JP3842775B2 - Ground improvement device and ground improvement method using the same - Google Patents

Description

  The present invention relates to a ground improvement device and a ground improvement method using the same.

Conventionally, as one form of the ground improvement device, a drilling blade body is provided at the lower end portion of the drilling shaft body extending in the vertical direction, and a stirring blade body is provided on the outer peripheral surface of the drilling shaft body located above the drilling blade body. The excavation blade body excavates the ground, and the excavated soil is agitated by the agitating blade body, and the solidification material is discharged from the solidification material discharge portion provided at a predetermined location. There is one in which the ground is improved by kneading and solidifying (see, for example, Patent Document 1).
JP-A-3-63312

  However, in the ground improvement device described above, when the soil excavated by the excavating blade body is kneaded with the solidified material discharged from the solidified material discharge portion while being stirred by the stirring blade body, it is supplied into the excavation hole ( In proportion to the amount of solidified material discharged, a portion of the excavated soil may be discharged from the excavation hole to the ground, but if such soil is not discharged smoothly, As a result, the surrounding surface of the excavation hole is displaced outward (lateral displacement), which adversely affects the existing underground structures around the soil improvement ground. It causes problems such as impact and the ground surface rising.

Therefore, in the present invention, a drilling blade body is provided at the lower end portion of the drilling shaft body that extends in the vertical direction, and a stirring blade body is provided on the outer peripheral surface of the drilling shaft body located above the drilling blade body. The ground is excavated by the body, and the solidified material and the excavated soil are mixed by discharging the solidified material from the solidified material discharging portion provided at a predetermined location while stirring the excavated soil by the stirring blade body. In the ground improvement device designed to improve the ground by solidifying, a ground displacement detection means for detecting the outward displacement of the peripheral surface of the excavation hole is provided, and the outer peripheral surface of the excavation shaft is rotated. The earthing blade body that can be selected from the stop operation is provided, and the earthing blade body is located at the upper position of the outer shaft of the excavation shaft body and above the ground surface in a state not interlocked with the outer shaft. A certain non-interlocking position and the middle part of the outer shaft below the non-interlocking position Between the outer shaft and the interlocking position that is interlocked with the outer shaft, the raising / lowering position can be changed in the vertical direction, and the stop operation is selected at the non-interlocking position, and at the interlocking position The rotation operation is selected, and the rotation operation at the interlocked position is an operation for excavating a part of excavated soil to the ground by excavating while rotating positively integrally with the excavation shaft body. It is possible to discharge a part of the excavated soil to the ground by the rotating action of the soil wing body when the ground displacement detection means detects a displacement greater than the predetermined allowable displacement. A ground improvement device is provided.

  Moreover, this invention has the characteristics also in the following ground improvement construction methods.

(1) The ground is excavated by the excavating blade body provided at the lower end portion of the excavating shaft body extending in the vertical direction, and the excavated soil is agitated by the stirring blade body provided on the outer peripheral surface of the excavating shaft body, and predetermined. a solidifying agent and kneaded with ground improvement construction method to solidify the ejected from solidifying material discharge portion provided in a location,
The earthing blade body is provided on the outer peripheral surface of the excavation shaft body so that the rotation operation and the stop operation can be selected. The earthing blade body is the upper position of the outer shaft of the excavation shaft body and the ground surface. Between the non-interlocking state position that is in the non-interlocking state with the outer shaft and the interlocking state position that is in the middle portion of the outer shaft below the non-interlocking state position and in the interlocking state with the outer shaft. The raising / lowering position can be changed in the vertical direction, the stop operation is selected at the non-interlocking position, and the rotation operation is selected at the interlocking position. The soil is not discharged to the ground by the earth wing body, and the soil is not discharged to the ground by the soil wing body. If a displacement greater than the predetermined allowable displacement is detected for each displacement, By positioning the blade member to the interlock state position by excavation while integrally rotates forward with the drilling shaft, and having a soil discharging step of forcibly discharged to the ground part of the excavated soil Ground improvement method.

(2) Excavation and agitation where the ground is excavated by an excavating blade provided at the lower end of the excavating shaft extending vertically, and the excavated soil is agitated by an agitating blade provided on the outer peripheral surface of the excavating shaft. has a step, a ground improvement method to solidify by kneading a soil excavated with solidified material ejected from the solidifying material discharge portion provided in a predetermined position, the rotation operation to the outer peripheral surface of the drilling shaft The earthing wing body is provided so that it can be selected from the stopping operation and the earthing wing body is located at the upper position of the outer shaft of the excavating shaft body and above the ground surface and is not connected to the outer shaft. The up / down position can be changed in the vertical direction between the non-interlocking state position, which is the interlocking state, and the interlocking state position which is in the middle of the outer shaft below the non-interlocking state position and is interlocking with the outer shaft. And the stop operation is selected at the non-interlocking position, and The rotation operation is selected at a state position, and the excavation / stirring step is performed with a predetermined tolerance for the outward displacement of the peripheral surface of the excavation hole while excavating the ground with the excavation blade body. When a displacement amount greater than the displacement amount is detected, the soil removal blade body is positioned in the interlocked position and moved forward while rotating positively integrally with the excavation shaft body, and the excavated unnecessary soil is removed. An unnecessary soil discharging process forcibly discharging to the ground by the above, and a soil non-discharging process for stopping the excavated soil after discharging the unnecessary soil and not discharging the excavated soil to the ground by the discharging wing body, A ground improvement method characterized by kneading and solidifying a solidified material discharged from a solidified material discharge portion provided at a predetermined location and excavated soil in the soil non-discharge process.

(1) In the present invention described in claim 1, the excavation blade body is provided at the lower end of the excavation shaft body extending in the vertical direction, and the stirring blade body is provided on the outer peripheral surface of the excavation shaft body located above the excavation blade body. The excavated blade body was excavated with the excavating blade body, and the excavated soil was excavated with the solidified material by discharging the solidified material from the solidified material discharge portion provided at a predetermined location while stirring the excavated soil with the stirring blade body. In the ground improvement device adapted to improve the ground by kneading and solidifying the soil, a ground displacement amount detection means for detecting the outward displacement of the peripheral surface of the excavation hole is provided, and the excavation shaft body On the outer peripheral surface, there is provided an earthing blade body that can be selected between a rotating operation and a stopping operation, and the earthing blade body is an upper position of the outer shaft of the excavation shaft body and is located above the ground surface and outside. An unlinked position that is unlinked with the shaft and an outside position below the unlinked position. It is possible to change the raising / lowering position in the up-down direction between the side shaft midway position and the interlocking state position that is interlocking with the outer shaft, and the stop operation is selected at the non-interlocking state position, The rotation operation is selected at the interlocking position,
The rotation operation at the interlocked position is an operation of excavating while rotating positively integrally with the excavation shaft body and forcibly discharging a part of the excavated soil to the ground. When a displacement amount equal to or greater than the displacement amount is detected, a part of the soil excavated by the rotation operation of the soil discharging blade body can be discharged to the ground.

  In this way, when the soil excavated by the excavating blade body is kneaded with the solidified material discharged from the solidified material discharge unit while being stirred by the stirring blade body, it is proportional to the amount of the solidified material discharged. It is sufficient if a part of the soil excavated in this way is discharged from the excavation hole to the ground. However, if the soil is not discharged smoothly, the soil wing body is rotated to Can be forced to discharge to the ground.

  Therefore, when the solidified material is supplied (discharged) into the excavation hole and the contents (soil and solidification material) in the excavation hole increase, the displacement of the peripheral surface of the excavation hole to the outside (lateral displacement) Can be suppressed within an allowable range.

  As a result, it is possible to reliably prevent the occurrence of problems such as adversely affecting existing underground structures provided around the soil-improved ground and the ground surface rising.

(2) this onset light according to claim 2, excavating ground by excavating blade provided at the lower end of the drilling shaft which extends in the vertical direction, provided the excavated soil on the outer peripheral surface of the drilling shaft while stirring by the stirring blade body has, a ground improvement construction method to solidify by kneading a solidifying material ejected from the solidifying material discharge portion provided in a predetermined position, rotation and stop actions in the outer peripheral surface of the drilling shaft The earthing wing body is provided at the upper position of the outer shaft of the excavation shaft body and above the ground surface in a state not interlocked with the outer shaft. The vertical position can be changed in the up and down direction between a certain non-interlocking state position and an outer shaft midway position below the non-interlocking state position and the interlocking state position interlocking with the outer shaft. The stop operation is selected at the non-interlocking position, and the interlocking position is at the position. Being adapted to the rolling operation is selected, the earth removal blade body is stopped in a non-interlocked state position that is above the ground surface, does not discharge excavated soil on the ground by earth removal blade body soil non discharging step In the same soil non-discharge process, when a displacement amount greater than a predetermined permissible displacement amount is detected for the outward displacement of the peripheral surface of the excavation hole, the excavation shaft is positioned at the interlocked position. It has a soil discharging process in which a part of the excavated soil is forcibly discharged to the ground while being excavated while being rotated forward integrally with the body .

  In this way, in the ground improvement process, a soil discharge process and a soil non-discharge process are provided, and if necessary, a part of the soil excavated in the soil discharge process is discharged by the discharging blade body. The displacement to the outside of the hole surface (lateral displacement) can be controlled within the allowable range, and when it is unnecessary, the soil is not discharged in the soil non-discharge process. Occurrence of a problem that the excavation hole collapses due to the surrounding earth pressure can be surely prevented by the proper soil discharge.

(3) this onset light according to claim 3, excavating ground by excavating blade provided at the lower end of the drilling shaft which extends in the vertical direction, provided the excavated soil on the outer peripheral surface of the drilling shaft A ground improvement method in which the solidification material discharged from the solidification material discharge portion provided at a predetermined location and the excavated soil are mixed and solidified. The excavation shaft body is provided with an earthing blade body that is provided with a rotation operation and a stop operation that can be selected. The earthing blade body is an upper position of the outer shaft of the excavation shaft body and the ground. Between the non-interlocking position that is above the surface and not interlocking with the outer shaft, and the interlocking position that is in the middle of the outer shaft below the non-interlocking position and is interlocking with the outer shaft The up / down position can be freely changed in the vertical direction and the stop position is set at the non-interlocking position. The operation is selected, and the rotation operation is selected at the interlocking position, and the excavation / stirring step is performed on the outer side of the peripheral surface of the excavation hole while excavating the ground with the excavation blade body. When a displacement greater than the predetermined permissible displacement is detected , the excavator is excavated by excavating while the earthing blade is positioned in the interlocked position and rotating positively integrally with the excavation shaft. Unnecessarily soil discharging process for forcibly discharging the soil to the ground by the soil discharging blade body,
The soil wing body is stopped after discharging the unnecessary soil, and the soil excavated soil is not discharged to the ground by the soil wing body. The solidification provided at a predetermined place in the soil non-discharge process The solidified material discharged from the material discharge part and the excavated soil are kneaded and solidified.

  In this way, in the excavation and agitation process, for example, when there is unnecessary soil that significantly reduces the solidification effect of the solidified material, such as a humus soil layer, the unnecessary soil is previously grounded in the unnecessary soil discharge process. By discharging in the step, it is possible to satisfactorily ensure the effect of kneading the solidified material and the excavated soil and chemically solidifying them in the subsequent steps.

  And the work of kneading and solidifying the solidified material and excavated soil is done in the soil non-discharge process, so that waste that the solidified material kneaded with soil is discharged to the ground does not occur. As a result, the ground improvement work can be performed effectively and efficiently.

  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. A guide body 12 guides 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 directly 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, by adding a straight intermediate blade piece 27d in the left-right direction to improve the stirring efficiency of excavated soil, by forming the solidification material introduction path 33 in the straight intermediate blade piece 27d, Such a solidifying 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 ends 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.

  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. Inevitably, the excavated soil can be mixed between the two agitating blades 27 and 28, and 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 the earthing blade body 40 that can select the rotation operation and the stopping operation is provided on the outer peripheral surface of the excavation shaft body 7. A part of the soil excavated by the rotating motion can be discharged to the ground.

  Therefore, the ground improvement device A as the first embodiment and the ground improvement method by the ground improvement device A will be described below, and then the ground improvement device A and the ground improvement device A as the second embodiment. Explains the ground improvement method by.

[Ground improvement device as the first embodiment]
As shown in FIG. 1, a soil removal blade 40 provided in the ground improvement device A as the first embodiment includes a cylindrical support piece 41 that covers a part of the outer peripheral surface of the outer shaft 21, and the cylindrical support. An earth discharging blade piece 42 formed in a spiral shape along the axial direction is provided on the outer peripheral surface of the piece 41.

  Then, at the upper end of the cylindrical support piece 41, connecting pin insertion holes 43, 43 are formed in a transverse penetrating shape, while transverse engagement grooves 44, 44 are formed at predetermined locations on the outer peripheral surface of the outer shaft 21. The coupling pin insertion holes 43, 43 are aligned with the transverse engagement grooves 44, 44, and the connection pins 45, 45 with the axis line in the left-right direction can be freely inserted into and removed from the connection pin insertion holes 43, 43. The clutch means C for connecting and releasing the cylindrical support piece 41 to and from the outer shaft 21 by inserting is formed.

  In addition, as shown in FIG. 4 (a), the earth discharging wing body 40 is fitted to the upper portion of the outer shaft 21, and is fixed to the guide body 12 via a fixing pin 46, so that it is not connected to the outer shaft 21. As shown in FIG. 4 (c), it is fitted in the middle of the outer shaft 21 and linked to the outer shaft 21 via the connecting pin 45, as shown in FIG. 4 (c). The position can be freely changed by moving up and down (sliding) in the vertical direction between the outer shaft 21 and the connected state (interlocking state; clutch connection state).

[Ground improvement method as the first embodiment]
Next, a ground improvement method as a first embodiment for performing ground improvement work by the ground improvement device A described above will be described with reference to FIG.

  (1) As shown in FIG. 4 (a), the soil excavated by the excavating blade 10 is solidified and discharged from the first and second solidifying material discharge portions 29 and 32 while being stirred by the relative stirring blade body 9. Kneading with material (ground improvement process).

  At this time, the earth discharging wing body 40 is fixed to the guide body 12 via the fixing pin 46 and is disposed at a position where it is not connected to the outer shaft 21 (not linked).

  Here, a part of the soil excavated in proportion to the amount of the solidified material discharged may be discharged from the excavation hole H to the ground, but the discharge of the soil may not be smoothly performed.

  (2) Then, as shown in FIG. 4 (b), as the contents (soil and solidified material) in the excavation hole H increase, the peripheral surface of the excavation hole H is displaced outward (sideward). When the displacement is detected, the displacement amount is detected by the underground displacement amount detection means 47 disposed in the vicinity of the excavation hole H. The underground displacement amount detection means 47 detects the predetermined allowable displacement amount. When the above displacement amount is detected, as shown in FIG. 4 (c), the excavation shaft body 7 is moved upward by a required width (for example, a width corresponding to approximately half of the vertical width of the earth wing body 40). In the same state, the earth wing body 40 disposed at the upper part of the excavation shaft body 7 is lowered to the vicinity of the surface of the ground G, and the connecting pin insertion holes 43, 43, and connecting the earthing blade body 40 to the outer shaft 21 by inserting the connecting pins 45, 45 having the axis line in the left-right direction into the connecting pin insertion holes 43, 43 (linked state) .

  Subsequently, the fixing pin 46 that fixes the earthing wing body 40 to the guide body 12 is pulled out to release the earthing wing body 40 from being fixed.

  (3) As shown in FIGS. 4 (c) and 4 (d), the excavation shaft body 7 is excavated while being rotated forward, so that the excavation shaft body 7 is integrally rotated with the excavation shaft body 7 while being rotated forward. Let

  Then, a part of the excavated soil is forcibly discharged to the ground by the discharge blade piece 42 of the soil discharge blade body 40 (soil discharge step).

  Accordingly, when the solidified material is supplied (discharged) into the excavation hole H and the contents (soil and solidification material) in the excavation hole H increase, the displacement (side) of the peripheral surface of the excavation hole H increases. Direction displacement) can be suppressed within an allowable range.

  As a result, it is possible to reliably prevent the occurrence of problems such as adversely affecting existing underground structures provided around the soil-improved ground and the ground surface rising.

  (4) As shown in FIG. 4 (e), excavation and agitation work is performed to a predetermined depth, and then the excavation shaft body 7 is pulled up while being inverted.

  At this time, the solidified material is discharged from the first and second solidified material discharge portions 29 and 32, and the excavated soil and the solidified material are kneaded by the relative stirring blade body 9.

  (5) The kneaded soil and the solidified material are solidified.

  Further, when the underground displacement detected by the underground displacement detection means 47 becomes less than a predetermined allowable displacement, the rotation of the excavation shaft 7 is temporarily stopped, and the connecting pins 45, 45 can be pulled out, the connection between the excavation shaft body 7 and the earthing blade body 40 can be released (non-interlocking state), and the earthing blade body 40 can be supported by the guide body 12 (soil non-discharge process). .

  And ground improvement work (ground improvement process) can also be restarted while excavating the excavation shaft 7 in such a state.

  At this time, since the earth discharging wing body 40 is supported by the guide body 12 and is in a rotation stopped state, the excavated soil is not discharged, and the peripheral surface of the excavation hole H is surrounded by excessive soil discharge. It is possible to reliably prevent the occurrence of a problem of collapse due to the earth pressure.

  In the present embodiment, the clutch means C is configured to connect / release the earthing blade body 40 to / from the excavation shaft body 7 by inserting / removing the connecting pins 45, 45. Any structure can be used as long as the rotating operation and the stopping operation of the wing body 40 can be selected, and the structure is not limited to the above.

  5 and 6 show the structure of the clutch means C as another embodiment, and the clutch means C has a tapered guide body whose diameter is increased upward at the upper end portion of the cylindrical support piece 41. 50, and a plurality of (three in this embodiment) sandwiching bodies 51, 51, 51 are fixed in the circumferential direction between the inner peripheral surface 50a of the tapered guide body 50 and the outer peripheral surface 21a of the outer shaft 21. And a taper surface 51a is formed on the outer peripheral surface of each sandwiching body 51 along the inner peripheral surface of the taper guide body 50, and the tapered surface 51a is formed on the inner periphery of the taper guide body 50. It is in contact with the surface 50a.

  And between the bifurcated connecting pieces 53, 53 projecting from the upper part of each sandwiching body 51 and the bifurcated cylinder supporting pieces 54, 54 projecting from the upper part of the cylindrical support piece 41, An electric telescopic cylinder 55 that extends and contracts in the direction is interposed. Reference numerals 56 and 57 denote connecting pins.

  In this way, by extending each telescopic cylinder 55, each clamping body 51 is slid upward and moved between the inner peripheral surface 50a of the tapered guide body 50 and the outer peripheral surface of the outer shaft 21. A gap is formed so that the tapered guide body 50 and the outer shaft 21 can be brought into a non-connected state (non-interlocking state; clutch disengaged state).

  In addition, by shortening each telescopic cylinder 55, each sandwiching body 51 is slid downward so that each sandwiching body is interposed between the inner peripheral surface of the taper guide body 50 and the outer peripheral surface of the outer shaft 21. The taper guide body 50 and the outer shaft 21 can be brought into a connected state (interlocking state; clutch connected state) by interposing 51 in a crimped state.

[Ground improvement device as the second embodiment]
In the ground improvement device A as the second embodiment, as shown in FIG. 7, two earthing blade bodies 40, 40 are disposed below the outer shaft 21 located directly above the relative stirring blade body 9. The lower earthing wing body 40 is connected to the outer shaft 21, and the upper earthing wing body 40 is connected to the outer shaft as necessary, like the earthing wing body 40 of the first embodiment. It is connected to 21 or disconnected.

  In this way, in the ground improvement device A as the second embodiment, unnecessary soil that reduces the solidification effect of the solidification material is forcibly discharged in advance by the soil discharging blade 40, and then, The ground improvement work can be performed efficiently and effectively.

[Ground improvement method as the second embodiment]
Next, a ground improvement method as a second embodiment for performing ground improvement work by the ground improvement device A described above will be described with reference to FIG.

  (1) Before starting the ground improvement work, for example, it is investigated whether or not there is unnecessary soil that significantly reduces the solidification effect of the solidified material, such as the humus soil layer B shown in FIGS. 7 and 8.

  (2) The lengths of the soil removal blades 40, 40 are set to reach the depth of the humus layer B, and both soil removal blades 40, 40 are attached to the outer shaft 21 of the excavation shaft 7. It connects via the connecting pins 45 and 45 (interlocking state).

  (3) As shown in FIG. 8 (a), the ground G is excavated by the excavation blade body 10 provided at the lower end of the excavation shaft body 7 extending in the vertical direction, and the excavated soil D is excavated by the excavation shaft body 7. Is stirred by a relative stirring blade body 9 provided on the outer peripheral surface (excavation / stirring step).

  At this time, the soil discharging blade bodies 40 and 40 rotate integrally with the outer shaft 21 and discharge a part of the soil D excavated by the excavating blade body 10 to the ground (unnecessary soil discharging step).

  Then, if necessary, water can be discharged from the first solidification material discharge part 29 and the second solidification material discharge part 32, and excavation / stirring efficiency can be ensured satisfactorily.

  (4) As shown in FIGS. 8 (b) and 8 (c), the excavation / mixing operation and the soil removal operation are continued until the lower end portion of the lower soil discharge blade 40 reaches the humus layer B (unnecessary soil discharge Process), once the humus soil in the excavation hole H is discharged to the ground and the soil D, which is deeper than the humus soil layer B, is discharged to the ground, the excavation / mixing work and the soil removal work are temporarily stopped. Let

  (5) As shown in FIG. 8 (c), the upper stage discharging wing body 40 is fixed to the guide body 12 through the fixing pin 46, and the connecting pin 45 is pulled out to connect the same earth discharging wing body 40 to the outer shaft. Release connection with 21 (non-linked state).

  At this time, the lower earthing blade body 40 remains connected to the outer shaft 21 via the connecting pin 45.

  (6) As shown in FIG. 8 (d), the excavation / stirring operation is resumed.

  At this time, the solidified material is discharged from the first and second solidified material discharge portions 29 and 32, and the excavated soil and the solidified material are kneaded by the relative stirring blade body 9.

  In the excavation / agitation step, the excavated soil body 40 is not rotated, so that part of the excavated soil D is not discharged to the ground (soil non-discharge step).

  Note that the lower earthing blade body 40 rotates integrally with the outer shaft 21, and conveys a part of the excavated soil D upward, but is discontinuous with the upper earth discharging blade body 40. Therefore, it is not discharged to the ground only by moving in the excavation hole H.

  (7) As shown in FIGS. 8 (d) and 8 (e), excavation and agitation work is performed to a predetermined depth, and then the excavation shaft body 7 is pulled up while being inverted.

  At this time, the solidified material is discharged from the first and second solidified material discharge portions 29 and 32, and the excavated soil and the solidified material are kneaded by the relative stirring blade body 9.

  (8) The kneaded soil and the solidified material are solidified.

  Thus, in the excavation / stirring process, for example, when there is unnecessary soil that significantly reduces the solidification effect of the solidified material, such as the humus soil layer B, the unnecessary soil is previously removed in the unnecessary soil discharging process. By discharging to the ground, it is possible to satisfactorily ensure the effect of kneading the solidified material and the excavated soil and chemically solidifying them in the subsequent steps.

  And the work of kneading and solidifying the solidified material and excavated soil is done in the soil non-discharge process, so that waste that the solidified material kneaded with soil is discharged to the ground does not occur. As a result, the ground improvement work can be performed effectively and efficiently.

  9 and 10 show a modification example of the ground improvement device A according to the second embodiment described above, and a ground improvement method using the ground improvement device A as a modification example.

[Transformation Example 1]
FIG. 9 shows a ground improvement device A as a modified example 1 and a ground improvement method using the same, and the ground improvement device A has the same basic structure as the ground improvement device A as the second embodiment described above. However, the length of one soil wing body 40 is set to reach the depth of the humus soil layer B, and the humus soil layer B in the excavation hole H is discharged by the soil wing body 40. Thereafter, the difference is that the guide body 12 is fixed via the fixing pin 46 in a state where the connection with the outer shaft 21 is released.

  In this way, in the kneading step, the load on the soil removal blade body 40 during the kneading can be reduced by completely releasing the connection of the soil discharge blade body 40 from the outer shaft 21.

[Transformation example 2]
FIG. 10 shows a ground improvement device A as a modification example 2 and a ground improvement method using the ground improvement device A. The ground improvement device A has the same basic structure as the ground improvement device A as the second embodiment described above. However, the length of one earthing wing body 40 is set to a length that reaches the depth of the humus soil layer B, and the earthing wing body 40 is connected to and fixed to the outer shaft 21. The difference is that the humus soil layer B in the excavation hole H is discharged by the earth discharging blade body 40, and thereafter excavation, agitation, and kneading operations are performed while being connected to the outer shaft 21.

  In this manner, the humus soil is surely discharged, and the work of releasing the connection of the soil discharging blade body 40 can be saved, thereby improving the work efficiency.

Side explanatory drawing of the ground improvement apparatus which concerns on this invention as 1st Embodiment. The partially cutaway side view of a drilling shaft body and a relative stirring blade body. FIG. Process explanatory drawing of ground improvement work. The sectional top view of the clutch means as other embodiments. FIG. 6 is a cross-sectional view taken along the line I-I in FIG. 5. Side surface explanatory drawing of the ground improvement apparatus which concerns on this invention as 2nd Embodiment. Process explanatory drawing of the ground improvement work by the ground improvement apparatus. Process explanatory drawing of the ground improvement operation | work by the ground improvement apparatus as the modification example 1. FIG. Process explanatory drawing of the ground improvement work by the ground improvement apparatus as the modification example 2. FIG.

Explanation of symbols

A Ground improvement device G Ground 1 Base machine 2 Solidification material supply part 3 Base machine body 4 Leader

Claims (3)

A drilling blade is provided at the lower end of the drilling shaft extending in the vertical direction, a stirring blade is provided on the outer peripheral surface of the drilling shaft located above the drilling blade, and the ground is excavated by the drilling blade. The ground is improved by mixing the solidified material and the excavated soil by solidification by discharging the solidified material from the solidified material discharge part provided at a predetermined location while stirring the excavated soil with the stirring blade body. In the ground improvement device designed to perform
A ground displacement detection means is provided to detect the outward displacement of the outer surface of the excavation hole, and an earth wing body is provided on the outer peripheral surface of the excavation shaft so that rotation and stop operations can be selected. ,
The earthing blade body is an upper position of the outer shaft of the excavation shaft body, an unlinked position that is above the ground surface and is unlinked with the outer shaft, and an outer shaft below the unlinked position. It is possible to change the raising / lowering position in the vertical direction between the intermediate position and the interlocking position that is interlocked with the outer shaft, and the stop operation is selected at the non-interlocking position, and the interlocking state The rotation operation is selected by position,
The rotation operation in the interlocking position is an operation for excavating while rotating forward integrally with the excavation shaft body and forcibly discharging a part of the excavated soil to the ground.
When a displacement amount greater than a predetermined allowable displacement amount is detected by the underground displacement amount detection means, a part of the soil excavated by the rotating operation of the soil wing body can be discharged to the ground. Ground improvement device. The ground is excavated by the excavating blade provided at the lower end of the excavating shaft extending in the vertical direction, and the excavated soil is agitated by the agitating blade provided on the outer peripheral surface of the excavating shaft and provided at a predetermined location. a solidified material ejected from the solidifying material discharge unit and kneaded ground improvement construction method to be solidified,
It uses the earthing blade that is provided on the outer peripheral surface of the excavation shaft so that rotation and stop can be selected .
The earthing blade body is an upper position of the outer shaft of the excavation shaft body, an unlinked position that is above the ground surface and is unlinked with the outer shaft, and an outer shaft below the unlinked position. The raising / lowering position can be changed in the vertical direction between the intermediate position and the interlocking position that is interlocked with the outer shaft, and the stop operation is selected at the non-interlocking position. The rotation operation is selected with
A soil non-discharge process in which the soil wing body is stopped at a non-interlocking position above the ground surface, and the excavated soil is not discharged to the ground by the soil wing body;
In the same soil non-discharge process, when a displacement greater than a predetermined permissible displacement is detected for the outward displacement of the peripheral surface of the excavation hole, the excavation shaft body A ground improvement method characterized by having a soil discharging process in which a part of excavated soil is forcedly discharged to the ground by excavating while rotating forward integrally . Excavation and agitation processes are provided in which the ground is excavated by the excavating blade provided at the lower end of the excavating shaft extending in the vertical direction, and the excavated soil is agitated by the agitating blade provided on the outer peripheral surface of the excavating shaft. And
A ground improvement method for solidifying by solidifying the solidified material discharged from the solidified material discharge part provided at a predetermined location and the excavated soil ,
It uses the earthing blade that is provided on the outer peripheral surface of the excavation shaft so that rotation and stop can be selected .
The earthing blade body is an upper position of the outer shaft of the excavation shaft body, an unlinked position that is above the ground surface and is unlinked with the outer shaft, and an outer shaft below the unlinked position. The raising / lowering position can be changed in the vertical direction between the intermediate position and the interlocking position that is interlocked with the outer shaft, and the stop operation is selected at the non-interlocking position. The rotation operation is selected with
The excavation / stirring step is performed when a displacement amount greater than a predetermined allowable displacement amount is detected with respect to the outward displacement of the peripheral surface of the excavation hole while excavating the ground with the excavation blade body. An unnecessary soil discharging step of forcibly discharging the excavated unnecessary soil to the ground by the discharging wing body, and digging while positively rotating integrally with the excavating shaft body .
A soil non-discharge process in which the soil wing body is stopped after unnecessary soil discharge, and the excavated soil is not discharged to the ground by the soil wing body,
A ground improvement method characterized by kneading and solidifying a solidified material discharged from a solidified material discharge portion provided at a predetermined location and excavated soil in the soil non-discharge process.

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