JP2004027492A - Foundation improvement device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a foundation improvement device capable of efficiently improving a linear or a flat foundation. <P>SOLUTION: A lower excavating blade 2 is installed at the lower part of an excavating shaft 1, and a side excavating vertical blade 12 extending upward from the tip of the lower excavating blade 2 is installed on the lower excavating blade 2. After the ground is excavated to such a depth that the upper end of the side excavating vertical blade 12 is not sunk from a ground surface by rotating the excavating shaft 1, the excavating shaft 1 is linearly moved in a side direction as viewed in a plane while rotating the excavating shaft 1. Thus a linear foundation with a width equal to the diameter D of the lower excavating blade 2 as viewed in a plane can be improved by the side excavating vertical blade 12. By performing this linear foundation improvement in parallel without intervals, the foundation can be flattened. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a soil improvement device, and in particular, discharges a lime-based or cement-based slurry-type solidifying agent (hereinafter, also simply referred to as a solidifying agent) while excavating the ground in civil engineering and construction foundation work. Also, the present invention relates to a ground improvement device (also referred to as a mixing and stirring device for excavated soil) for solidifying, shaping, and improving the ground by mixing, stirring, and solidifying the solidifying agent and excavated soil.
[0002]
[Prior art]
As this type of ground improvement apparatus, there is an apparatus provided with a digging wing (lower digging wing) near a tip (lower end) of a rotating digging shaft. This is generally provided with a stirring blade having a smaller diameter than the drilling wing, which is provided at an appropriate position on the drilling shaft above the drilling wing and extends laterally when viewed from the axial direction of the drilling shaft. The excavated soil is configured to be stirred and mixed. A discharge port for discharging a solidifying agent in the form of a slurry is provided at, for example, the tip of the excavating shaft. During the excavation process, the solidifying agent is discharged into excavated soil, mixed, stirred, and then solidified ( Curing).
[0003]
[Problems to be solved by the invention]
In such a conventional device, the excavation axis at the same site is rotated without moving in a plan view (as viewed from above), and the ground is excavated by the excavation wing by moving the excavation shaft downward, so that the excavated soil is removed. By mixing and stirring with a solidifying agent to solidify the portion, the ground improvement is performed in a columnar shape. For this reason, in such a conventional device, for example, when the ground is to be improved in a plan view, in a straight line (band shape) with a width corresponding to the size of the excavation diameter, or when the vertical and horizontal sides in the plan view are the excavation diameters, for example, There is a problem that the construction efficiency is extremely low when the ground is to be improved to a square of about 5 to 10 times and the ground is flat.
[0004]
This is because, in the above-described conventional apparatus, since the excavation can be performed only when the excavation axis is moved downward, the excavation diameter is set to be a width, and the ground is to be improved over a desired length in a plan view, in a straight line. If so, the following steps are performed. That is, at the starting position at the scheduled portion of the ground improvement (hereinafter, also simply referred to as improvement), the excavation shaft is moved down while rotating, and first, the first excavation, mixing with the solidifying agent, and stirring are performed. Hereinafter, excavation and mixing and stirring with excavated soil and a solidifying agent are also simply referred to as excavation. That is, excavation may mean not only excavation but also mixing and stirring of a solidifying agent and excavated soil. Then, after raising the excavation axis from the first excavation site, the second excavation is performed by lowering the rotation while rotating the excavation axis. At this time, in a plan view, the excavation axis is moved in a lateral direction in a straight line at a constant distance (for example, about 2/3 of the excavation diameter) so that the first excavation site and the second excavation site partially overlap. And excavate at the moved part.
[0005]
Then, after the excavation, the excavation axis is pulled up, the excavation axis is similarly moved by a fixed distance, and excavation is repeated, and excavation is continuously performed over a predetermined range (distance). The ground improvement was carried out by rotating the excavating shaft in a rotating, pulling, and lateral direction, and repeating the rotating lowering, pulling, and a lateral movement, so that the ground became substantially band-shaped in plan view. Here, the reason why the shape is substantially band-shaped is that the ground is improved in a state where the circles partially overlap at the front and rear excavation positions in plan view. That is, since the excavating shaft must be raised and then excavated by moving the excavating shaft downward at the next portion, there is a problem that workability of construction is poor. In addition, there is a problem that the excavation efficiency is poor because the excavation is performed with the excavation diameter (excavation site) overlapped by about 1/3 of the excavation diameter in plan view in the above example. The reason why the excavation is performed in this manner is to make the improved portion continuous.
[0006]
Moreover, such overlapping of the excavated parts does not merely reduce the excavation efficiency, but also causes an imbalance in excavation resistance due to excavating over a part that has already been excavated and a part that has not been excavated. . For this reason, in such excavation, the excavation axis tends to escape to a part with less excavation resistance, that is, to the excavated part side (ground side), so that the excavation axis is correctly held vertically and is difficult to move down. There were also problems. In addition, since the excavation is performed adjacent to the previously improved column, there is a problem that the improved unstirred soil is mixed with the improved (excavated) previously improved column. Furthermore, since the excavation by the excavation wing becomes circular in a plan view, if the excavation is performed by shifting the position of the excavation axis as described above, it does not mean that the ground has been improved by a certain width in the plan view.
[0007]
Such a problem is not limited to the case where the ground is improved linearly in a plan view, and the same applies to the case where the ground is improved in a flat shape. That is, in this case, the linear ground improvement described above is excavated such that a part of one side is overlapped in plan view in the longitudinal direction.
[0008]
The present invention has been devised in view of such problems in the conventional ground improvement device, and provides a ground improvement device capable of efficiently performing a straight ground improvement or a flat ground improvement in plan view. Its purpose is to:
[0009]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a lower excavation formed near the lower end of a rotating excavation shaft so that the ground can be excavated when the excavation shaft is rotated and moved down. In a ground improvement device equipped with wings,
The lower excavation wing has side excavation vertical wings extending upward from the tip thereof, and when the excavation axis is rotated in the ground and moved laterally, the side ground can be excavated. A ground improvement device characterized by being formed.
[0010]
In the present invention, since the vertical wing for side excavation is provided, first, the excavation shaft is rotated and moved down, and the lower excavation wing excavates to a depth at which the upper end of the vertical wing for side excavation does not sink from the ground. After mixing and stirring, the excavation axis is moved in a horizontal direction in a plan view while rotating the excavation axis. By doing so, it is possible to improve the ground in a straight line with the width of the lower excavation wing in plan view. Further, by moving in a curved shape, it is possible to improve the ground in a curved shape in which the diameter of the lower excavation wing is a width. Further, if such a linear ground improvement in a plan view is performed in parallel with no space between them, the flat plate can be improved. Thus, according to the apparatus of the present invention, since there is a vertical wing for side excavation, it is not necessary to raise the excavation axis and move down the excavation axis at the next part to excavate, as in the related art, Since it is sufficient to move the excavation shaft while rotating it, the construction efficiency and construction performance are extremely good.
[0011]
Then, when rotating the excavation shaft and excavating vertically with the lower excavation wing, after digging deeper than the depth (height) of the side excavation vertical wing and mixing and stirring, while rotating the excavation shaft, It is moved (hereinafter, referred to as lateral movement) within a range obtained by subtracting the radius of the excavation axis from half of the excavation diameter in a horizontal direction in plan view (hereinafter, referred to as 1/2 of the excavation diameter). By doing so, the ground can be expanded in a deep part in the ground by the excavation, mixing, and agitation by the side excavation vertical blades. Then, while rotating the digging axis, the digging axis revolves around the position of the digging axis at the time of the first digging within a range of 1/2 or less of the digging diameter in plan view, so that it is concentric in the deep part. The ground can be improved with a large vertical cross section.
[0012]
The configuration of the invention according to claim 2 is characterized in that the side excavation vertical blades include upper excavation horizontal blades extending laterally from the upper end to the excavation axis side, and by rotating the excavation axis in the ground. The ground improvement device according to claim 1, wherein an upper ground is formed so as to be excavable when the ground moves.
[0013]
According to the ground improvement device of the second aspect of the invention, the following operation and effect can be obtained in addition to the operation and effect of the ground improvement device of the first aspect. In other words, in this case, since there is an upper excavation horizontal blade, after excavating vertically, that is, downward with the lower excavation blade, deeper than the vertical dimension of the side excavation vertical blade, while rotating the excavation shaft, In the horizontal direction within a range obtained by subtracting the radius of the digging axis from の of the digging diameter (hereinafter referred to as 掘 削 of the digging diameter), and then move up the digging axis. In the present apparatus, since there is an upper excavation horizontal blade, such upward movement enables excavation and mixing and agitation up to the ground surface at the laterally moved portion. Then, after excavation to the ground surface at the laterally moved portion, the excavator moves laterally within 1/2 of the excavation diameter while rotating the excavation axis, and further descends to a predetermined depth. Thus, thereafter, by repeating such a process, a straight ground improvement in plan view, with the width of the lower excavation wing as a width, can be efficiently performed at a deep depth.
[0014]
In the ground improvement device according to the second aspect, it is preferable that the upper excavation lateral blade has a tip near the excavation axis fixed to the excavation axis as described in the third aspect. This is because, if fixed in this way, the strength of the upper excavation lateral wing can be increased.
[0015]
According to a fourth aspect of the present invention, in the ground improvement apparatus according to the second aspect, the excavation axis is inserted into an outer pipe connected to a driving unit that can rotate or stop around the excavation axis. And a lower end of the outer pipe exists between the lower excavation wing and the upper excavation horizontal wing, and a projecting portion that projects laterally at a position between the upper and lower parts near the lower end of the outer pipe. The projecting portion has a projecting length that does not interfere with the side excavating vertical blade when the excavating shaft is rotated and the rotation of the outer tube is stopped, and A ground improvement device characterized in that a tip of the horizontal wing for an excavation axis is rotatably fitted to the outer pipe.
[0016]
In this apparatus, when excavating by rotating the excavation axis, when the outer pipe is not rotated, or when the outer pipe is given a different rotation from the excavation axis, the extruded portion is provided. Has the effect of stopping the rotation of the excavated soil that is about to rotate. Therefore, efficient mixing and stirring can be performed. The number of protrusions can be one or more. The projection may have a simple shape, or may be capable of three-dimensional mixing and stirring.
[0017]
Furthermore, in the ground improvement device according to any one of claims 1 to 4, the vertical wing for side excavation may extend so as to be substantially parallel to the excavation axis. When the vertical blades for side excavation are parallel as described above, the excavation resistance caused by the vertical blades for side excavation can be reduced when the excavation axis is moved downward to perform excavation and mixing and stirring.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
A first embodiment of a ground improvement device according to the present invention will be described in detail with reference to FIGS. However, the following embodiments are configured by joining steel components to each other by welding or the like. In the figure, 101 is a ground improvement device, and 1 is its excavation axis (rotary drive axis). The excavating shaft 1 has a substantially cylindrical shape (hollow cylindrical shape), and is a hydraulic motor (hereinafter referred to as a hydraulic motor) for driving the excavating shaft to be rotated and attached to the tip of a bendable arm 105 of a moving vehicle (for example, a backhoe) (not shown). The excavating shaft 1 is connected, for example, vertically, and can be rotated right or left at a desired number of rotations, stopped, and controlled freely. Then, the excavating shaft 1 is configured to be able to move in an arbitrary direction, such as a vertical direction or a lateral direction, by driving the arm 1 while rotating the excavating shaft 1.
[0019]
In the vicinity of the lower end portion of the excavation shaft 1, a lower excavation wing 2 having a predetermined diameter (length) D1 for excavating the ground is provided in a projecting manner in a direction substantially perpendicular to the excavation shaft 1 by welding. . The lower excavation wing 2 is provided with an excavation claw 4 along its lower edge. Although not shown, a discharge port of a slurry-like solidifying agent is provided at the tip of the excavating shaft 1, and the solidifying agent is discharged from the pressure source into the excavated soil through the inside of the excavating shaft 1. It is configured as follows.
[0020]
On both ends of the lower excavation wing 2 of the excavation shaft 1, side excavation vertical wings 12 extending substantially parallel to the excavation shaft 1 and extending upward are formed. An excavation claw 14 is provided outside the side excavation vertical wing 12 (on the side opposite to the excavation shaft 1). The plurality of excavating claws 14 are provided at regular intervals. In addition, the stirring blade 6 is fixed to the excavation shaft 1 so as to protrude laterally at an intermediate portion of the vertical height of the side excavation vertical blade 12. A slight gap is provided between the tip of the stirring blade 6 and the inside of the side digging vertical blade 12. However, both may be joined and fixed without providing such an interval.
[0021]
When the ground of a flat ground is improved by the apparatus of the present embodiment, the following is performed. The excavating shaft 1 is held vertically, rotated, and pushed (moves down) from the ground surface (ground surface) G into the ground. Then, the lower excavation wing 2 that rotates integrally and excavates in a columnar shape with the length D as the diameter. At this time, the excavated soil is mixed and stirred by the stirring blades 6 rotating simultaneously. In such an apparatus of the present embodiment, for example, when the ground is improved in a straight line, the columnar excavation is excavated to a depth not deeper than the upper end 12a of the side excavation vertical blade 12, and the solidifying agent is discharged. The lower excavation wing 2 is held at the depth position while mixing and stirring.
[0022]
Then, while the excavating shaft 1 is being rotated, the excavating shaft 1 is moved laterally while maintaining the vertical position. This movement may be performed by moving a moving vehicle, by controlling the arm 105 so that only the excavation shaft 1 moves, or by moving and controlling both. By laterally moving in this manner, the ground is excavated in the lateral direction by the vertical wings 12 for side excavation. In this excavation, by moving the excavation shaft 1 in a plan view to a predetermined position while discharging the solidifying agent, the ground improvement is performed linearly with the diameter D of the lower excavation wing 2 as a width in the movement range. Done. Thus, according to the present apparatus, if the depth is equal to or less than the height of the side excavation vertical wing 12, the excavation is first performed vertically to that depth, and thereafter the excavation axis 1 is viewed in a plan view and the horizontal direction. Since the excavation can be performed in a straight line simply by moving in a straight line, such ground improvement can be efficiently performed. Note that the height (length in the vertical direction) of the vertical wing 12 for side excavation may be set to be equal to or more than a general ground improvement depth. In the case of improving the flat plate, such straight excavation may be performed in parallel without any interval.
[0023]
Further, in such an apparatus, the ground can be improved to have a convex shape in a longitudinal sectional view. That is, the excavating shaft 1 is rotated and moved downward, and is excavated, mixed, and agitated vertically by the lower excavating wing 2 to be deeper than the depth of the side excavating vertical wing 12. After that, while rotating the excavating shaft 1, it is viewed in a plan view, and laterally within a range obtained by subtracting the radius of the excavating shaft 1 from 掘 削 of the excavating diameter D in the lateral direction (hereinafter referred to as 掘 削 of the excavating diameter). It moves so as to revolve the revolving (rotating) excavation shaft 1 around the position where the excavation shaft 1 was located in plan view, the center position in the first column excavation. By doing so, the excavation, mixing, and agitation of the side excavation vertical wings 12 can improve the ground in a vertical cross-section, which has an enlarged diameter in the deep part, and a convex shape.
[0024]
Next, a second embodiment of the ground improvement device will be described in detail with reference to FIGS. 3 and 4. However, this soil improvement device 201 is different from the above-described embodiment only in that an upper excavation lateral blade 22 extending horizontally from the upper end 12a of the side excavation vertical blade 12 toward the excavation axis 1 is provided. , Only the differences will be described, and the same portions will be denoted by the same reference numerals and description thereof will be omitted. That is, in this embodiment, the upper excavation horizontal blade 22 extends from the upper end 12a of the side excavation vertical blade 12 toward the excavation shaft 1, and the tip of the upper excavation horizontal blade 22 is separated from the excavation shaft 1. However, in this example, it is fixed to the excavation shaft 1 for maintaining strength. The upper excavation lateral blades 22 are provided with excavation claws 24 along the outside, that is, along the upper edge.
[0025]
In the apparatus of this embodiment, since the upper excavation lateral blades 22 are provided, the excavation shaft 1 is rotated after excavating vertically and deeper than the vertical dimension (height) of the side excavation vertical blades 12 and mixing and stirring. While moving it laterally within a range obtained by subtracting the radius of the digging shaft 1 from の of the digging diameter D in a plan view (hereinafter, referred to as の of the digging diameter), the digging shaft 1 is then moved upward. By moving, excavation and mixing and agitation can be performed up to the ground surface at the laterally moved portion. Then, while rotating the excavation shaft 1, it is moved in the lateral direction by, for example, the excavation diameter, and at that position, is vertically moved downward by the previous depth, and the vertical dimension of the side excavation vertical wing 12. Drill deeper. Thus, thereafter, by repeating such a process, a straight ground improvement with the width of the lower excavation wing 2 as a width in a plan view can be efficiently performed at a deep depth. That is, in the present embodiment, even when the excavating shaft 1 is moved upward, the excavation can be performed by the upper excavating lateral blades 22, so that extremely efficient excavation can be performed.
[0026]
Next, an embodiment (third embodiment) of the ground improvement apparatus 301 according to claim 4 will be described with reference to FIGS. 5 and 6. However, in the ground improvement apparatus 301, the excavation shaft 1 is inserted into the outer pipe 31 that can be rotated (forward or reverse) or stopped around the excavation shaft 1 with respect to the above-described configuration. The only difference is that a protruding portion 41 protruding in the lateral direction is fixed to a portion near the lower end portion of the tube 31. Therefore, the difference will be mainly described, and the same portions will be denoted by the same reference numerals. The description thereof will be omitted as appropriate. That is, in the present embodiment, the lower excavation wing 2 extends laterally at the tip of the excavation shaft 1, and the side excavation vertical wing 12 extends upward at the tip of the lower excavation wing 2 substantially parallel to the excavation shaft 1. I have. An upper excavation horizontal blade 22 extends horizontally from an upper end 12 a of the side excavation vertical blade 12 toward the excavation shaft 1 and the outer pipe 31. The tip of the upper excavation lateral wing 22 is fixed to a ring 32 rotatably fitted to the outer tube 31. Excavation claws 14 and 24 are provided on the outside of the vertical wing 12 for side excavation and on the upper edge of the horizontal wing 22 for upper excavation in the same manner as in the above embodiment.
[0027]
On the other hand, the lower end of the outer pipe 31 is configured to be located at an upper and lower intermediate position between the lower excavation wing 2 and the upper excavation lateral wing 22. A projecting portion 41 projecting in the lateral direction is fixed to the outer tube 31 at a position closer to the lower end of the outer tube 31 and at an upper and lower intermediate position between the lower excavating wing 2 and the upper excavating lateral blade 22. . The protruding portion 41 is a strip having a protruding length that does not interfere with the side excavating vertical blades 12 when the excavating shaft 1 is rotated and the rotation of the outer tube 31 is stopped. It is configured to make. The upper end of the outer tube 31 is connected to a rotary drive source (not shown) so that the outer tube 31 can be rotated and stopped separately from the drive shaft 1.
[0028]
However, in the case of such a ground improvement apparatus 301, when excavation is performed by rotating the excavation shaft 1 while the outer pipe 31 is stopped or while rotating the excavation shaft 1 in the opposite direction. Since the projecting portion 41 is fixed to the outer pipe 31, even if there is excavated soil that is going to rotate around the excavation axis 1, the projecting portion 41 stops the co-rotation. Therefore, uniform mixing and stirring of the excavated soil and the solidifying agent can be obtained, and efficient mixing and stirring can be performed. The number of the protruding portions 41 may be one or more, and may be provided above the upper excavation lateral wing 22.
[0029]
In the above description, the lower excavation wing 2 has a linear shape extending to both sides as viewed from above, but may have a + shape intersecting the excavation axis 1 as a center in plan view. In that case, the vertical wings for side excavation may be provided so as to extend upward at each tip of each lower excavation wing, or may be provided only at the opposing end thereof, and may be set appropriately. . The upper excavation horizontal blades may also be provided at the upper end of all the side excavation vertical blades, or may be provided only on the opposing side excavation vertical blades, and may be set as appropriate. .
[0030]
【The invention's effect】
According to the present invention, in addition to the lower excavation wing, the side digging vertical wing is provided, so that the upper end of the side digging vertical wing is excavated to a depth that does not sink into the ground, mixed and stirred. By rotating the excavation shaft while moving it linearly in a plan view and in the lateral direction, it is possible to improve the ground in a straight line with a width of the diameter of the lower excavation wing in plan view. In addition, when such linear ground improvement is performed in parallel with no space in plan view, the flat plate can be improved. As described above, according to the apparatus of the present invention, since there are the vertical wings for side excavation, it is troublesome work to raise the excavation axis and move down the excavation axis at the next part to perform excavation as in the conventional case. Regardless of the procedure, by rotating the excavation axis and moving it in the lateral direction, the ground can be improved in a plan view and in a straight line. Therefore, construction efficiency can be improved.
[Brief description of the drawings]
FIG. 1 is a front view of a first embodiment of the present invention.
FIG. 2 is a plan view taken along line AA of FIG. 1;
FIG. 3 is a front view of a second embodiment of the present invention.
FIG. 4 is a plan view of FIG. 3;
FIG. 5 is a front view of a third embodiment of the present invention.
FIG. 6 is a plan view of FIG. 5;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Excavation axis 2 Lower excavation wings 4, 14, 24 Excavation claw 12 Vertical wing 22 for side excavation Horizontal wing 31 for upper excavation Outer pipe 41 Projection part 101, 201, 301 Ground improvement device

Claims (5)

In the ground improvement device including a lower excavation wing formed near the lower end of the rotating excavation shaft so that the ground can be excavated when the excavation shaft is rotated and moved down,
The lower excavation wing is provided with a side excavation vertical wing extending upward from a tip of the lower excavation wing, so that when the excavation axis is rotated in the ground and moved laterally, the side ground can be excavated. A ground improvement device characterized by being formed. The side digging vertical wing includes an upper digging horizontal wing extending laterally from an upper end thereof to the digging axis side, and when the digging axis is rotated and moved upward in the ground, the upper ground is raised. The ground improvement device according to claim 1, wherein the ground improvement device is formed so as to be excavable. The ground improvement device according to claim 2, wherein the upper excavation lateral wing has a tip near an excavation axis fixed to the excavation axis. In the ground improvement device according to claim 2, the excavation axis is inserted into an outer pipe connected to a driving unit capable of rotating or stopping around the excavation axis, and a lower end of the outer pipe is The lower excavation wing and the upper excavation horizontal wing are present between the upper and lower sides, at a position near the lower end portion of the outer tube between the upper and lower sides, a protrusion protruding in the lateral direction is provided. When the excavation shaft is rotated and the rotation of the outer tube is stopped, the excavation shaft has a projection length that does not interfere with the side excavation vertical blades. A ground improvement device which is rotatably fitted to a pipe. The ground improvement device according to any one of claims 1 to 4, wherein the side excavation vertical wing extends so as to be substantially parallel to the excavation axis.

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