JP4885830B2 - Excavation and stirring tool for ground improvement equipment - Google Patents

Description

  The present invention relates to a drilling / stirring tool for a ground improvement device.

  In the case of a seismic isolation structure building, the building containing the seismic isolation device and the pile foundation that supports it are not integrated, but the ground strength of the site ground of the building is increased by ground improvement construction. Can be listed. At this time, since the vibration propagation during an earthquake varies depending on the soil quality, it is necessary to limit the bottom ground to a ground layer with constant vibration propagation in the structural design of the base-isolated structure building.

  Therefore, there are many gravel layers that are the same as the site ground that are selected as stable ground with constant vibration propagation. However, when a highly viscous or semi-consolidated highly viscous soil layer exists at a shallower depth than the gravel layer, the highly viscous soil layer is called a substantially impervious layer. Although the particles are densely assembled, the viscosity distribution is often inhomogeneous even on the same site ground, which makes it difficult to transmit the same vibration.

  Therefore, when the foundation of a base-isolated structure building is constructed by ground improvement, if there is a highly viscous soil layer at a depth shallower than the bottom ground, a consolidated or semi-consolidated viscous soil layer It is necessary to construct a good improved column by stirring and mixing.

  By the way, as a ground improvement apparatus for the purpose of improving solidification of soft ground, there is a ground improvement apparatus in which a plurality of auxiliary blades for longitudinal shearing are provided on a stirring blade (for example, see Patent Document 1).

That is, the ground improvement device rotates the plate-like wing extending in the horizontal direction, shears the improved soil in the horizontal direction to perform stirring and mixing, and further increases the stirring effect in the vertical direction. In order to generate the action of shearing the plate, a plate-like longitudinal shear blade is suspended from the bottom horizontal plate blade attached to the outer shaft, and the end face of the longitudinal shear blade is shaped like a blade. By making tangential direction, shear resistance is reduced.
JP-A-8-199557

  However, the above-described ground improvement device is supposed to solidify and improve soft ground or ordinary ground, and therefore, due to the soil properties of the consolidated or quasi-consolidated highly viscous soil layer. In conducting ground improvement construction, there was a lack of aggressiveness in establishing a method to cope with the technical difficulties.

  Here, the viscous soil layer is a soil layer composed of extremely fine soil particles that are densely packed. Adhesive strength is generated when water is mixed and stirred. Moreover, it is called a substantially water-impermeable layer and is highly self-supporting due to the adhesion of dense soil particles. The ground in which the soil layer is consolidated or semi-consolidated is particularly self-supporting and has a strong imperviousness.

  If solidified soil blocks that retain rich self-sustainability remain within a range where excavation and stirring are performed while discharging cement milk into the soil that retains such soil properties, the volume of the remaining soil blocks The gap in which cement milk can stay in the soil that is being stirred in inverse proportion to the amount of water decreases. In addition, since the soil at the outer peripheral wall and the tip of the cylindrical columnar hole produced by excavation and agitation is also highly impervious, moisture in the cement milk that has accumulated in the hole may exude to the soil outside the hole. There is a great concern that the excess cement milk will not be accommodated in the soil gap in the hole, and the excess cement milk will be affected by the discharge flow rate pressure and will be instantaneously excavated and mixed with stirring. In this case, a predetermined amount of cement milk necessary for solidification improvement is insufficient, which becomes a factor of insufficient expression of solidification strength.

  When mixing and mixing such a ground with the longitudinal shear blade of the ground improvement device described above, a plate mounted in a parallel arrangement with lead suspended on the lower surface of the lowermost horizontal plate blade mounted on the outer blade It is necessary to maintain an appropriate interval for preventing the occurrence of the “co-rotation phenomenon of the ground” to which the highly viscous soil adheres as the interval between the parallel wings, that is, the longitudinal shear blades. If the parallel spacing is not appropriate, the viscous soil adhering to each wing is increased each time the depth of excavation is increased, and the wing-to-blade spacing is integrated and integrated as the wing rotates. It is because it goes around.

  In this case, since the vertical length of the longitudinal shear blade is reduced by the cohesive soil that co-rotates, the shear depth of the soil by the wing also becomes shallow, and part of the adhered soil peels and separates during pulling out. For example, there is a concern that the unmodified soil block remains in the improved column.

  Therefore, if the parallel spacing of the blades is appropriately maintained, the number of installed longitudinal shear blades in the left and right blade length ranges of the horizontal plate blades radiating in the shape of a dragonfly blade from the left and right diagonals around the rotation axis is Limited.

  In addition, the end face of the longitudinal shear blade has a blade shape, and shears the highly viscous ground with high self-supporting properties such as consolidated or quasi-consolidated by rotating the planar orientation direction in the tangential direction. Even so, the concentric circles at the positions where the longitudinal shear blades are installed are grooved within the width of the thickness of the blade, and the number of longitudinal shear blades is limited as described above. In addition, the grooves formed by the longitudinal shear blades shearing the ground into concentric circles and the ground located in the groove-like spacing remain self-supporting, and the remaining amount is negligible However, it cannot be said that the operation effect for generating the gap required for storing and retaining the discharged cement milk in the ground is excellent.

  In addition, even if a lot of shear work time is spent with the longitudinal shear wing in order to reduce the remaining amount of the ground with its independence, the wall thickness of the wing intended to shear the ground is not so thick, Even if the soil existing in the groove-like trajectory sheared by the wall thickness is overlapped, the effect of reducing the remaining amount is poor, and it is discharged during the time spent for the work. It can be said that it is difficult to store and retain most of the cement milk in the soil.

  Therefore, in the present invention, excavation extending in the vertical direction is performed in a ground improvement device in which ground improvement is performed by discharging the improvement material while excavating and stirring the ground and kneading the improvement material and the excavated soil.・ Agitator blade with a radially extending portion extending in the radial direction is attached to the outer peripheral surface of the agitator shaft, and a diffusion blade is attached to the radially extending portion of the agitator blade. A pair of diffuser blades extending in the opposite direction are arranged opposite to each other, and the facing distance between the diffuser blades is gradually increased from the downstream side to the upstream side in the rotational direction so that the excavated soil passing between both diffused blade pieces is diffused. An object of the present invention is to provide an excavation / stirring tool for a ground improvement device characterized by being formed wide.

  Further, the following configuration is also characterized.

  (1) A plurality of stirring blades are provided on the outer peripheral surface of the excavation / stirring shaft, the radially extending portions of each stirring blade are arranged on substantially the same plane, and the diffusion blades provided on each radially extending portion are The diffuser blades provided in the radially extending portions are arranged so as to be displaced in the radial direction, and the rotational trajectories of the diffuser blades provided in the adjacent radially extending portions are arranged so as to partially overlap.

  (2) Excavation / stirring shaft extending in the vertical direction in a ground improvement device that discharges the improved material while excavating and stirring the ground and kneads the improved material and the excavated soil. Has an inner / outer double shaft structure consisting of an inner shaft and an outer shaft rotating in opposite directions, and a drilling blade having a drilling blade is provided at the lower end of the inner shaft, and is positioned above the drilling blade. The stirring blade having a radially extending portion extending in the radial direction is attached to the outer peripheral surface of the outer shaft, and the diffusion blade is attached to the radially extending portion of the stirring blade and / or the excavating blade. Is interposed between the agitating blade and the excavating blade, and the diffusion blade disposes a pair of diffusion blade pieces extending in the rotation direction of the agitating blade in an opposing state so that the excavated soil passing between the two diffusion blade pieces diffuses. As shown, the distance between the two diffusion blades facing each other is changed from the downstream side to the upstream side in the rotational direction. Gradually that it is formed in the wide.

  (3) A plurality of the radially extending portions and / or excavating blades of the stirring blades are arranged on substantially the same plane, and each of the radially extending portions and / or the diffusion blades provided on the excavating blades may include other radial extending portions and Arranged so that the diffused blades provided on the excavating blades are displaced in the radial direction and the rotation trajectories of the adjacent radial extending portions and / or diffused blades provided on the excavating blades are partially overlapped. The excavation / stirring tool for the ground improvement device according to claim 3, wherein

  (4) Excavation / stirring shaft extending in the vertical direction in the ground improvement device that discharges the improvement material while excavating / stirring the ground and kneading the improved material and the excavated soil. Has an inner / outer double shaft structure consisting of an inner shaft and an outer shaft rotating in opposite directions, and a drilling blade having a drilling blade is provided at the lower end of the inner shaft, and is positioned above the drilling blade. Then, a stirring blade having a radially extending portion extending in the radial direction is attached to the outer peripheral surface of the outer shaft, and a diffusion blade is interposed between the stirring blade and the excavation blade. Change the posture so that the spacing between the two diffusion blades gradually increases from the downstream side to the upstream side in the rotational movement direction in conjunction with the rotation of the reversing stirring blade and excavation blade. The excavated soil that passes through is to be diffused.

  (1) In the present invention described in claim 1, in the ground improvement device which performs ground improvement by discharging the improvement material while excavating and stirring the ground, and kneading the improvement material and excavated soil, A stirring blade having a radially extending portion extending in the radial direction is attached to the outer peripheral surface of the excavation / stirring shaft extending in the vertical direction, and a diffusion blade is attached to the radially extending portion of the stirring blade. A pair of diffusion blades extending in the rotation direction of the stirring blades are arranged in an opposing state, and the facing distance between the two diffusion blade pieces is set downstream in the rotation direction so that the excavated soil passing between the two diffusion blade pieces is diffused. The width is gradually increased from the side to the upstream side.

  Accordingly, the diffusion blade attached to the radially extending portion of the stirring blade moves in the rotation direction integrally with the stirring blade, and passes the excavated soil between the pair of diffusion blade pieces forming the diffusion blade. At this time, since the facing distance between the pair of diffusion blade pieces is gradually increased from the downstream side to the upstream side in the rotation direction, the soil of the excavated soil passes while being diffused between the two diffusion blade pieces. Then, the soil in the diffusion state and the improving material such as cement milk are stirred by the stirring blade, and the excavated soil is fluidized firmly. As a result, the quality of the improved column can be ensured satisfactorily.

  In particular, even when excavated soil is highly viscous soil, the entire excavated soil volume can be fluidized quickly. The fluidization of highly viscous soils, that is, substantially impervious soils that are highly self-supporting, is evidence that cement milk has been impregnated in the soil, that is, between the adhered and concentrated soil particles. By discharging cement milk into the soil that has loosened and fluidized, the synergistic effect of the stirring blade having the stirring function and the diffusion blade having the diffusion function loosens the soil particles and loosens the soil particles. The synergistic effect of increasing the gap between them and impregnating the gap with the cement milk is repeated in a chain, thereby promoting fluidization of the soil. Also, the outer surface of the diffusion wing piece functions like the side of the ship, and the soil is diffused in the outward diffusion direction like the ship wake along the rotation trajectory of the diffusion wing, and mixed with cement milk. Is promoted.

  As a result, the cement milk that permeates and stays in the soil is homogenized and increased in volume, and the cement milk can be prevented from escaping outside the flowing soil. Therefore, the predetermined amount of the improving material added to the soil is satisfied, and it becomes possible to construct an improved column body that maintains good quality.

  (2) In the present invention described in claim 2, a plurality of stirring blades are provided on the outer peripheral surface of the excavation / stirring shaft, and the radially extending portions of the stirring blades are arranged on substantially the same plane, and each radially extending portion The diffuser blades installed in the above are arranged so that they are displaced in the radial direction from the diffuser blades provided in the other radially extending portions, and the rotation trajectories of the diffuser blades provided in the adjacent radially extending portions partially overlap. It is arranged to do.

  In this way, the plurality of diffusion blades are moved on a substantially identical horizontal plane so as to draw a circular orbit around the excavation / stirring shaft, so that the mutual distance gradually increases from the downstream side to the upstream side in the rotation direction. When excavated soil passes between a pair of diffused blades arranged so as to become, the bond between the soils is dispersed, and the improvement material, for example, cement milk is mixed in the gap to promote fluidization as improved soil Thus, the kneadability can be further improved.

  In addition, the diffusion blades provided in the radial extension portions of the plurality of stirring blades are arranged so as to be displaced in the radial direction from the diffusion blades provided in the other radial extension portions, and are disposed in the adjacent radial extension portions. Since the rotation trajectories of the provided diffusion blades are arranged so as to partially overlap, the soil in the entire radial extension portion of the stirring blade can be evenly diffused and fluidized.

  Furthermore, a substantially uniform load can be applied to each stirring blade via the diffusion blade body. As a result, it is possible to avoid an overload from acting on some of the stirring blades, and to prevent a problem that some of the stirring blades are damaged in a shorter time than usual due to the overload. Therefore, kneadability can be improved, the life of each stirring blade can be made uniform, and as a result, the life of each stirring blade can be extended.

  (3) In the present invention described in claim 3, in the ground improvement device in which ground improvement is performed by discharging the improvement material while excavating and stirring the ground, and kneading the improvement material and the excavation soil. The excavating / stirring shaft extending in the vertical direction has an inner / outer double shaft structure consisting of an inner shaft and an outer shaft rotating in opposite directions, and a drilling blade having a drilling blade is provided at the lower end of the inner shaft. A stirring blade having a radially extending portion extending in the radial direction is attached to the outer peripheral surface of the outer shaft so as to be positioned above the drilling blade, and attached to the radially extending portion and / or the drilling blade of the stirring blade. A diffusion blade is attached, and the diffusion blade is interposed between the stirring blade and the excavation blade, and the diffusion blade has a pair of diffusion blade pieces extending in the rotation direction of the stirring blade in an opposed state, and both diffusion blades The facing distance between the two diffusion blades is set so that the excavated soil passing between the two pieces is diffused. And gradually formed a wide upstream from the rolling direction of the downstream side.

  In this way, since the diffusion blade is interposed between the agitating blade and the excavating blade rotating in opposite directions, even if the excavated soil excavated by the excavating blade is highly viscous soil, Can be diffused steadily with a diffusion blade to form a diffusion soil, and an improved material such as cement milk can be mixed with the diffusion soil and fluidized as improved soil, and then stirred with a stirring blade. Fluidization can be promoted. As a result, the kneadability between the excavated soil and the improved material can be further improved.

  (4) In the present invention described in claim 4, a plurality of radially extending portions and / or excavating blades of the stirring blade are arranged on substantially the same plane, and the diffusion blades provided on each radially extending portion and / or the drilling blade. Is arranged in a position shifted in the radial direction from the other radial extension part and / or the diffusion blade provided on the excavation blade, and the rotation trajectory of the diffusion blade provided on the adjacent radial extension part and / or excavation blade. Are arranged so that they partially overlap.

  In this way, the same effect as that of the diffusion blade according to claim 2 can be obtained, but in particular, a diffusion blade is provided on each of the radially extending portion of the stirring blade and the excavation blade rotating in opposite directions. In such a case, the highly viscous soil that is the excavated soil can be efficiently diffused by the diffusion blades that are moved in opposite directions, and the kneadability and fluidity with the cement milk that is the improving material are further improved. be able to.

  (5) In the present invention described in claim 5, in the ground improvement device in which ground improvement is performed by discharging the improvement material while excavating and stirring the ground, and kneading the improvement material and the excavation soil. The excavating / stirring shaft extending in the vertical direction has an inner / outer double shaft structure consisting of an inner shaft and an outer shaft rotating in opposite directions, and a drilling blade having a drilling blade is provided at the lower end of the inner shaft. A stirrer blade having a radially extending portion extending in the radial direction is attached to the outer peripheral surface of the outer shaft so as to be positioned above the excavator blade, and a diffusion blade is provided between the agitator blade and the excavator blade. At the same time, the diffusion blade is positioned so that the facing distance between the pair of diffusion blade pieces gradually becomes wider from the downstream side to the upstream side in the rotational movement direction in conjunction with the rotation of the agitating blade and the excavating blade that are relatively reversed. Change so that the excavated soil passing between both diffused blades is diffused. .

  In this way, the posture of the pair of diffusion blade pieces is changed so as to gradually widen from the downstream side to the upstream side in the rotational movement direction in conjunction with the rotation of the agitating blade and the excavating blade that are relatively reversed. In addition, since the excavated soil passing between the two diffusion blade pieces is diffused, the same effect as in the third aspect can be obtained, and in addition, the stirring blade or the excavation blade is linked with the rotation. Thus, the diffusibility of the highly viscous soil and the mixing with the cement milk can be improved by the pair of movable diffusion blades whose postures are changed.

  Hereinafter, an embodiment of an excavation / stirring tool of a ground improvement device according to the present invention will be described with reference to the drawings.

[First Embodiment]
1A is a side view of the digging / stirring tool A as the first embodiment, and FIG. 1B is a cross-sectional plan view of the digging / stirring tool A. FIG.

  Here, the ground improvement device (not shown) includes an excavation / stirring tool A and a lifting / lowering drive support unit (such as a base machine) that supports the excavation / stirring tool A so that it can be moved up and down and forward / reversely driven. And an improvement material supply section (not shown) for supplying the improvement material to the excavation / stirring tool A, and discharging the improvement material while excavating / stirring the ground. The ground is improved by kneading the excavated soil. The improvement material is not limited to solidified material such as cement milk, but is a chemical agent or agent that neutralizes, extinguishes, or purifies the ground or groundwater contaminated with harmful substances to make it pollution-free, for example, first chloride Iron or ferric chloride can be used.

  As shown in FIG. 1, the excavation / stirring tool A is provided with a stirring blade 2, a kneading action blade 3, and a drilling blade 4 at the lower end of the excavation / stirring shaft 1. The excavation / stirring shaft 1 is formed in a hollow tubular shape extending in the vertical direction, and a stirring blade 2, a kneading working blade 3, and a drilling blade 4 are attached to the lower part of the outer peripheral surface, and the space inside the tubular is supplied with an improvement material An improvement material discharge section (not shown) is provided at the lower end as well as a path, and the improvement material is supplied and discharged from the above-described improvement material supply section → improvement material supply path → improvement material discharge section.

  The agitating blade 2 is formed in an arc shape by bulging the midway part 2c outward, and its base end 2a is fixed to the lower end portion of the outer peripheral surface of the excavating / stirring shaft 1, while the excavating / stirring shaft 1 The tip 2b is loosely fitted to the outer peripheral surface of the boss portion 5 that is rotatably fitted around the peripheral surface. A plurality (three in the present embodiment) of the stirring blades 2 are provided at equal intervals in the circumferential direction of the excavation / stirring shaft 1.

  As shown in FIG. 1, the kneading action blade 3 includes the boss portion 5 and a plurality of kneading action bodies 6 formed by extending the boss portion 5 in the radial direction (two sets in this embodiment). , 7.

  And the boss | hub part 5 is formed in the cylinder shape, it fits rotatably around the outer peripheral surface of the excavation and stirring shaft 1, and the front-end | tip 2b of the stirring blade 2 is loosely fitted in the middle part of the outer peripheral surface. 8 and 9 are stopper bodies that restrict the boss portion 5 from sliding in the axial direction of the excavation / stirring shaft 1.

  Further, the kneading action body 6 has a base end attached to the upper surface of the boss portion 5 positioned just above the tip 2b, which is the outside of the stirring blade 2, and linearly extends in the radial direction of the boss portion 5. The guide rotating body 11 formed in a disk shape is rolled along the unexcavated ground G (see FIGS. 3 and 4) via the rotating support shaft 10 at the distal end of the kneading working body 6. The kneading action body 6 is attached freely and freely reciprocally in the extending direction. A pressure spring 12 serving as an elastic biasing member is interposed between the rotary spindle 10 and the kneading acting body 6 to elastically move the guide rotating body 11 in the advance direction (direction in which the unexcavated ground G is pressed). Energized.

  In addition, the outer peripheral end portion of the guide rotator 11, which is the tip of the kneading action body 6, is arranged at an outer position than the bulging end of the stirring blade 2, so that the guide rotator 11 is always unexcavated. It rolls along the ground G (see FIGS. 3 and 4). Furthermore, as shown in the end view of FIG. 2, both side surfaces 6 a, 6 a of the kneading action body 6 are inclined so as to be inclined to the front, bottom, and rear height (with the downstream side in the excavation rotation direction as the front) with respect to the vertical direction. There is a surface. A plurality of kneading action bodies 6 (two in this embodiment) are provided on the excavation / stirring shaft 1 at positions symmetrical with respect to the axis thereof.

  The kneading action body 7 has a base end attached to the lower part of the peripheral surface of the boss portion 5 that is the inner side of the stirring blade 2, and the tip is straight in the radial direction of the boss portion 5 to a position near the bulging end of the stirring blade 2. It is formed by extending it. A plurality (two in this embodiment) of the kneading action bodies 7 are provided on the excavation / stirring shaft 1 so as to be arranged at symmetrical positions on the axis.

  The excavation blade 4 is formed by integrally forming a pair of stirring blade bodies 13 and 13 extending in the radial direction of the excavation / stirring shaft 1 at positions symmetrical to the axis of the excavation / stirring shaft 1. A plurality of excavating blades 14 are formed in close contact with each other. A kneading action blade 3 is disposed immediately above the excavation blade 4, and a stirring blade 2 is disposed immediately above the kneading action blade 3. The improvement material discharge unit (not shown) is provided at the lower end of the excavation / stirring shaft 1 and not only at the lower end central portion of the excavation blade 4 but also at the portion of the excavation / stirring shaft 1 located inside the stirring blade 2. You can also.

  In this way, by arranging the kneading action body 6 that rotates in the same direction at different rotational speeds or rotation speeds between the excavating blade 4 and the stirring blade 2 that rotate in the same direction, The kneading of the excavated soil can be made steady.

  A diffusion blade body 15 is provided in the radially extending portion 2 d that forms the lower part of the stirring blade 2 disposed immediately above the excavation blade 4.

  That is, as shown in FIGS. 3 and 4, three stirring blades 2 are arranged on the outer peripheral surface of the excavation / stirring shaft 1 at equal intervals in the circumferential direction of the excavation / stirring shaft 1. Diffusion blade bodies 15 are suspended from the lower surface of the radially extending portion 2 d of the blade 2, and each diffusion blade body 15 is disposed at a position immediately above the excavation blade 4.

  As shown in FIG. 3 which is a bottom explanatory view, the diffusion blade body 15 has a pair of plate-like diffusion blade pieces 16 and 16 extending in the rotation direction on the lower surface of the radially extending portion 2d, and the mutual distance is They are formed in a “C” shape as viewed from the bottom so that the width gradually increases from the downstream side in the rotational direction to the upstream side. In the present embodiment, the diffusion blade pieces 16 and 16 are formed in a flat plate shape, but the side surface shape of the diffusion blade pieces 16 and 16 is a shape that can smoothly diffuse and guide the excavated soil. If it is, it will not be restricted to this, It can also form in the curved arc shape.

  In addition, with the diffusion blade body 15 arranged on the outermost side of the radial extension portion 2d as a reference, the diffusion blade body 15 is placed on the excavation / stirring shaft 1 side in the radial extension portion 2d adjacent to the downstream side in the rotation direction. Diffusion blade body 15 is further biased toward the excavation / stirring shaft 1 side in the radially extending portion 2d adjacent to the downstream side in the rotation direction, and is used as a reference diffusion blade body. The diffusion blade piece 16 outside the diffusion blade body 15 adjacent to the downstream side in the rotation direction is located in a rotation locus formed on substantially the same horizontal plane by the diffusion blade pieces 16 and 16 on the inner and outer sides. A diffusion blade piece 16 outside the diffusion blade body 15 adjacent to the downstream side in the rotation direction is positioned in a rotation locus formed on substantially the same horizontal plane by the diffusion blade pieces 16 and 16 inside and outside the blade body 15. I have to.

  The first embodiment is configured as described above. As shown in FIG. 5, the excavation / stirring tool A is moved downward while rotating the excavation / stirring shaft 1 in the clockwise direction a in plan view. When excavated, the guide rotator 11 rolls and moves along the unexcavated ground G, and the kneading action body 6 rotates in the counterclockwise direction b in plan view around the excavation / stirring shaft 1 in conjunction therewith. I am doing so. P1 is an excavation direction, and K1 is a rolling / moving locus of the guide rotator 11.

  Therefore, the agitating blade 2 connected to the excavation / stirring shaft 1 and driven to rotate, and the kneading action blade 3 rotated as described above rotate in the opposite directions, and the excavated soil and Relative stir the improver. At this time, the excavated soil agitated by the stirring blade 2 and the kneaded soil of the improving material are kneaded, and the kneading action bodies 6 and 7 of the working blade 3 are kneaded densely, so that the kneadability can be improved. .

  As shown in FIG. 6, when the excavating / stirring tool A is pulled upward while rotating the excavating / stirring shaft 1 in the counterclockwise direction b in plan view, the guide rotator 11 rolls along the unexcavated ground G. The kneading action body 6 is rotated in the clockwise direction a in plan view around the excavation / stirring shaft 1 in conjunction with the movement / movement. P2 is a drawing direction, and K2 is a rolling / moving locus of the guide rotator 11.

  Therefore, the stirring blade 2 that is rotationally driven in conjunction with the excavation / stirring shaft 1 and the kneading action blade 3 that is rotationally operated as described above rotate in opposite directions to improve the excavated soil and the improvement. Relatively stir the material. At this time, when the agitating blade 6 kneads the excavated soil agitated inward and the kneaded soil of the improved material, the kneading action bodies 6 and 7 of the working blade 3 knead and the excavating / stirring tool A is pulled upward. The kneadability can also be improved.

  In addition, by providing the above-mentioned improvement material discharge part (not shown) in the part of the excavation / stirring shaft 1 located directly below the kneading action body 7, the improvement material is discharged from the improvement material discharge part. The improved material and the excavated soil can be kneaded densely by the stirring blade 2 and the kneading action body 7 which are relatively stirred.

  Further, in the present embodiment, the setting of the both side surfaces 6a and 6a of the kneading action body 6 (formation of inclined surfaces) is performed so that the kneading action blade 3 is opposite in rotation direction to the stirring blade 2. Although stirring is performed, the kneading action blade 3 can be prevented from rotating, or can be rotated at a different rotational speed in the same direction as the stirring blade 2.

  At this time, the three sets of diffusion blades 15, 15, 15 are moved so as to form a circular orbit around the excavation / stirring shaft 1 on substantially the same horizontal plane at a position immediately above the excavation blade 4. As shown in FIG. 2, excavated soil passes between a pair of diffusion blade pieces 16 and 16 arranged in a letter “C” shape in a bottom view so that the mutual distance gradually increases from the downstream side to the upstream side in the rotation direction. In order to disperse the bonds between the soil g, the improvement material, for example, cement milk is mixed in the gap, and fluidization is promoted as improved soil, thereby further improving the kneadability. Can do. d1 is an internal diffusion direction between the diffusion blade pieces 16 and 16. Further, the outer side surfaces of the diffusion blade pieces 16, 16 arranged in the shape of the letter “C” in the bottom view function like the side of the ship, and the soil follows the rotation trajectory of the diffusion blade body 15. Like the wake, it is diffused in the external diffusion direction d2, and mixing with cement milk is promoted.

  Here, a discharge section (not shown) for discharging the improved material and air can be provided at the lower end of the excavation / stirring shaft 1, but the excavation / stirring shaft located between the stirring blade 2 and the excavation blade 4. 1 can be provided and discharged near the diffusion blade 15. In this way, by discharging the improving material or air from the discharge section, the soil can be dispersed and diffused with these discharge pressures. As a result, it is possible to improve the agitation and kneading properties between the improved material and the soil, and the improved material is discharged from a discharge unit (not shown) in the vicinity of the dispersed and fluidized excavated soil. It becomes easy to knead densely by the stirring blade 2 and the kneading action body 7 for relatively stirring the material and the excavated soil.

  In addition, the diffusion blade body 15 is disposed in the three stirring blades 2 arranged at equal intervals in the circumferential direction of the excavation / stirring shaft 1, with one diffusion blade body 15 being displaced in the radial direction. 15, a substantially equal load can be applied to each stirring blade 2. As a result, it is possible to avoid an overload from acting on some of the stirring blades 2 and to prevent a problem that some of the stirring blades 2 are damaged in a shorter time than usual due to the overload. it can. Therefore, kneadability can be improved, the life of each stirring blade 2 can be made uniform, and as a result, the life of each stirring blade 2 can be extended.

  Further, the diffusion blade piece 16 outside the diffusion blade body 15 adjacent to the downstream side in the rotation direction in the rotation locus formed on the substantially same horizontal plane by the diffusion blade pieces 16 and 16 inside and outside the diffusion blade body 15. Therefore, soil on substantially the same horizontal plane can be evenly dispersed and diffused.

  FIG. 7 shows a first modification of the above-described first embodiment, in which the vertical shunting blade piece 17 is interposed between the diffusion blade pieces 16, 16, and as described above, the diffusion blade pieces 16, In addition to the soil diversion / diffusion in the left-right direction by 16, the vertical diversion-forming blade piece 17 causes the soil diversion / diffusion in the vertical direction. d3 is an upper diffusion direction, and d4 is a lower diffusion direction.

  FIG. 8 shows a second modification example of the first embodiment described above, wherein the diffusion blade pieces 16 and 16 are respectively provided with the vertical direction diverting blade pieces 17 and 17 projecting in the left and right directions so as to diffuse. In addition to the shunting / diffusion of soil in the left-right direction by the wing pieces 16, 16, vertical shunting / diffusion of the soil is made by the up-down direction shunt forming wing pieces 17, 17.

  In the first embodiment and the first and second modification examples described above, the case where the diffusion blade body 15 is provided in the radially extending portion 2d has been described. However, the diffusion blade body 15 is provided on the excavation blade 4. , And the diffusion blade body 15 can be disposed between the radially extending portion 2d and the excavation blade 4, and in this case, the same effect can be obtained.

[Second Embodiment]
9A is a side view of the digging / stirring tool A as the second embodiment, and FIG. 9B is a cross-sectional plan view of the digging / stirring tool A. FIG.

  The excavation / stirring shaft 1 of the excavation / stirring tool A as the first embodiment has a uniaxial structure, but the excavation / stirring shaft 1 of the excavation / stirring tool A as the second embodiment has two inner and outer shafts. It has a structure.

  That is, the base machine of the ground improvement device (not shown) is provided with a counter rotating gear mechanism, and the upper end portion of the excavating / stirring shaft 1 extending vertically is detachably attached to the counter rotating gear mechanism. ing. The excavation / stirring shaft 1 includes a cylindrical inner shaft 20 formed by extending in the vertical direction, and a cylindrical outer shaft 21 formed by extending in the vertical direction so as to surround the outer periphery of the inner shaft 20. The inner shaft 20 and the outer shaft 21 are rotated in the opposite directions around the same axis via a counter rotating gear mechanism by a driving motor. ing.

  An inner stirring blade 22 is attached to the inner shaft 20, while an innermost stirring blade 23 and an outer stirring blade 24 are attached to the outer shaft 21. The excavation blade 4 is attached to the lower end of the inner shaft 20 so as to be positioned directly below the outer stirring blade 24. The space inside the cylindrical inner shaft 20 serves as an improvement material supply path, and an improvement material discharge section (not shown) is provided at the lower end of the inner shaft 20, so that the improvement material is the same as in the first embodiment described above. The improved material supply unit → the improved material supply path → the improved material discharge unit is supplied and discharged.

  The inner stirring blade 22 is formed in an arc shape by expanding the midway portion 22 c outward, and has a base end 22 a fixed to the lower end portion of the outer peripheral surface of the inner shaft 20 and a distal end on the outer peripheral surface of the outer shaft 21. 22b is loosely fitted. A plurality (two in the present embodiment) of the inner stirring blades 22 are disposed on the inner shaft 20 at positions symmetrical with respect to the inner shaft 20. The innermost agitating blade 23 has a proximal end fixed to the lower end of the outer peripheral surface of the outer shaft 21 inside the inner agitating blade 22, and has a distal end extending straight in the radial direction so as to be near the inner agitating blade 22. Is arranged. A plurality (three in the present embodiment) of the innermost stirring blades 23 are provided on the outer shaft 21 at equal intervals in the circumferential direction of the outer shaft 21. The outer agitating blade 24 is formed in an arc shape by bulging the middle portion 24c outwardly from the inner agitating blade 22, and its base end 24a is fixed to the lower portion of the outer peripheral surface of the outer shaft 21, A distal end 24 b is loosely fitted on the outer peripheral surface of the inner shaft 20. A plurality (three in the present embodiment) of the outer agitating blades 24 are provided on the outer shaft 21 at equal intervals in the circumferential direction of the outer shaft 21.

  As in the first embodiment, the diffusion blade body 15 is suspended from the lower surface of the radially extending portion 24d of each outer stirring blade 24, and each diffusion blade body 15 is disposed immediately above the excavation blade 4. is doing.

  Thus, the soil / improving material diffusing effect by the diffusion blade body 15 can be obtained as in the case of the first embodiment, and the relative inversion stirring by the inner / innermost / outer stirring blades 22, 23, 24 can be achieved. The effect is obtained.

  A discharge part (not shown) for discharging the improved material and air can be provided at the lower end of the inner shaft 20, but the excavation / stirring shaft 1 located between the outer stirring blade 24 and the excavating blade 4 can be provided. It can be provided in the portion and discharged near the diffusion blade 15. In this way, by discharging the improving material or air from the discharge section, the soil can be dispersed and diffused with these discharge pressures. As a result, it is possible to improve the stirring and kneading properties between the improving material and the soil.

[Third Embodiment]
FIG. 10A is a side view of the digging / stirring tool A as the third embodiment, and FIG. 10B is a sectional plan view of the digging / stirring tool A.

  The excavation / stirring tool A as the third embodiment has a basic structure similar to that of the excavation / stirring tool A as the second embodiment described above, but the radially extending portion 24d of the outer agitating blade 24 is. In place of the lower surface of the excavation blade 4, a diffusion blade body 15 is projected on the upper surface of the stirring blade bodies 13 and 13 of the excavation blade 4 toward the lower surface of the radially extending portion 24d. The difference is that one is disposed on each of the upper surfaces of the pair of stirring blade bodies 13, 13 arranged in line-symmetrical positions around the 20 axial cores so as to be displaced in the radial direction.

  Thus, the soil / improving material diffusing effect by the diffusion blade body 15 can be obtained as in the case of the first embodiment, and the relative inversion stirring by the inner / innermost / outer stirring blades 22, 23, 24 can be achieved. The effect is obtained.

[Fourth Embodiment]
FIG. 11A is a side view of the excavation / stirring tool A as the fourth embodiment, and FIG. 11B is a cross-sectional plan view of the excavation / stirring tool A.

  The excavation / stirring tool A as the fourth embodiment is a combination of the second embodiment and the third embodiment. Then, as shown in the bottom explanatory view of FIG. 12, the diffusion blade body 15 suspended from the lower surface of the radially extending portion 24d of the outer stirring blade 24 and the upper surfaces of the stirring blade bodies 13 and 13 of the excavation blade 4 are projected. The diffused wing bodies 15 are arranged so as to be displaced from each other in the radial direction of the inner shaft 20 so that they do not interfere with each other when they rotate in opposite directions. c is a clockwise direction in a bottom view, and d is a clockwise direction in a bottom view.

  In this way, the diffusion blades 15 that are relatively reversed and moved in substantially the same plane facilitate easy mixing of the improved material and the excavated soil, and the soil / improved material diffusion effect becomes a synergistic effect. It is possible to improve the conversion efficiency.

[Fifth Embodiment]
FIG. 13A is a side view of the excavation / stirring tool A as the fifth embodiment, and FIG. 13B is a cross-sectional plan view of the excavation / stirring tool A.

  The excavation / stirring tool A as the fifth embodiment is a combination of the second embodiment and the third embodiment. The diffusion blade body 15 suspended from the lower surface of the radially extending portion 24 d of the outer stirring blade 24 and the diffusion blade body 15 projecting from the upper surfaces of the stirring blade bodies 13 and 13 of the excavation blade 4 are formed on the inner shaft 20. They are arranged opposite to each other in the axial direction, so that they do not interfere when they rotate and move in opposite directions.

  In this way, the soil / improving material diffusing effect by each diffusion wing body 15 relatively reversingly moved in the vicinity of substantially the same plane becomes a synergistic effect, and the diffusion / fluidization efficiency can be improved.

  FIG. 14 shows a modified example of the fifth embodiment described above. The vertical shunting blade piece 17 is interposed between the diffusion blade pieces 16 and 16, and the diffusion blade pieces 16 and 16 are used as described above. In addition to the diversion / spreading of the soil in the left-right direction, the vertical diversion-forming blade piece 17 allows the vertical diversion / spreading of the soil. The diffusion blade body 15 suspended from the lower surface of the radially extending portion 24d of the outer stirring blade 24 is provided with a plate-like vertical flow dividing blade piece 17 between the diffusion blade pieces 16 and 16, and the same. The vertical direction diverting blade piece 17 is inclined upward from the downstream side in the rotational movement direction to the upstream side. Further, a diffusion blade body 15 projecting from the upper surface of the stirring blade bodies 13 and 13 of the excavation blade 4 is provided with a plate-like vertical diverting blade piece 17 interposed between the diffusion blade pieces 16 and 16. The vertical diverting blade piece 17 is inclined downward from the downstream side in the rotational movement direction to the upstream side. d3 is an upper diffusion direction, and d4 is a lower diffusion direction.

  In this way, the vertical diversion effect is ensured satisfactorily by the vertical diversion blades 17 that move relative to each other.

[Sixth Embodiment]
FIG. 15A is a side view of the excavation / stirring tool A as the sixth embodiment, and FIG. 15B is a cross-sectional plan view of the excavation / stirring tool A.

  As in the second to fifth embodiments, the excavation / stirring tool A as the sixth embodiment has the diffusion blade 15 interposed between the outer stirring blade 24 and the drilling blade 4 that are relatively reversed. In the blade 15, the facing distance w between the pair of diffusion blade pieces 16, 16 gradually becomes wider from the downstream side to the upstream side in the rotational movement direction in conjunction with the rotation of the outer stirring blade 24 and the excavating blade 4 that are relatively reversed. Thus, the difference is that the excavated soil passing between the two diffusion blade pieces 16 and 16 is diffused.

  That is, a plurality of sets (two sets in this embodiment) of diffusion blades 15 are provided on the lower surface of the radially extending portion 24d of the outer stirring blade 24, and each of the diffusion blades 15 extends in the vertical direction. In the embodiment, two) the diffusion blade piece support shafts 30 are vertically suspended, and the cylindrical boss portions 31 are loosely fitted to the respective diffusion blade piece support shafts 30 so as to extend in the radial direction of the respective cylindrical boss portions 31. A plurality of diffusion blade pieces 16 (two in the opposite position in this embodiment) are attached to face each other via the supporting arm 32, and each diffusion blade piece 16 is rotated around the axis of each diffusion blade piece support shaft 30. Supports freely.

  Each diffusion blade piece 16 is formed in a narrow plate shape extending in the vertical direction, and the outer surface is formed in a substantially circular arc surface centering on the diffusion blade piece support shaft 30 in plan view. Moreover, the diffusion blade pieces 16 and 16 supported on the lower surface of the radial extension portion 24d via the diffusion blade piece support shafts 30 and 30 face each other closest to each other in the extension direction of the radial extension portion 24d. I have to.

  In addition, a tension spring 33 as an elastic means for posture restoration is interposed between the diffusion blade piece support shaft 30 and the support arm 32, and the diffusion blade piece 16 whose posture is changed by the tension spring 33 is shown in FIG. The initial posture (i) (f) shown in FIG. Here, as shown in FIG. 16, the initial posture (a) (f) is a posture in which the diffusion blade pieces 16 and 16 face each other closest to each other in the extending direction of the radially extending portion 24d. In the posture (b) (c), the diffusion blade pieces 16 and 16 facing each other are pressed by an action piece 34 described later, and rotate in opposite directions around the diffusion blade piece support shafts 30 and 30, respectively. Thus, the posture is changed to a “C” shape with the mutual facing space w widened. The changed posture (d) (e) is a posture in the middle of restoration to the initial posture (b) (f).

  Further, on the upper surface of the stirring blade body 13 of the excavating blade 4, a planarly tapered triangular column-shaped action piece 34 is projected to act on the diffusion blade pieces 16, 16 facing the action piece 34, The diffusion blade pieces are pivoted in opposite directions around the diffusion blade piece support shafts 30 and 30, respectively, so that the facing distance w between the diffusion blade pieces 16 and 16 is gradually increased. That is, in conjunction with the rotation of the outer agitating blade 24 and the excavating blade 4 that are relatively reversed, the action piece 34 is in the mutual attitude of the diffusion blade pieces 16 and 16, and the facing distance w is downstream in the rotational movement direction of the outer agitating blade 24. When the action is released by the passage of the action piece 34, the diffusion blade pieces 16 and 16 are restored to their initial postures by the tension springs 33 and 33. I have to.

  Specifically, referring to the plan view of FIG. 16, the radially extending portion 24d of the outer stirring blade 24 rotates counterclockwise, whereas the stirring blade body 13 of the excavating blade 4 rotates clockwise. Rotate. Accordingly, as shown in the changed posture (b) (c), the action piece 34 also rotates in the clockwise direction, acts on the outer surfaces of the two diffusion blade pieces 16 and 16 facing each other in a push-open manner, and has a radius. The outer diffusion blade piece 16 revolving around the center of the outer shaft 21 integrally with the direction extending portion 24d is rotated counterclockwise around the diffusion blade piece support shaft 30 and the inner diffusion blade piece 16 is rotated around the diffusion blade piece support shaft. Rotate around 30 clockwise. At this time, the facing distance w between the diffusion blade pieces 16 and 16 is changed so as to gradually become wider from the downstream side in the rotational movement direction of the outer stirring blade 24 to the upstream side.

  As described above, the facing distance w between the pair of diffusion blade pieces 16 and 16 gradually increases from the downstream side to the upstream side in the rotational movement direction in conjunction with the rotation of the outer stirring blade 24 and the excavation blade 4 that are relatively reversed. In particular, since the excavated soil passing between the two diffusion blade pieces 16 and 16 is diffused to the maximum in the maximum change posture (c) shown in FIG. The effect similar to that of the pair of fixed diffusion blade pieces 16 and 16 of the fifth embodiment can be obtained, and in addition, the posture is linked to the rotation of the outer agitating blade 24 and the excavating blade 4 that are relatively reversed. The movable pair of diffusion blades 16 and 16 that are changed can improve the diffusibility of the highly viscous soil and the mixing with the cement milk.

  Note that, contrary to the present embodiment, that is, the action piece 33 is suspended from the lower surface of the radially extending portion 24 d of the outer stirring blade 24, while the diffusion blade pieces 16, The same effect can be obtained also when 16 is supported rotatably.

(A) is a side view of the excavation / stirring tool as the first embodiment, and (b) is a sectional plan view of the excavation / stirring tool. The end view of a kneading agent. Explanatory drawing of a bottom face of a diffusion wing body. The soil dispersion | distribution explanatory drawing by a diffusion wing body. Explanatory drawing. Drawing explanatory drawing. (A) is front expansion explanatory drawing of the diffusion wing | blade body as a 1st modification of 1st Embodiment, (b) is II sectional drawing of (a), (c) is the soil dispersion | distribution by an up-down direction shunting blade piece Illustration. (A) is front expansion explanatory drawing of the diffusion wing | blade body as a 2nd modification of 1st Embodiment, (b) is the II-II sectional view taken on the line of (a). (A) is a side view of a digging / stirring tool as a second embodiment, and (b) is a sectional plan view of the digging / stirring tool. (A) is a side view of a digging / stirring tool as a third embodiment, and (b) is a sectional plan view of the digging / stirring tool. (A) is a side view of a digging / stirring tool as a fourth embodiment, and (b) is a sectional plan view of the digging / stirring tool. Plane explanatory drawing of a diffusion wing body. (A) is a side view of a digging / stirring tool as a fifth embodiment, and (b) is a sectional plan view of the digging / stirring tool. (A) is front expansion explanatory drawing of the diffusion wing | blade body as a modification example of 5th Embodiment, (b) is the III-III sectional view taken on the line of (a). (A) is side surface explanatory drawing of the excavation and stirring tool as 6th Embodiment, (b) is the IV-IV cut | disconnection plane explanatory drawing of (a). The attitude | position change explanatory drawing of a diffusion wing body. The diffusion expansion explanatory drawing of a diffusion wing body.

Explanation of symbols

A Excavation / stirring tool G Unexcavated ground 1 Excavation / stirring shaft 2 Stirring blade 3 Kneading action blade 4 Excavation blade 15 Diffusion blade body 16 Diffusion blade piece

Claims (5)

In the ground improvement device that improves the ground by discharging the improved material while excavating and stirring the ground, and kneading the improved material and the excavated soil,
Agitating blades equipped with a radially extending portion extending in the radial direction are attached to the outer peripheral surface of the excavation / stirring shaft extending vertically, and a diffusion blade is attached to the radially extending portion of the stirring blade,
In the diffusion blade, a pair of diffusion blade pieces extending in the rotation direction of the stirring blade are arranged in an opposing state, and the facing distance between the two diffusion blade pieces is rotated so that the excavated soil passing between the two diffusion blade pieces is diffused. An excavation / stirring tool for a ground improvement device, characterized in that the width is gradually increased from the downstream side to the upstream side in the direction.   A plurality of stirring blades are provided on the outer peripheral surface of the excavation / stirring shaft, and the radially extending portions of each stirring blade are arranged on substantially the same plane, and the diffusion blades provided on each radially extending portion are extended in the other radial direction. The diffusion blades provided in the part are arranged so as to be displaced from each other in the radial direction, and the rotation trajectory of the diffusion blade provided in the adjacent radial extension part is arranged so as to partially overlap. The excavation / stirring tool for the ground improvement device according to claim 1. In the ground improvement device that improves the ground by discharging the improved material while excavating and stirring the ground, and kneading the improved material and the excavated soil,
The excavating / stirring shaft extending in the vertical direction has an inner / outer double shaft structure consisting of an inner shaft and an outer shaft rotating in opposite directions, and a drilling blade having a drilling blade is provided at the lower end of the inner shaft. A stirring blade having a radially extending portion extending in the radial direction is attached to the outer peripheral surface of the outer shaft so as to be positioned above the drilling blade, and attached to the radially extending portion and / or the drilling blade of the stirring blade. Install the diffusion blade, interpose the diffusion blade between the stirring blade and the excavation blade,
In the diffusion blade, a pair of diffusion blade pieces extending in the rotation direction of the stirring blade are arranged in an opposing state, and the facing distance between the two diffusion blade pieces is rotated so that the excavated soil passing between the two diffusion blade pieces is diffused. An excavation / stirring tool for a ground improvement device, characterized in that the width is gradually increased from the downstream side to the upstream side in the direction.   A plurality of the radially extending portions and / or excavating blades of the stirring blades are arranged in substantially the same plane, and the diffusion blades provided on each of the radially extending portions and / or the drilling blades are other radial extending portions and / or excavating blades. The blades are arranged so as to be displaced in the radial direction from the diffusion blades provided on the blades, and the rotation trajectories of the diffusion blades provided on the adjacent radial extension portions and / or the excavation blades are arranged so as to partially overlap. The excavation / stirring tool for the ground improvement device according to claim 3. In the ground improvement device that improves the ground by discharging the improved material while excavating and stirring the ground, and kneading the improved material and the excavated soil,
The excavating / stirring shaft extending in the vertical direction has an inner / outer double shaft structure consisting of an inner shaft and an outer shaft rotating in opposite directions, and a drilling blade having a drilling blade is provided at the lower end of the inner shaft. A stirrer blade having a radially extending portion extending in the radial direction is attached to the outer peripheral surface of the outer shaft so as to be positioned above the excavator blade, and a diffusion blade is provided between the agitator blade and the excavator blade. With intervening,
The diffusion blade is changed in posture so that the facing distance between the pair of diffusion blade pieces gradually becomes wider from the downstream side to the upstream side in the rotational movement direction in conjunction with the rotation of the agitating blade and the excavating blade that are relatively reversed. An excavation and agitation tool for a ground improvement device, wherein the excavated soil passing between both diffusion blade pieces is diffused.

Images