JP3739831B2 - Method for producing improved consolidated body in the ground - Google Patents

Description

[0001]
[Industrial application fields]
The present invention discharges a lime-based or cement-based slurry-like solidifying agent while excavating a soft ground into a columnar shape, etc. in civil engineering, construction foundation work, etc., and mixes and stirs the excavated soil and the solidifying agent. , which is formed by consolidation relates to the manufacturing method of improving Katayuitai (columnar Katayuitai) of the ground.
[0002]
[Prior art]
Conventionally, an improved consolidated body in the ground (hereinafter, also referred to as an improved consolidated body) is a manufacturing apparatus having a drilling blade and a solidifying agent discharge port at or near the tip of a rotating excavation longitudinal axis (rotating shaft) ( With the ground improvement device), the ground is excavated at a predetermined depth toward the ground with the excavating blade at the tip while rotating the excavating vertical axis, and the excavated soil is mixed with a predetermined solidifying agent and stirred. It was formed by solidifying. The improved consolidated body formed in this way generally has a cylindrical structure with a uniform cross section.
[0003]
[Problems to be solved by the invention]
The improved solidified body manufactured by the above-described conventional manufacturing apparatus has a problem that the cross section is circular and uniform (constant), so that it tends to sink unequally relative to the surrounding ground as time passes. was there. This is because the improved solidified body has a uniform cross-section and has low friction with the surrounding ground (soil) and is not sufficiently restrained by the surrounding ground. It appears so prominently. Therefore, in the past, the total height (pile length) of the improved consolidated body has to be high (long), and not only does the construction time increase, but the volume increases accordingly. There was a problem that a large amount of solidifying agent was required and the cost was increased.
[0004]
An object of the present invention is to provide a suitable method for producing an improved solidified body in which such problems as described above are eliminated.
[0006]
[Means for Solving the Problems]
In order to solve the above problem, a method for producing an improved consolidated body in the ground according to the present invention comprises an excavation vertical axis that can be freely controlled in vertical movement and rotation. In the manufacturing apparatus, the excavation vertical axis includes a horizontal axis body having a predetermined length arranged in a substantially perpendicular manner to the excavation vertical axis, and the horizontal axis body is provided by predetermined rotation driving means. It can be rotated around the axis of the horizontal shaft body, and the ground can be excavated by rotating the horizontal shaft body around the axis of the horizontal shaft body (outer peripheral surface). And a drilling mixing stirring claw capable of mixing and stirring the excavated soil and the solidifying agent, and the radial length of the horizontal shaft body of the drilling mixing stirring claw is substantially the same . , Using equipment for manufacturing improved consolidated bodies in the ground,
While rotating and moving the excavation vertical axis, the horizontal shaft is rotated around its axis to excavate the ground in plan view with the excavation mixing agitating claw in a substantially circular shape, and the solidifying agent is excavated soil. A first step in which a substantially columnar unconsolidated body is formed by discharging and mixing and stirring in,
In this first step, only the excavation vertical axis is stopped, the horizontal axis is rotated while further lowering the excavation vertical axis, and the solidification agent is excavated to a predetermined depth by the excavation mixing stirring claw. Is discharged into the excavated soil and mixed and stirred, so that a non-cylindrical unconsolidated body whose cross-sectional area is smaller than the cross-sectional area of the substantially cylindrical unconsolidated body is below the substantially cylindrical unconsolidated body. And a second step formed subsequently to
The formed unconsolidated body is then solidified to form an improved consolidated body in the ground .
[0008]
[Operation and effect of the invention]
According to the method for manufacturing an improved consolidated body in the ground according to the present invention, the vertical axis of excavation in the manufacturing apparatus (hereinafter also referred to as a manufacturing apparatus or simply an apparatus) is rotated and moved downward, and is disposed substantially orthogonally to it. By rotating the horizontal shaft body provided in (1) around its axis, the ground can be excavated in a substantially circular shape in plan view with the excavating and mixing agitating claw provided on the outer side of the horizontal shaft body. Therefore, as a first step, a solidified agent is discharged into the excavated soil while excavating at a predetermined depth and mixed and agitated to obtain a substantially cylindrical unconsolidated state (unconsolidated body). It is formed.
[0009]
Then, as the second step, only the excavation vertical axis in the first step is stopped and the horizontal axis is rotated while further lowering the excavation vertical axis, and the ground is excavated to a predetermined depth by the excavation mixing stirring claw. While the solidifying agent is discharged into the excavated soil and mixed and agitated, the non-consolidated non-consolidated material whose cross-sectional area is smaller than the cross-sectional area of the substantially cylindrical unconsolidated material is Formed subsequently under the body. Subsequently, by repeating these first step and second step an appropriate number of times, unconsolidated bodies having different cross-sectional areas up and down are formed. After the formation of the unconsolidated body, the excavated vertical axis is lifted up while controlling the position (orientation) of the horizontal axis body viewed from above to the position in the second step, and the unconsolidated body Wait for the solidification. Thus, in the ground, an improved solidified body having a plurality of recesses is formed on the side surface with an interval in the vertical direction, and the surrounding soil enters the recesses, so that the settlement can be effectively prevented. Can be consolidated.
[0010]
【Example】
Illustrating a method of manufacturing the improved solid sintered body according to the present invention in detail with reference to the accompanying drawings, an embodiment embodying but improvements Katayuitai 1 thus is manufactured in the manufacturing method according to the present embodiment before that Will be described with reference to FIGS. As shown in FIG. 1, the improved consolidated body 1 according to this example includes small-diameter portions 3 and 3 positioned between the cylindrical large-diameter portions 2 and 2, and the large-diameter portion 2 and the small-diameter portion vertically. 3 is formed in the ground G so that it is positioned repeatedly. However, the cross-sectional shape of the small-diameter portion 3 is a rectangular shape substantially inscribed in the cross-sectional shape (substantially circle) of the large-diameter portion 2 (see FIGS. 2 and 3). Thus, in this example, of the side surface 1a of the improved consolidated body 1, the side surface of the small diameter portion 3, that is, the lower surface 2b of the large diameter portion 2 above each small diameter portion 3 and the upper surface 2c of the large diameter portion 2 below. Since the space 3 forms the recess 3a and the surrounding soil has entered here, the settlement of the improved consolidated body 1 is effectively prevented.
[0011]
Such an improved consolidated body 1 can be formed (manufactured) by the apparatus illustrated in FIGS. 4 to 6. That is, in the figure, reference numeral 21 denotes an excavation longitudinal axis (rotation drive shaft) having a substantially cylindrical shape, and the tip (lower end) is formed in a tapered conical shape to form a longitudinal excavation portion 22, which is not shown. The rotation and rotation stop are freely controlled by the control means, and can be moved up and down at a predetermined speed.
[0012]
Further, in this example, a solidifying agent discharge capable of discharging a slurry-like solidifying agent pumped from a pumping source through a pipe (not shown) inside the drilling vertical axis 21 is provided near the tip of the excavating vertical axis 21. An outlet 23 is provided. A portion near the tip of the excavation vertical axis 21 is provided with a horizontal shaft body 24 having a predetermined length L1 arranged in a direction substantially orthogonal to the excavation vertical axis 21, and the horizontal axis body 24 has a predetermined shape. It can be rotated around its axis J by the rotation driving means. However, in this example, the rotation driving means is coupled to the shafts of the hydraulic motors 25 of the two shafts provided inside the excavation vertical axis 21 and at the intersection thereof. Is connected to an external power unit through a pipe (not shown), and rotation and stop are controlled.
[0013]
Further, the horizontal shaft body 24 is capable of excavating the ground G by rotating the horizontal shaft body 24 about its axis J over the entire length (L1) with respect to the outer side (outer peripheral surface). A number of excavating and mixing stirring claws 26 capable of mixing and stirring the solidifying agent are provided. However, the excavating and mixing agitating claw 26 in this example has a distal end portion 26a having a bowl shape, the length L2 in the radial direction of the horizontal shaft body 24 is substantially the same, and the length L1 of the horizontal shaft body 24 is the same. It is set smaller.
[0014]
When using this apparatus, the excavating and mixing agitating claws 26 and 26 are grounded to the soft ground G, and the excavating vertical axis 21 is moved downward (excavated) while rotating at a predetermined rotational speed. When the horizontal shaft body 24 is rotated under the propulsion direction, the horizontal shaft body 24 rotates integrally with the excavation vertical axis 21 around the excavation vertical axis 21.
[0015]
That is, by rotating and moving the excavation vertical axis 21 while rotating the horizontal shaft body 24 about its axis J, the ground G is viewed in a plan view with the excavation mixing agitating claw 26 in the horizontal direction from the center of the excavation vertical axis 21. The shaft body 24 can be excavated into a substantially circular shape having a radius (1 / 2L1) to the substantially distal end. Strictly speaking, this radius is the distance from the center of the excavation longitudinal axis 21 to the tip of the outermost excavation mixing stirring claw 26. Therefore, as a first step, a substantially solid cylindrical body is formed by discharging the slurry-like solidifying agent into the excavated soil while excavating at a predetermined depth and mixing and stirring.
[0016]
Then, as the second step, only the rotation of the excavation vertical axis 21 in the first step is stopped, and the horizontal shaft body 24 is rotated while the excavation vertical axis 21 is further lowered, and the ground G is predetermined by the excavation mixing stirring claw 26. By discharging the solidifying agent into the excavated soil while excavating the depth, and mixing and stirring, a plane view (transverse section) having a size of approximately L1 × L2 follows the substantially columnar unconsolidated body. A substantially rectangular unconsolidated body is formed.
[0017]
Subsequently, by repeating these first step and second step an appropriate number of times, an unconsolidated body that is not a straight columnar shape but has different cross-sectional areas up and down is formed. May be lifted up while controlling the position (orientation) of the horizontal shaft body 24 viewed from above to the position in the second step, and the solidified body may be solidified. Note that only the horizontal shaft body 24 may be rotated at the time of this pulling up. Thus, after solidification of the unconsolidated body, as shown in FIG. 1 to FIG. 3, the improved consolidated body 1 having a plurality of concave portions 3a is manufactured (formed) on the side surface 1a at intervals in the vertical direction. Is done.
[0018]
7 and 8, the method of the present invention as a reference example and shows the improved Katayuitai 1 manufactured by another process, this thing, the ground G, both circular in concentrically It has a large diameter part 2 and a small diameter part 3 .
[0019]
As shown in FIGS. 9 and 10, the improved consolidated body produced by the present invention has a hydraulic cylinder 27 or the like built in the horizontal shaft body 24 and another horizontal shaft at the tip of the rod. A housing 24a is connected as a body, and the housing 24a can be controlled to extend and contract as indicated by an arrow in FIG. 9 from the distal end side of the horizontal shaft body 24. The housing 24a is also connected to the horizontal shaft body 24. also by the fact to be provided the same excavation mixture stirred pawl 36 and drilling mixing agitation pawls 26 provided, it can be easily formed. Of course, the excavation mixing agitating claw 36 rotates about the axis of the horizontal axis body 24 together with the excavation mixing agitation claw 26 of the horizontal axis body 24.
[0021]
In the apparatus shown in FIGS . 9 and 10, in the above, the horizontal shaft body 24 and the excavation vertical axis 21 are rotated about each axis while the casing 24a is extended from the distal end side of the horizontal shaft body 24 to excavate a predetermined depth. Next, the horizontal shaft body 24 is rotated without rotating the excavating vertical axis 21 in a state in which the casing 24a is contracted, and the excavation and mixing is carried out to a predetermined depth. Thus, an improved solidified body having a rectangular cross section having a relatively small small diameter portion can be formed.
[0022]
The excavating and mixing agitating claw of the apparatus used for the manufacturing method according to the present invention is exemplified by the tip portion formed in a bowl shape in the above embodiment, but the shape and structure depend on the soil and the softness of the ground. What is necessary is just to design suitably according to excavation resistance. That is, depending on the soil, it may be a continuous or discontinuous spiral. In the case of a spiral one, the excavated soil can be moved in the horizontal direction (axial direction of the horizontal shaft body) during the excavation and mixing process, so that the mixing and stirring is performed more homogeneously. Can be combined with ties. In the case of the excavating and mixing agitating claw shown in FIGS. 4 to 6, it is preferable that the entire ground be scratched when the horizontal shaft rotates once in order to improve excavation efficiency. Moreover, even if it is set as the excavation mixing stirring nail | claw of any shape and structure, it is good to provide over substantially the full length of a horizontal shaft body.
[Brief description of the drawings]
FIG. 1 is a front view showing an example of an improved consolidated body in the ground manufactured by a manufacturing method according to the present invention.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
3 is a cross-sectional view taken along line BB in FIG.
FIG. 4 is a main part front view for explaining an embodiment in which a manufacturing apparatus used in the method for manufacturing an improved consolidated body in the ground according to the present invention is embodied.
FIG. 5 is a partial perspective view for explaining the horizontal shaft body and the excavation mixing stirring claw in FIG. 4;
6 is a cross-sectional view taken along the line CC of FIG.
FIG. 7 is a perspective view of an improved consolidated body manufactured by a manufacturing method different from the manufacturing method of the present invention, shown as a reference example .
8 is a cross-sectional view taken along the line DD of FIG.
FIG. 9 is a front view of an essential part for explaining another embodiment embodying a production apparatus used in the method for producing an improved consolidated body in the ground according to the present invention.
10 is a side view of the horizontal shaft body and the excavation mixing stirring claw in FIG. 9. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Improved consolidated body 1a Side surface 3a of improved consolidated body Recess 21 Excavation vertical axis 24 Horizontal axis body 26, 36 Excavation mixing stirring claw G Ground J Axis of horizontal axis body

Claims (1)

An apparatus for producing an improved consolidated body in the ground, comprising an excavation vertical axis that can be freely controlled in vertical movement and rotation, wherein the excavation vertical axis has a predetermined arrangement in a position substantially perpendicular to the excavation vertical axis A horizontal shaft body having a length is provided in a penetrating manner, and the horizontal shaft body can be rotated around the axis of the horizontal shaft body by a predetermined rotation driving means, and is disposed outside the horizontal shaft body. On the other hand, the horizontal shaft body is provided with an excavation mixing stirring claw capable of excavating the ground by rotating around its axis and capable of mixing and stirring the excavated soil and the solidifying agent, The length of the horizontal shaft body of the excavating and mixing agitating claw is substantially the same in the radial direction , using an improved consolidated body manufacturing apparatus in the ground,
While rotating and moving the excavation vertical axis, the horizontal shaft is rotated around its axis to excavate the ground in plan view with the excavation mixing agitating claw in a substantially circular shape, and the solidifying agent is excavated soil. A first step in which a substantially columnar unconsolidated body is formed by discharging and mixing and stirring in,
In this first step, only the excavation vertical axis is stopped, the horizontal axis is rotated while further lowering the excavation vertical axis, and the solidification agent is excavated to a predetermined depth by the excavation mixing stirring claw. Is discharged into the excavated soil and mixed and stirred, so that a non-cylindrical unconsolidated body whose cross-sectional area is smaller than the cross-sectional area of the substantially cylindrical unconsolidated body is below the substantially cylindrical unconsolidated body. And a second step formed subsequently to
A method for producing an improved consolidated body in the ground, characterized in that an improved consolidated body is formed in the ground by subsequently solidifying the formed unsolidified body .

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