JP2005307675A - Ground improving construction method and ground improving machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ground improving construction method and a ground improving machine for performing construction comparatively easily by reducing operator's burden. <P>SOLUTION: A mixing and stirring head 5 mounted at a tip of an arm 4 of a base machine 1 is inserted into the ground, and the mixing and stirring head 5 excavates and moves in the lateral direction while digging soil at an original position and mixing and stirring solidifying agent to construct an improved wall body 23 in the ground. At this time, the following processes (a), (b) are alternately repeated: (a) a non-running excavation process in which the direction of construction of the improved wall body 23 and the direction of running of the base machine 1 are parallel and the mixing and stirring head 5 excavates and moves in the direction of construction of the improved wall body 23 in the ground using degree of freedom of turn of the arm 4 in a non-running condition of the base machine 1, and (b) a non-excavation running process in which the base machine 1 itself runs and moves in parallel with the direction of construction of the improved wall body 23 and in the direction of excavation and moving of the mixing and stirring head 5 instead of procedures in the non-running excavation process. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a ground improvement method and a ground improvement machine, and in particular, with a shovel type excavator as a base machine, a mixing type equipped with a chain-type mixing agitating blade that moves in a vertical direction around the arm tip of the base machine. After installing the mixing head and penetrating the mixing stirring head into the ground, in addition to discharging the solidified material, excavating the original soil with the mixing stirring blade and mixing and stirring the original soil and the solidified material The present invention relates to a ground improvement method and a ground improvement machine for constructing a continuous improved wall body in the ground by moving a mixing stirring head in a lateral direction.

  As a technique related to this kind of ground improvement, for example, as described in Patent Document 1, stirring mixing in which an endless chain having stirring blades is wound around the tip of an arm of a shovel excavation machine that functions as a base machine. Assuming the use of a ground improvement machine equipped with a head that can swing and swivel, when constructing a polygonal cylindrical (improved) structure in the ground, the center position of the area that should become the cylindrical structure With the base machine in a stationary state, a cylindrical shape is obtained by using both the moving movement in the longitudinal direction of one side of the polygon and the swinging movement in parallel with the penetration and extraction of the stirring and mixing head into the ground. The vertical wall is constructed at a position corresponding to one side of the structure, and the vertical wall that is continuous with the existing vertical wall is constructed sequentially by repeating the above vertical wall construction process multiple times. Many In the method to construct the shape of the tubular structures have been proposed.

In addition, the fixed position of the base machine and the mixing agitation head is fixed without using the above swing function, and the mixing agitation head is moved along with the base machine to form a linear wall as an underground continuous wall. It is said that it is possible to build an improved wall body in the ground.
JP 2004-108136 A (FIGS. 10 to 13)

  However, in order to construct a polygonal cylindrical structure like the former in the ground, it is not necessary to continuously run the base machine itself, but in parallel with continuously turning the arm of the base machine. The mixing and stirring head needs to be swung and swung in real time, which not only places a heavy burden on the operator, but also makes it difficult to maintain the straightness of the vertical wall corresponding to one side of the cylindrical structure to be constructed.

  In addition, when constructing a straight improved wall as an underground continuous wall like the latter, the arm itself and the mixing and stirring head do not need to be swiveled, but the base machine itself is always kept at a very low speed. In particular, it is difficult to synchronize the running of the base machine itself and the excavating movement of the mixing and stirring head, and even in this case, it is difficult to maintain the straightness of the improved wall to be constructed. there were.

  The present invention has been made paying attention to such a problem, and is intended to provide a ground improvement method and a ground improvement machine that can reduce the burden on the operator and can perform the construction relatively easily. .

  The invention according to claim 1 uses a shovel type excavator as a base machine, and attaches a mixing agitation head provided with a chain-type agitation agitating blade in the vertical direction to the tip of the arm of the base machine. After the agitation head has penetrated into the ground to a predetermined depth, the mixing agitation head is mixed while discharging the solidified material and excavating the in situ soil with a mixing agitating blade and mixing and agitation of the in situ soil and the solidified material. The ground improvement that builds a continuous improved wall body corresponding to the width dimension of the orbiting moving surface of the mixing stirring blade in the ground by moving the stirring blade laterally digging with the orbiting moving surface from the top to the bottom as the excavation surface It is assumed that it is a construction method.

  In addition, the following (a) non-traveling excavation step and (b) non-digging travel step are alternately repeated.

  (A) After setting the direction in which the improved wall is to be constructed and the traveling direction of the base machine to be substantially parallel, the mixing agitation head is grounded using the degree of freedom of arm rotation when the base machine is not traveling. Non-traveling excavation process in which excavation moves in the direction of construction of the improved wall.

  (B) Instead of digging and moving the mixing agitation head using the degree of freedom of arm rotation, non-digging is performed in which the base machine itself travels in the digging movement direction of the mixing and agitation head substantially parallel to the construction direction of the improved wall body. Traveling process.

  In this case, as described in claim 2, the base machine is a crawler type, and in the non-traveling excavation process, the degree of freedom of raising and lowering the arm in addition to the degree of freedom of turning of the upper swivel base in the base machine is set. In the non-digging traveling process, while the excavation by the mixing agitation head is stopped, the base machine itself is only approximately the same distance as the traveling distance of the mixing agitating head in the non-traveling digging process. Moving and moving is desirable for improving the construction quality.

  More preferably, as described in claim 3, both of the one traveling movement distance of the mixing agitation head in the non-traveling digging process and the one traveling movement distance of the base machine in the non-digging traveling process are both in plan view. The arm turning angle should be within 30 degrees.

  In the construction under the ground improvement method according to any one of claims 1 to 3, as described in claim 4, the mixing agitation head is used by using the degree of freedom of rotation of the arm in the non-traveling excavation process. Is moved in the direction of construction of the improved wall body in the ground, the entire moving surface of the mixing stirring blade does not deviate from the region where the improved wall body should be constructed, and the axis of the arm in plan view And a ground improvement machine in which the mixing and stirring head is fixedly supported with respect to the arm tip of the base machine so that the circumferentially moving surfaces of the mixing and stirring blades are parallel or form a predetermined angle.

  In this case, as described in claim 5, when the mixing agitation head is directly attached to the arm tip of the base machine, the axis of the arm in a plan view and the circumferential moving surface of the mixing agitation blade are substantially perpendicular to each other. It is desirable that the mounting agitation head is fixedly supported on the arm tip by interposing an intermediate bracket between the mounting bracket and the arm tip.

  Therefore, in at least the first aspect of the invention, the continuous improved wall body which is the underground wall is constructed by alternately and continuously repeating the non-traveling excavation process and the non-digging travel process as described above. However, for example, when trying to construct a straight improvement wall body, the non-traveling excavation process involves a pivoting movement of the arm, and therefore the movement path of the mixing and stirring head is locally linear. Similarly, in the non-digging traveling process, the mixing agitation head is moved on the base machine side while being in a fixed position, and accordingly, the attitude of the mixing agitation head slightly changes and is strictly as described above. In this case, the movement locus of the mixing and stirring head is not locally linear. Even if these movement trajectories have local meandering or undulation due to the local non-linearity of the movement trajectory of the mixing and stirring head, the linearity of the constructed improved wall body as a whole Is sufficiently secured.

  In particular, as described in claims 2 and 3, by making the travel distance of the mixing agitation head in the non-traveling digging process equal to the travel distance of the base machine in the non-digging travel process. The above-mentioned local meandering or swell repetition pitch becomes equal, which is preferable in ensuring the linearity of the improved wall as described above.

  According to the first aspect of the present invention, it is possible to perform construction relatively easily even by an operator who does not have skill by simply repeating the non-traveling excavation process and the non-digging traveling process alternately. In addition to cost reduction, for example, when constructing a straight improved wall body, the linearity of the entire improved wall body is ensured, so that there is an advantage that the construction quality does not deteriorate.

  In particular, as described in claims 2 and 3, by making the digging movement distance of the mixed stirring head in the non-digging digging process and the running movement distance of the base machine in the non-digging digging process both equal, There is an advantage that it becomes easier to ensure the linearity of the entire improved wall body when constructing the improved wall body.

  According to invention of Claim 4, 5, there exists an advantage which can implement easily the construction method which repeats a non-traveling excavation process and a non-digging traveling process alternately.

  FIGS. 1-12 is a figure which shows the more concrete embodiment of the ground improvement construction method and the ground improvement machine suitable for the ground improvement construction method which concern on this invention.

  In particular, FIG. 1 shows the overall structure of a ground improvement machine. As shown in the figure, the ground improvement machine is an endless track (crawler) excavator excavation machine that is one of general-purpose construction machines, such as a crawler track. A hydraulic excavator or backhoe having 1a is formed as a base machine (base machine) 1, and the tip of a tiltable boom 3 mounted on a swing base 2 as an upper swing body is also tiltable. Further, a so-called trencher type mixing agitating head 5 for excavating the in-situ soil and mixing agitation with the solidified material (ground improvement material) is attached to the end of the arm 4 as described later. 6 is detachably mounted.

  2 and 3, the stirring and mixing head 5 winds an endless drive chain 10 between an upper driving wheel 8 and a lower driven wheel 9 of a prismatic frame 7 extending in the vertical direction, A plurality of mixing stirring blades 11, 11,... Described later are mounted at the outer periphery of the drive chain 10 at equal pitches, and a solidified material discharge device 12 is provided at the tip of the frame 7, for example, The slurry-like solidified material that has been pumped by a pump (not shown) and supplied via the pipe 13 is discharged from the solidified material discharge device 12. Then, the mixing agitating blades 11, 11... Move together with the drive chain 10 by starting the hydraulic motor 14 provided in the upper part of the frame 7 and capable of rotating in the forward and reverse directions. The mixing agitation head 5 penetrates into the ground, and the mixing agitation process with the solidified material is performed together with the excavation of the in-situ soil as will be described later.

  The drive chain 10 is guided by a guide roller 15 provided on the frame 7 and is given a predetermined tension by a tension roller 17 supported by a leaf spring 16 on the frame 7 side. The drive wheel 8 for driving the drive chain 10 to circulate needs to be a chain sprocket that meshes with the drive chain 10, but the driven wheel 9 does not necessarily need to be a chain sprocket.

  An attachment bracket 19 having a connection hole 18 is connected to the upper end of the frame 7 which is a main element of the mixing and stirring head 5, and the attachment bracket 19 can be attached to and detached from the tip of the arm 4 of the base machine 1. In addition, an intermediate bracket 6 that is 90 degrees out of phase with the mounting bracket 19 can be connected to the mounting bracket 19, and the intermediate bracket 6 can also be attached to and detached from the tip of the arm 4 of the base machine 1. It has become. Thus, when the mounting bracket 19 is directly connected to the arm 4 of the base machine 1 and when the intermediate bracket 6 connected to the mounting bracket 19 is connected to the arm 4 of the base machine 1, the mixing and stirring head for the arm 4 is used. As the mounting orientation of 5, the orientation can be varied by 90 degrees in plan view.

  Here, the plurality of mixing stirring blades 11, 11,... Mounted on the drive chain 10 have a plurality of cutting blades 20, a front side auxiliary blade 21 and a back side auxiliary blade 22 as shown in FIG. As shown in FIG. 9, nine types of A to I in total are prepared by mixing the cutting blades 20 and the auxiliary blades 21 and 22 with their numbers and positions slightly different from each other. The agitating blades 11, 11,... Are mounted on the entire circumference of the drive chain 10 at a constant pitch in a specific order.

  Next, a procedure for constructing a substantially straight improved wall body 23 having a predetermined depth in the ground in the plan view shown in FIG. 6 using the above ground improvement machine will be described.

  First, set the traveling direction B by the crawler belt 1a of the base machine 1 to be parallel to the longitudinal direction of the improved wall body 23 to be constructed, and at the same time, the plane of the boom 3 and the arm 4 with respect to the traveling direction B As shown in FIG. 7A, the mixing and agitation head 5 is in an upright state. Position so that Further, since the position of the improved wall body 23 to be constructed is displayed on the ground surface with white lines such as lime, as shown in FIG. 6, the tip of the mixing and stirring head 5 in the plan view (farthest from the base machine 1 side). The surface) is matched with one surface 23a (corresponding to a normal line when the improved wall to be built has a predetermined curvature) 23a at the construction start position of the improved wall 23.

  As a result, portions corresponding to the tight side and the loose side of the drive chain 10 in the mixing and stirring head 5, that is, the circumferentially moving surfaces of the mixing and stirring blades 11, 11,... Coincide with the position of the improved wall body 23 to be constructed. Will do.

  In this state, that is, in the non-running stop state of the base machine 1, the drive chain 10 of the mixing and stirring head 5 is driven forward and backward as shown in FIG. 8, and the mixing and stirring blades 11, 11,. While repeating forward rotation and reverse rotation alternately, a penetration thrust is applied to the mixing and stirring head 5 using the degree of freedom of raising and lowering the boom 3 and arm 4 of the base machine 1, and the mixing and stirring head 5 is left in its original position. It penetrates into the ground.

  Then, if the mixing and stirring head 5 has penetrated to a predetermined depth as shown in FIG. 7B while maintaining the state of FIG. 6, the drive chains 11, 11,. In the construction direction of the improved wall body 23 as shown in FIG. 9 (A), the base machine 1 itself is stopped and moved in the direction B in parallel with the longitudinal direction of the improved wall body 23 to be constructed. The position of the base machine 1 is more advanced than the position of the mixing and stirring head 5, that is, the axis in the plan view of the boom 3 and the arm 4 of the base machine 1 is the initial 0 degree position (in FIGS. 6 and 9). The base machine 1 is traveled and moved by a predetermined amount so that the position is about +15 degrees with respect to the state (B).

  In this state, the drive chain 10 of the mixing and agitating head 5 is again driven to rotate. At this time, as shown in FIG. 10, unlike the previous case, the drive chain 10 is driven to rotate forward, and the mixing stirring blade 11 that faces the construction direction of the improved wall body 23 (traveling direction B of the base machine 1), 11 are rotated so that the mixing stirring blades 11, 11... Rotate around from the upper side to the lower side. As a result, the mixing stirring blades 11, 11,... Are arranged on the side of the one orbiting moving surface 24 of the mixing stirring blades 11, 11,... That face the construction direction of the improved wall body 23 (traveling direction B of the base machine 1). The in-situ soil is positively excavated, and the in-situ excavated soil is mixed and agitated with the solidified material while being fed to the circumferentially moving surface side of the mixing agitating blades 11, 11. The digging force which tries to advance positively in the construction direction of the improved wall body 23 is generated in itself.

  In parallel with the excavation state by the mixing and agitation head 5, the boom 3 and the arm 4 of the base machine 1 pass through the previous 0 degree position as shown in FIGS. 9B and 9C. Then, the turning base 2 is swung at a low speed by an angle of about 30 degrees as a whole until reaching the position of FIG. As a result, an improved wall body 23 corresponding to the width dimension of the mixing and stirring head 5 is constructed in the portion through which the mixing and stirring head 5 has passed. In the present embodiment, such a construction process is called a non-traveling excavation process.

  In this case, as shown in FIGS. 9B and 9C, the tip of the mixing and stirring head 5 in a plan view does not protrude from one side surface 23a of the improved wall body 23 to be constructed. Further, the position of the mixing and stirring head 5 is controlled using the degree of freedom of raising and lowering the boom 3 and the arm 4. As described above, when the boom 3 and the arm 4 of the base machine 1 are swung about 30 as a whole, that is, the boom 3 and the arm 4 of the base machine 1 are swung by the distance b in the construction direction of the improved wall body 23. 9 (C), the mixing and stirring head 5 precedes the base machine 1 itself by about 15 degrees in the construction direction of the improved wall body 23 (-15 described above). Degree position).

  In this way, when the mixing and stirring head 5 reaches the position shown in FIG. 9C, the drive operation of the drive chain 10 and the mixing and stirring blades 11 and 11 in the mixing and stirring head 5 is temporarily stopped. Then, with the mixing and stirring head 5 left in its position, as shown in FIG. 11, the base machine 1 itself travels in the construction direction in parallel with the improved wall body 23 to be constructed. The traveling movement distance c at this time is set to a distance equivalent to the turning movement distance b of the previous mixing and stirring head 5 (see FIG. 9C). In the present embodiment, such a construction process is referred to as a non-digging traveling process. In this way, by moving the base machine 1 by the distance c with respect to the mixing and stirring head 5 in the stopped state to the state shown in FIG. 11B, this position is changed to that shown in FIG. That is, the same state as the position (position of +15 degrees) is reproduced.

  And after that, the above-mentioned non-traveling excavation process and the non-excavating travel process are alternately and continuously repeated to construct the improved wall body 23 in the ground. When the work is temporarily interrupted, such as when the construction work for one day is completed, the mixing and stirring head 5 is pulled up on the ground as shown in FIG. This is because in the improved wall body 23 that has already been constructed, consolidation by the solidifying material proceeds with time.

  In FIG. 12, the principal part top view of the improved wall body 23 constructed | assembled by alternately repeating the above non-traveling excavation processes and a non-excavating traveling process is shown. When the mixing agitating head 5 is swung together with the boom 3 and the arm 4 in the non-traveling excavation process, as described above, a part of the circumferential moving surface 24 that is the tip of the mixing agitating head 5 should be constructed. Since it manages so that it may not protrude from one side surface 23a of the wall body 23, on the other side surface 23b side, on the other side surface 23b side, the linearity on the one side surface 23a of the improved wall body 23 becomes good. The effect of the trajectory when the mixing stirring head 5 is swung together with the boom 3 and the arm 4 being an arc-shaped trajectory, that is, an improved wall to be constructed by a part of the orbiting moving surface 24 that is the tip of the mixing stirring head 5 Due to the projection from the other side surface 23b of the body 23, it does not become a linear shape, and the other side surface 23b side has a shape with local meandering or undulation as shown in FIG. However, even if the local linearity on the other side surface 23b side is not ensured, the linearity in the longitudinal direction of the improved wall body 23 as a whole is sufficiently ensured. It will never be.

  Here, as apparent from FIG. 12, the width dimension (width) of the constructed improved wall body 23 is the same as that on the other side face 23b side as described above with the width dimension of the mixing and stirring head 5 as the minimum width dimension W1. However, it is desirable in terms of workability and economical efficiency that the average width dimension W2 does not exceed 115%. In the non-traveling excavation process, the above requirement can be satisfied if the range in which the mixing and stirring head 5 is swung together with the boom 3 and the arm 4 is about 30 degrees as described above.

  FIG. 13 shows a second embodiment of the present invention.

  In the previous first embodiment, when the mixing stirring head 5 is swung in the non-traveling excavation process, the tip of the mixing stirring head 5 does not protrude from one side surface 23a of the improved wall body 23 to be constructed. In contrast, in the second embodiment, the center of the mixing and stirring head 5 in the plan view is always positioned on the center line C1 that bisects the width of the improved wall body 23. The construction was done while doing so.

  In this case, meandering or undulation occurs on both surfaces 23a and 23b of the improved wall body 23 constructed as shown in FIG. 14, but the reason is the same as in the first embodiment. Thus, the linearity in the longitudinal direction of the constructed improved wall body 23 as a whole is sufficiently ensured.

  FIG. 15 shows a third embodiment of the present invention.

  In this embodiment, when the improved wall body 23 is constructed in the ground in the vicinity of the existing house 25, in order to keep the base machine 1 as far as possible from the house 25, the axes of the boom 3 and the arm 4 in plan view are arranged. On the other hand, the mixing and stirring head 5 is attached to the tip of the arm 4 so that the circumferential moving surface 24 of the mixing and stirring blades 11, 11. This mounting form can be easily realized by using a type whose phase is shifted by 45 degrees with respect to the mounting bracket 19 on the side of the mixing and stirring head 5 instead of the intermediate bracket 6 shown in FIGS.

  Assuming that such a mixing and agitation head 5 is mounted, the traveling direction B of the base machine 1 by the crawler belt 1a is set parallel to the longitudinal direction of the improved wall body 23 to be constructed, as shown in FIG. On the other hand, the mixing and stirring head 5 is positioned at the construction start position of the improved wall body 23 in a state where the axes of the boom 3 and the arm 4 in a plan view are inclined so as to have a 45 degree relationship with the traveling direction B. . Similarly to the first embodiment, when the base machine 1 is stopped, the drive chain 10 and the mixing stirring blades 11, 11...

  Thereafter, as in the first embodiment, as a non-traveling excavation step, the mixing and stirring head is configured with the orbiting moving surface 24 in which the moving direction of the mixing stirring blades 11, 11,. 5, while excavating the in-situ soil and mixing and agitation of the solidified material, the mixing agitation head 5 is lowered to about 30 degrees together with the boom 3 and the arm 4 by using the degree of freedom of rotation of the swivel base 2 of the base machine 1. 15B, the improved wall body 23 is constructed in the part through which the mixing and stirring head 5 has passed. In this case, the center of the mixing and stirring head 5 in plan view during the turning operation is managed so as to be always located on the center line C1 that bisects the width dimension of the improved wall body 23.

  When the mixing and stirring head 5 is in the state shown in FIG. 15B, the rotation of the mixing and stirring blades 11 and 11 and the swirling operation of the mixing and stirring head 5 are temporarily stopped at that position.

  Then, as the non-digging traveling process, the base machine 1 is caused to travel by a predetermined amount in the construction direction of the improved wall body 23 from the state of FIG. The vehicle is moved by a distance equal to the amount of movement, and the angle formed by the traveling direction B of the base machine 1 and the axes of the boom 3 and the arm 4 in plan view is about 45 degrees in exactly the same manner as in FIG. Reconfigure as follows.

  Thereafter, the improved wall body 23 is constructed by alternately and continuously repeating the non-traveling excavation process and the non-excavating travel process. In this case, as described above, in the non-traveling excavation process, the center of the mixing and stirring head 5 in a plan view during the turning operation is always positioned on the center line C1 that bisects the width dimension of the improved wall body 23. By managing, the improved wall body 23 is constructed in such a manner that the both side surfaces meander or swell, as in FIG.

  According to this embodiment, it becomes possible to remarkably suppress noise and vibration that will be exerted on the house 25 side with the construction of the improved wall body 23.

Side explanatory drawing which shows the whole structure of the ground improvement machine which concerns on this invention. FIG. 2 is an enlarged explanatory view showing details of the mixing and stirring head of FIG. 1. Side surface explanatory drawing of FIG. It is an enlarged view which shows the detail of the mixing stirring blade in FIG.2, 3, (A) is a front view, (B) is a top view of the figure (A), (C) is a right view of the figure (A). Explanatory drawing which shows the arrangement | sequence of the mixing stirring blade in FIG. Plane explanatory drawing at the time of starting construction of an improved wall. FIG. 7A is a side view of FIG. 6, and FIG. 7B is a side view showing a state in which the mixing and stirring head has penetrated into the ground from the state of FIG. The front view in the middle of penetration of (B) of Drawing 7. (A)-(C) Plane explanatory drawing which shows the construction procedure of the improved wall body from the state of (B) of FIG. The front view in the state of (A) of FIG. 9, (B). Plane | planar explanatory drawing which shows the construction procedure of the improved wall body following the state of (C) of FIG. FIG. 12 is an enlarged plan explanatory view of an improved wall constructed in the procedure of FIGS. 9 and 11. It is a figure which shows the 2nd Embodiment of this invention, (A)-(C) Plane explanatory drawing which shows the construction procedure of an improved wall body. Explanatory drawing of an expansion plane of the improved wall body constructed | assembled in the procedure of FIG. It is a figure which shows the 3rd Embodiment of this invention, (A), (B) Plane explanatory drawing which shows the construction procedure of an improved wall body.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base machine 1a ... Crawler belt 2 ... Turning base (upper turning body)
DESCRIPTION OF SYMBOLS 3 ... Boom 4 ... Arm 5 ... Mixing stirring head 6 ... Intermediate bracket 10 ... Drive chain 11 ... Mixing stirring blade 23 ... Improved wall body 24 ... Circulation moving surface

Claims (5)

Using an excavator excavator as a base machine, a mixing agitation head equipped with a chain-type mixing agitation blade that moves in the vertical direction is attached to the tip of the arm of the base machine. After intrusion, the mixing stirrer circulates from the top to the bottom while discharging the solidified material and excavating the original soil with the mixing stirrer blade and mixing the original soil with the solidified material. It is a ground improvement method to construct a continuous improved wall body corresponding to the width dimension of the orbiting moving surface of the mixing stirring blade in the ground by digging and moving in the lateral direction with the moving surface as the excavation surface,
The ground improvement construction method characterized by alternately repeating the non-traveling excavation process of the following (a) and the non-excavating travel process of (b).
(A) After setting the direction in which the improved wall is to be constructed and the traveling direction of the base machine to be substantially parallel, the mixing agitation head is grounded using the degree of freedom of arm rotation when the base machine is not traveling. Non-traveling excavation process in which excavation moves in the direction of construction of the improved wall.
(B) Instead of digging and moving the mixing agitation head using the degree of freedom of arm rotation, non-digging is performed in which the base machine itself travels in the digging movement direction of the mixing and agitation head substantially parallel to the construction direction of the improved wall body. Traveling process. The base machine is a crawler type,
In the non-traveling digging process, the mixing agitation head is digged and moved using the degree of freedom of raising and lowering the arm in addition to the degree of freedom of turning of the upper swivel base in the base machine,
In the non-digging traveling process, the base machine itself is caused to travel by approximately the same distance as the digging movement distance of the mixed stirring head in the non-traveling digging process in a state where the digging by the mixed stirring head is stopped. The ground improvement construction method according to claim 1.   The one advancing travel distance of the mixing agitating head in the non-traveling excavation process and the one travel travel distance of the base machine in the non-advancing traveling process are both within 30 degrees as the turning angle of the arm in plan view. The ground improvement construction method according to claim 2, wherein the ground improvement construction method is used. A ground improvement machine for use in the ground improvement method according to any one of claims 1 to 3,
In the non-traveling excavation process, when the mixing agitation head is excavated and moved in the ground in the direction of construction of the improved wall using the degree of freedom of arm rotation, the entire moving surface of the mixed agitating blade builds the improved wall. The mixing and stirring head is fixed to the tip of the arm of the base machine so that it does not deviate from the area to be processed and the axis of the arm in plan view is parallel to the orbiting surface of the mixing and stirring blade or both form a predetermined angle. A ground improvement machine characterized by being supported. The mixing agitation head includes a mounting bracket so that the axis of the arm in a plan view and the circumferential movement surface of the mixing agitation blade are substantially perpendicular when mounted on the arm tip of the base machine directly,
The ground improvement machine according to claim 4, wherein the mixing agitation head is fixedly supported on the arm tip by interposing an intermediate bracket between the mounting bracket and the arm tip.

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