JP7309665B2 - Wing excavator and wall pile construction method - Google Patents

Description

The present invention relates to a wing excavator and a wall pile construction method.

As a method of strengthening the bearing capacity of wall piles such as continuous underground walls, a method of forming a widened portion (or a widened bottom portion or an extended portion) on one or both of the two wide surfaces of the wall pile (one side widened bottom, double bottom widened) is mentioned. With this widened portion, it is possible to increase the pull-out resistance of the wall pile in addition to increasing the bearing capacity of the wall pile. Therefore, a wall pile having a widened portion is suitable as a foundation pile for a high-rise building, a super-high-rise building, a high-rise tower, or the like, which has a large aspect ratio, a prominent overturning moment, and a high-rise tower. In addition, this widened portion is sometimes referred to as a "projection" or "node", and a plurality of protruding or node-shaped widened portions are intermittently formed in the extending direction of the wall perpendicular to the wall thickness direction. and a form in which a widened portion is formed continuously in the extending direction of the wall.

Conventionally, various construction methods for wall piles having the widened portions have been proposed. One construction method includes a kelly bar that rotates about a vertical axis, and a bucket that is attached to the tip of the kelly bar and rotates with the rotation of the kelly bar to excavate the ground. This is a pile construction method for constructing a pile having a knot-shaped extension using. More specifically, a step of inserting a closed bucket into a pre-formed borehole, and repeating forward and reverse rotation of the kelly bar within a predetermined angle range while opening the bucket allows the bucket to enter the borehole. A step of excavating a part of the wall surface to form an expansion space corresponding to the knot-like expansion, and placing concrete in the excavation hole to form a pile having the knot-like expansion. (see Patent Document 1, for example).
Another construction method includes a shaft portion having a rectangular column portion with a rectangular planar shape, and an enlarged bottom portion with a circular planar shape in which the bottom portion of the shaft portion is enlarged in the support layer of the ground, and the enlarged bottom portion is the shaft portion. A method of constructing a pile configured to expand laterally over the entire circumference at the bottom of a pile. More specifically, it includes a first step of drilling a hole for forming the shaft, and a second step of enlarging the bottom of the hole after the first step. In the first step, an excavator body suspended from the ground, an excavating tooth provided on the excavator body and rotating around a horizontal axis, an attitude detection device for detecting the attitude of the excavator body, and the attitude of the excavator body are detected. Using a reverse circulation type horizontal multi-axis excavator with an attitude correction device, the posture of the excavator body is detected by the posture detection device, and the posture of the excavator body is corrected by the posture correction device. drill a hole; In the second step, a reverse circulation type excavator having a rod to which a plurality of shafts are connected, an excavator body attached to the tip of the rod, and a widening bit provided on the excavator body so that the radius of rotation can be adjusted. is used to widen the bottom of the hole excavated in the first step (see, for example, Patent Document 2).

JP-A-2006-45780 JP 2012-167450 A

In any of the wall pile construction methods of Patent Documents 1 and 2, an earth drill excavator is applied as the base machine of the bottom-enlarging excavator, the bottom-enlarging bucket is mounted on the tip of the Kelly bar, and the bottom-enlarging bucket is opened at a predetermined depth, Enlarged bottom excavation is performed by rotating the bucket. When the Kelly bar is used for wide-bottom excavation in this way, since the driving motor is located on the ground, the driving torque is reduced, and there is a problem that the excavable depth is limited. Further, for example, in Patent Document 1, by forming a hole for a knot-shaped extension on one side of a rectangular excavation hole, it is possible to construct a wall pile having an extension without interfering with the border of the adjacent land. there is However, since this method excavates while supporting the expanded bottom bucket with a Kelly bar, there is a problem that the expanded bottom bucket is displaced due to the reaction force during excavation, which pushes the Kelly bar and lowers the accuracy of excavation. there is

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a wing-expanding excavator and a wall pile construction method that can cope with various excavation depths and excel in excavation accuracy.

In order to achieve the above object, one aspect of the expanded wing excavator according to the present invention includes:
A hole wall of a wall pile having a base machine and a wing-expanding excavating body suspended from the base machine by a wire, and having a widened portion on at least one of two wide sides of the wall pile of a rectangular parallelepiped shape. A wing excavator for building,
The expanded wing excavating body,
a frame having a pivot shaft extending in a direction orthogonal to the wall thickness of the wall pile in a plan view and having a stabilizer that applies reaction force to the hole wall;
a wing expanding cutter rotatable in the wall thickness direction of the wall pile with respect to the rotating shaft;
a rotation driving means for rotating the blade expansion cutter with respect to the rotation shaft;
a rotary driving means for rotating the blade expansion cutter;
and reaction force specifying means for specifying the reaction force.

According to this aspect, by applying the wing-expansion excavation body suspended by the wire (inserting the wing-expansion excavation body by wiring) without applying the Kelly bar, the wing-expansion excavation body is placed in the ground. Since it can be driven, it is possible to construct the hole wall of the widened portion of the wall pile while responding to various excavation depths. In addition, by controlling the posture of the wing-expanded excavator while applying a reaction force to the hole wall with the stabilizer, the hole wall of the widened portion of the wall pile can be created with excellent excavation accuracy. Furthermore, by providing the reaction force specifying means for specifying the reaction force that the stabilizer receives from the hole wall, it is possible to prevent the ground from collapsing due to the application of excessive pressing force from the stabilizer to the ground, and the reaction force specifying means By adjusting the stroke amount of the stabilizer based on the specified reaction force, it is possible to accurately adjust the position of the wing expansion excavation body. Makes it possible to create pore walls.

According to this aspect, by applying the wing-expansion excavation body suspended by the wire (inserting the wing-expansion excavation body by wiring) without applying the Kelly bar, the wing-expansion excavation body is placed in the ground. Since it can be driven, it is possible to construct the hole wall of the widened portion of the wall pile while responding to various excavation depths. Furthermore, by controlling the posture of the expanded wing excavating body while applying a reaction force to the hole wall with the stabilizer, the hole wall of the widened portion of the wall pile can be created with excellent excavation accuracy. In the wing-expanded excavator of this aspect, a crawler crane, a truck crane, or the like can be applied as a base machine for suspending the wing-expanded excavator by a wire. A rotating shaft extends in a direction orthogonal to the wall thickness of the wall pile in the frame having the wing expanding excavating body, and the wing expanding cutter is attached to the rotating shaft so as to be rotatable in the wall thickness direction of the wall pile. there is That is, like the conventional openwork excavation method (for example, the SATT method), the wing expansion cutter rotates in the direction perpendicular to the wall thickness direction of the wall pile (the extension direction of the wall pile), The rotation direction of the blade expansion cutter differs by 90 degrees from the excavation method. By excavating while the wing expansion cutter rotates around the rotation axis in the rectangular parallelepiped wall pile, it is possible to create the hole walls of the widened part on both of the two wide surfaces. If there is an adjoining land boundary such as a public-private boundary on one side of the wide face, the hole wall of the widened part can be created only on one side of the wide face, which is the opposite side of the adjoining land boundary.

In another aspect of the wing-expanded excavator according to the present invention, the outer shape of the frame is a rectangular parallelepiped elongated in the longitudinal direction of the rotation shaft when viewed from the front,
The stabilizer has a belt-like shape having a width in the longitudinal direction of the rotation shaft of the frame,
It is characterized in that the band-shaped stabilizers are provided on the upper and lower sides of each of the two wide surfaces of the rectangular parallelepiped frame so as to freely protrude in a direction orthogonal to the wide surfaces.

According to this aspect, in the form in which the outer shape of the frame constituting the wing-expanded excavating body is a rectangular parallelepiped that is long in the longitudinal direction of the rotation axis when viewed from the front, the stabilizer has a large width in the frame in the longitudinal direction of the rotation axis. It has a band shape with an area, and the stabilizer is attached to the upper and lower sides of the two wide faces of the rectangular parallelepiped frame so that it can freely project, so that the pressing force per unit area when the stabilizer presses the hole wall is reduced. can be reduced as much as possible. As a result, it is possible to effectively suppress collapse of the hole wall when the stabilizer presses the hole wall.

In another aspect of the wing-expansion excavator according to this aspect, the wing-expansion excavator further has a controller,
The controller is
a stabilizer driving unit that drives the stabilizer;
a blade expansion cutter drive unit that drives the rotation drive means and the rotation drive means;
a storage unit that stores the specific reaction force value identified by the reaction force identification means and a reaction force threshold value;
a computing unit that compares the reaction force threshold and the specific reaction force value,
When the calculation unit determines that the specific reaction force value exceeds the reaction force threshold value, the blade expansion cutter drive unit reduces the rotational speed of the blade expansion cutter with respect to the rotational drive means. and executing control to increase the rotation speed of the blade expansion cutter with respect to the rotation drive means.

According to this aspect, in the controller, the specific reaction force value identified by the reaction force identification means and the reaction force threshold value are compared, and when it is determined that the specific reaction force value exceeds the reaction force threshold value, the wing expansion cutter Excessive pressing of the pore wall by the stabilizer and collapse of the pore wall caused by this can be suppressed by executing the predetermined control by the driving unit. Concrete control by the controller includes control to decrease the rotation speed of the blade expansion cutter with respect to the rotation drive means and control to increase the rotation speed of the blade expansion cutter with respect to the rotation drive means by the blade expansion cutter drive section. be. By controlling the rotation speed of the blade expansion cutter to decrease, the pressing force (pressing force, pushing force) applied to the hole wall when the blade expansion cutter rotates is reduced. In addition, by increasing the rotation speed of the blade expansion cutter while reducing the rotation speed of the blade expansion cutter, the hole wall is quickly loosened by the blade expansion cutter with a high rotational speed. The pressing force applied to the wall can be further reduced, and excavation is enhanced by the wing expansion cutter rotating at a high speed, so that the widened portion forming hole can be formed efficiently.

Another aspect of the wing-expanding excavator according to the present invention is characterized by including any one of the following as the reaction force specifying means.
A: a pressure sensor mounted on the stabilizer,
B: Based on the relationship between the reaction force and the torque value of at least one of the rotational torque when the blade expansion cutter rotates and the rotational torque when the blade expansion cutter rotates, which is built into the controller and is A reaction force identification unit that identifies the reaction force.

According to this aspect, the measured reaction force value measured by the pressure sensor installed in the stabilizer, or the reaction force specifying unit inside the controller (both the pressure sensor and the reaction force specifying unit are the reaction force specifying means By comparing the specific reaction force value specified in (example) with the reaction force threshold value, it becomes possible to control the stroke amount of the stabilizer with high accuracy. Here, in a mode in which the stabilizer is equipped with a pressure sensor, the measured reaction force value measured by the pressure sensor is received by the receiving unit of the controller, and the measured reaction force value is stored in the storage unit from the receiving unit. . In this form, the measured reaction force value becomes the specific reaction force value.
On the other hand, when the reaction force value is specified by the reaction force specifying unit in the controller, the rotational torque of the blade expansion cutter specified by the rotary drive means and the rotational torque of the blade expansion cutter specified by the rotary drive means A torque (pushing torque against the ground) is received by the receiver of the controller as a specific reaction force value. That is, in this embodiment, the specified reaction force value includes the specified rotational torque and rotational torque. On the other hand, the correlation between the ground reaction force (or ground strength) at the construction site and the rotation torque and rotational torque that generate this ground reaction force was investigated by test construction prior to the implementation work, or as in the past. These correlation data are stored in the controller's storage section. The stroke amount of the stabilizer is controlled based on the specified reaction force value specified by any one of these forms of reaction force specifying means.

Further, in the wing-expanding excavator according to this aspect, it is preferable that a plurality of wing-expanding cutters are rotatably arranged side by side in the longitudinal direction of the rotation shaft.
According to this configuration, the plurality of blade expansion cutters arranged in the longitudinal direction of the rotary shaft are rotated to excavate, thereby efficiently forming the hole wall of the widened portion extending in the extension direction of the wall pile. . For example, in a single-row multi-shaft type wing expansion excavator in which a plurality of wing expansion cutters are rotatably attached to one rotation shaft, all the wing expansion cutters are rotated in the same direction around the rotation shaft. For example, by rotating it clockwise, the hole wall of the widened portion is formed on one of the two wide surfaces of the rectangular parallelepiped wall pile. Next, by rotating all the blade expansion cutters in the other counterclockwise direction, which is the same direction, around the rotation axis, the hole wall of the widened portion is formed on the other of the two wide surfaces of the rectangular parallelepiped wall pile. can do.

Further, in the wing-expansion excavator according to this aspect, in a plan view, a plurality of rotating shafts are arranged side by side at intervals, and a plurality of wing-expanding cutters are rotatably arranged side by side in the longitudinal direction of each of the rotating shafts. may be
According to this configuration, the plurality of rotating shafts are arranged side by side at intervals, and the plurality of wing expanding cutters in the longitudinal direction of each rotating shaft are rotated to excavate, thereby excavating in the extending direction of the wall pile. The hole wall of the widened portion extending to the width can be formed more efficiently. For example, in a two-row multi-shaft type wing expansion excavator in which a plurality of wing expansion cutters are rotatably attached to two rotating shafts arranged side by side, it is attached to one of the rotating shafts Rotate all the blade expansion cutters in the same direction, for example, clockwise, and simultaneously rotate all the blade expansion cutters attached to the other rotary shaft in the same direction, i.e., counterclockwise. As a result, the hole walls of the widened portion can be formed simultaneously on both of the two wide surfaces of the rectangular parallelepiped wall pile.

Further, in the wing-expansion excavator according to this aspect, the wing-expansion excavator further has a mud pump, and the wing-expansion cutter is arranged around a shaft that rotates about the rotation shaft and the shaft. The shaft of at least one blade expansion cutter among the plurality of blade expansion cutters may be formed with a mud discharge passage that communicates with the mud pump and through which the drilling mud passes.
According to this configuration, excavated mud that accumulates inside the rectangular parallelepiped wall pile when the hole wall of the widened portion is formed is discharged by the mud lifting pump through the mud discharge passage in the shaft of the blade expansion cutter. can do. Therefore, for example, it is applied to a rotary excavator having a mud discharge mechanism that is applied when creating the hole wall of a rectangular parallelepiped wall pile (wall pile general part), and when creating the hole wall of the widened part. The wing expansion excavator can form the hole wall of the widened portion and drain the generated excavation mud without alternating with the wing expansion excavator.

Further, in the wing-expansion excavator according to this aspect, the wing-expansion excavator further includes a water supply pump, and at least one wing-expansion cutter among the plurality of wing-expansion cutters (for example, the center of the three wing-expansion cutters The shaft of the blade expansion cutter) has a double-tube structure with an inner tube and an outer tube, one of which is a mud discharge passage, and the other is supplied from a water supply pump. It may be a water supply passage for supplying fluid to the drilling bit. For example, in a configuration in which water is supplied between the inner pipe and the outer pipe and mud is discharged through the inner pipe, a water injection hole is provided in the outer pipe, and water is supplied between the inner pipe and the outer pipe through the water injection hole. Alternatively, water may be supplied from the ground between the inner pipe and the outer pipe. According to this configuration, even if drilling mud adheres to the drilling bit when the wing expansion cutter drills an adhesive silt layer or the like, the fluid supplied from the water supply pump is drilled through the water supply passage. Drilling mud can be removed from the drilling bit by feeding the bit. Therefore, there is no problem that drilling mud adheres to the drilling bit and makes drilling impossible.
In addition, if the grain size of the soil at the tip of the blade expansion cutter is large, the tip of the blade expansion cutter may become clogged. A rod-shaped member that can be removed may be provided, and this configuration enables smooth mud removal.

In addition, one aspect of the wall pile construction method according to the present invention is
A method for constructing a wall pile having a general portion of a rectangular parallelepiped wall pile and a widened portion on at least one of two wide sides of the general portion, comprising:
A step of forming a general part preparation hole of the rectangular parallelepiped wall pile with a general part excavator;
By the blade expansion excavator, the stabilizer applies a reaction force to the hole wall, and while specifying the reaction force at any time, the blade expansion cutter is rotated and rotated in the width expansion direction to form the general hole. When a widened portion forming hole is formed in at least one of the two wide surfaces of, at this time, an overcut portion is provided at the lower end of the general portion forming hole, and the widened portion forming hole is formed in the overcut portion A B step for storing the drilling mud of
a C step of discharging excavated mud accumulated in the overcut portion by at least the general excavator;
A D step of installing a reinforcing bar cage in the general part preparation hole, pouring concrete into the general part preparation hole and the widened part preparation hole, and constructing a wall pile having a widened part;
In the step B, when the specified reaction force exceeds a preset reaction force threshold value, control is executed to increase the rotation speed of the blade expansion cutter and decrease the rotation speed. do.

According to this aspect, the general portion of the rectangular parallelepiped wall pile and the The hole wall of the wall pile having the widened portion on at least one of the two wide surfaces of the general portion can be efficiently formed. After creating the hole for creating the general part, when creating the hole for creating the widening part, by providing an overcut part at the lower end of the hole for creating the widening part, the excavated mud generated when creating the hole for creating the widening part is temporarily removed. It is possible to store the mud temporarily, and then smoothly discharge the mud by the general excavator. Furthermore, in step B, the reaction force applied to the hole wall by the stabilizer is specified at any time, and when the specified reaction force exceeds a preset reaction force threshold, the rotation speed of the blade expansion cutter is increased. By executing control to reduce the rotation speed, the pressing force applied to the hole wall when the blade expansion cutter rotates can be reduced, and the hole wall can be quickly loosened by the blade expansion cutter having a high rotational speed. Since the excavability is enhanced by this, it is possible to efficiently form the widened portion forming hole while suppressing the collapse of the hole wall.

Here, the "general section excavator" includes, for example, a horizontal multi-axis excavator having a mud discharge mechanism, and the like, and is an excavator of a different form from the expanded wing excavator according to the present invention. Further, in step C, "at least draining the excavation mud accumulated in the overcut part by the general excavator" means that the excavation mud is removed only by the general excavator such as the horizontal multi-axis excavator. Other than that, it is included to clear the drilling mud by the expanded wing excavator according to the invention in addition to the general excavator. For example, as described above, when applying a wing expansion excavator in which mud is discharged by a mud pump through a mud discharge passage in the shaft of the wing expansion cutter, the latter mud discharge form is applied. be able to.

In addition, in the wall pile construction method of this embodiment, the B process and the C process may be performed respectively on the two wide surfaces of the general part preparation hole. According to this construction method, for example, by applying the single-row multi-shaft type wing expansion excavator according to the present invention, in the B process and the C process, the widened part is formed on one of the two wide surfaces of the rectangular parallelepiped general part preparation hole. It is possible to form a forming hole, and then similarly form a widened portion forming hole on the other wide side of the general portion forming hole in the B process and the C process.

In addition, in the wall pile construction method of this embodiment, when using a wing expansion excavator in which a plurality of rotating shafts are arranged in parallel, the B process and the C process are performed on the two wide surfaces of the general part preparation hole. may be performed at the same time. According to this construction method, for example, by applying the two-row multi-shaft wing expansion excavator according to the present invention, in the B process and the C process, on both of the two wide surfaces of the rectangular parallelepiped general part preparation hole The widened portion forming hole can be formed at the same time.

Further, another aspect of the wall pile construction method according to the present invention is to specify the stroke amount of the stabilizer when positioning the rotating shaft having the wing expansion excavation body to the design central axis of the general part preparation hole. further comprising an E step, wherein the E step is performed prior to the B step,
In the B step, the wing-expansion excavating body, the rotary shaft of which is positioned on the design center axis in the E step, is rotated.

According to this aspect, by further having the E step of specifying the stroke amount of the stabilizer when positioning the rotation axis of the wing expansion excavating body to the design center axis of the general part preparation hole, After precisely positioning the rotating shaft of the blade-expansion excavating body on the design central axis, it becomes possible to form the widened portion forming hole with high precision in the B step.

ADVANTAGE OF THE INVENTION According to the wing-expansion excavator and the construction method of a wall pile of this invention, it can respond to various excavation depths, and can construct the wall pile which has a widened part under the excellent excavation accuracy.

1 is a side view of an example of a wing-expanding excavator according to an embodiment; FIG. 1 is a front view of an example of a wing-expanding excavating body of the wing-expanding excavator according to the embodiment; FIG. 1 is a perspective view of an example of a wing-expanding excavating body of the wing-expanding excavator according to the embodiment; FIG. FIG. 3 is a view taken in the direction of arrow IV in FIG. 2 and is a side view of an example of the expanded wing excavating body. FIG. 3 is a view viewed in the direction of arrow V in FIG. 2 and is a bottom view of an example of the wing-expanded excavating body. It is a side view of an example of the rotation drive means which has a wing expansion excavation body. (a) is a bottom view of a blade expansion cutter having a mud discharge passage, and (b) is a bottom view of the blade expansion cutter having a mud discharge passage and a water supply passage. It is a figure which shows an example of the hardware constitutions of the controller which comprises a wing expansion excavator with peripheral equipment. It is a figure which shows an example of the functional structure of the controller which comprises a wing expansion excavator. It is process drawing of an example of the construction method of the wall pile which concerns on embodiment.

Hereinafter, a wing expansion excavator and a wall pile construction method according to an embodiment will be described with reference to the accompanying drawings. In addition, in the present specification and drawings, substantially the same components may be denoted by the same reference numerals, thereby omitting duplicate descriptions.

[Expanded wing excavator according to the embodiment]
First, an example of an expandable wing excavator according to an embodiment will be described with reference to FIGS. 1 to 9. FIG. Here, FIG. 1 is a side view of an example of a wing-expanded excavator according to the embodiment, and FIG. 3 is a perspective view of an example of a wing-expanding excavating body of the wing-expanding excavator according to the embodiment. 4 is a view in the direction of arrow IV in FIG. 2, which is a bottom view of an example of a wing-expanded excavating body, and FIG. 5 is a view in the direction of arrow V in FIG. FIG. 6 is a bottom view of an example, and FIG. 6 is a side view of an example of the rotary drive means of the expanded wing excavating body.

For example, the wing expansion excavator 60 constructs a wall pile having a general portion of a rectangular parallelepiped wall pile and a widened portion on at least one of the two wide surfaces of the general portion. It is an excavator that is applied when forming the widened portion forming hole D2 from the general portion forming hole D1 (or the guide forming hole). It is carried out by excavators in general. In addition, the wall pile to be constructed has a plurality of projections or nodes intermittently in the extending direction of the wall on both of the two wide surfaces of the general part of the rectangular parallelepiped wall pile, or on one of the two wide surfaces. There is a form in which a widened part having a shape is formed, and a form in which a widened part continuous in the extending direction of the wall is formed.

The wing expansion excavator 60 includes a base machine 10 composed of a crawler crane that can freely travel on the ground surface G, a controller 50 installed in an operation room of the base machine 10, and a boom of the base machine 10. and a wing-expanding drilling body 30 attached to the tip of the wire 20 . In addition to the crawler crane, the base machine 10 may be other heavy machinery such as a truck crane that can freely travel and wire the wing-expanded excavating body 30 into the excavation hole via the wire 20 .

The wing expansion excavator 30 includes a frame 31 constructed by assembling steel materials, a stabilizer 32 extending and retracting toward the hole wall on the side of the frame 31, and a rotating shaft 34 at the lower end of the frame 31 so as to be rotatable. and a plurality of wing cutters 33 attached thereto.

The general part preparation hole D1 shown in FIG. 1 is illustrated so that the wall thickness direction can be visually recognized, and the direction perpendicular to the wall thickness direction of the wall pile (extending direction of the wall pile) is the direction perpendicular to the paper surface. The illustrated wing expansion cutter 33 rotates in the wall thickness direction X1 or X2 about a rotation shaft 34 extending in a direction orthogonal to the wall thickness of the wall pile, thereby turning the widened portion forming hole D2. create. That is, unlike the conventional openwork excavation method (SATT method) in which the wing expansion cutter rotates in a direction perpendicular to the wall thickness direction of the wall pile to excavate directly under the buried object, etc. The rotational directions of the blade cutters 33 are different by 90 degrees. FIG. 1 shows the wall pile formation hole D formed by forming the widened portion formation hole D2 on each of the two wide sides of the general portion formation hole D1. If there is an adjacent land boundary such as a public-private boundary on the left side of the hole D1, the widened portion preparation hole D2 is formed only on the right side of the wide surface of the general portion preparation hole D1, which is the opposite side of the adjacent land boundary. A prepared hole D is formed.

Further, the wing expansion excavator 60 shown in FIG. 1 has a mud discharge pump 40 placed on the ground. are familiar with As will be described in detail below, by operating the mud discharge pump 40, the mud excavated by the wing expanding cutter 33 can be discharged to the ground, and the mud discharge mechanism is provided. The expanded wing excavator 60 is also capable of discharging sludge in the same manner as a general horizontal multi-axis excavator.

As shown in FIGS. 2 to 4, the outer shape of the frame 31 is a rectangular parallelepiped that is elongated in the longitudinal direction of the rotation shaft 34 when viewed from the front. A band-shaped wide-area stabilizer 32 having a width t1 in the longitudinal direction of the shaft 34 is provided so as to freely protrude in the X3 direction (hole wall side), which is a direction perpendicular to the wide surface. Extension control of each stabilizer 32 is executed by stabilizer driving means 32a formed of a hydraulic cylinder or the like.

By appropriately extending each stabilizer 32, the attitude control of the wing-expanded excavating body 30 can be executed while applying a reaction force to the hole wall. That is, after the attitude control of the wing-expansion excavator 30 is performed by each stabilizer 32, each wing-expansion cutter 33, 33A is rotated in the X1 direction or the X2 direction up to a desired angle in the same direction about the rotation shaft 34. This makes it possible to form the widened portion forming hole D2 with high excavation accuracy on at least one of the two wide surfaces of the general portion forming hole D1. By adjusting the amount of expansion by the stabilizer 32, it is possible to form the general portion forming holes D1 with various wall thicknesses.

In particular, the stabilizer 32 in the illustrated example has a large area with the width t1 of the frame 31. Therefore, when the stabilizer 32 applies a reaction force to the hole wall to form the widened portion forming hole D2, the hole The pressing force per unit area applied to the wall can be reduced as much as possible, and collapse of the hole wall when forming the widened portion forming hole D2 can be effectively suppressed.

Further, as shown in FIG. 4, when forming the widened portion forming hole D2, a wing expansion excavating body 30 is inserted into the general portion forming hole D1 having a width t2 in the wall thickness direction, and is applied to the left and right hole walls. By projecting the stabilizers 32 on the upper and lower sides of the left and right wide surfaces of the frame 31 with corresponding stroke amounts, the axis of the rotating shaft 34 is positioned on the design central axis L of the general part preparation hole D1. can be done. In this way, the widened portion forming hole D2 is formed after the axial center of the rotating shaft 34 is positioned on the design central axis L of the general portion forming hole D1, so that the widened portion forming hole D2 is constructed with high accuracy. it becomes possible to Incidentally, by adjusting the stroke amount of the stabilizer 32, it is possible to form the general portion forming holes D1 with various wall thicknesses.

On the other hand, at the lower end of the frame 31, one rotating shaft 34 extends in a direction orthogonal to the wall thickness of the wall pile. 33 are rotatably arranged side by side. Thus, the expanded wing excavator 60 of the illustrated example is a single-row multi-shaft type (single-row three-shaft type) excavator.

Of the three blade expansion cutters 33, the blade expansion cutters 33 at the left and right ends have a rotary motor 35 mounted on their heads to rotate themselves. It is rotatable by driving force transmitted from the motor 35 . Therefore, as shown in FIG. 5, the rotation of the leftmost blade expansion cutter 33 in the Y1 direction causes the center blade expansion cutter 33A to rotate in the Y2 direction via the gear. The blade expansion cutter 33 at the right end rotates in the Y2 direction by its own rotary motor 35 independently of the central blade expansion cutter 33A.

The wing expansion cutters 33, 33A have a shaft 33a that rotates about the rotation shaft 34, and a plurality of excavation bits 33b arranged around the shaft 33a. As shown in FIG. 2, the adjacent blade expanding cutters 33, 33A are arranged so as to partially overlap each other in such a manner that both excavating bits 33b do not interfere with each other. Therefore, when the shafts 33a of the blade expansion cutters 33, 33A are rotated and excavated, there is no unexcavated region, and the entire area is uniformly excavated by the three blade expansion cutters 33, 33A.

Since the central wing expansion cutter 33A does not have a rotary motor 35 in its head, the circulation pipe 38 leading to the mud discharge pump 40 and the hollow shaft 33a can be communicated.

In FIG. 4, the widened portion forming hole D2 is formed so as to form the overcut portion D3 below the general portion forming hole D1. As a result, the excavation mud generated during the formation of the widening section forming hole D2 can be temporarily stored in the overcut section D3, and the general excavator such as a horizontal multi-axis excavator or the expanded wing excavator 60 can be used. , it becomes possible to drain excavated mud from the overcut portion D3.

Further, as shown in FIG. 6, the rotation of the plurality of blade expanding cutters 33 and 33A about the rotation shaft 34 is performed by two hydraulic cylinders 37 (rotation An example of driving means). As shown in FIG. 6, when rotating the plurality of blade expansion cutters 33 and 33A in the X1 direction, which is the left direction, the piston rod 37a of the hydraulic cylinder 37 on the right side is extended in the Z1 direction so that the piston A plurality of blade expansion cutters 33 and 33A can be simultaneously rotated in the X1 direction via a link 37b rotatably attached to the tip of a rod 37a. On the other hand, when rotating the plurality of blade expansion cutters 33 and 33A in the X2 direction, which is the right direction, the piston rod 37a of the hydraulic cylinder 37 on the left side is extended in the Z2 direction so that the tip of the piston rod 37a A plurality of blade expanding cutters 33 and 33A can be simultaneously rotated in the X2 direction via a rotatably mounted link 37b.

FIG. 7 is a view of two types of blade expansion cutters viewed from below, FIG. 7(a) is a view of a blade expansion cutter having a mud discharge passage viewed from below, and FIG. FIG. 10 is a bottom view of an expansion cutter having a mud passage and a water supply passage; A blade expansion cutter 33A shown in FIG. 7(a) has a mud discharge passage 33c in the center of a shaft 33a. Of the three blade expansion cutters 33 and 33A that are rotatably arranged side by side with respect to the rotary shaft 34, the central blade expansion cutter 33A has a mud discharge passage 33c. By operating the mud discharge pump 40, the excavated mud generated during the formation of the widened portion preparation hole D2 can be discharged to the ground through the mud discharge passage 33c and the circulation pipe .

On the other hand, the wing expansion cutter 33B shown in FIG. 7(b) has a double-pipe structure having an inner pipe and an outer pipe, the inner pipe serving as the mud discharge passage 33e and the outer pipe serving as the fluid supplied from the water supply pump. is a water supply passage 33d for supplying water to the excavation bit 33b. For example, when the wing expansion cutter 33 excavates an adhesive silt layer or the like, even if excavation mud adheres to the excavation bit 33b, the fluid supplied from the water supply pump is supplied to the excavation bit 33b through the water supply passage 33d. The drilling mud can be removed from the drilling bit 33b by supplying it. As described above, in the configuration in which the centrally located blade expansion cutter 33B of the three blade expansion cutters 33 and 33B has a double pipe structure having the mud discharge passage 33e and the water supply passage 33d, for example, the blade expansion cutter A water supply pump (not shown) is provided inside the excavating body 30 .

According to the wing-expansion excavator 60, the wing-expansion excavator 30 suspended by the wire 20 is wired to the general-part preparation hole D1 to form the widened-section preparation hole D2 without applying a Kelly bar. Since the wing-expansion excavating body 30 can be driven in the ground, it is possible to form the widened portion forming hole D2 while responding to various excavation depths. Furthermore, by controlling the posture of the expanded wing excavating body 30 while applying a reaction force to the hole wall by the stabilizer 32, the widened portion forming hole D2 can be formed with excellent excavation accuracy.

Furthermore, according to the wing-expanding excavator 60, the four stabilizers 32, each having a wide belt-like area, are provided so as to extend freely above and below the two wide surfaces of the frame 31, respectively, and the strokes of the four stabilizers 32 are adjusted. By forming the widened portion forming hole D2 while applying a reaction force to the wall, it is possible to form the widened portion forming hole D2 with high accuracy while suppressing collapse of the hole wall.

Next, an example of the hardware configuration and functional configuration of the controller 50 that forms the wing expansion excavator 60 will be described with reference to FIGS. 8 and 9. FIG. Here, FIG. 8 is a diagram showing an example of the hardware configuration of a controller that configures the wing-expanded excavator together with peripheral devices, and FIG. 9 is a view that illustrates an example of the functional configuration of the controller that configures the wing-expanded excavator. is.

As shown in FIG. 8, the controller 50 includes a CPU (Central Processing Unit) 51, a RAM (Random Access Memory) 52, a ROM (Read Only Memory) 53, a HDD (Hard Disc Drive) 54, and an NVRAM (Non-Volatile RAM). ) 55, etc., which are connected by a system bus so as to be capable of data communication.

Various programs and data used by the programs are stored in the ROM 53 . The RAM 52 is used as a storage area for loading programs stored in the ROM 53 and as a work area for the loaded programs. The CPU 51 implements various functions by processing programs loaded in the RAM 52 . For example, the optimal pressing force from the stabilizer 32 according to the strength of the ground (reaction force threshold corresponding to the pressing force by the stabilizer 32 that does not cause the hole wall to collapse) is stored, and the pressing force by the stabilizer 32 is within this reaction force threshold. , the stroke amount of the stabilizer 32 is controlled, and attitude control of the wing-expanded excavating body 30 is executed. In addition, when the reaction force that the stabilizer 32 receives from the ground temporarily exceeds the reaction force threshold, control is executed to increase the rotation speed of the blade expansion cutters 33 and 33A and decrease the rotation speed. The HDD 54 stores programs and various data used by the programs. Various setting information and the like are stored in the NVRAM 55 .

When an operator operates various control levers and the like in the control room of the base machine 10 , the controller 50 controls the operation of various devices (hardware) that constitute the wing expansion excavator 60 . That is, a rotary drive means 35 for rotating the blade expansion cutter 33, a rotary drive means 37 for rotating the blade expansion cutter 33 in the wall thickness direction with respect to the wall pile with respect to the rotary shaft 34, and the force that the stabilizer 32 receives from the hole wall. The reaction force identifying means 58 for identifying the force, the stabilizer driving means 32a for projecting the stabilizer 32, and the like are controlled. Here, as will be described in detail below, the reaction force specifying means 58 is formed by either a pressure sensor provided in the stabilizer 32 or a reaction force specifying section 502 built in the controller 50 .

When the reaction force identifying means 58 is a pressure sensor, the reaction force that the stabilizer 32 receives from the hole wall is measured at any time by the pressure sensor 58, and the measured reaction force value is sent to the controller 50 at any time. there is On the other hand, when the reaction force identification unit 58 is the reaction force identification unit 502 built in the controller 50, the rotational torque when the blade expansion cutter 33 rotates and the rotation torque when the blade expansion cutter 33 rotates A torque value such as torque is transmitted to the controller 50 at any time. In the latter case, the controller 50 identifies the reaction force that the stabilizer 32 receives from the hole wall based on the received torque value.

As shown in FIG. 9 , the controller 50 has a receiving section 500 , a reaction force specifying section 502 , a computing section 504 , a wing expansion cutter driving section 506 , a stabilizer driving section 508 and a storage section 510 .

When the reaction force identifying means 58 is a pressure sensor, the reaction force that the stabilizer 32 receives from the hole wall is monitored by the pressure sensor 58 at any time, and the reaction force value measured by the pressure sensor 58 is received by the receiver 500 . Further, when the reaction force specifying unit 58 is the reaction force specifying unit 502 built in the controller 50, the rotational torque when the blade expansion cutter 33 rotates or the rotational torque when the blade expansion cutter 33 rotates A torque value such as is received by the receiving unit 500 .

In the storage unit 510, the pressing force (the reaction force received by the stabilizer 32) when the hole wall collapses is specified in advance as the reaction force threshold at the construction site. For example, the natural ground reaction force (or natural ground strength) at the construction site is specified by test construction prior to the actual construction, and the specified reaction force threshold is stored in the storage unit 510 . In addition, in the storage unit 510, the correlation between the natural ground reaction force at the construction site and the rotation torque and rotation torque that generate this natural ground reaction force is similarly determined by test construction prior to the implementation work, or by past These correlation data are stored in the storage unit 510 after being specified by empirical rules for similar ground.

When the reaction force identification unit 58 is a pressure sensor, the reaction force identification unit 502 determines the measured reaction force value stored in the storage unit 510 as the specific reaction force value. On the other hand, when the reaction force specifying unit 58 is the reaction force specifying unit 502, the reaction force specifying unit 502 calculates the reaction force corresponding to the torque value such as the rotating torque or the rotating torque of the expanding blade cutter 33 based on the correlation data described above. value is determined as a specific reaction force value.

The calculation unit 504 compares the reaction force threshold stored in the storage unit 510 with the specific reaction force value identified by the reaction force identification unit 502 . Then, when the calculation unit 504 determines that the specific reaction force value exceeds the reaction force threshold value, the blade expansion cutter drive unit 506 causes the rotary drive unit 37 to control the rotation speed of the blade expansion cutter 33 to decrease. In addition, control to increase the rotational speed of the blade expansion cutter 33 is executed on the rotation drive means 35 .

By controlling the rotation speed of the blade expansion cutter 33 to decrease, the pressing force applied to the hole wall when the blade expansion cutter 33 is rotated can be reduced, and the hole wall collapse can be suppressed. In addition, by increasing the rotation speed of the blade expansion cutter 33 while reducing the rotation speed of the blade expansion cutter 33, the hole wall is quickly loosened by the blade expansion cutter 33, which rotates at a high speed. The pressing force applied from the cutter 33 to the hole wall can be further reduced, and the expanding blade cutter 33, which rotates at a high speed, enhances the excavation performance, so that the widened portion forming hole can be formed efficiently.

Further, the stroke amount of the stabilizer 32 when positioning the rotating shaft 34 of the wing expansion excavating body 30 to the design center axis L (see FIG. 4) in the general part preparation hole D1 is specified in advance, and this stroke amount is specified. It is stored in the storage unit 510 . When forming the widening section forming hole D2, the wing expansion excavating body 30 is accommodated in the general section forming hole D1, and when controlling its attitude, each stabilizer 32 is extended based on the stroke amount stored in the storage section 510. After the control is executed to position the rotary shaft 34 on the design central axis L of the general portion forming hole D1, the widened portion forming hole D2 is formed, whereby the widened portion forming hole D2 can be formed with high accuracy. be possible.

[Method of Construction of Wall Pile According to Embodiment]
Next, an example of a wall pile construction method according to the embodiment will be described with reference to FIG. 10 . Here, FIG. 10 is a process drawing of an example of the construction method of the wall pile according to the embodiment in order from (a) to (g). Here, in the wall pile construction method shown in the drawings, a widened portion preparation hole D2 is formed by a wing expansion excavator 60 having a single-row multiaxial wing expansion excavator 30 shown in FIGS. 1 to 9, and a wall pile is constructed. It is a way to

In step (a), a general section preparation hole D1 for rectangular parallelepiped wall piles is formed by a general section excavator 70, which is, for example, a low-head horizontal multi-axis excavator. A pair of left and right cutters is a horizontal two-axis cutter drum 71 arranged at the lower end of the excavator body, connected to the hydraulic unit via a power cable, and rotated by the driving force of the hydraulic unit to loosen the ground. . Further, the mud pump 72 is connected to a sediment separator (not shown) through a hose, sucks up the sediment from the hole together with the water in the hole, and sends the sediment to the sediment separator (above, process A). .

After the general section preparation hole D1 is prepared, in step (b), the general section excavator 70 and the wing expansion excavator 60 are exchanged, and through the wire 20 suspended from the base machine 10 consisting of a crawler crane, , the wing expansion excavation body 30 is suspended to a predetermined depth of the general part preparation hole D1. Then, the attitude control of the wing-expansion excavation body 30 is performed while the plurality of stabilizers 32 of the wing-expansion excavation body 30 apply reaction force to the hole wall.

Here, the stroke amount of each stabilizer 32 is adjusted to control the extension of each stabilizer 32 in order to position the rotating shaft 34 of the wing expansion excavating body 30 on the design central axis L (see FIG. 4) in the general part preparation hole D1. to position the rotating shaft 34 on the design central axis L of the general portion forming hole D1 (the above is the E step).

Next, in step (c), excavation is performed while rotating the plurality of wing expanding cutters 33 to the left of the general part forming hole D1 in the X1 direction to a predetermined rotation angle about the rotating shaft 34. A widened portion forming hole D2 is formed on the left side of the general portion forming hole D1. Here, in forming the widened portion forming hole D2, the widened portion forming hole D2 is formed so as to form an overcut portion D3 below the general portion forming hole D1. As a result, excavated mud generated during the formation of the widened portion forming hole D2 can be temporarily stored in the overcut portion D3.

In forming the widened portion forming hole D2, the widened portion forming hole D2 is formed while monitoring the reaction force that the stabilizer 32 receives from the hole wall at any time by the reaction force specifying means 58 . Here, the reaction force specifying means 58 is formed by either a pressure sensor equipped on the stabilizer 32 or a reaction force specifying section 502 built inside the controller 50 . As described above, when the reaction force specifying means 58 is a pressure sensor, the reaction force that the stabilizer 32 receives from the hole wall is monitored by the pressure sensor 58 at any time, and the reaction force value measured by the pressure sensor 58 (specific reaction force value ) and the reaction force threshold. On the other hand, when the reaction force specifying unit 58 is the reaction force specifying unit 502 built in the controller 50, the rotational torque when the blade expansion cutter 33 rotates and the rotational torque when the blade expansion cutter 33 rotates is applied to the correlation between the pre-specified torque value and the ground reaction force to specify the ground reaction force, and this specified reaction force value is compared with the reaction force threshold. The reaction force threshold is a reaction force value when the hole wall in the ground at the construction site collapses, and this reaction force threshold is also specified in advance.

If it is determined that the specific reaction force value exceeds the reaction force threshold value, the rotation speed of the blade expansion cutter 33 by the rotation drive means 37 is reduced, and the blade expansion cutter 33 is rotated by the rotation drive means 35. The widened portion forming hole D2 is formed while increasing the speed. By reducing the rotation speed of the blade expansion cutter 33, the pressing force applied to the hole wall when the blade expansion cutter 33 is rotated is reduced, and the hole wall collapse can be suppressed. In addition, by increasing the rotation speed of the blade expansion cutter 33 while reducing the rotation speed of the blade expansion cutter 33, the hole wall is quickly loosened by the blade expansion cutter 33, which rotates at a high speed. The pressing force applied from the cutter 33 to the hole wall can be further reduced, and the blade expansion cutter 33, which rotates at a high rotational speed, improves the excavation performance, so that the widened portion forming hole D2 can be formed efficiently (the above , B step).

Next, in step (d), the expanded wing excavator 60 and the general excavator 70 are exchanged, and the excavated mud temporarily stored in the overcut section D3 is discharged outside by the general excavator 70 . In step (c), by operating the mud discharge pump 40, it is also possible to discharge a part of the excavated mud by the expanded wing excavator 60 (above, step C).

After the excavation mud is removed from the overcut part D3, in step (e), the general excavator 70 and the wing expansion excavator 60 are exchanged again, and the wing expansion excavator 30 is moved to the predetermined depth of the general section creation hole D1. The attitude of the wing-expanded excavating body 30 is controlled while it is suspended and the stabilizer 32 applies a reaction force to the hole wall. Then, excavation is performed while rotating a plurality of blade expanding cutters 33 to the right side of the general portion forming hole D1 in the X2 direction up to a predetermined rotational angle around the rotating shaft 34, whereby the general portion forming hole D1 is excavated. A widened portion forming hole D2 is formed on the right side. Also in forming the widened portion forming hole D2, the widened portion forming hole D2 is formed so as to form an overcut portion D3 below the general portion forming hole D1 (these are the second steps B and C). .

Next, in step (f), the wing expansion excavator 60 and the general excavator 70 are exchanged again, and excavated mud temporarily stored in the overcut portion D3 by the general excavator 70 is discharged to the outside. Thus, as shown in step (g), a wall pile formation hole D is formed by the general portion formation hole D1 and the left and right widened portion formation holes D2.

After the wall pile construction hole D is constructed, although illustration is omitted, a reinforcing bar cage is installed in the general section construction hole D1, and concrete is placed in the general section construction hole D1 and the widened section construction hole D2 to form the widened section. Install the wall piles that have

According to the wall pile construction method shown in the figure, by applying the wing expansion excavator 60 when forming the widened portion forming hole D2, the widened portion forming hole D2 can be formed while corresponding to various excavation depths. Furthermore, by controlling the posture of the wing-expansion excavating body 30 while applying a reaction force to the hole wall, the widened-portion-creating hole D2 can be created with excellent excavation accuracy. If there is a border between the public and private sectors on one side of the general part preparation hole D1, the widening part preparation hole D2 is prepared only on the opposite side of the neighboring land boundary (for example, the height ( d), the wall pile formation hole is formed), and the wall pile is constructed.

Although illustration is omitted, a method of forming the widened portion forming hole D2 by a wing expanding excavator having a two-row multiaxial wing expanding excavating body and constructing the wall pile may be used. In this construction method, a plurality of wing expansion cutters are simultaneously rotated to the left and right sides of the general section preparation hole up to a predetermined rotation angle while excavating the general section preparation hole. It is possible to efficiently form the widened portion forming holes on the left and right sides.

It should be noted that other embodiments may be possible in which other components are combined with the above-described configurations, etc., and the present invention is not limited to the configurations shown here. . Regarding this point, it is possible to change without departing from the gist of the present invention, and it can be determined appropriately according to the application form.

10: Base machine 20: Wire 30: Expanded excavating body 31: Frame 32: Stabilizer 32a: Stabilizer drive means 33, 33A: Expanded blade cutter 33a: Shaft 33b: Excavation bit 33c: Mud discharge passage 33d: Water supply passage 33e: Exhaust Mud passage 34: Rotating shaft 35: Rotary motor (rotation driving means)
36: Gearing 37: Hydraulic Cylinder (Rotating Drive Means)
37a: Piston rod 37b: Link 38: Flow pipe 40: Mud discharge pump 50: Controller 58: Pressure sensor (reaction force specifying means)
60: Expanded wing excavator 70: General excavator (horizontal multi-axis excavator)
71: Cutter drum 72: Mud lifting pump 500: Receiving unit 502: Reaction force identification unit (reaction force identification means)
504: Operation unit 506: Wing expansion cutter drive unit 508: Stabilizer drive unit 510: Storage unit G: Ground D: Wall pile creation hole D1: General part creation hole D2: Widening part creation hole D3: Overcut part

Claims (5)

A hole wall of a wall pile having a base machine and a wing-expanding excavating body suspended from the base machine by a wire, and having a widened portion on at least one of two wide sides of the wall pile of a rectangular parallelepiped shape. A wing excavator for building,
The expanded wing excavating body,
a frame having a pivot shaft extending in a direction orthogonal to the wall thickness of the wall pile in a plan view and having a stabilizer that applies reaction force to the hole wall;
a wing expanding cutter rotatable in the wall thickness direction of the wall pile with respect to the rotating shaft;
a rotation driving means for rotating the blade expansion cutter with respect to the rotation shaft;
a rotary driving means for rotating the blade expansion cutter;
a reaction force specifying means for specifying the reaction force;
a controller ;
The controller is
a stabilizer driving unit that drives the stabilizer;
a blade expansion cutter drive unit that drives the rotation drive means and the rotation drive means;
a storage unit that stores the specific reaction force value identified by the reaction force identification means and a reaction force threshold value;
a computing unit that compares the reaction force threshold and the specific reaction force value,
When the calculation unit determines that the specific reaction force value exceeds the reaction force threshold value, the blade expansion cutter drive unit reduces the rotational speed of the blade expansion cutter with respect to the rotational drive means. A wing-expansion excavator, characterized in that it executes control and controls the rotational drive means to increase the rotation speed of the wing-expansion cutter. The outer shape of the frame is a rectangular parallelepiped that is long in the longitudinal direction of the rotation shaft and is rectangular when viewed from the front,
The stabilizer has a belt-like shape having a width in the longitudinal direction of the rotation shaft of the frame,
The wing expansion excavation according to claim 1, characterized in that the band-shaped stabilizers are provided on the upper and lower sides of each of the two wide surfaces of the rectangular parallelepiped frame so as to freely extend in a direction orthogonal to the wide surfaces. machine. 3. The expandable wing excavator according to claim 1 , wherein any one of the following is provided as said reaction force specifying means.
A: a pressure sensor mounted on the stabilizer,
B: Based on the relationship between the reaction force and the torque value of at least one of the rotational torque when the blade expansion cutter rotates and the rotational torque when the blade expansion cutter rotates, which is built into the controller and is A reaction force identification unit that identifies the reaction force. A method for constructing a wall pile having a general portion of a rectangular parallelepiped wall pile and a widened portion on at least one of two wide sides of the general portion, comprising:
A step of forming a general part preparation hole of the rectangular parallelepiped wall pile with a general part excavator;
With the wing expansion excavator according to any one of claims 1 to 3, the stabilizer applies a reaction force to the hole wall, and while specifying the reaction force at any time, the wing expansion cutter is rotated and widened. direction to form a widened portion forming hole in at least one of the two wide surfaces of the general portion forming hole, and at this time, an overcut portion is provided at the lower end of the general portion forming hole, and the excess portion is formed. A step B of accumulating excavated mud when the widened portion forming hole is formed in the excavated portion;
a C step of discharging excavated mud accumulated in the overcut portion by at least the general excavator;
A D step of installing a reinforcing bar cage in the general part preparation hole, pouring concrete into the general part preparation hole and the widened part preparation hole, and constructing a wall pile having a widened part;
In the step B, when the specified reaction force exceeds a preset reaction force threshold value, control is executed to increase the rotation speed of the blade expansion cutter and decrease the rotation speed. , construction method of wall piles. The wall pile construction method further includes an E step of specifying a stroke amount of the stabilizer when positioning the rotating shaft having the wing expansion excavation body to the design central axis of the general part preparation hole, Performing the E step prior to the B step,
5. The wall pile construction method according to claim 4 , wherein, in the step B, the wing-expanding excavating body whose rotating shaft is positioned on the design central axis in the step E is rotated.

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