JPS6117971B2 - - Google Patents

Description

[Detailed description of the invention] When improving deep soft ground, a ground improvement agent consisting of a ground hardening agent and additives used in combination as necessary is injected at high pressure from the tip of a penetrating shaft that penetrates into the ground. The method used is to mix it with the surrounding ground.

In the conventional method, as shown in Fig. 1, an underground penetrating shaft b equipped with a cutting blade a at the tip is rotated by a drive unit c disposed on the ground and penetrates into the ground. When the depth is reached, the underground penetration axis b
The ground improvement agent supplied from the hose d swivel e through the hole drilled in the hole is jetted out at high pressure from the tip injection port f while rotating the underground penetration shaft b and gradually pulling it out. At this time, the ground improvement material and the ground are mixed by the turbulent flow in the ground due to the flow of the high-pressure jet fluid, and by the swirling action of the penetration axis and therefore the spout in the horizontal plane.

However, in the conventional methods described above, it is difficult to sufficiently mix the soil improvement material and the ground. Therefore, as shown in Figure 2, the underground penetration axis b
In addition, as shown in Fig. 3, a stirring blade g is provided below the jetting port f, and a jetting port h is provided at the tip of the stirring blade g so that the ground improvement agent is also spouted from the jetting port h. It has also been proposed that
In this way, devices with stirring blades can better mix the soil improvement agent with the ground, but stirring blades have a large resistance force when rotating and pulling out the shaft that penetrates the ground, making it difficult for the equipment to handle. The power required is extremely large.

If a large amount of soil improvement agent is used, it is possible to achieve a soil improvement effect even if the soil improvement agent and the ground are not sufficiently mixed, but the volume of the soil will increase by the amount of soil improvement agent filled. Therefore, unless this expansion pressure is dispersed, it will prevent the soil improvement agent from being ejected, and it is impossible to fill the soil improvement agent in excess of a certain amount due to the relationship with the ejection pressure, and the degree of mixing of the soil improvement agent with the ground may also be affected. descend. Also, the heavy use of soil improvement materials is economically constrained. Therefore, the key to soil improvement comes down to how to evenly disperse and mix a small amount of soil improvement agent into the ground using small amounts of power.

From this point of view, the conventional method described above is a method in which the soil improvement agent is injected in a fixed direction relative to the axis of underground penetration, so it is difficult to improve the uniform distribution and uniform mixing of the soil improvement agent with the ground. The only options are to reduce the pulling speed of the underground penetrating shaft, increase its rotation speed, or increase the number of spouts for the ground improvement agent. However, a reduction in the pulling speed of the underground penetrating shaft leads to a decrease in work efficiency, an increase in the rotation speed of the underground penetrating shaft requires a large amount of power, and an increase in the number of ground improvement agent spouting ports does not involve a decrease in discharge pressure. , there is a risk that the mixing effect may be reduced. In addition, increasing the arrangement density of the ejection ports may reduce the unevenness of the ground.
In other words, due to the presence of unconformity surfaces, crack-like pore surfaces, and ultra-soft layers interposed between the strata, ejected materials from the ground improvement agent ejection ports located close to each other in the same direction are drawn into the previous ejected infiltration path. Otherwise, the soil conditioner may not be dispersed or stirred properly.

The present invention has been proposed in view of the above circumstances, and includes a ground improvement agent jetting body that is rotatable around an axis perpendicular to the shaft center on the outside of the tip of the underground penetrating shaft. After the underground penetration shaft penetrates into the ground, the above-mentioned body is rotated while moving up and down, and the ground improvement agent is injected into the ground through the spout which is arranged at an angle with the rotation axis of the body. A ground improvement method characterized by spraying and dispersing in a mesh pattern such as a three-dimensional trochoid, cycloid, or sawtooth curve in the outward direction perpendicular to the axis of penetration and stirring and mixing with the ground without using a stirring blade. The aim is to create a new and useful product that can evenly disperse a small amount of soil improvement agent with a small amount of power and mix it evenly with the soil, even in soil with a complex structure, without using stirring blades. The point is that it provides a ground improvement method.

As described above, in the present invention, after an underground penetration shaft is penetrated into the ground, a ground improvement agent jetting drive is provided outside the tip of the penetration shaft so as to be rotatable around an axis perpendicular to the shaft center. By rotating the body while moving it up and down, and at the same time injecting the ground improvement agent from the jet nozzle arranged at an angle with the rotation axis of the body, the soil improvement agent is injected in a direction perpendicular to the axis of underground penetration. In contrast, the soil improvement agent is injected and dispersed into the ground in a mesh pattern such as trochoid, cycloid, or sawtooth curve, so it can be used not only in homogeneous ground but also in strata with cracks and ultra-soft layers.
Even in complex-structured ground, the soil improvement agent can be evenly dispersed and mixed without the ejection direction being distorted by the strength or weakness of the ground, and a high soil improvement effect can be obtained with a small amount of soil improvement agent. .

At this time, by appropriately selecting the curing agent that constitutes the soil improvement agent and the curing accelerator or retarder added thereto, and adjusting the jetting pressure and jetting amount ratio, the soil improving agent and the hardening agent can be combined. The degree of mixing with the ground and the curing rate can be adjusted over a wider range, and the range of application of the method of the present invention is expanded.

As described above, according to the method of the present invention, the dispersion and mixing performance of the soil improvement agent is improved, and therefore a stirring blade is not required on the shaft penetrating into the ground, and a small amount of soil improvement agent is uniformly distributed in the ground with a small amount of power. can be dispersed and mixed.

Further, the present invention provides an underground penetrating shaft having no stirring blades, and an underground penetrating shaft disposed outside the tip of the underground penetrating shaft so as to be rotatable about an axis perpendicular to the shaft center, and A ground improvement device characterized by comprising a ground improvement agent spouting body in which a soil improvement agent spouting port is arranged at an inclined angle, and a rotation drive device for the same body. This allows ground improvement methods to be carried out effectively.

The present invention will be described below with reference to the illustrated embodiments.

FIG. 4 shows an outline of the soil improvement device used in the method of the present invention, which includes a base machine portion comprising a power section 1 and a mast 2, a shaft end mechanism A to be described later at the tip, and a drive means at the top. 3 and a swivel 4, etc., and a ground improvement agent preparation and high-pressure pumping plant (not shown). Note that the base machine, preparation of soil improvement agent, and high-pressure pumping plant are the same as those of the conventional system, so their explanations will be omitted.

5 and 6 show details of the underground penetrating device part, and the underground penetrating shaft B driven and rotated by the driving means 3 is formed in a double structure, and the shaft main body 5
The inner cylinder 6 can be rotated and a sliding key (not shown) can be used.
are fitted so as to be slidable in the axial direction. A shaft end mechanism A is provided in a portion of the shaft body 5 that extends downward from the inner cylinder 6, and the ground improvement is performed between the hub front half 8 and the hub rear half 9, which are attached to the lower end of the inner cylinder 6 via bolts 7. A agent jetting propellant 10 is rotatably held, and a cutting blade 11 is attached to the front half 8 of the hub. The shaft end mechanism portion of the shaft body 5 has a polygonal cross section as shown in FIG. 6, and has protrusions 12 on each surface thereof.
A pair of upper and lower shifters 13 and 14 fitted into the same polygonal cross section holds a bearing 15 having a square outer shape and a circular hole on each side, and is fixed by a nut 16. A crank pin 17, which protrudes from the back surface of the ejecting body 10 and is offset from the central axis thereof, is rotatably fitted into the same bearing 15. The ejecting agent is provided with an ejection port for the improving agent offset from the center point so that the ejecting direction is at a certain angle with the rotation axis of the ejecting agent, and the back surface of the ejecting agent 10 is in contact with the surface of the protrusion 12. The through holes that are in watertight contact with each of the jet ports 18 and 18' via the sliding piece 19 are connected to the shaft body 5 by a so-called rotary joint and slide joint structure (not shown) in hydraulic equipment. Horizontal holes 20, 21 and vertical holes 22,
It is connected to 23. A soil improvement agent is supplied to the vertical holes 22 and 23 via a swivel 4 from a soil improvement agent mixing and pressure feeding plant through a hose 24 in the same manner as in a known device of this type. There is.

25 is an outer cylinder that covers the inner cylinder 6;
The inner cylinder 6 is slidably supported by an upper bearing 26 and a lower bearing 27 provided at the inner cylinder 5 . 2 in the diagram
8 is a joint part between the upper and lower underground penetration shafts B.

In the illustrated embodiment, a pair of left and right underground penetration shafts B are disposed, and the upper and lower portions of each outer cylinder 25 are firmly connected to a column 30 via a connecting arm 29, and a regulating mechanism is provided at the upper part. The case 31 of C is connected to the outer cylinder of the driving means 3 via a connecting member 32, and the left and right cases 31 are connected via a bracket 33 by a connecting member 34. In the figure, 35 is a connecting member that connects the outer cylinders of the left and right drive means 3.

Inside the case 31 is a bearing box 36 with a small diameter section extending above and below an intermediate large diameter section, the large diameter section serving as a piston and the small diameter section serving as a shaft.
1 as a cylinder, which is fitted in a watertight and slidable manner, and upper and lower hydraulic chambers 37 and 38 are formed between the upper and lower stages of the bearing box 36 and the case 31, respectively. , 38 are connected to hydraulic hoses 39 and 40, respectively, and the upper end of the inner cylinder 6 is rotatably supported by the bearing box 36 via a thrust bearing 41.

Further, the pair of left and right underground penetration shafts B are driven by a driving means 3.
The connecting member 35 of the driving means 3, the connecting member 34 of the regulating mechanism C, and the upper part of the support column 30 are engaged with the mast 2, and are rotated in parallel with the mast 2. It is designed to slide up and down.

Since the illustrated embodiment is configured as described above, when power is transmitted from the power section 1 to the drive means 3, the shaft body 5 rotates together with the inner cylinder 6, and the shaft end mechanism A at the tip rotates accordingly. Rotate. At this time, when the underground penetrating shaft B is lowered along the mast 2, the ground is cut by the excavating blade 11, and the underground penetrating shaft B penetrates into the ground.

When the underground penetration shaft B penetrates to a predetermined depth, pressure oil is supplied from the hydraulic unit to the hydraulic chambers 37 and 38 in the regulating mechanism C via the hydraulic hoses 39 and 40, and the bearing box 36 receives hydraulic pressure. It slides up and down inside the hanging case 31. Since the bearing box 36 is engaged with the inner cylinder 6 via the thrust bearing 41, the inner cylinder 6 slides in the vertical direction with respect to the shaft body 5.

When the inner cylinder 6 and the shaft body 5 move relative to each other in the axial direction in this way, the hubs 8 and 9 fixed to the inner cylinder 6 also move in the axial direction with respect to the shaft body 5. Jetting propellant 10 held between hubs 8 and 9
Since the crank pin 17, which is disposed offset with respect to the rotational axis, is fitted into the bearing 15 which is clamped to the shifters 13 and 14 fixed to the shaft body 5, the shaft body 5 and Due to the relative movement with the hubs 8 and 9, the jetting body 10 rotates or swings around its axis.

On the other hand, hose 2 from the soil improvement agent mixing and pumping plant
When the soil improving agent is supplied under high pressure to the through holes 22, 23 of the shaft body 5 through the shaft body 5, the soil improving agent reaches the jetting ports 18, 18' of the jetting body 10. The respective jet ports 18, 18' are arranged so as to be inclined from the axis of the jet jet 10, and as the jet jet 10 rotates around its axis, the jet direction changes from time to time. change. In addition, since the jetting body 10 rotates in a horizontal plane with the rotation of the shaft body 5, the ground improvement agent drawn on the cylindrical surface, which is at a certain distance from the jetting ports 18, 18' and has the underground penetration shaft as its axis, Looking at the trajectory of the injection line, it can be seen that due to the relationship between the rotation of the shaft body 5, the rotation speed or rocking speed of the jet extruder 10, the amount of movement of the bearing box 36, and the amount of deflection of the crank pin 17 of the jet extruder 10, Even if the shaft end mechanism A is located at a certain depth underground, the trajectory of the injection line of the improver will be shifted three-dimensionally above and below the depth position of the shaft end mechanism A, resulting in a trochoid/cycloid.・Or draw a sawtooth curve. If the rotational speed and rocking speed are adjusted so that the jet ports 18, 18' do not completely return to their original positions in one rotation of the shaft end mechanism A, but are slightly shifted, this curve will change with each rotation. A phase shift occurs, resulting in a mesh-like appearance. Further, when the underground penetrating shaft B is pulled up while rotating the shaft body 5 and the ejecting body 10, these curve groups are successively superimposed, and the locus becomes a mesh-like shape of a toroid curve, a cycloid curve, or a sawtooth curve.

By ejecting the ground improvement agent into the ground in the form of a trochoid, cycloid, or sawtooth curve, it can be used not only in homogeneous ground, but also in ground with complex structures such as cracks and strata sandwiching ultra-soft layers. Even in this case, the soil improvement agent is evenly dispersed and mixed without being distorted in the ejection direction depending on the strength of the ground, and excellent soil improvement effects can be achieved with a small amount of soil improvement agent.

In addition, in the illustrated embodiment, the ejection propellant 10 has two
Since the spout ports 18 and 18' for the ground improvement agent are installed, the curing agent and the curing accelerator or curing retarder are injected separately and mixed in the ground. However, by adjusting the curing time, it is possible to prevent the curing agent from curing in the path up to the ejection ports 18, 18'. Furthermore, compressed air, a foaming agent, or a lubricating admixture can be ejected from one of the ejection ports to reduce the injection disturbance resistance of the ground to the injection of the soil improving agent and mix it with the ground. Furthermore, by appropriately selecting the curing agent and additives, and adjusting their ejection pressure and ejection amount ratio, the range of adjustment of the mixing range and curing rate can be widened, and the range of application of the present method can be further expanded. It will be expanded.

In addition, as mentioned above, the dispersion and mixing performance of the ground improvement agent is improved, so there is no need for a stirring blade in particular, and the underground penetrating shaft has a triple structure of the shaft main body 5 inner cylinder 6 outer cylinder 25, and the inner part Since only the rotating part rotates and the rotating part does not directly contact the ground, torque can be directly transmitted to the shaft end mechanism without loss. Furthermore, the underground penetrating shaft has a triple structure as described above, which is compatible with the presence of the support column 30. It can withstand strong penetration resistance and enables deep ground improvement.

Furthermore, since the main parts of the driving part such as the driving means 3 and the regulating mechanism C are arranged on the ground, it is durable and easy to maintain.

Furthermore, since the rotation of the injection propellant 10 is performed mechanically, the rotation is reliable and can be adjusted in harmony with the withdrawal of the underground penetration shaft, so that the injection network of the soil improvement agent in the ground can be effectively created. Can be set.

FIG. 7 shows another embodiment of the drive mechanism for the ejection propellant.

A notched gear 42 having a center on the same axis as the jetting body (not shown) is protruded from the back surface of a spouting body (not shown) equipped with spouting ports 18, 18', and a polyhedral shaped gear 42 is protruded from the outer periphery of the lower end of the shaft body. It is adapted to engage and disengage from a pair of left and right racks 43 and 44 protruding from the protrusion 12.
The notched gear 42 has a tooth bottom diameter corresponding to the tooth tip spacing of the racks 43 and 44, and has a notched gear structure having teeth in an arc portion corresponding to the projected dimension of the tooth bottom diameter.

When the notched gear 42 is moved upward from the position indicated by the dotted line in FIG. 7 by the action of the regulating mechanism C, the teeth of the notched gear 42 mesh with the right rack 44 and rotate to the right. However, the notched gear 42 and the right rack 44 no longer mesh with each other. At this time, the most distal tooth of the notch gear 42 starts to mesh with the rack 43 on the left side. At this position, when the notch gear 42 starts a downward movement by the action of the regulating mechanism C, the notch gear 42 is moved to the left rack 4.
3, descends while continuing to turn to the right, and reaches the position shown by the dotted line, where it disengages from the rack 43 on the left and meshes with the rack 44 on the right, resulting in the above-mentioned initial state. . Thereafter, by repeating the above-mentioned operation, the notch gear 42 and, by extension, the ejection propellant are continuously rotated, and the ejection ports 18, 18' are rotated continuously.
The soil improvement agent is evenly distributed and injected into the ground.

In addition, although the embodiment has been explained using vertical sliding motion as an example of the relative movement of the underground penetration shaft of the double structure,
The same effect can be produced even if the relative motion is rotational motion between the double structures.

Although the present invention has been described above with reference to embodiments, the present invention is, of course, not limited to such embodiments, and can be modified in various ways without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

Fig. 1 is a partially vertical side view showing the operating status of a conventional ground improvement device, Figs. 2 and 3 are slope views of the tip of the underground penetration shaft, and Fig. 4 is a ground improvement device according to the present invention. A side view showing the operating state of the soil improvement device used in the improved construction method, Figure 5 is a partial vertical cross-sectional side view of the main part, and Figure 6 is a cross-sectional plan view of the left half of the shaft end mechanism of the underground penetrating shaft. , FIG. 7 is a front view showing another embodiment of the drive mechanism for the ejection propellant. A...Shaft end mechanism, B...Earth penetration shaft, C...Regulation mechanism, 5...Shaft body, 6...Inner cylinder, 8...Hub front half, 9...Hub rear half, 10... Ground improvement agent jetting agent, 13... Shifter, 14... Shifter, 15... Bearing, 17... Crank pin, 1
8, 18'...Ground improvement agent spout, 25...Outer cylinder, 31...Case, 36...Bearing box, 37...
Hydraulic chamber, 38... Hydraulic chamber, 39... Hydraulic hose,
40... Hydraulic hose, 41... Thrust bearing, 42... Notch gear, 43... Rack, 44...
...Ratsuku.

Claims (1)

[Scope of Claims] 1. A ground improvement agent ejector is disposed outside the tip of the underground penetrating shaft, and is rotatable around an axis perpendicular to the axis thereof, and the underground penetrating shaft is penetrated into the ground. After that,
The substrate is rotated while moving up and down, and the ground improvement agent is applied in a three-dimensional manner in an outward direction perpendicular to the axis of underground penetration through a spout that is arranged at an angle to the rotation axis of the substrate. A ground improvement method characterized by spraying and dispersing in a mesh pattern such as a trochoid, cycloid, or sawtooth curve, and stirring and mixing it with the ground without using a stirring blade. 2. An underground penetrating shaft without stirring blades, and an underground penetrating shaft disposed on the outside of the tip of the underground penetrating shaft so as to be rotatable around an axis perpendicular to the shaft center, and at an angle inclined to the rotation axis. 1. A ground improvement device comprising: a ground improvement agent jetting body provided with a soil improvement agent spout; and a rotation drive device for the same body.