepest part of soft and hard soil to thoroughly mix and apply the soil improvement agent. Upper and lower width l' ₁
It is repeatedly moved up and down within the range of . Figure 12a
As shown in FIG. 2, after the processing machine penetrates into the target ground to a predetermined depth, the hydraulic cylinder 10 is operated under the control of the limit switch mechanism 27 constituting the position detection mechanism, and the multi-stage switching valve 18 is activated.
The position where the soil improvement agent is discharged from both the upper and lower improvement agent discharge ports 15 and 12 (the position shown in Fig. 3b)
Displace it to. Then, between the lower limit positions shown in FIGS. 12a and 12e and the upper and lower positions shown in _FIG .
As shown in FIGS. 2b and 2e, the soil is repeatedly moved up and down while discharging the soil conditioner from both discharge ports 15 and 12 and stirring the soil by rotating the stirring shaft 5. The up and down movement of the processor is carried out at a speed of, for example, about 0.5-1 m/min, and is repeated for, for example, about 5-15 minutes.

If a ground improvement agent such as cement milk is not mixed into the soil relatively early after being applied, it will harden by itself and will no longer function as a soil improvement agent, but the top and bottom width l' ₁ is small. In addition, since the ground improvement agent discharged from the improvement agent discharge port 15 on the upper side during both penetration and withdrawal is applied to the soil being stirred in the stirring section, the improvement agent application in the above mode is Even if this is done, the function of the ground improvement agent is not substantially inhibited. And the 12th place in the deepest part of the soft ground
When carrying out construction in the manner shown in the figure, a high proportion of the ground improvement agent is applied to the soil by discharge from the upper and lower improvement agent discharge ports 15 and 12, so that the intended degree of soil reinforcement in the deepest part of the ground can be achieved at an early stage. This results in a reduction in working time.

If the soil at the top of the soft ground is very soft like floating mud, and the processing machine is placed at the top of the ground and is moved up and down repeatedly in the final construction process of each cycle, the same method as explained above can be applied. By repeatedly moving the processing machine up and down while simultaneously discharging the soil improvement agent from the upper and lower improvement agent discharge ports 15 and 12, the working time can be similarly shortened.

Next, the second embodiment shown in Figs. 7-11 will be explained. In this second embodiment, as shown in Figs. In addition to the two stirring shafts 5 connected to the lower ends of the two supported transmission shafts 3 with couplings 6, a coupling 6 is attached to the lower end of the transmission shaft 3' that passes through the pouring pipe 1. There is another stirring shaft 5' connected to the shaft 5', and the former stirring shaft 5' is equipped with a digging/stirring blade 4A and a stirring blade 4B, and the latter, which is slightly shorter in length, is equipped with a digging and stirring blade 4A and a stirring blade 4B. A stirring blade 4B is attached to the stirring shaft 5'.
Only the blades 4 on each stirring shaft 5 as shown in FIG.
The rotary loci of the blades A and 4B and the rotary locus of the blade 4B on the stirring shaft 5' partially overlap when viewed from above, respectively. In order to rotationally drive the stirring shafts 5, 5' via the transmission shafts 3, 3', a drive section 7 similar to the one described above is provided at the upper end of the processing machine. Here, a multi-stage switching valve 18' is supported by the drive section 7. Each transmission shaft 3 is divided into a plurality of parts in the length direction and the divided parts are connected to each other, and the lowermost transmission shaft part 3a is formed in a hollow shape, and each transmission shaft part A swivel device 16 is provided on 3a, and the multistage switching valve 1
8' and the swivel device 16 are connected by a connecting pipe 17' which has bendable parts at both ends and is fixedly supported on the casting pipe 1, and the connecting pipe 17' and the swivel device 16 are connected from the multi-stage switching valve 18' to the connecting pipe 17' and The soil improvement agent is sent into the hollow transmission shaft portion 3a through the swivel device 16, and from the transmission shaft portion 3a through the hollow stirring shaft 5 and from the lower improvement agent discharge port 12 of the stirring shaft 5. , the improving agent can be discharged. In addition, the two improver discharge pipes 14' connected to the multi-stage switching valve 18' at the bendable part at the upper end are connected to the casting pipe 1.
The upper improver discharge port 15 at the lower end of the discharge pipe 14' is located above the stirring blade 4B.

In this second embodiment, the multi-stage switching valve 1
As shown in FIG. 7, two improver feed pipes 11 are connected to the fuel cell 8', and the multi-stage switching valve 18' is constructed as a rotary valve as described below. That is, as shown in FIG. 10, the valve 18' is constructed by fitting a rotor 41 into a valve case 40 so as to be rotationally displaceable, and one half and the other half in the axial direction of the valve 18' are respectively , continuity between one improving agent feed pipe 11 and one connecting pipe 17' and improving agent discharge pipe 14';
It is meant to control the interruption. In each valve half, the improver feed pipe 11
are connected to the inlet port 42 and the improver discharge pipe 1
4' is connected to the outlet port 43 and the connecting pipe 1
7' is connected to another outlet port 44 in the valve case 40, and a communication hole 47 for communicating between the two notch grooves 45, 46 is formed in the rotor. 41.
The formation phase of each port 42, 43, 44 and the formation angle range of each notch groove 45, 46 are the 10th
In the rotational phase of the rotor 41 shown in FIG.
2 and the outlet port 43 are the notch groove 45 and the communication hole 4.
7 and the notch groove 46, and in the rotational phase of the rotor 41 shown in FIG. 10b,
Notch groove 45 connects inlet port 42 and outlet port 44
The notch groove 46 faces the output port 43, and the inlet port 42 communicates with the outlet port 43 via the notch groove 45, the communication hole 47, and the notch groove 46. The rotor 41 is also connected to another outlet port 44 through a notched groove 45, and is further connected to the rotor 41 shown in FIG. 10c.
In the rotational phase of , the notch groove 45 connects to the inlet port 42
The notch groove 46 faces the outlet port 44 across the outlet port 44, and the notch groove 46 is removed from the outlet port 43 position, and the notch groove 45 is formed between the inlet port 42 and the outlet port 44.
It is set up so that it can be communicated via. That is, the multistage switching valve 18'
Similar to the multi-stage switching valve 18' in the embodiment, the ground improvement agent is supplied from the improvement agent feed pipe 11 to
In the state shown in Figure a, the improver flows only into the improver discharge pipe 14' and is discharged only from the upper improver outlet 15 at the end of the pipe 14', and in the state shown in Figure 10b, the improver flows into the improver discharge pipe 14'. and into the connecting pipe 17'.The upper improving agent outlet 15 and the lower improving agent outlet 12
Furthermore, in the state shown in FIG.
The improver is discharged only from the lower improving agent discharge port 12 at the end.

In order to switch the multi-stage switching valve 18', as shown in FIG.
A hydraulic cylinder 10' is provided, the piston rod end of which is connected to an operating lever 48 fixed to the rotor shaft 41a.

Since the deep mixing machine according to the second embodiment illustrated in FIGS. 7-11 is configured as described above, it is different from the deep mixing machine according to the first embodiment described above. In exactly the same way, it can be used in the manner shown in Fig. 6, and when the processing machine is repeatedly moved up and down in the deepest part or the top of soft ground, the 12th
The soil improvement agent can be simultaneously discharged from the upper and lower improvement agent discharge ports 15 and 12 and supplied into the ground in the same manner as shown in the figure.

In addition, in the multi-stage switching valve 18 in the first embodiment, the number of selective stopping positions of the improver injection pipe 9 may be further increased, or in the multi-stage switching valve 18' in the second embodiment, the selective stopping positions of the rotor 41 may be further increased. By further increasing the amount, the improver discharge pipe 1
4 or 14' and the amount of soil improvement agent flowing into the connecting pipe 17 or 17', and therefore the discharge rate of the soil improvement agent from the upper improvement agent outlet 15 and the lower improvement agent outlet 12, It can also be made controllable.

As is clear from the above description, the deep mixing processing machine of the present invention is provided with improver discharge ports 15 and 12 at the upper and lower parts of the excavation and stirring mechanism at the lower end of the processor, and these improver discharge ports. 15, 12, the first position where the soil improvement agent is discharged only from the upper improving agent outlet 15 and the lower improving agent outlet 1.
The switching valve 18 has a second position in which the soil improvement agent is discharged only from 2, and a third position in which the soil improvement agent is discharged from both the upper improvement agent discharge port 15 and the lower improvement agent discharge port 12. , 18', and the switching valve 1 is selectively displaced to each of the above-mentioned positions by the displacement drive means 10, 10' whose operation is controlled by the position detection mechanism 27.
8 and 18', and has the following advantages.

That is, since the deep mixing treatment machine of the present invention is provided with the upper and lower improver discharge ports 15, 12 and the switching valve 18 or 18 as described above, the mode of use will be described in detail with reference to FIG. As described above, the soil improvement agent is discharged into the target ground both when the treatment machine penetrates and when it is pulled out, and the improvement agent is supplied into the target soil at a high rate twice, and is stirred multiple times. , the soil improvement agent can be stirred and kneaded into the target ground much more uniformly than in the conventional case, and in particular, the switching valves 18 and 18' simultaneously release the soil improvement agent from the upper and lower improvement agent discharge ports 15 and 12. Since the improver is configured to be able to be selectively displaced to the position where it is discharged, it can be used in hard and soft soils at the deepest depths, as previously described in detail with reference to Figure 12 as another usage mode. When the treatment machine is repeatedly moved up and down while discharging the improver and stirring the ground soil at the top of the soft ground made of extremely soft soil such as floating mud, the upper and lower improver discharge ports 15, By simultaneously discharging and applying the soil improvement agent from 12, it is possible to increase the application rate of the soil improvement agent, improve the efficiency of the soil improvement work, and shorten the work time.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway schematic front view showing a first embodiment of the present invention, Fig. 2 is a schematic plan view showing the arrangement of members in the first embodiment, and Figs. 3 a, b, and c.
4 is a partially cutaway and partially longitudinal sectional front view of the first embodiment, and FIG. 5 is a longitudinal sectional view showing the essential parts of the first embodiment in different states. A plan view of one member in the first embodiment, FIGS. 6 a-i are explanatory diagrams showing one usage mode of the first embodiment in order, and FIG. 7 is a second embodiment of the present invention. FIG. 8 is a schematic plan view showing the arrangement of members in the second embodiment, and FIG. 9 is a schematic plan view showing the arrangement of other members in the second embodiment. 10 is a schematic cross-sectional view of one member in the second embodiment, FIG. 11 is a schematic side view showing a part of the second embodiment, and FIGS. 12 a to 6 are FIG. 3 is an explanatory diagram showing a usage mode different from that shown in FIG. 1... Casting pipe, 3, 3'... Transmission shaft, 4A...
Drilling/stirring blade, 4B... Stirring blade, 5, 5'... Stirring shaft, 7... Drive section, 9... Improver injection pipe, 9
a, 9b... annular convex portion, 9c, 9d... communicating hole,
10, 10'... Hydraulic cylinder, 11... Improver feed pipe, 12... Lower improver discharge port, 13... Valve case, 13a... Pipe connection part, 13c, 13
d... Annular convex portion, 14, 14'... Improver discharge pipe, 15... Upper improver discharge port, 16... Swivel device, 17, 17'... Connecting pipe, 18, 18'...
...Multi-stage switching valve, 22...Seal plate, 23,
24, 25, 26... Seal ring, 40... Valve case, 41... Rotor, 42... Inlet port, 43, 44... Outlet port, 45, 46...
Notch groove, 47...Communication hole.

Claims (1)

[Claims] 1 Improver discharge ports are provided at the upper and lower parts of the excavation and stirring mechanism at the lower end of the processing machine, and among these improver discharge ports, a first soil improver is discharged from only the upper improver discharge port. a second position in which the soil improvement agent is discharged only from the lower improvement agent discharge port, and a third position in which the soil improvement agent is discharged from both the upper improvement agent discharge port and the lower improvement agent discharge port, A deep mixing processing machine characterized by being provided with a switching valve that is selectively displaced to each of the above-mentioned positions by a displacement drive means whose operation is controlled by a position detection mechanism. .