JP2011226254A - Soil improvement device, and soil improvement method, earthquake resistant construction method and construction foundation practice using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost by eliminating waste of a soil improvement part and also to realize a simple and compact structure.SOLUTION: The device comprises: main drilling revolving shafts 2 with three axes which are set in parallel to each other; main drilling cutters 20 which are fixed to the lower end of the main drilling revolving shafts 2 and rotate horizontally; sub drilling revolving shafts 3 arranged in parallel to the main drilling revolving shafts 2; drive wings 30 which are fixed to the lower ends 3a of the sub drilling revolving shafts 3 and rotate horizontally; first connecting-shafts 4A which support each main drilling revolving shaft 2 rotatably while connecting the respective main drilling revolving shafts 2 horizontally; transfer revolving shafts 31 inserted and supported rotatably around the connecting-shafts 4A while rotating around the horizontal axes which intersect perpendicularly to the axial direction C1 of the connecting-shafts 4A; sub drilling cutters 32 which are fixed to both ends of the transfer revolving shafts 31 and rotate around the transfer revolving shafts 31; and sub wings 33 extending towards the diameter directions outside from the transfer revolving shafts 31.

Description

  The present invention excavates the ground, adds a ground improvement material to the excavated portion, mixes with the excavated soil, and improves the ground by stirring, a ground improvement method using the ground improvement method, seismic resistance method, It relates to the building foundation method.

Conventionally, as ground improvement work, excavating the ground into blocks or walls and loosening the ground, for example, adding ground improvement material, mixing with the loosened ground, stirring, etc. A construction method is known (see, for example, Patent Document 1).
In Patent Document 1, a plurality of rods are arranged so that adjacent excavation blades do not contact each other, and a stirring blade is provided above the excavation blade of each rod. The ground improvement is such that the stirring blade is rotated in a direction different from the rotation direction of the rod, and the excavation blade is rotated together with the rod to move downward in the ground while mixing and stirring by the stirring blade. An apparatus is disclosed.

  Further, as a general ground improvement device, a triaxial rod is moved downward in the ground, and a propeller-like kneading blade and a spiral moving blade are arranged on the rod, and these kneading blades There is a device in which the moving blades and the moving blades are alternately arranged so as not to interfere between adjacent rods. In this case, as shown in FIG. 25, the ground improvement regions M11 (two-dot chain lines) created by the respective rods overlap each other, for example, when constructing a ground improvement wall used as a temporary earth retaining wall. An area where the wall surface can be formed (area M10 in FIG. 25) is an effective cross section of the temporary retaining wall.

Japanese Patent Laid-Open No. 11-217820

However, in the conventional ground improvement device, as shown in FIG. 25, the adjacent ground improvement regions M11 and M11 are excavated by overlapping each other, and the portion outside the wall surface of the ground improvement wall does not have an effective cross section. That is, there is a problem that the effective cross section becomes smaller with respect to the improved diameter. Therefore, a part of the circular shape improved by excavation with the excavating blade corresponds to an extra excavation portion that does not function as an effective cross section, and the ground improvement portion is wasteful, so that cost reduction has been demanded.
In recent years, there has been an increasing demand for ground improvement work in narrow spaces in urban areas, and there has been a need for a simple and downsized structure, and there is room for improvement in that respect.

  The present invention has been made in view of the above-described problems. A ground improvement device capable of reducing the cost by eliminating waste of the ground improvement part and realizing a simple and downsized structure, and the same The purpose is to provide ground improvement methods, seismic construction methods, and basic building construction methods.

  In order to achieve the above object, the ground improvement device according to the present invention is a ground improvement device that performs ground improvement by moving in the ground, and is rotated around a vertical axis and provided in parallel with each other. A rotating shaft, a first excavating blade fixed to the lower end of the first rotating shaft and rotating horizontally, and arranged between the adjacent first rotating shafts in parallel to the first rotating shaft, the rotation of the first rotating shaft is A second rotating shaft that is transmitted and rotated about the vertical axis, a driving blade that is fixed to the lower end of the second rotating shaft and rotates in the horizontal direction, and a plurality of the first rotating shafts are coupled in the horizontal direction, A connection shaft that rotatably supports the first rotation shaft, a third rotation shaft that rotates about a horizontal axis that is orthogonal to the axial direction of the connection shaft, and that is rotatably inserted and supported with respect to the connection shaft; A second shaft fixed to both ends of the rotation shaft and rotating about the third rotation shaft; A cutting blade and a driven blade extending radially outward from the third rotating shaft, wherein the driven blade is disposed in the rotation locus of the driving blade, and the rotation of the driving blade is transmitted to the driven blade. The two excavating blades are formed between a primary excavation region that forms a rotation trajectory of each adjacent first excavation blade and a common outer tangent of a circle of the adjacent primary excavation region when viewed from the axial direction of the first rotation shaft. It is located in the secondary excavation area.

  The ground improvement method according to the present invention is a ground improvement method using the ground improvement device described above, wherein the ground improvement device is installed on the ground to be improved, and a plurality of first excavating blades are provided together with the first rotating shaft. Rotating and excavating the ground in the primary excavation area, and transmitting the rotation of the second rotating shaft from the driving blade to the driven blade, and the ground in the secondary excavating area by the second excavating blade fixed to the third rotating shaft And excavating the ground in the primary excavation region and the secondary excavation region, and mixing and agitation the ground improvement material.

  Moreover, the seismic construction method according to the present invention is a seismic construction method for improving the ground around the structure using the above-described ground improvement device, and the ground improvement device is put into the ground to be improved surrounding the ground under the structure. And a step of excavating the primary excavation region and the secondary excavation region with the first excavation blade and the second excavation blade, and mixing the ground improvement material into the excavated ground and stirring to form an outer peripheral improvement portion; And is characterized in that the fluctuation of the ground under the structure surrounded by the outer peripheral improvement portion is regulated.

  In the present invention, a primary excavation region formed by excavation of a plurality of first excavation blades and a secondary excavation region formed between a common circumscribed line of adjacent primary excavation regions by excavation of the second excavation blades. By forming the ground improvement region, the entire excavation cross section can be an effective cross section as a ground improvement wall. In other words, since the entire primary excavation area has an effective cross section, a part of the primary excavation area does not function as a ground improvement wall as in the conventional case, so that no excessive excavation occurs. Therefore, the outer diameter of the first excavating blade can be made smaller than that of the conventional excavating blade, and the amount of ground improvement material corresponding to the portion corresponding to the excessive excavation can be reduced. Costs can be reduced and the apparatus can be downsized.

  Further, the rotation of the first rotating shaft is transmitted to the second rotating shaft, the rotational force is transmitted from the driving blade fixed to the lower end of the second rotating shaft to the driven blade, and the third rotating shaft rotates together with the driven blade. Therefore, the second excavating blade rotates, that is, the second excavating blade is driven by using the rotational force of the first rotating shaft, so that the driving means for the second rotating shaft can be omitted, and the cost can be reduced. As a result, the structure of the apparatus can be simplified.

  Moreover, in this invention, since a ground improvement apparatus is made into a simple structure and can be reduced in size, it can be used as an attachment of working machines, such as a backhoe. Therefore, even in a narrow space, the ground improvement device can be introduced to form a ground improvement wall. In this case, by forming the outer periphery improvement portion so as to surround the ground under the existing structure, the horizontal movement of the ground under the structure surrounded by the outer periphery improvement portion is restricted, and fluctuations are suppressed. Therefore, the destruction of the ground can be prevented. Therefore, the vibration of the structure during an earthquake can be reduced and the structure can be prevented from being destroyed.

  Further, in the ground improvement device according to the present invention, it is preferable that a plane including the rotation trajectory of the second excavating blade is arranged along the inner side of the common circumscribing line when viewed from the axial direction of the first rotation shaft.

  In the present invention, an effective section formed by the primary excavation region and the secondary excavation region can be reliably excavated without excavating a range wider than the secondary excavation region by the second excavation blade.

  Moreover, in the ground improvement apparatus which concerns on this invention, it is preferable that the connection shaft has the length dimension which contact | abuts the inner wall surface excavated with all the 1st excavation blades.

  In the present invention, since both end surfaces of the connecting shaft are in contact with the inner wall surface excavated by the first excavating blade and are in a state of being hardly displaced in the horizontal direction, the first excavating blade is rotated for excavation. It is possible to prevent the joint shaft from rotating together with the first rotation shaft.

  In the ground improvement device according to the present invention, the first rotating shaft is provided with a first transmission blade extending radially outward from the central axis, and the second rotating shaft has a diameter from the central axis. More preferably, a second transmission blade extending outward in the direction is provided, and the second transmission blade is disposed in the rotation locus of the first transmission blade.

  According to the present invention, since the central axes of the first transmission blade and the second transmission blade are parallel and the second transmission blade is disposed within the rotation locus of the first transmission blade, the first transmission blade rotates together with the first rotation shaft. The first transmission blade that makes contact with the second transmission blade rotates the second transmission blade around the central axis of the second rotation shaft, and the second rotation shaft rotates through the second transmission blade. . That is, since the second rotating shaft can be rotated only by the rotational force transmitted from the first rotating shaft without providing an original rotation driving means, the apparatus can be simplified.

  In the ground improvement device according to the present invention, it is preferable that at least one of the first rotating shaft and the second rotating shaft is provided with a stirring blade that rotates together with the rotating shaft.

  In the present invention, the stirring blade provided on at least one of the first rotating shaft and the second rotating shaft rotates with the rotation of the first excavating blade and the second excavating blade, and the excavated soil is mixed uniformly and effectively. Can be stirred. And since the stirring blade is fixed at a predetermined position in the axial direction of the rotating shaft, the position of the stirring blade with respect to the excavation position does not change even when the ground improvement device is moved downward together with excavation, so that the stable Stirring can be performed.

  Further, in the ground improvement device according to the present invention, the driven blade is provided on one end side across the connecting shaft of the third rotating shaft, and the stirring blade rotating together with the third rotating shaft is disposed on the other end side of the third rotating shaft. And the stirring blade is preferably located outside the rotation trajectory of the driving blade.

  In the present invention, the excavated soil in the secondary excavation region excavated by the second excavating blade can be mixed and stirred by the agitating blade rotating with the third rotating shaft.

  Further, in the seismic construction method using the ground improvement device according to the present invention, the ground surface side ground between the structure and the outer periphery improvement portion may be improved by the ground improvement device to form the surface improvement portion. .

  In the present invention, the structure and the outer peripheral improvement portion are connected by the surface improvement portion, and the structure can be integrated, and the resistance to the horizontal force that the outer peripheral improvement portion receives from the ground is increased, so that the seismic performance can be further improved. it can.

  Further, the seismic construction method using the ground improvement device according to the present invention is a seismic construction method for ground improvement of the ground directly supporting the structure using the ground improvement device described above, and in the ground to be improved directly under the structure. Improve the outer circumference by adding the ground improvement device and excavating the primary and secondary excavation areas with the first and second excavating blades and mixing the excavated ground with the ground improvement material and stirring. And a step of forming a portion, and the outer peripheral improvement portion regulates the fluctuation of the ground directly under the structure.

Further, in the building foundation method using the ground improvement device according to the present invention, the building foundation method for improving the ground directly supporting the structure using the above-described ground improvement device, the ground to be improved directly under the structure. A step of introducing a ground improvement device, and excavating the primary excavation region and the secondary excavation region with the first excavation blade and the second excavation blade, and mixing the ground improvement material into the excavated ground and stirring And a step of forming an outer periphery improvement portion, and the outer periphery improvement portion regulates the fluctuation of the ground directly under the structure.
In this case, the base of the structure may be provided at the upper end of the outer periphery improving portion.

  In the present invention, it is possible to construct an outer periphery improving portion directly under the structure in advance and directly support the structure on the outer periphery improving portion. That is, since the position of the outer peripheral improvement portion to be constructed does not have to be provided outside the structure in plan view, it can be applied to a structure such as a house where the site is narrow and the work space is small. Therefore, in addition to the effects of reducing the construction cost and reducing the size of the apparatus described above, there is an effect that it can be applied in a narrow place.

Further, in the building foundation construction method using the ground improvement device according to the present invention, the foundation foundation construction method for improving the ground around the structure using the above-described ground improvement device, the improvement target ground surrounding the ground under the structure A step of introducing a ground improvement device, and excavating the primary excavation region and the secondary excavation region with the first excavation blade and the second excavation blade, and mixing the ground improvement material into the excavated ground and stirring And a step of forming an outer periphery improvement portion, and the variation of the ground under the structure surrounded by the outer periphery improvement portion is regulated.
In this case, the upper end of the outer periphery improving portion may be provided with a surface improving portion obtained by improving the ground on the ground surface side with a ground improving device or a foundation of a structure made of concrete.
Further, an opening may be provided in the center of the foundation in plan view, and a structure may be placed on the opening edge.

  In this invention, the outer periphery improvement part is previously constructed in the improvement object ground surrounding the ground under the structure, and the structure can be supported on the outer periphery improvement part. And it is also possible to provide a surface improvement part or a concrete foundation at the upper end of the outer periphery improvement part, and to support the structure by the outer periphery improvement part via this foundation. Moreover, when providing an opening in the center part of a foundation, the construction amount of a foundation can be decreased and it becomes possible to reduce construction cost.

According to the ground improvement device of the present invention, and the ground improvement method, seismic resistance method, and building foundation method using the same, the entire cross section excavated by the first excavation blade and the second excavation blade is used as the ground improvement wall. Therefore, it is possible to eliminate the ground improvement material added to the overexcavation portion as in the prior art, so that the cost can be reduced.
In addition, since the second excavating blade is driven using the rotational force of the first rotating shaft via the second rotating shaft, the driving means for the second rotating shaft can be omitted, so that the cost can be reduced. In addition, a simple and downsized structure can be realized.

It is a front view which shows the structure of the ground improvement apparatus by embodiment of this invention. It is a side view of the ground improvement apparatus shown in FIG. It is an AA arrow directional view shown in FIG. It is an enlarged view of the excavation part of the ground improvement apparatus shown in FIG. It is the BB sectional view taken on the line shown in FIG. It is a figure which shows the rotation locus | trajectory of a main excavation cutter and a stirrer. It is CC sectional view taken on the line shown in FIG. It is the figure which showed the excavation part of FIG. 4 in detail. It is an enlarged view of the excavation part of the ground improvement apparatus shown in FIG. It is the DD sectional view taken on the line shown in FIG. It is the EE sectional view taken on the line shown in FIG. It is a horizontal sectional view of the ground improvement part by a ground improvement device. It is explanatory drawing of the seismic construction method using the ground improvement apparatus by this Embodiment, Comprising: (a) is a side view, (b) is the figure seen from the top. It is explanatory drawing of the earthquake-proof construction method by a 1st modification, Comprising: (a) is a side view, (b) is a top view. It is explanatory drawing of the earthquake-resistant construction method by a 2nd modification, Comprising: (a) is a side view, (b) is a top view. It is explanatory drawing of the earthquake-proof construction method by a 3rd modification, Comprising: (a) is a side view, (b) is a top view. It is explanatory drawing of the earthquake-resistant construction method by a 4th modification, Comprising: (a) is a side view, (b) is a top view. It is explanatory drawing of the earthquake-resistant construction method by a 5th modification, Comprising: (a) is a side view, (b) is a top view. It is explanatory drawing of the building basic construction method by a 6th modification, Comprising: (a) is a side view, (b) is a top view. It is explanatory drawing of the building basic construction method by a 7th modification, Comprising: (a) is a side view, (b) is a top view. It is a side view for demonstrating the building basic construction method by the 8th modification. It is a side view for demonstrating the building basic construction method by a 9th modification. It is a side view for demonstrating the building basic construction method by a 10th modification. It is a side view for demonstrating the building basic construction method by the 11th modification. It is a horizontal sectional view of the ground improvement part by the conventional ground improvement apparatus.

  Hereinafter, a ground improvement device according to an embodiment of the present invention, a ground improvement method using the ground improvement method, an earthquake resistant construction method, and a building foundation construction method will be described with reference to the drawings.

  The code | symbol 1 of FIG. 1 thru | or FIG. 3 has shown the ground improvement apparatus 1 by this Embodiment. The ground improvement device 1 is a device for forming a ground or block-like ground improvement portion, and is used as an attachment attached to the tip of an arm of a working machine (not shown) such as a backhoe. The ground improvement part is constructed by moving the ground in the vertical direction while rotating the excavating blades provided at the lower ends of each of the earth, adding the ground improvement material to the excavated soil, mixing, and stirring. Is.

Here, as the ground improvement material added to the excavated soil, an appropriate agent such as a liquid material such as cement milk or a powdered material can be employed depending on the purpose of the ground improvement.
In the following description, “excavated soil” may refer to a mixture of the ground excavated by the ground improvement device 1 and the ground improvement material.
Moreover, since the working machine to which the ground improvement device 1 is attached as an attachment is a self-propelled backhoe or the like that is generally used as described above, detailed description thereof is omitted here.
Furthermore, the “width direction” of the ground improvement device 1 refers to a length dimension in the left-right direction toward the paper surface in FIG.

  The ground improvement device 1 rotates around a central axis O1 forming a vertical axis, and a plurality of (three axes in the present embodiment) main excavation rotary shafts 2 (2A, 2B, 2C) (first axis) provided in parallel to each other. Rotation shaft), the main excavation cutter 20 (20A, 20B, 20C) (first excavation blade) fixed to the lower end of the main excavation rotation shaft 2 and horizontally rotated, and the adjacent main excavation rotation shafts 2, 2 A sub-excavation rotary shaft 3 (second rotary shaft) arranged in parallel with the main excavation rotary shaft 2 in the middle, a driving blade 30 fixed to the lower end 3a of the sub-excavation rotary shaft 3 and rotating in the horizontal direction, and the main excavation The rotating shafts 2 and 2 are connected in the horizontal direction, and the connecting shaft 4 (4A) that rotatably supports each main excavation rotating shaft 2 and a horizontal axis (center axis C2) orthogonal to the axial direction C1 of the connecting shaft 4A. ) Rotate around and supported so as to be freely rotatable with respect to the connecting shaft 4A. The transmission rotary shaft 31 (third rotary shaft), the auxiliary excavation cutter 32 (second excavation blade) that is fixed to both ends of the transmission rotary shaft 31 and rotates around the transmission rotary shaft 31, and the transmission rotary shaft 31 And a driven blade 33 extending radially outward from the outer periphery.

  The three main excavation rotary shafts 2A, 2B, and 2C have the same length in the axial direction, and an upper end 2b is rotatably supported with respect to a support frame 5 (described later). A tip blade 21 pointed downward is provided at the tip of the main excavation rotating shaft 2.

The three main excavation rotary shafts 2 and the two sub-excavation rotary shafts 3 are supported at a plurality of positions in the axial direction in parallel with each other and at regular intervals by the connecting shafts 4 (4A to 4E).
Here, these connection shafts 4 correspond to the “connection shafts” of the present invention in which the first connection shaft 4A located immediately above the main excavation cutter 20 is second in order from the first connection shaft 4A upward. A connecting shaft 4B, a third connecting shaft 4C, and a fourth connecting shaft 4E are arranged.

As shown in FIG. 4, in the main excavation cutter 20 (20A, 20B, 20C), a rod-shaped wing body 20a extends radially outward from the lower end 2a of the main digging rotary shaft 2, and the circumference of the wing body 20a is increased. A plurality of cutting bits 20b are arranged on the surface, and rotate around the central axis O1 together with the main excavation rotary shaft 2 and rotate in the primary excavation region M1 (rotation by the two-dot chain line main excavation cutter 20 shown in FIG. Excavate).
Here, in the main excavation cutter 20, the reference numeral 20A is a first main excavation cutter, the reference numeral 20B is a second main excavation cutter, and the reference numeral 20C is a third main excavation cutter as necessary.

  The main excavation rotating shaft 2 is provided with a flow path in the entire axial direction, and the ground improvement material supplied to the upper end 2b flows to the lower end 2a. And the peripheral surface of the lower end 2a of the main excavation rotating shaft 2 is provided with a spout 7 for injecting the ground improvement material in communication with the internal flow path. As the cutter 20 rotates, it is jetted radially outward and mixed with the excavated soil.

As shown in FIG. 1, the main excavation rotary shaft 2 and the sub excavation rotary shaft 3 are provided with stirring blades 23A, 23B, 36A, and 36B that rotate together with the rotary shafts 2 and 3 at predetermined positions in the respective axial directions. ing. Each of these stirring blades 23A, 23B, 36A, and 36B has a shape in which a plurality of blades extend outward in the radial direction.
Specifically, at the position close to the main excavation cutter 20 (more precisely, the position between the first connection shaft 4A and the second connection shaft 4B), the first agitating blade 23A of the main excavation rotary shaft 2 and the auxiliary excavation It arrange | positions so that it may not mutually interfere in the position where the 2nd stirring blade 36A of the rotating shaft 3 shifted | deviated. Further, only the third agitating blade 23B of the main excavation rotary shaft 2 is provided at a position on the lower side in the vertical direction across the third connecting shaft 4C in the axial middle portion of each rotary shaft 2, 3, and Only the fourth stirring blade 36B of the sub-excavation rotary shaft 3 is provided at the position. Thus, the agitating soil can be satisfactorily agitated by densely arranging the agitating blades 23A and 36A near the main excavation cutter 20 of the ground improvement device 1.

Next, a drive mechanism for rotating the main excavation rotary shaft 2 and the sub excavation rotary shaft 3 will be described.
As shown in FIG. 1, the support frame 5 that rotatably supports the upper end 2b of the main excavation rotary shaft 2 includes a connecting portion 51 for connecting to the arm of the working machine described above, and the main excavation is inside. A drive motor 6 that provides rotational power to the rotary shaft 2 is provided. The connecting portion 51 has an engagement hole 51a for detachably attaching via an arm tip of the work machine and an engagement pin 52 (see FIGS. 2 and 3).

The drive shaft 61 of the drive motor 6 is coaxially fixed to the upper end 2b of the second main excavation rotary shaft 2B. The drive shaft 61 is provided with a first gear 62 coaxially, and the first gear 62 meshes with the second gear 63 and the third gear 64, respectively. As for the 2nd gearwheel 63 and the 3rd gearwheel 64, each rotating shaft 63a, 64a is being fixed to the 2nd main excavation rotating shaft 2C and the upper end 2b of the 1st main excavating rotating shaft 2A on the same line. In other words, the second main excavation rotary shaft 2B is rotated by the rotation of the drive motor 6, and the first and third main excavation rotary shafts 2A and 2C are also rotated through the gears 62, 63 and 64. Yes.
As the rotation direction of the main excavation rotary shaft 2 and the main excavation rotary shaft 20, as shown in FIG. 6, the second main excavation rotary shaft 2B directly connected to the drive shaft 61 of the drive motor 6 among the three axes. When the second main excavation cutter 20B rotates in one direction of rotation (the direction of arrow E2, counterclockwise in FIG. 6), the first main excavation cutter 20A and the third main excavation cutter 20C located on both sides thereof are It rotates in the opposite rotation direction (arrow E1 direction, clockwise rotation direction in FIG. 6).

Further, as shown in FIG. 1, first transmission blades 22 extending radially outward from the central axis O1 are provided at the upper ends 2b of the first main excavation rotary shaft 2A and the third main excavation rotary shaft 2C, respectively. It has been. On the other hand, each of the two sub-excavation rotary shafts 3 is provided with second transmission blades 35 extending radially outward from the central axis O2.
The second transmission blade 35 is arranged in the rotation locus of the first transmission blade 22, that is, the second transmission blade 35 is rotated by the rotation of the first transmission blade 22. The rotating shaft 3 is structured to rotate around the central axis O2.

Next, the configuration of the connecting shaft 4 (4A to 4E) for keeping the main excavation rotary shaft 2 and the sub excavation rotary shaft 3 parallel to each other and at a constant interval will be described with reference to the drawings.
As shown in FIGS. 7 and 8, the connecting shaft 4 includes a cylindrical support portion 41 through which the rotary shafts 2 and 3 are rotatably inserted, and a horizontal connecting portion between the adjacent cylindrical support portions 41 and 41 in the horizontal direction. Bar 42. Then, locking projections 44 for restricting the vertical movement of the cylindrical support part 41 are provided on the circumferential surface of the rotating shafts 2 and 3 over a part or the entire circumference of the cylindrical support part 41. It has been.

  Further, as shown in FIG. 8, the first connecting shaft 4A is different from the other second to fifth connecting shafts 4B to 4E in that both ends are excavated by all the main excavation cutters 20A, 20B, and 20C. It is the length dimension (width dimension L of the ground improvement apparatus 1 shown in FIG. 4) which contacts the wall surface G0 (two-dot chain line shown in FIG. 8). Specifically, the first connecting shaft 4A is configured such that the center of the connecting shaft 4 from each of the cylindrical support portions 41 and 41 that are engaged with the first excavation rotating shaft 2A and the third excavating rotating shaft 2C located on both sides of the three axes. Overhang bars 43, 43 projecting outward in the direction of the axis C <b> 1 are provided on the same line as the horizontal bar 42. The end surface 4a of the overhang bar 43 is in contact with the inner wall surface G0 described above. That is, when the ground improvement device 1 moves downward along with excavation, both end surfaces 4a and 4a of the first connecting portion 4A are always in contact with the inner wall surface G0.

Next, the configuration of the sub-excavation cutter 32 that rotates by the rotation power transmitted from the sub-excavation rotary shaft 3 and the drive structure thereof will be described.
As shown in FIGS. 8 to 11, the first connecting portion 4A has a transmission rotation in which a central axis C2 is arranged in a horizontal direction perpendicular to the central axial direction C1 between the cylindrical support portions 41 and 41. The shaft 31 is rotatably supported by the rotation support portion 45. That is, the transmission rotation shaft 31 can rotate around its central axis C2. A blade support member 38 is provided at both ends of the transmission rotary shaft 31, and a sub-excavation cutter 32 extending from the blade support member 38 toward the radially outer side centering on the central axis C <b> 2 of the transmission rotary shaft 31 is provided. ing.

  The driven blade 33 is provided on one end side with respect to the axial center (rotation support portion 45) of the transmission rotation shaft 31, and is disposed in the rotation locus of the drive blade 30. That is, the driven blade 33 and the driving blade 30 are arranged in a positional relationship where they interfere with rotation, and the rotational power of the driving blade 30 is transmitted to the driven blade 33.

  Further, on the other end side of the transmission rotary shaft 31, a fifth stirring blade 34 that rotates together with the transmission rotary shaft 31 is provided. The fifth agitating blade 34 protrudes radially outward from the transmission rotating shaft 31 and has a length that is located outside the rotation locus of the driving blade 30, and does not interfere with the driving blade 30. 31 is configured to rotate together. By rotating together with the transmission rotary shaft 31 in the fifth stirring blade 34, the excavated soil in the secondary excavation region M2 (see FIG. 6) excavated by the sub excavation cutter 32 can be mixed and stirred. .

Further, as shown in FIG. 9, the sub excavation cutter 32 is provided at a size and a position that does not interfere with the main excavation cutter 20.
Further, as shown in FIG. 6, the secondary excavation cutter 32 includes a primary excavation region M <b> 1 that forms respective rotation trajectories of the adjacent main excavation cutters 20 as viewed from the central axis direction O <b> 1 of the main excavation rotation shaft 2, and both It is located in the secondary excavation area M2 formed between the circle and the common outer tangent T of the primary excavation area M1. In addition, as shown in FIG. 5, a plane including the rotation trajectory of the sub excavation cutter 32 is arranged along the inner side of the common circumscribing line T.

Next, the ground improvement method using the ground improvement apparatus 1 mentioned above is demonstrated.
As shown in FIG. 1, in the present embodiment, the ground improvement device 1 is used as an attachment for a backhoe (not shown), and the connecting portion 51 of the support frame 5 is attached to the arm tip of the backhoe. Then, after the ground improvement device 1 is installed on the ground to be improved, a downward force is applied to the ground improvement device 1 in the vertical direction by the backhoe, and the excavation reaction force is taken to obtain the three-axis main excavation rotary shafts 2A, 2B, 2C. At the same time, the main excavation cutters 20A, 20B, and 20C are rotated to excavate the ground in the primary excavation region M1 (FIG. 6). At this time, the rotation of the secondary excavation rotary shaft 3 is transmitted to the driven blade 33 via the drive blade 30, and the ground of the secondary excavation region M <b> 2 (FIG. 6) is transferred by the secondary excavation cutter 32 fixed to the transmission rotary shaft 31. Excavate.
By performing the ground improvement in this way, as shown in FIG. 12, a ground improvement portion M composed of a primary excavation region M1 and a secondary excavation region M2 is formed.

In addition, the ground excavation soil excavated in the primary excavation area M1 and the secondary excavation area M2 is mixed with the ground improvement material, and the stirring blades 23A, 23B, 36A, and 36B provided on the main excavation rotary shaft 2 and the sub excavation rotary shaft 3 The excavated soil is uniformly and effectively mixed and stirred by the stirring blade 34 provided on the transmission rotating shaft 31. Since these stirring blades 23A, 23B, 36A, and 36B are fixed at predetermined positions in the axial direction of the rotary shafts 2 and 3, even if the ground improvement device 1 is moved downward together with the excavation, the main excavation cutter 20 On the other hand, since the position of the stirring blade does not change, stable stirring can be performed.
Moreover, the ground improvement material added to excavation soil is injected toward the ground from the jet nozzle 7 shown in FIG. 4 provided in the lower end 2a of the main excavation rotating shaft 2.

Next, the action of the ground improvement device 1 will be described more specifically based on the above-described FIG. 1 to FIG.
In the ground improvement device 1, between the primary excavation region M1 by excavation of the plurality of main excavation cutters 20A, 20B, and 20C and the common outer tangent line T of the adjacent primary excavation region M1 by excavation of the sub excavation cutter 32. By forming the ground improvement portion M including the secondary excavation region M2 to be formed, the entire excavation cross section can be an effective cross section as a ground improvement wall.
In other words, since the entire primary excavation area M1 has an effective cross section, a part of the primary excavation area does not function as a ground improvement wall as in the conventional case, and is not dug. Therefore, the outer diameter dimension of the main excavation cutter 20 can be made smaller than that of the conventional excavation blade, and the amount of ground improvement material corresponding to the portion corresponding to the excavation can be reduced. Costs can be reduced and the apparatus can be downsized.

  Further, the rotation of the main excavation rotary shaft 2 is transmitted to the sub excavation rotary shaft 3, and the rotational force is transmitted from the drive blade 30 fixed to the lower end 3 a of the sub excavation rotary shaft 3 to the driven blade 33. A configuration in which the transmission rotary shaft 31 rotates and the sub-excavation cutter 32 rotates, that is, the sub-excavation cutter 32 is driven by using the rotational force of the main excavation rotary shaft 2, so that the driving means for the sub-excavation rotary shaft 3 is omitted. The cost can be reduced and the structure of the apparatus can be simplified.

  Further, in the ground improvement device 1, the plane including the rotation trajectory of the sub excavation cutter 32 is arranged along the inner side of the common circumscribing line T as viewed from the axial direction of the main excavation rotary shaft 2. An area wider than the area M2 is not excavated by the auxiliary excavation cutter 32, and the effective cross section formed by the primary excavation area M1 and the secondary excavation area M2 can be excavated reliably.

  In addition, since both end surfaces 4a and 4a of the first connecting shaft 4A are in contact with and stretched against the inner wall surface G0 excavated by the main excavation cutter 20, the main excavation cutter 20 is not easily displaced in the horizontal direction. It is possible to prevent the first connecting shaft 4A from rotating together with the main excavation rotating shaft 2 when excavating by rotating.

Further, in the ground improvement device 1, the central axes O 1 and O 2 of the first transmission blade 22 of the main excavation rotary shaft 2 and the second transmission blade 35 of the sub excavation rotary shaft 3 are parallel to each other, and the first transmission blade 22. Since the second transmission blade 35 is disposed within the rotation locus of the second transmission blade 35, the first transmission blade 22 rotating together with the main excavation rotating shaft 2 contacts the second transmission blade 35, so that the second transmission blade 35 is sub-excavated. The auxiliary excavation rotary shaft 3 rotates around the central axis O <b> 2 of the rotary shaft 3 via the second transmission blade 35.
That is, the auxiliary excavation rotary shaft 3 can be rotated only by the rotational force transmitted from the main excavation rotary shaft 2 without providing an original rotation driving means, and thus the apparatus can be simplified.

Next, the earthquake-proof method using the ground improvement apparatus 1 mentioned above is demonstrated based on drawing.
As shown in FIGS. 13A and 13B, the earthquake-resistant method according to the present embodiment is based on the ground improvement around the structure K using the ground improvement device 1 described above.
That is, the ground improvement device 1 shown in FIG. 1 is put into the improvement target ground in the area surrounding the ground under the structure K, and the primary excavation area M1 and the secondary excavation area M2 are performed by the main excavation cutter 20 and the sub excavation cutter 32. The ground improvement part 10A is formed by mixing and stirring the ground improvement material in the excavated ground.

  The ground improvement device 1 according to the present embodiment has a simple structure as described above, and can be miniaturized, so that it can be used as an attachment for a work machine such as a backhoe. Therefore, even in a narrow space, the ground improvement device 1 can be introduced to form the ground improvement portion 10A. In this case, by forming the outer peripheral improvement portion 11 so as to surround the ground under the existing structure K, the horizontal movement of the ground under the structure K surrounded by the outer peripheral improvement portion 11 is restricted and fluctuated. Therefore, the ground can be prevented from being destroyed. Therefore, the vibration of the structure K during an earthquake can be reduced, and destruction of the structure K can be prevented.

As described above, in the ground improvement device according to the present embodiment, and the ground improvement method, seismic resistance method, and building foundation method using the same, the entire area excavated by the main excavation cutter 20 and the sub excavation cutter 32 (primary excavation area). Since M1 and the secondary excavation area M2) can be made into an effective cross section as a ground improvement wall, it becomes possible to eliminate the ground improvement material added to the overexcavation portion as in the conventional case, so that the cost can be reduced. Can be achieved.
In addition, since the secondary excavation cutter 32 is driven by using the rotational force of the main excavation rotary shaft 2 via the secondary excavation rotary shaft 3, the driving means for the secondary excavation rotary shaft 3 can be omitted. In addition to reduction, a simple and miniaturized structure can be realized.

  Next, modifications of the present embodiment will be described with reference to the accompanying drawings. However, the same or similar members and parts as those of the above-described embodiment are denoted by the same reference numerals, and the description thereof is omitted. A configuration different from the above will be described.

The first to fifth modifications shown in FIGS. 14 to 18 are other examples of the seismic construction method according to the above-described embodiment, and the ground improvement device 1 (see FIG. 1) is used similarly to the above-described embodiment. We are constructing.
In the seismic construction method according to the first modification shown in FIGS. 14A and 14B, the ground improvement portion 10 </ b> B in which the corner improvement portions 12 are disposed at the inner corner portions of the four corners of the outer periphery improvement portion 11 having a rectangular shape in plan view. Is provided. The corner portion improving portion 12 is provided at a position of 45 degrees obliquely with respect to each side of the outer periphery improving portion 11.

  The ground improvement part 10C by the seismic construction method of the second modification shown in FIGS. 15A and 15B is the ground on the ground surface side between the structure K and the outer periphery improvement part 11 having a rectangular shape in plan view. Each of the inner corners at the four corners of the outer periphery improvement part 11 is improved by the ground improvement device 1 (see FIG. 1), and a triangular corner surface improvement part 13 (surface improvement part) is formed in plan view.

  The ground improvement part 10D by the earthquake-resistant construction method of the third modification shown in FIGS. 16A and 16B is improved by the ground improvement apparatus 1 (see FIG. 1) over the entire inner surface of the outer periphery improvement part 11 having a rectangular shape in plan view. The entire surface improved portion 14 (surface improved portion) is formed.

  The ground improvement part 10E by the earthquake-resistant construction method of the 4th modification shown to Fig.17 (a), (b) has provided the overhang | projection improvement part 15 in the outer side of the outer periphery improvement part 11 of planar view square shape. That is, the structure K of the fourth modification example has a vertically long shape (a rectangular shape that is long in the vertical direction toward the paper surface in FIG. 17B) in plan view, and is arranged at a fixed interval with respect to the structure K. Similarly, the outer periphery improving portion 11 has a vertically long shape in a plan view. And the overhang | projection improvement part 15 is extended and formed in the direction orthogonal to both the long side part centers 11a and 11a of the outer periphery improvement part 11, and has the function to reinforce the both sides.

  The ground improvement part 10F by the 5th modification shown to Fig.18 (a), (b) is the division improvement which makes the shape of a rice field by planar view so that a division may be partitioned at the time of construction before constructing a structure. The portion 16 is formed by the ground improvement device 1 (see FIG. 1).

In the ground improvement portions 10A to 10F of the first to fifth modifications, the outer periphery improvement portion 11 (the partition improvement portion 16) is formed so as to surround the ground under the structure K as in the above-described embodiment. Thus, since the horizontal movement of the ground below the structure K is restricted and fluctuations are suppressed, the ground can be prevented from being destroyed.
In the second modification and the third modification, the structure K and the outer peripheral improvement portion 11 are connected by the corner surface improvement portion 13 and the entire surface improvement portion 14, respectively, so that integration can be achieved, and the outer peripheral improvement portion. Since the proof strength with respect to the horizontal force which 11 receives from a ground is raised, there exists an effect which can improve a seismic performance further.

  Next, the sixth to eleventh modifications shown in FIGS. 19 and 24 are other examples of the seismic construction method according to the above-described embodiment, and are the building foundation construction method for the structure K. It is constructed using the ground improvement device 1 (see FIG. 1) in the same manner as the above.

A ground improvement portion 10G according to the sixth modification shown in FIGS. 19A and 19B is an earthquake resistant construction method for improving the ground directly supporting the structure K such as a house, and the ground is directly under the structure K. The improvement device 1 (see FIG. 1) is inserted to excavate a predetermined region, and the outer periphery improvement portion 11 is formed by mixing and excavating the ground improvement material to the excavated ground. This outer periphery improvement part 11 is arrange | positioned along the outer peripheral part of the structure K by planar view, The fluctuation | variation of the ground directly under the structure K is controlled.
Further, an inverted T-shaped fabric foundation 16 is provided at the upper end of the outer periphery improving portion 11 in a sectional view of the structure K, and the structure K is constructed on the cloth foundation 16 via a foundation beam 17. Yes.

  In the sixth modification, it is possible to construct the outer periphery improving portion 11 directly under the structure K in advance and directly support the structure K on the outer periphery improving portion 11. In other words, since the position of the outer periphery improving portion 11 to be constructed does not have to be provided outside the structure K in a plan view, it is also applicable to a structure K such as a house where the site is narrow and the work space is small. Can do. Therefore, in the same way as the above-described embodiment, in addition to the effects of reducing the construction cost and downsizing the apparatus, there is an effect that it can be applied in a narrow place.

  20 (a) and 20 (b), the seventh modification shown in FIGS. 20 (a) and 20 (b) uses a solid foundation 18 instead of the cloth foundation 16 (see FIG. 19) in the ground improvement section 10G of the sixth modification described above. Provided at the upper end, the outer peripheral support portion 11 directly supports the structure K thereon via the solid base 18.

In the eighth to eleventh modifications shown in FIGS. 21 to 24, the structure K is supported on the outer peripheral improvement portion 11 provided so as to surround the ground below the structure K as in the above-described embodiment. It is a basic construction method.
The ground improvement part 10H according to the eighth modification shown in FIG. 21 mounts the outer peripheral part of the foundation composed of the surface improvement part 14 on the upper end 11b of the outer periphery improvement part 11, and the structure K is placed via the surface improvement part 14. The structure is supported by the outer periphery improving portion 11. Instead of the surface layer improvement portion 14, a solid solid foundation may be used.

  In the ninth modification shown in FIG. 22, in the ground improvement portion 10H of the eighth modification shown in FIG. 21 described above, a notch recess 14a is provided at the outer peripheral lower edge portion of the surface improvement portion 14, and this notch recess 14a is provided as the outer periphery improvement portion. 11, and the structure K is supported by the outer periphery improving portion 11 through the surface improving portion 14. Instead of the surface layer improvement portion 14, a solid solid foundation may be used.

  The ground improvement part 10I according to the tenth modification shown in FIG. 23 is provided with an outer peripheral base 19 having an opening formed in the center in plan view of the foundation made of the surface layer improvement part in the above-described eighth modification of FIG. The structure K is placed on the opening edge 19a. In addition, the outer periphery foundation 19 is good also as concrete instead of a surface layer improvement part.

  The eleventh modification shown in FIG. 24 is the same as the tenth modification shown in FIG. 23 described above, except that a notch recess 19b is provided on the lower peripheral edge of the outer periphery base 19, and this notch recess 19b is placed on the outer periphery improvement part 11. The structure K is configured to be supported by the outer peripheral improvement portion 11 via the surface improvement portion 14. In this modification as well, the outer peripheral foundation 19 can be made of concrete instead of the surface layer improvement portion.

As mentioned above, although the ground improvement apparatus by this invention, and the ground improvement method using this, the earthquake-resistant construction method, and the embodiment of the building foundation construction method were demonstrated, this invention is not limited to said embodiment, The Changes can be made as appropriate without departing from the spirit of the invention.
For example, in the present embodiment, a single drive motor 6 causes a three-axis main excavation rotary shaft 2 and a two-axis sub-excavation through gears 62, 63, 64, the first transmission blade 22, and the second transmission blade 35. Although it is set as the rotational drive structure which rotates the rotating shaft 3, it is not limited to such a structure. A structure in which all the rotation shafts are rotated only by gears may be used.

Further, the configuration of the outer diameter size, arrangement, shape, quantity, and the like of the main excavation cutter 20 and the lucky excavation cutter 32 can be arbitrarily set. Furthermore, the number of main excavation rotary shafts 2 and sub excavation rotary shafts 3, the length dimension, and the like can be arbitrarily set according to the specification conditions of the apparatus.
Furthermore, the configuration of the stirring blades 23A, 23B, 26A, 36B, and 34, such as the size, arrangement, shape, and quantity, can be appropriately set according to the geology of the improvement target ground, the excavation speed, and the like.
Further, the installation position and the installation quantity of the connecting shaft 4 in the vertical direction are not limited to the present embodiment, and can be arbitrarily set.

Moreover, although the ground improvement apparatus 1 by this Embodiment is used as an attachment attached to working machines, such as a backhoe, it is not restrict | limited to such a usage form, For example, it installs in a special stand It can also be used.
Furthermore, the position and depth of the ground improvement portions 10A to 10F by the seismic method, the distance between the structure K and the outer peripheral improvement portion 11, the thickness dimension of the surface improvement portion, etc. are not particularly limited.

1 Ground improvement device 2 Main excavation rotating shaft (first rotating shaft)
3 Sub-excavation rotation axis (second rotation axis)
4 connecting shaft 4a end face 5 support frame 6 drive motor 10A to 10I ground improvement part 11 outer periphery improvement part 13 corner part surface improvement part (surface improvement part)
14 Whole surface improvement part (surface improvement part)
15 Overhang improvement part 16 Cloth foundation 18 Solid foundation 19 Perimeter foundation 20 Main excavation cutter (first excavation blade)
22 1st transmission blade 23A, 23B Agitation blade 30 Drive blade 31 Transmission rotating shaft (3rd rotating shaft)
32 Secondary drilling cutter (second drilling blade)
33 driven blade 34 stirring blade 35 second transmission blade 36A, 36B stirring blade 43 overhang bar K structure M1 primary excavation area M2 secondary excavation area T common external tangent

Claims (15)

A ground improvement device that moves the ground and improves the ground,
A plurality of first rotating shafts rotating around a vertical axis and provided in parallel with each other;
A first excavating blade fixed to the lower end of the first rotating shaft and rotating horizontally;
A second rotating shaft that is arranged in parallel with the first rotating shaft in the middle between the adjacent first rotating shafts, and that rotates around the vertical axis by transmitting the rotation of the first rotating shaft;
A driving blade fixed to the lower end of the second rotating shaft and rotating in a horizontal direction;
A plurality of first rotating shafts connected in the horizontal direction, and a connecting shaft that rotatably supports each first rotating shaft;
A third rotating shaft that rotates about a horizontal axis orthogonal to the axial direction of the connecting shaft and is rotatably inserted and supported with respect to the connecting shaft;
A second excavating blade fixed to both ends of the third rotating shaft and rotating around the third rotating shaft;
A driven blade extending radially outward from the third rotating shaft;
With
The driven blade is disposed in a rotation locus of the driving blade, and the rotation of the driving blade is transmitted to the driven blade.
The second excavation blade includes a primary excavation region that forms a rotation trajectory of each of the adjacent first excavation blades and a common outer tangent of a circle of the adjacent primary excavation region when viewed from the axial direction of the first rotation shaft. A ground improvement device, which is located in a secondary excavation region formed between the two.   2. The ground improvement according to claim 1, wherein a plane including a rotation trajectory of the second excavating blade is disposed along the inner side of the common circumscribing line when viewed from the axial direction of the first rotating shaft. apparatus.   The ground improvement device according to claim 1 or 2, wherein the connecting shaft has a length dimension in which both ends thereof are in contact with an inner wall surface excavated by all the first excavating blades. The first rotating shaft is provided with a first transmission vane extending radially outward from a central axis thereof,
The second rotating shaft is provided with a second transmission blade extending radially outward from the central axis thereof,
The ground improvement device according to any one of claims 1 to 3, wherein the second transmission blade is disposed in a rotation locus of the first transmission blade.   The ground improvement device according to any one of claims 1 to 4, wherein at least one of the first rotating shaft and the second rotating shaft is provided with a stirring blade that rotates together with the rotating shaft. . The driven blade is provided on one end side with the connecting shaft of the third rotating shaft interposed therebetween,
On the other end side of the third rotating shaft, a stirring blade that rotates together with the third rotating shaft is provided,
The ground improvement device according to any one of claims 1 to 5, wherein the stirring blade is located outside a rotation locus of the driving blade. A ground improvement method using the ground improvement device according to any one of claims 1 to 6,
Installing the ground improvement device on the ground to be improved, and rotating the plurality of first excavating blades together with the first rotating shaft to excavate the ground in the primary excavation region;
Transmitting the rotation of the second rotating shaft from the driving blade to the driven blade, and excavating the ground in the secondary excavation region by the second excavating blade fixed to the third rotating shaft;
Mixing and stirring a ground improvement material in the ground excavated in the primary excavation area and the secondary excavation area;
The ground improvement method using the ground improvement apparatus characterized by having. An earthquake-resistant construction method for improving the ground around a structure using the ground improvement device according to any one of claims 1 to 6,
Introducing the ground improvement device into the ground to be improved surrounding the ground under the structure;
The step of excavating the primary excavation region and the secondary excavation region with the first excavation blade and the second excavation blade, and mixing the ground improvement material with the excavated ground to form an outer peripheral improvement portion When,
Have
A seismic construction method using a ground improvement device characterized in that fluctuation of the ground under the structure surrounded by the outer periphery improvement portion is regulated.   9. The ground improvement device according to claim 8, wherein a ground surface side ground between the structure and the outer periphery improvement portion is improved by the ground improvement device to form a surface improvement portion. Seismic construction method used. An earthquake-resistant construction method for improving the ground directly supporting a structure using the ground improvement device according to any one of claims 1 to 6,
Introducing the ground improvement device into the ground to be improved directly under the structure;
The step of excavating the primary excavation region and the secondary excavation region with the first excavation blade and the second excavation blade, and mixing the ground improvement material with the excavated ground to form an outer peripheral improvement portion When,
Have
A seismic construction method using a ground improvement device, characterized in that fluctuation of the ground directly under the structure is restricted by the outer periphery improvement portion. A foundation construction method for ground improvement of the ground directly supporting the structure using the ground improvement device according to any one of claims 1 to 6,
Introducing the ground improvement device into the ground to be improved directly under the structure;
The step of excavating the primary excavation region and the secondary excavation region with the first excavation blade and the second excavation blade, and mixing the ground improvement material with the excavated ground to form an outer peripheral improvement portion When,
Have
A foundation construction method using a ground improvement device, characterized in that fluctuations in the ground directly under the structure are regulated by the outer peripheral improvement portion.   The building foundation method according to claim 11, wherein a foundation of the structure is provided at an upper end of the outer peripheral improvement portion. A construction foundation method for improving the ground around a structure using the ground improvement device according to claim 1,
Introducing the ground improvement device into the ground to be improved surrounding the ground under the structure;
The step of excavating the primary excavation region and the secondary excavation region with the first excavation blade and the second excavation blade, and mixing the ground improvement material with the excavated ground to form an outer peripheral improvement portion When,
Have
A building foundation construction method using a ground improvement device characterized in that fluctuation of the ground under the structure surrounded by the outer periphery improvement portion is regulated.   The base of the said structure which consists of the surface improvement part which improved the ground on the ground surface side with the said ground improvement apparatus, or the concrete is provided in the upper end of the said outer periphery improvement part. Building basic construction method using the ground improvement device of the building.   The building foundation construction method using the ground improvement device according to claim 14, wherein an opening is provided in a central portion of the foundation in plan view, and the structure is placed on an edge of the opening.

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