JPH0641948A - Multishaft foundation improving machine - Google Patents

Abstract

PURPOSE:To improve the strength of foundation by providing a pair of auxiliary improving shafts severally having an axial center in two lines forming a fixed included angle having the axial center of a main improving shaft as a vertex, and constructing an auxiliary improving pillar in a space between main improving pillars for unifying the main and the auxiliary improving pillar. CONSTITUTION:The axial centers of auxiliary improving shafts 200, 300 are positioned in two lines forming an included angle of 90 degrees having the axial center of one or more main improving shafts 100 as a vertex. Next, the areas of circles drawn by excavating blades 210, 310 and the area of a circle drawn by an excavating blade 110 are partially overlapped. Next, after excavation is executed to fixed depth as a solidifying agent is discharged at the shafts 100, 200, 300, each shaft is drawn up with its reverse rotation, and the main and the auxiliary improving pillar are mixed and stirred. After similar work is repeated in adjacent section to finish the first line, the second and later lines are executed in order. Thus, the occurrence of nonimproved part between the main improving pillars can be prevented, and the whole of improved area can be unified to increase resisting power against earthquake horizontal force, and moreover the structure of a device can be simple and tough.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-axis ground improvement machine for ground improvement of a structural foundation in civil engineering and construction work.

[0002]

2. Description of the Related Art The conventional ground improvement of a structure foundation has been carried out by a circular improved column shown in FIG. 6 or a rectangular improved column shown in FIG. In the case of the circular improved column, the ground improved machine having the uniaxial improved shaft provided with the excavation blade and the jet of the solidified material at the lower end of the shaft body and the stirring blades of a plurality of stages above the improved shaft Or the adjacent improved columns 1 and 1 are overlapped with each other as shown in FIG.
Alternatively, as shown in FIG. 6, the ground improvement of the structure foundation is performed by a multi-axis ground improvement machine in which two or more single shafts are arranged side by side.

Further, in the case of using the improved rectangular column, as shown in FIGS. 8 and 9, the excavation blades 11 and 21 at the tips of the shafts 10 and 20 are used for excavation while the jet port 1 at the tip is excavated.
The solidification material is discharged from 2, 22 to stir the soil and the solidification material in the ground, and the box-shaped casing 30 breaks the soil into a rectangle, and at the time of drawing, the solidification material is discharged from the upper ejection ports 13 and 23 while the solidification material is discharged. And the solidifying material are stirred, and the box-shaped casing 30 shapes the earth and sand into a rectangle to construct the rectangular improved columns, and the rectangular improved columns 2 are adjacent to each other as shown in FIG. 7 to improve the ground of the structure foundation. It was

Further, in the case of another rectangular improved column,
As shown in FIG. 10, a ground improvement machine was used in which a pair of improved shafts 40, 50 were equipped with vertical agitators 42, 52 consisting of vertical agitator blades 42b, 52b and gear boxes 42a, 52a.

The vertical stirring devices 42 and 52 are the shaft 4
It is driven by converting the horizontal rotation of 1, 51 into vertical rotation by the gear boxes 42a, 52a. With the above structure, as shown in FIG. 11, the spectacle-shaped cross section 4 and the vertical stirring device 42, which are partially overlapped by the horizontal rotation of the shafts 41 and 51,
A rectangular improved column 2 with a pair of elongated rectangular cross sections 5a, 5b (shown by hatching) according to 52 was formed.

[0006] Using the above-mentioned ground improvement machine, as shown in Fig. 7, the rectangular improvement columns 2 are arranged adjacent to each other to improve the ground of the structure foundation.

[0007]

However, in the case of the circular improved pillar 1 by the uniaxial or multiaxial ground improving machine, it is difficult to improve the area 100%. Since the circular improved columns 1 are partially overlapped with each other, an unimproved portion 6 as shown by hatching in FIG. 6 remains between the circular improved columns 1. In order to eliminate the unimproved portion 6, it is necessary to increase the overlap distance (lap distance), and it is necessary to largely scrape off the improved pillar. Therefore, not only is it uneconomical, but when the strength development of the already-improved columns has already been completed, the lap construction itself is difficult, and further construction defects such as misalignment occur.

Further, in the case of the rectangular ground improvement machine shown in FIGS. 8 and 10, since it is difficult to perform the lap construction, the adjacent rectangular improved columns 2 cannot be integrated. Therefore, the horizontal force at the time of the earthquake could not be supported, and the role of ground improvement of the structural foundation could not be fulfilled. Further, the ground improvement machine shown in FIG. 10 has a complicated excavation mechanism and is easily broken. Although the ground improvement machine shown in FIGS. 8 and 9 has a simple structure, mixing and stirring properties are poor, and lap construction is impossible.

The present invention has been made to remedy the above-mentioned drawbacks, and eliminates the space surrounded by the projection area of the excavation blades of the adjacent main improved shaft from the projection area of the excavation blades of the secondary improved shaft. According to the present invention, there is provided a multi-axis ground improvement machine in which an unimproved part does not remain between improved columns.

[0010]

The present invention comprises a main improved shaft,
A pair of sub-improved shafts having their axes on two lines forming an included angle of 90 degrees with the shaft center as the apex are provided, and the main and sub-improved shafts each have an excavation blade at the tip of the shaft body. In addition to being fixed, a jet of solidifying material is provided, a plurality of stirring blades are fixed above the excavation blade, and at least one connecting arm is attached over each shaft body in a loosely fitted state. The pair of sub-improved shafts has a smaller diameter than the outer diameter of the main-improved shaft excavation blade, and the projected area of the irrigation circle of each of the main-improved shafts is on the line forming the 90 degrees. The excavation wing partially overlaps the projected area of the irrigation circle.

Further, according to the present invention, a plurality of main improved shafts arranged side by side on a straight line, and the straight lines extending from the axial center of the main improved shafts located on both sides of the plurality of main improved shafts to the both sides, respectively.
A two-axis sub-improved axis centered on a line forming an angle of degrees,
A plurality of main and sub-improvement axes, the sub-improvement axis having a center at the apex of an equilateral triangle whose base is a straight line forming the axis of the main improvement axes adjacent to each other of the main improvement axes including the main improvement axes on both sides. An excavation blade is fixed to the tip of each shaft and a jet of solidifying material is provided on the shaft, and a plurality of stages of stirring blades are fixed above the excavation blade, and the shaft is extended over each shaft. At least one connecting arm is loosely fitted, the plurality of sub-improvement shafts have a smaller diameter than the outer diameter of the excavation blade of the main improvement shaft, and the projected area of the irrigation circle of each excavation blade is the above-mentioned. It is characterized in that the excavation blade of the main improved shaft partially overlaps with the projected area of the circle on the line forming the angle of 45 degrees and on each side sandwiching the apex angle forming 90 degrees of the right triangle.

A co-rotation preventing blade is loosely fitted between the shafts between the excavation blade and the lowest stirring blade, and both ends of the co-rotation preventing blade are connected to the main improved shaft or It is characterized in that it extends from the axis of each of the improved shafts by the length of the radius of gyration of the excavation blades of the secondary improved shafts.

[0013]

The sub-improvement shaft forms the sub-improvement column in the space surrounded by the main-improvement columns constructed by the adjacent main-improvement shafts. In addition, the co-rotation preventive blade that does not rotate during construction shears the soil mass generated by excavating the excavating blade with the rotating excavating blade to make it fine.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a plan view of the same, and FIG. 3 shows the layout of improved columns for ground improvement of a structure foundation constructed by the multi-axial ground improvement machine of the present invention. FIG. 4 is a plan view showing an improved pillar by one construction of a ground improvement machine having three improved shafts of the present invention, and FIG. 5 is a plan view of a ground improvement machine having a plurality of main improved shafts of the present invention. It is a top view of the improved pillar by construction.

FIGS. 1 and 2 show a ground improvement machine having three improved axes, where 100 is a main improved axis and 200 and 300 are sub-improved axes.
The sub-improved shafts 200 and 300 have their axes centered on two lines a and b forming an included angle of 90 degrees with the axis 0 of the main improved shaft 100 as the apex. Then, the area of the circle for excavation blades 210, 310 of the sub-improved shafts 200, 300 partially overlaps the area of the circle for excavation blades 110 of the main improved shaft 100 as shown in FIG. It has become.

Then, the main improved shaft 100 and the sub improved shaft 20
0 and 300 have drilling blades 110 and 21 at the tips, respectively.
Nos. 0 and 310 are fixed, and the solid material jetting port 13
0, 230, 330 are drilled. The excavation blade 11
Above the 0, 210, 310 are a plurality of stages of stirring blades 120,
220, 320 are fixed, and each shaft body 140, 24
0, 340 and at least one connecting arm 101
Are attached in a loosely fitted state.

Between each of the excavating blades 110, 210 and 310 and the lowermost stirring blades 120, 220 and 320, each shaft 1 is provided.
40, 240, 340, the co-rotation preventing blade 102 is attached in a loosely fitted state, and both ends of the co-rotation preventing blade 102 are excavation blades 210, 310 of the sub-improved shafts 200, 300.
By the length of the turning radius of
It extends from the zero axis. The co-rotation preventing blade 102 may be omitted, but if it is not provided, the strength of the improved column becomes weak because the mixing of the earth and sand and the solidifying material is poor.

Although FIG. 1 and FIG. 2 have been described in the case where the main improved shaft 100 is a single shaft, it may be a plurality of shafts having two or more shafts as shown in FIG. Although the main improvement shaft 100 has two axes in FIG. 5, a ground improvement machine in a plurality of cases will be described with reference to this, and a plurality of main improvement shafts 100 are arranged in parallel on a straight line f.
A main improved shaft having a center c on lines d and e that make an angle of 45 degrees with the straight line f from the axis 0 of the main improved shaft 100 at both ends toward both sides; A sub-improvement axis centered on the apex c of an equilateral triangle 0c0 whose base is a straight line connecting the axes 0 and 0 of the main improvement axes adjacent to each other of the improvement axis is provided. The structure of the main improved shaft and the sub-improved shaft in this case is the same as that in the case of the single main improved shaft described above, and therefore will be omitted.

A process of performing ground improvement of a structure foundation by using the multi-axis ground improvement machine of the present invention will be described in the case where two main improvement axes are provided. As shown in FIG. 3, two main improved shafts 401, 402
And excavation of the three sub-improved columns 501, 502, and 503 are performed up to a predetermined depth while discharging the solidifying material. However, sub-improvement pillar 5
No. 03 does not discharge the solidified material and only excavates. Next, the five improved shafts are lifted while rotating in the reverse direction, and the positive and secondary improved columns indicated by hatching are mixed and stirred.

Next, the two main improvement columns 403, 4 next to it
04 and three sub-improved columns 503, 504, 505 drilling,
Discharge, mix, stir and lift the solidified material. Also in this case, the sub-improvement pillar 505 is dug. Then, the solidified material is discharged to the sub-improved column 503 which was previously dug. As described above, when the first row is completed, the second and third rows are constructed. In the case of constructing the right end of each row in the case of this figure, all three solidifying materials are discharged and constructed on the sub-improved columns.

The above description has been made in the case where the number of the main improved shafts is two. However, the construction is the same whether the number of the main improved shafts is one or three or more, but the construction speed becomes faster as the number of the main improved shafts increases. .

[0022]

According to the present invention described in detail above, not only the unimproved portion is eliminated, but also the main improved pillars and the main improved pillars and the sub-improved pillars are overlapped with each other, and the ground is improved integrally. Therefore, it is possible to improve the ground with resistance to horizontal force during an earthquake. Further, the structure is simpler than that of the conventional ground improvement machine for rectangular improved columns, the mixture of the solidifying material and the earth and sand is good, and the strength of the improved columns is large.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a plan view showing an embodiment of the present invention.

FIG. 3 is a plan view showing an arrangement of improved columns for ground improvement of a structure foundation constructed by the multiaxial ground improvement machine of the present invention.

FIG. 4 is a plan view of an improved pillar by one-time construction of a ground improvement machine having three improved shafts of the present invention.

FIG. 5 is a plan view of an improved pillar by a single construction of a ground improvement machine having a plurality of main improved shafts of the present invention.

FIG. 6 is a layout drawing of circular improved columns in the ground improvement of a structure using a conventional single-axis or multi-axis ground improvement machine.

FIG. 7 is a layout view of rectangular improved columns in the ground improvement of a structure using a conventional ground improvement machine.

FIG. 8 is a front view of a ground improvement machine having a conventional box type casing.

FIG. 9 is a plan view of a ground improvement machine having a conventional box-type casing.

FIG. 10 is a front view of a ground improvement machine having a conventional vertical stirring device.

11 is a plan view of an improved column using the ground improvement machine of FIG.

[Explanation of symbols]

 100 Main improved shaft 200, 300 Secondary improved shaft 110, 210, 310 Excavation blade 120, 220, 320 Stirring blade 130, 230, 330 Jet outlet 140, 240, 340 Shaft 101 Connection arm 102 Co-rotation prevention blade 401, 402, 403, 404 Main improvement column 501, 502, 503, 504, 505 Sub improvement column f Straight line 0 Main improvement axis axis c Sub improvement axis axis d, e line

Claims (3)

[Claims] 1. A main improved shaft and a shaft center of which are apexes, and 9
A pair of sub-improved shafts having axes on two lines forming an included angle of 0 degree, and the main and sub-improved shafts each have an excavation blade fixed to the tip of the shaft body and a solidifying material. Is provided, a plurality of stages of stirring blades are fixed above the excavation blade, and at least one connecting arm is attached over each shaft body in a loosely fitted state. The excavation blade of the shaft has a smaller diameter than the outer diameter of the excavation blade of the main improved shaft, and the projected area of the irrigation circle of each digging blade is a projection of the circle of the edged blade of the main improved shaft on the line forming the 90 degrees. A multi-axis ground improvement machine characterized by overlapping in area. 2. A plurality of main improved shafts arranged side by side on a straight line, and an angle of 45 degrees from the axis of the main improved shafts located on both sides of the plurality of main improved shafts to the straight lines, respectively. It has a center on the apex of an equilateral triangle whose base is a straight line that intersects the axes of the main improvement axes adjacent to each other of the two main improvement axes including the main improvement axes on both sides and the main improvement axis on both sides. A sub-improvement shaft, wherein the plurality of main and sub-improvement shafts have excavation blades fixed to the tip end of each shaft body and provided with a jet of solidifying material, and a plurality of stages above the excavation blade. Stirring blades are fixed, and at least one connecting arm is attached over each shaft body in a loosely fitted state, and the plurality of sub-improvement shafts have a diameter smaller than the outer diameter of the excavation blade of the main improvement shaft, Moreover, the projected area of the irrigation circle of each excavation blade is a line forming the angle of 45 degrees. A multi-axis ground improvement machine characterized in that the excavation blade of the main improved axis partially overlaps with the projected area of an irrigation circle on the sides of the right triangle and the apex angle of 90 degrees of the right triangle. 3. A co-rotation preventing vane is loosely fitted between the shafts between the excavating blade and the lowermost stirring blade,
The both ends of the co-rotation preventing blade extend from the axis of each of the improved shafts by the length of the radius of gyration of the excavation blade of the main modified shaft or the sub modified shaft. 2. The multi-axis ground improvement machine described in 2.