JP3955842B2 - Ground improvement device - Google Patents

Description

  The present invention relates to a ground improvement device.

  Conventionally, as one form of the ground improvement device, an inner shaft and an outer shaft are formed as an inner and outer double shaft, and both the inner and outer shafts can be rotated in reverse to each other. In addition, there is one that includes a relative stirring blade body that is attached so as to relatively reversely rotate the inner stirring blade and the outer stirring blade at the inner and outer positions (see, for example, Patent Document 1).

A packing is interposed between the lower outer peripheral surface of the inner shaft and the inner peripheral surface of the lower end portion of the outer shaft, so that the kneaded material of the excavated earth and sand and the solidified material enters between the inner shaft and the outer shaft. To prevent it from rising.
JP-A-3-63312

  However, in the ground improvement device described above, the upper part of the excavation shaft body is supported by the leader, but the lower end part is not supported. Excavation occurs from the gap formed between the outer peripheral end face of the packing and the inner peripheral surface of the outer shaft when the outer shaft is misaligned and the packing is damaged, or when the inner shaft and the outer shaft are misaligned. There is a problem that the kneaded product of the earth and sand and the solidified material enters between the inner shaft and the outer shaft and rises.

  As a result, the kneaded material is solidified between the inner shaft and the outer shaft, and the excavation shaft body cannot be reused, so that it is necessary to prepare a large number of excavation shaft bodies, The construction cost is high.

Therefore, in the present invention, an inner shaft and an outer shaft are formed as inner and outer double shafts, and both the inner and outer shafts can be rotated in reverse to each other. In a ground improvement device comprising a relative agitating blade body that is attached to relatively reversely rotate the blade and the outer agitating blade at the inner and outer positions, a lower part of the excavation shaft body located above the relative agitating blade body. A seal portion is provided, and the seal portion is a ring that restricts the passage of ring-shaped packing and earth and sand in a cylindrical space formed between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft. A passage restriction body such as earth and sand is arranged, and the passage restriction body such as earth and sand is impregnated with grease on a cloth-like material, and a kneaded mixture of excavated earth and sand and solidified material that has penetrated through the cloth-like material is formed. in combination with the grease, Tei so as to form a cylindrical jacket with a semi-solidified state It is intended to provide a soil modifying apparatus according to claim.

  The present invention is also characterized by the following configuration.

(1) An excavation shaft body in which an inner shaft and an outer shaft are formed as inner and outer double shafts, and the inner and outer shafts can be reversely rotated with each other. In a ground improvement device comprising a relative agitating blade body that is attached so as to relatively reversely rotate the agitating blade at the inner and outer positions, a seal portion is provided at a lower portion of the excavation shaft body located above the relative agitating blade body. The seal portion is provided in a cylindrical space formed between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft. An equal passage restricting body is provided, and a plurality of ring-shaped packing and earth and sand passage restricting bodies are alternately arranged in the axial direction of the excavation shaft body.

  (2) The seal portion is detachably attached to the inner shaft at the lower portion of the excavation shaft body, and the inner shaft forming body that forms a part of the inner shaft, and the outer shaft is detachably attached to the outer shaft. An outer shaft forming body that forms a part of the inner shaft, and a ring-shaped packing disposed in a cylindrical space formed between the inner and outer shaft forming bodies and a passage regulating body such as earth and sand to form an outer shaft. The body is formed by detachably connecting a plurality of divided pieces formed by dividing vertically in the axial direction.

  (3) Passage regulating bodies such as earth and sand shall be made by impregnating cloth with grease.

(1) According to the first aspect of the present invention, an excavation shaft body in which an inner shaft and an outer shaft are formed as inner and outer double shafts, and both the inner and outer shafts can be reversely rotated with each other; In a ground improvement apparatus comprising a shaft body and a relative stirring blade body that is mounted so as to relatively reversely rotate the inner stirring blade and the outer stirring blade at the inner and outer positions, the shaft is positioned above the relative stirring blade body. A seal portion is provided at a lower portion of the excavation shaft body, and the seal portion is formed in a cylindrical space formed between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft, and ring-shaped packing, earth and sand, etc. A ring-shaped sediment control body, such as a ring-shaped sediment that regulates the passage of soil, is arranged , and the sediment-controlling body, such as sediment, is impregnated with excavated sediment that has penetrated through the fabric by impregnating the fabric with grease. The kneaded product with the material is combined with the grease to form a cylindrical covering in a semi-solid state. Unishi to have.

  In this way, since the packing and the passage regulating body such as earth and sand are arranged in the cylindrical space, the inner shaft and the outer shaft are misaligned due to the resistance that the relative stirring blade body receives from the earth and sand during excavation. In such a case, the centering and other passage restrictors can suppress the misalignment and prevent the packing from being damaged. As a result, the waterproof function of the packing can be ensured satisfactorily.

At this time, the passage restriction body such as earth and sand impregnates the cloth with grease, and the kneaded material of the excavated earth and the solidified material that has penetrated through the cloth is combined with the grease so that the cylinder is semi-solidified. Since the covering body is formed, it is possible to reliably regulate the rise of earth and sand having a relatively large particle diameter.
As a result, it is possible to further improve the water stop effect by the packing and the effect of preventing the kneaded material from entering and rising by the passage regulating body such as earth and sand.

  And by replacing the seal and the sand and sand passage restriction body as necessary, it is possible to reliably prevent the kneaded material from entering and rising between the inner shaft and the outer shaft, The excavation shaft can be reused, and the construction cost can be reduced.

(2) In the present invention described in claim 2, an excavation shaft body in which the inner shaft and the outer shaft are formed as inner and outer double shafts, and both the inner and outer shafts can be reversely rotated with each other, and In a ground improvement apparatus comprising a shaft body and a relative stirring blade body that is mounted so as to relatively reversely rotate the inner stirring blade and the outer stirring blade at the inner and outer positions, the shaft is positioned above the relative stirring blade body. A seal portion is provided at a lower portion of the excavation shaft body, and the seal portion is formed in a cylindrical space formed between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft, and ring-shaped packing, earth and sand, etc. A ring-shaped sediment control body that regulates the passage of sand is arranged, and a plurality of ring-shaped packings and a sediment control body such as sediment are alternately arranged in the axial direction of the excavation shaft body. Yes.

  In this way, it is possible to improve the water stop effect by the packing and the effect of preventing the kneaded material from entering and rising by the passage regulating body such as earth and sand.

  (3) In the present invention according to claim 3, the seal portion is detachably attached to the inner shaft at the lower portion of the excavation shaft body, and the inner shaft forming body forming a part of the inner shaft and the outer shaft. An outer shaft forming body that is detachably attached to form a part of the outer shaft, and a ring-shaped packing and earth and sand passing through a cylindrical space formed between the inner and outer shaft forming bodies are restricted. The outer shaft forming body is formed by detachably connecting a plurality of divided forming pieces formed by being vertically divided in the axial direction.

  In this way, the outer shaft forming body is formed by detachably connecting a plurality of split forming pieces formed by dividing vertically in the axial direction, so that by removing the split forming pieces, Maintenance and the like can be easily performed.

  Embodiments of the present invention will be described below with reference to the drawings.

  A shown in FIG. 1 is a ground improvement device according to the present invention, and the ground improvement device A includes a base machine 1 and a solidifying material supply unit 2.

  The base machine 1 includes a self-propelled base machine body 3 provided with a leader 4 extending in the vertical direction. A motor support 5 is attached to the leader 4 so as to be movable up and down, and a drive motor 6 is mounted on the motor support 5. Then, the upper end portion of the excavation shaft body 7 extending in the vertical direction is detachably attached to the drive motor 6 via the counter rotating gear mechanism 8, and the relative stirring blade body 9 is attached to the lower peripheral surface of the excavation shaft body 7. The excavation blade body 10 is attached to the lower end portion of the excavation shaft body 7. Reference numeral 12 denotes a guide / support for guiding and supporting the excavation shaft body 7 in the excavation direction.

  The solidification material supply unit 2 includes a solidification material storage tank and a solidification material supply pump (not shown), and connects the base end portion of the solidification material supply hose 11 to the solidification material supply pump. Is connected to the excavation shaft body 7 via a swivel joint (not shown).

  As shown in FIGS. 2 and 3, the excavation shaft body 7 is vertically extended so as to surround a cylindrical inner shaft 20 formed by extending in the vertical direction and the outer periphery of the inner shaft 20. The formed cylindrical outer shaft 21 forms an inner / outer double shaft structure, and the inner shaft 20 and the outer shaft 21 are arranged around the same axis via a counter rotating gear mechanism 8 by a driving motor 6. They are designed to rotate in opposite directions.

  A cylindrical body 22 formed by extending in the vertical direction is inserted into the inner shaft 20 to form an inner solidified material supply path 23 in the cylindrical body 22, while the outer periphery of the cylindrical body 22 is formed. An outer solidified material supply path 24 is formed between the surface and the inner peripheral surface of the inner shaft 20.

  Moreover, a communication path (not shown) is formed at the upper end portion of the inner shaft 20, and the inner solidification material supply path 23 and the outer solidification material supply path 24 are communicated with each other via the communication path, thereby solidifying material supply hose. The solidified material supplied through 11 can be divided and supplied to the inner solidified material supply path 23 and the outer solidified material supply path 24.

  Here, the excavation blade body 10 is attached to the lower end portion of the inner shaft 20 via the blade body attachment body 13, and the first solidifying material discharge portion 29 is provided on the blade body attachment body 13.

  And the 1st solidification material discharge part 29 forms the circular 1st solidification material discharge hole 29a in the surrounding wall of the blade body attachment body 13 formed in the cylinder shape, and the 1st solidification material discharge hole 29a is made into the inside solidification material. The solidified material connected to the supply path 23 and supplied through the inner solidified material supply path 23 is discharged downward from the first solidified material discharge hole 29a.

  2 and 3, the relative stirring blade body 9 includes an innermost stirring blade 26, an inner stirring blade 27 that rotates the outer periphery of the innermost stirring blade 26 in a relatively opposite direction, The outer periphery of the stirring blade 27 is provided with an outer stirring blade 28 that rotates in a relatively opposite direction, and the inner stirring blade 27 and the outer stirring blade 28 are formed in a substantially similar shape, and both the stirring blades 27, 28 are formed. By making the gap formed between them almost the same width over almost the entire area of both stirring blades 27 and 28, it is possible to prevent the swirling phenomenon of the excavated soil and to exhibit a precise stirring function. I am doing so.

  The innermost stirring blades 26 are formed so as to protrude radially from the lower end of the outer shaft 21, and are provided at a pair of symmetrical positions at the lower end of the outer shaft 21, and rotate in the direction a integrally with the outer shaft 21. Like to do.

  The inner stirring blade 27 is vertically moved between the upper and lower pair of upper and lower horizontal blade pieces 27a and 27b extending in the radial direction of the excavation shaft body 7 and the outer ends of the upper and lower horizontal blade pieces 27a and 27b. The tip of the upper horizontal wing piece 27a is attached to a ring-shaped wing piece support 30 that is formed in an arc shape from the longitudinal wing piece 27c that is extended in the direction and freely fitted to the outer peripheral surface of the outer shaft 21. On the other hand, the tip of the lower horizontal wing piece 27b is attached to the lower end portion of the inner shaft 20 so as to rotate integrally with the inner shaft 20 in the b direction.

  An intermediate horizontal wing piece 27d extending in a straight line in the left-right direction is formed between the central portion of the vertical wing piece 27c and the inner shaft 20, and is solidified in the intermediate horizontal wing piece 27d. An introduction path 33 is formed, and a second solidified material discharge portion 32 (described later) and the outer solidified material supply path 24 are connected through the solidified material introduction path 33.

  In this way, it is possible to increase the stirring efficiency of excavated soil by adding a straight intermediate horizontal blade piece 27d in the left-right direction, and to form the solidified material introduction path 33 in the straight intermediate horizontal blade piece 27d. Thus, the solidified material introduction path 33 can be formed as short and simple as possible, and the processing cost can be reduced.

  Further, a pair of the above-described inner stirring blades 27 is provided at a line-symmetrical position below the inner shaft 20. 31 is a small wing piece formed by projecting outward from the middle part of the vertical wing piece 27c.

  The outer stirring blade 28 is vertically moved between the upper and lower pair of upper and lower horizontal blade pieces 28a and 28b extending in the radial direction of the excavating shaft body 7 and the outer end portions of the upper and lower horizontal blade pieces 28a and 28b. It is formed in an arc shape from the vertical wing piece 28c that is extended in the direction, and the tip of the upper horizontal wing piece 28a is attached to the lower end portion of the outer shaft 21, while the outer peripheral surface of the inner shaft 20 is rotatable. The tip of the lower horizontal wing piece 28b is attached to the loosely fitted ring-shaped wing piece support 34 so as to rotate integrally with the outer shaft 21 in the direction a.

  Three outer stirring blades 28 are provided at regular intervals in the circumferential direction below the excavation shaft body 7. 35 is a small blade piece formed by projecting outward at the upper and lower portions of the vertical blade piece 28c, and the rotation trajectory of these small blade pieces 35, 35 is the small blade piece 31 provided on the inner stirring blade 27. It is arranged so as to overlap the rotation trajectory in the vertical direction, so that the excavated soil can be reliably stirred between the inner and outer stirring blades 27 and 28 that rotate in the opposite directions.

  Further, the inner agitation blade 27 is provided with a second solidifying material discharge portion 32 for discharging the solidifying material, and the second solidifying material discharge portion 32 according to the following will be described.

  That is, as shown in FIGS. 2 and 3, a second solidifying material discharge section 32 is provided at the intersection of the vertical blade piece 27c and the intermediate horizontal blade piece 27d of the inner stirring blade 27, and the second solidifying material is provided. The discharge part 32 forms a second solidified material discharge vertically elongated hole 32a extending in the vertical direction on the back surface of the vertical blade piece 27c (the surface opposite to the surface on the rotation direction side), and the back surface of the intermediate horizontal blade piece 27d. A second solidified material discharge oblong hole 32b extending in the horizontal direction is formed on the surface (the surface opposite to the surface on the rotation direction side), and both the holes 32a and 32b are communicated in a T-shape.

  The second solidified material discharge vertical / horizontal elongated holes 32a and 32b are connected to the outer solidified material supply path 24 through the solidified material introduction path 33 formed in the intermediate horizontal blade piece 27d.

  In this way, when the soft ground G is improved, the leader machine 4 is built by moving the base machine 1 to the ground improvement site, and the excavation shaft body 7 is rotated along the leader 4. By lowering, the ground G is excavated by the excavating blade body 10 and the excavated soil is agitated by the relative agitating blade body 9. c is an inner stirring blade side guide channel, and d is an excavation shaft body side guide channel.

  At this time, the solidification material is supplied from the solidification material supply unit 2 to the solidification material supply hose 11 → the swivel joint → the excavation shaft 7 → the first and second solidification material discharge units 29, 32. The solidified material is discharged from 32, and the solidified material is agitated uniformly in the excavated soil to solidify the excavated soil, thereby building a columnar or wall-shaped ground improvement body in the soft ground G. Thus, the ground G can be improved.

  In particular, the solidified material supplied to the outer solidified material supply path 24 can be discharged from the second solidified material discharge vertical / horizontal holes 32a and 32b of the second solidified material discharge section 32 through the solidified material introduction path 33. The second solidified material discharge vertical hole 32a is formed on the back surface opposite to the rotation direction of the inner stirring blade 27, so that the solidified material can be discharged smoothly and formed in the vertical vertical hole. Therefore, the solidified material can be discharged in the form of a vertically long strip.

  Moreover, since the inner stirring blade 27 rotates and moves in the excavation direction of the excavation shaft body 7, the solidified material film forms a continuous cylindrical film in the circumferential direction and the vertical direction. Solidified material can be evenly arranged in the excavation direction in the excavated soil.

  Further, since the second solidified material discharge oblong hole 32b is formed on the back surface opposite to the rotation direction of the inner stirring blade 27, the solidified material can be discharged smoothly and the horizontal oblong hole in the horizontal direction. Therefore, the solidified material can be discharged in a ring shape.

  Moreover, since the inner stirring blade 27 rotates and moves in the excavation direction of the excavation shaft body 7, the film of the solidified material forms a spiral belt-like film that is continuous in the circumferential direction and the vertical direction. The solidified material can be evenly arranged in the excavation direction in the excavated soil.

  Therefore, in this state, the excavated soil between the stirring blades 27 and 28 is forced to flow in the opposite direction by rotating the inner and outer stirring blades 27 and 28 that are overlapped on the inner and outer sides in opposite directions. Therefore, the excavated soil inevitably crosses between the two agitating blades 27 and 28, so that the excavated soil can be uniformly kneaded. Since a film can be formed, the excavated soil and the solidified material can be efficiently and uniformly kneaded.

  Here, in the solidified material, small pieces made of synthetic resin are dispersed and mixed in an appropriate amount, so that the small pieces made of synthetic resin can be mixed in the ground improvement body. The horizontal load acting on the improved body effectively functions to strengthen the yield strength against the bending and pulling force generated in the ground improved body, and as a result, the horizontal load resistance of the ground improved body can be increased.

  In the configuration as described above, the gist of the present invention is that, as shown in FIG. 2, a seal portion 40 is detachably provided at the lower portion of the excavation shaft body 7 positioned above the relative stirring blade body 9, and the seal The portion 40 includes a ring-shaped packing 41 and a ring-shaped earth and sand that regulates passage of earth and sand in a cylindrical space S formed between the outer circumferential surface of the inner shaft 20 and the inner circumferential surface of the outer shaft 21. This is because the equal passage restricting body 42 is provided.

  That is, as shown in FIGS. 2 and 4 to 6, the seal portion 40 is detachably attached to the inner shaft 20, and the outer peripheral surface of the inner shaft forming body 43 that forms a part of the inner shaft 20. The cylindrical space S is formed between the outer shaft 21 and the inner peripheral surface of the outer shaft forming body 44 that is detachably attached to the outer shaft 21 and forms a part of the outer shaft 21. In the body 43, the formed body piece 45 is formed in a cylindrical shape with the axis line in the vertical direction, and the fitting connection female piece 46 is formed at the upper end portion of the formed body piece 45, while the formed body piece A fitting connection male piece 47 is formed at the lower end of 45.

  Then, the upper fitting connecting male piece 49 is formed at the lower end of the upper inner shaft forming body 48 that forms a part of the inner shaft 20, while the lower inner shaft forming body 50 that forms a part of the inner shaft 20 is formed. A lower fitting connecting female piece 51 is formed at the upper end.

  In this manner, the fitting and connection female piece 46 of the inner shaft forming body 43 is fitted to the upper fitting and connection male piece 49 of the upper inner shaft forming body 48 from below, and the fitting and connecting female piece Connecting pin insertion holes 52, 52 formed by passing through 46 in a direction orthogonal to the axial direction, and a connecting pin engaging recess 53 formed on the outer peripheral surface of the upper fitting connecting male piece 49 in a direction orthogonal to the axial direction. , 53 are connected to each other, and the connecting pins 54, 54 are inserted to be connected.

  Further, the lower connecting and connecting female piece 51 of the lower inner shaft forming body 50 is fitted with the fitting and connecting male piece 47 of the inner shaft forming body 43 from below, and the outer periphery of the fitting and connecting male piece 47 Connection pin engaging recesses 55, 55 formed in the direction orthogonal to the axial direction on the surface, and connection pin insertion holes 56, 56 formed by penetrating the lower fitting connection female piece 51 in the direction orthogonal to the axial direction, A connecting pin insertion hole (not shown) formed by penetrating a lower outer shaft forming body (described later) in a direction orthogonal to the axial direction is matched, and the connecting pins 57 and 57 are inserted and connected. .

  The outer shaft forming body 44 is detachable from the sides of the side end portions 58a, 58a, 58a, 58a of a plurality (two in this embodiment) of the divided forming pieces 58, 58 formed by being vertically divided in the axial direction. Are connected to each other. 59 is a connecting pin hole.

  Further, at the upper end of the outer peripheral surface of each divided forming piece 58, a fitting positioning protruding piece 60 protruding upward and a connecting piece 62 having a connecting hole 61 penetrating in the vertical direction are provided, while each divided forming piece is provided. The lower end of the outer peripheral surface of 58 is provided with a fitting positioning concave piece 63 that is concave upward and a connecting piece 65 having a connecting hole 64 that penetrates in the vertical direction.

  Further, a connecting piece 68 having a fitting positioning concave piece 66 concave upward and a connecting hole 67 penetrating in the vertical direction at the lower end portion of the outer peripheral surface of the upper outer shaft forming body 72 forming a part of the outer shaft 21. On the upper end of the outer peripheral surface of the lower inner shaft forming body 73 that forms a part of the outer shaft 21, a fitting positioning protruding piece 69 that protrudes upward and a connecting hole 70 that penetrates in the vertical direction are provided. A connecting piece 71 is provided.

  In this way, the fitting positioning protrusions 60 formed at the upper end portions of the outer peripheral surfaces of the divided forming pieces 58 are fitted into the fitting positioning concave portions 66 formed at the lower end portions of the upper outer shaft forming body 72. In addition, the connecting hole 67 of the connecting piece 68 formed at the lower end portion of the outer peripheral surface of the upper outer shaft forming body 72 is aligned with the connecting hole 61 of the connecting piece 62 formed at the upper end portion of the outer peripheral surface of each divided forming piece 58. Thus, a connection pin (not shown) is inserted into and connected to both the connection holes 61 and 67.

  Then, the fitting positioning protrusions 69 formed on the upper end portion of the outer peripheral surface of the lower outer shaft forming body 73 are fitted to the fitting positioning concave pieces 63 formed on the lower end portion of the outer peripheral surface of each divided forming piece 58. The connection holes 64 of the connection pieces 65 formed at the upper end of the outer peripheral surface of the lower inner shaft forming body 50 are aligned with the connection holes 64 of the connection pieces 65 formed at the lower end of the outer peripheral surface of each divided formation piece 58, The connection pins 74 (see FIG. 6) are inserted into the connection holes 64 and 70 for connection.

  On the outer peripheral surface of the formed body piece 45 of the inner shaft forming body 43, as shown in FIGS. 4 to 6, a plurality of (in this embodiment, five) ring-shaped packings 41 are fixed in the vertical axial direction. Are fitted with an interval of.

  Here, as shown in FIG. 4, the inner diameter W1 of the packing 41 is formed to be smaller in diameter by W3 × 2 than the outer diameter W2 of the formed body piece 45 and is fitted to the outer peripheral surface of the formed body piece 45. In such a case, it is deformed into an umbrella shape as shown in FIGS.

  And formed between the packing 41 arranged on the uppermost stage and the flange piece 75 formed on the upper part of the formed body piece 45, between the packings 41, 41, and below the packing 41 arranged on the lowermost stage. On the outer peripheral surface of the body piece 45, a ring-shaped passage regulating body 42 such as earth and sand is arranged.

  In this way, a plurality of ring-shaped packings 41 and sand and sand passage restricting bodies 42 are alternately arranged on the outer peripheral surface of the formed body piece 45 in the axial direction.

  Here, the earth and sand passage restricting body 42 is formed by impregnating a cloth-like material with grease and winding it around the outer peripheral surface of the formed body main piece 45.

  As shown in FIG. 6, when the outer shaft forming body 44 is disposed outside the inner shaft forming body 43, the outer peripheral edge portion of the packing 41 and the outer peripheral edge portion of the earth and sand passage restricting body 42 are outside. The shaft forming body 44 is crimped to the inner peripheral surface in the radial direction.

  The embodiment according to the present invention is configured as described above, and according to the present embodiment, the following operations and effects occur.

  That is, since the packing 41 and the sediment passage restricting body 42 are disposed in the cylindrical space S so as to be crimped in the radial direction, the relative agitating blade body 9 is provided with the excavated sediment in the ground improvement work. Even when the inner shaft 20 and the outer shaft 21 are misaligned due to the resistance received from the passage, the misalignment is prevented by the passage regulating body 42 such as earth and sand and the packing 41 is prevented from being damaged. Can do. As a result, the water stop function of the packing 41 can be ensured satisfactorily.

  At this time, as shown in FIG. 5, the sand and the like passage restricting body 42 enters the kneaded material K of the excavated earth and sand and the solidified material from the lower direction Z between the inner shaft 20 and the outer shaft 21. To prevent it from rising. As a result, the kneaded material K can be prevented from solidifying at a portion between the inner shaft 20 and the outer shaft 21 located above the seal portion 40.

  Then, by replacing the packing 41 of the seal portion 40 and the passage regulating body 42 such as earth and sand as necessary, the kneaded material K is reliably prevented from entering and rising between the inner shaft 20 and the outer shaft 21. Therefore, the excavation shaft body 7 can be reused, and the construction cost can be reduced.

  In addition, since the ring-shaped packing 41 and the passage restriction body 42 such as earth and sand are arranged alternately in the axial direction of the formed body piece 45, the water stopping effect by the packing 41 and the passage restriction body such as earth and sand are provided. The effect of preventing the intrusion / rise of the kneaded material K by 42 can be improved.

  Further, since the passage regulating body 42 such as earth and sand is formed by impregnating a cloth-like material with grease and wound around the outer peripheral surface of the formed body main piece 45, the inner shaft 20 and the outer shaft 21 are formed by grease. When the kneaded material K enters, while the relative reversal rotation property is smoothed, the earth and sand, the solidifying material, and the grease in the kneaded material K are combined to form a cylindrical covering in a semi-solidified state. It is possible to reliably regulate the rise of earth and sand having a relatively large particle size. As a result, it is possible to further improve the water stop effect by the packing 41 and the intrusion / rise prevention effect of the kneaded material by the passage regulating body 42 such as earth and sand.

  Further, the passage regulating body 42 such as earth and sand can be made to rise above the ridge piece 75 in a state where water and a solidifying material (for example, cement) are diluted.

  In this case, even if the diluted water and the solidified material are solidified between the inner shaft 20 and the outer shaft 21, they can be easily separated and discharged only by giving a slight impact to the excavating shaft body 7. .

Explanatory drawing of the ground improvement apparatus which concerns on this invention. The partially cutaway side view of a drilling shaft body and a relative stirring blade body. FIG. Installation explanatory drawing of packing of a seal part. The exploded explanatory view of the seal part. Sediment etc. passage regulation explanatory drawing of packing and earth and sand passage regulation bodies.

Explanation of symbols

A Ground improvement device 1 Base machine 2 Solidified material supply part 3 Base machine body 4 Reader 5 Motor support 6 Drive motor 7 Excavation shaft body 8 Counter rotating gear mechanism 9 Relative stirring blade body
10 Drilling blade

Claims (3)

An excavation shaft body in which the inner shaft and the outer shaft are formed as inner and outer double shafts, and the inner and outer shafts can be rotated in the reverse direction, and the inner agitation blade and the outer agitation blade are provided on the excavation shaft body. In a ground improvement device comprising a relative agitating blade attached to rotate in a reverse direction relative to the inner and outer positions,
A seal portion is provided at a lower portion of the excavation shaft body located above the relative stirring blade body, and the seal portion is formed in a cylindrical space formed between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft. In addition, a ring-shaped packing and a ring-shaped earth and sand passage regulating body for regulating the passage of earth and sand are arranged and configured .
Sediment passage restriction body is made by impregnating a cloth with grease, and the kneaded mixture of excavated earth and sand and solidified material that has penetrated through the cloth is combined with the above grease to form a cylindrical coating in a semi-solid state. A ground improvement device characterized by forming a body . An excavation shaft body in which the inner shaft and the outer shaft are formed as inner and outer double shafts, and the inner and outer shafts can be rotated in the reverse direction, and the inner agitation blade and the outer agitation blade are provided on the excavation shaft body. In a ground improvement device comprising a relative agitating blade attached to rotate in a reverse direction relative to the inner and outer positions,
A seal portion is provided at a lower portion of the excavation shaft body located above the relative stirring blade body, and the seal portion is formed in a cylindrical space formed between the outer peripheral surface of the inner shaft and the inner peripheral surface of the outer shaft. In addition, a ring-shaped packing and a ring-shaped earth and sand passage regulating body for regulating the passage of earth and sand are arranged and configured.
A ground improvement device in which a plurality of ring-shaped packings and passage regulating bodies such as earth and sand are alternately arranged in the axial direction of the excavation shaft body. The seal portion is detachably attached to the inner shaft at the lower part of the excavation shaft body, and an inner shaft forming body that forms a part of the inner shaft, and a part of the outer shaft that is detachably attached to the outer shaft. An outer shaft forming body forming a ring, and a ring-shaped packing disposed in a cylindrical space formed between both inner and outer shaft forming bodies and a passage regulating body such as earth and sand,
The ground improvement device according to claim 1 or 2, wherein the outer shaft forming body is formed by detachably connecting a plurality of divided forming pieces formed by being vertically divided in the axial direction.

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