JP7407078B2 - How to install wall piles - Google Patents

Description

The present invention relates to a method for constructing wall piles .

As a method to strengthen the bearing capacity of wall piles such as continuous underground walls, a method of forming a widened part (or widened bottom part, expanded part) on one or both of the two wide sides of the wall pile (one-sided widening, double-sided widening) can be mentioned. This widened portion not only increases the supporting force of the wall pile, but also increases the pull-out resistance of the wall pile. Therefore, wall piles with widened portions are suitable as foundation piles for high-rise buildings, skyscrapers, high-rise towers, etc., which have a large aspect ratio, have a significant overturning moment, and can pose problems in pull-out force. Note that this widened part is sometimes called a "protrusion" or "knot", and a plurality of protruding or knot-like widened parts are formed intermittently in the extending direction of the wall perpendicular to the wall thickness direction. There are some forms in which a wide part is formed continuously in the extending direction of the wall.

Conventionally, various construction methods for wall piles having the above-mentioned widened portions have been proposed. One construction method uses a drilling device that includes a kelly bar that rotates in the vertical direction as an axis, and a bucket that is attached to the tip of the kelly bar and can be opened and closed in the radial direction to rotate and excavate the ground as the kelly bar rotates. This is a pile construction method that uses the method to construct piles with knot-like extensions. More specifically, the process involves inserting a closed bucket into a pre-formed borehole, and repeating forward and reverse rotations of the Kelly bar within a predetermined angle range while opening the bucket to insert the bucket into the borehole. The process involves excavating a part of the wall surface to form an expansion space corresponding to the knot-like extension, and pouring concrete into the excavation hole to form a pile with the knot-like extension. (For example, see Patent Document 1).
Another construction method includes a shaft portion having a rectangular pillar portion having a rectangular planar shape, and an enlarged bottom portion having a circular planar shape where the bottom of the shaft portion is enlarged in the support layer of the ground, and the enlarged bottom portion has a rectangular pillar portion having a rectangular planar shape. This is a method of constructing a pile that is configured to expand laterally over the entire circumference at the bottom of the pile. More specifically, the method includes a first step of excavating 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, the excavator body is suspended from the ground, the excavator teeth are installed on the excavator body and rotate around a horizontal axis, the attitude detection device detects the attitude of the excavator body, and the attitude of the excavator body is detected. Using a reverse circulation horizontal multi-axis excavator with an attitude correction device, the attitude of the excavator is detected by the attitude detection device, and the attitude of the excavator is corrected using the attitude correction device. Drill a hole. In the second process, a reverse circulation type excavator is used, which has a rod to which multiple axes are connected, an excavator body attached to the tip of the rod, and a widening bit provided on the excavator body so that the rotation radius can be adjusted. The bottom of the hole excavated in the first step is expanded using the following method (see, for example, Patent Document 2).

Japanese Patent Application Publication No. 2006-45780 Japanese Patent Application Publication No. 2012-167450

In both 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-expanding excavator, a bottom-expanding bucket is mounted on the tip of a Kelly bar, and the bottom-expanding bucket is opened at a predetermined depth. Bottom-expanding excavation is performed by rotating the bucket. When using a Kelly bar to perform bottom-expanding excavation in this way, there is a problem in that the drive motor is located above ground, so the drive torque is reduced and there is a limit to the depth that can be excavated. Furthermore, for example, in Patent Document 1, it is stated that by forming a hole for a knot-shaped extension part on one side of a rectangular excavation hole, a wall pile having an extension part can be constructed without interfering with the border of adjacent land. There is. However, since excavation is carried out while supporting the bottom-expanding bucket with a kelly bar, there is a problem that the kelly bar is pushed by the reaction force during excavation, causing the bottom-expanding bucket to shift, reducing excavation accuracy. There is.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a wall pile construction method that can cope with various excavation depths and has excellent excavation accuracy.

In order to achieve the above object, one aspect of the wide-wing excavator according to the present invention is as follows:
a base machine; and a wide-wing excavation body suspended from the base machine by a wire; A wide-wing excavator that creates
The expanded wing excavation body is
A frame having a rotation axis extending in a direction perpendicular to the wall thickness of the wall pile in a plan view, and having a stabilizer that takes a reaction force to the hole wall;
a winged cutter that is rotatable in the wall thickness direction of the wall pile with respect to the rotation axis;
Rotation drive means for rotating the expanded blade cutter with respect to the rotation axis;
a rotational drive means for rotating the expanded blade cutter;
A plurality of drilling bits are provided on the bottom surface of the expanded blade cutter.

According to this aspect, by applying the expanded-wing excavated body suspended by a wire (introducing the expanded-wing excavated body by wiring) without applying a Kelly bar, the expanded-wing excavated body is placed underground. Since it can be driven, it is possible to create the hole wall of the widened part of the wall pile while responding to various excavation depths. In addition, by controlling the attitude of the expanded wing excavation body while applying a reaction force to the hole wall using the stabilizer, the hole wall of the widened portion of the wall pile can be created with excellent excavation accuracy.
Furthermore, since multiple drilling bits are provided on the bottom of the expanded blade cutter, the slime (or mud cake) formed on the bottom of the created hole wall can be removed using the drilling bits on the bottom of the expanded blade cutter. It is possible to prevent the construction of wall piles that are rough and have structural weaknesses due to slime. Here, the slime described above is formed by solidifying muddy water (stabilizing liquid) for protecting the hole wall, which is injected into the hole wall during the creation of the hole wall.
Here, "a plurality of drilling bits are provided on the bottom surface of the expanded blade cutter" includes various forms. One form is a type in which multiple drilling bits are literally provided on the bottom of the spread-wing cutter, and the other form is a flat claw type in which multiple drilling bits are consecutively provided on the bottom of the spread-wing cutter. In one embodiment, one or more scrapers are provided, and in another embodiment, both one or more scrapers and a plurality of drilling bits are provided on the bottom surface of the expanded blade cutter.
In the spread-wing excavator of this embodiment, a crawler crane, a truck crane, or the like can be used as a base machine for suspending the spread-wing excavator by a wire. In the frame of the expanded wing excavation body, a rotating shaft extends in a direction perpendicular to the wall thickness of the wall pile, and the expanded wing cutter is attached to the rotating shaft so as to be rotatable in the wall thickness direction of the wall pile. There is. In other words, like the conventional openwork excavation method (SATT method), the expanded blade cutter rotates in the direction perpendicular to the wall thickness direction of the wall pile (the direction in which the wall pile extends) and excavates directly beneath the buried object. The rotating direction of the expanded blade cutter is 90 degrees different from that of the conventional method. By performing excavation while the widening cutter rotates around the rotation axis in the rectangular parallelepiped wall pile, it is possible to create hole walls in the widening section on both of the two wide sides. If there is a boundary between neighboring properties, such as a public-private boundary, on one side of the two wide sides, the hole wall of the widening part can be constructed only on one side of the wide side, which is the opposite side of the boundary between the neighboring areas.

Further, in another aspect of the expanded-wing excavator according to the present invention, the tip of the expanded-wing cutter is provided with a plurality of radial blades extending radially outward from the central axis of the expanded-wing cutter,
The bottom surface of each radial wing is provided with one of the following bit configurations,
(1) A configuration in which a plurality of the drilling bits are provided at intervals, and each drilling bit provided in each radial wing is provided at a different position in the radial direction,
(2) a form in which the bottom surface of each radial blade is a scraper formed by a plurality of continuous drilling bits;
(3) A configuration in which the plurality of digging bits are provided on the bottom surface of some of the radial blades among the respective radial blades, and the scraper is provided on the bottom surface of the other portion of the radial blades.

According to this aspect, a plurality of radial blades are provided at the tip (lower end) of the expanded blade cutter and extend radially outward from the central axis of the expanded blade cutter, and are arranged at intervals on the bottom surface of each radial blade. A scraper in which a plurality of digging bits are provided, each of which is provided in each radial blade at a different position in the radial direction; By providing one of the following configurations: a configuration in which a plurality of drilling bits are provided on the bottom surface of some of the radial blades, and a configuration in which the bottom surface of another portion of the radial blades is a scraper. When the blade cutter rotates, it becomes possible to scrape the ground and slime (or mud cake) at the bottom end of the expanded blade cutter without missing any cutting.

Further, in the expanded-wing excavator according to this aspect, it is preferable that a plurality of expanded-wing cutters are rotatably arranged in parallel in the longitudinal direction of the rotating shaft.
According to this configuration, by rotating and excavating the plurality of widening cutters in the longitudinal direction of the rotation axis, it is possible to efficiently create a hole wall in the widening section extending in the extension direction of the wall pile. . For example, in a single-row multi-spindle type wide-wing excavator in which multiple wide-wing cutters are rotatably attached to one rotation axis, all the wide-wing cutters are moved in the same direction around the rotation axis. For example, by rotating the wall pile clockwise, a hole wall of the widened portion is created on one of the two wide sides of the rectangular parallelepiped wall pile. Next, by rotating all the widening blade cutters in the same direction, other counterclockwise, around the rotation axis, a hole wall of the widening part is created on the other of the two wide sides of the rectangular parallelepiped wall pile. can do.

Further, in the expanded-wing excavator according to this aspect, a plurality of rotating shafts are arranged side by side at intervals in a plan view, and a plurality of expanding-wing cutters are rotatably arranged side-by-side in the longitudinal direction of each rotating shaft. You can leave it there.
According to this configuration, a plurality of rotary shafts are arranged in parallel at intervals, and a plurality of expanded blade cutters in the longitudinal direction of each rotary shaft rotate and excavate, thereby excavating in the direction of extension of the wall pile. The hole wall of the widened portion extending in the width direction can be formed even more efficiently. For example, in a double-row multi-spindle type wide-wing excavator, in which a plurality of wide-wing cutters are rotatably attached to two rotating shafts arranged in parallel, Rotating all the expanding blade cutters in the same direction, for example, clockwise, and simultaneously rotating all the expanding blade cutters attached to the other rotating shaft in the same direction, for example, counterclockwise. Accordingly, the hole walls of the widened portion can be simultaneously created on both of the two wide sides of the rectangular parallelepiped wall pile.

Further, in the spread-wing excavator according to this aspect, the spread-wing excavator further includes a sludge pump, and the spread-wing cutter includes a shaft that rotates about the rotation axis and a shaft that is arranged around the shaft. At least one of the plurality of spread-wing cutters has a drilling bit, and a shaft of at least one of the plurality of spread-wing cutters may be formed with a mud drainage passage that communicates with the mud removal pump and allows drilling mud to pass therethrough.
According to this configuration, the excavated mud that accumulates inside the rectangular parallelepiped wall pile when the hole wall of the widening section is created is drained by the mud pump through the mud drainage passage in the shaft of the widening cutter. can do. Therefore, for example, a rotary excavator with a sludge removal mechanism that is applied when creating the hole wall of a rectangular parallelepiped wall pile (general part of the wall pile), and a rotary excavator that is applied when creating the hole wall of the widening section. It becomes possible to use the wide-wing excavator to create the hole wall in the widening section and to drain the generated drilling mud without having to alternately replace the wide-wing excavator with the wide-wing excavator.

In addition, in the spread-wing excavator according to this aspect, the spread-wing excavator further includes a water supply pump, and the spread-wing excavator further includes a water supply pump, and at least one of the plurality of spread-wing cutters (for example, the center of the three spread-wing cutters). The shaft of the expanded blade cutter) has a double pipe structure with an inner pipe and an outer pipe, one of which is a mud removal passage, and the other is provided by a water pump. It may also be a water supply passage that supplies fluid to the drilling bit. For example, in a configuration where water is supplied between the inner pipe and the outer pipe and sludge is removed 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 and outer pipes. According to this configuration, even if drilling mud adheres to the drilling bit when the spread-wing cutter excavates a sticky silt layer, etc., the fluid provided from the water pump can be used to excavate through the water supply passage. Drilling mud can be removed from the drilling bit by supplying it to the bit. Therefore, the problem of the drilling mud adhering to the drilling bit and making it impossible to excavate does not occur.
In addition, if the grain size of the earth and sand at the tip of the spread-wing cutter is large, there is a risk of blockage at the tip of the spread-wing cutter. A bar-like member for removing mud may be provided, and this configuration enables smooth mud removal.

Further, one aspect of the wall pile construction method according to the present invention is as follows:
A method for constructing a wall pile having a general part of a rectangular parallelepiped wall pile and an enlarged part on at least one of two wide sides of the general part, the method comprising:
A step of creating a general section hole for the rectangular parallelepiped wall pile using a general section excavator equipped with a cutter drum;
Using the widening excavator, create a widening hole on at least one of the two wide sides of the general section drilling hole, and at this time, the widening hole is drilled to a shallower depth than the design depth, and A step B in which an over-excavation portion is provided at the lower end of the hole, and the excavation mud obtained when the widening portion creation hole is created is stored in the over-excavation portion;
C step of draining the excavation mud accumulated in the over-excavation section by the general section excavator;
By drilling the widening section creation hole to the design depth with the widening excavator, the bottom of the widening section creation hole is roughed, and the rough mud generated during bottom roughening is collected in the over-digging section. D step of keeping
an E step of removing rough mud accumulated in the over-excavation section by the general section excavator;
It is characterized by having a step F of installing a reinforcing bar cage in the general part creation hole, pouring concrete into the general part creation hole and the widening part creation hole, and constructing a wall pile having a widened part. .

According to this aspect, by creating the general part creation hole (or guide creation hole) with the general part excavator and the creation of the widening part creation hole with the expanding wing excavator according to the present invention, the general part of the rectangular parallelepiped wall pile is It is possible to efficiently create a hole wall for a wall pile having a widened portion on at least one of the two wide sides of the general portion. After creating the hole for the general section, when creating the hole for the widening section, by providing an extra excavation section at the lower end of the hole for the general section, the excavated mud that is generated when creating the hole for the widening section can be temporarily removed. The mud can be temporarily stored in the tank, and the mud can then be smoothly removed using a general excavator.
Furthermore, in the B process of creating the widening part creation hole, the widening part creation hole is not created to the design depth, but is created to a shallower depth than the design depth, and in the subsequent D process, the widening part creation hole is created using a widening part excavator. By creating the hole to the designed depth and scouring the bottom of the widening hole, slime (or mud cake) formed by solidifying muddy water (stabilizing liquid) will remain at the bottom of the widening hole. This can prevent wall piles from being constructed that have structural weaknesses due to slime, etc.
Here, the "general excavator" includes, for example, a horizontal multi-axis excavator having a sludge removal mechanism, and is a different type of excavator from the spread-wing excavator according to the present invention.

Further, in another aspect of the wall pile construction method according to the present invention, in the step E, the upper end of the cutter drum suspended in the over-excavation part is set to be deeper than the lower end of the widening part creation hole. shall be.
According to this aspect, in the D process, the widening part creation hole is created to the design depth using the spreading blade excavator, and after the bottom of the widening part creation hole is roughened, in the next E process, the hole is suspended in the over-excavated part. By making the upper end of the cutter drum that constitutes the general section excavator deeper than the lower end of the widening section creation hole, the widening section where the coarse mud (removed slime) collected by the cutter drum is scraped. It can be prevented from being returned to the bottom of the hole.

Another aspect of the method for constructing wall piles according to the present invention is characterized in that the steps B to E are performed on two wide surfaces of the general hole.
According to this aspect, for example, by applying the single-row multi-axis type wide-wing excavator according to the present invention, the widening section is created on one of the two wide sides of the rectangular parallelepiped general section drilling hole in the B process to the E process. After forming the hole, it is possible to similarly form an enlarged portion forming hole on the other wide side of the general portion forming hole in steps B to E.
In addition, in this embodiment, when using a wide-wing excavator with multiple rotating shafts installed in parallel, processes B to E can be performed simultaneously on two wide surfaces of the general hole. can.

According to the wall pile construction method of the present invention, it is possible to cope with various excavation depths and to construct a wall pile having a widened portion with excellent excavation accuracy.

FIG. 1 is a side view of an example of a spread-wing excavator according to an embodiment. FIG. 2 is a front view of an example of a wing-spreading excavating body included in the wing-spreading excavator according to the embodiment. FIG. 3 is a side view of an example of the expanded-wing excavated body, which is a view taken in the direction of arrow III in FIG. 2; FIG. 3 is a perspective view taken in the direction of arrow IV in FIG. 2 and seen from diagonally below the tip of the expanded blade cutter. It is a side view of an example of the rotational drive means which the winged excavation body has. It is a process diagram of an example of the construction method of the wall pile based on embodiment. Continuing from FIG. 6, it is a process diagram of an example of the construction method of the wall pile according to the embodiment.

Hereinafter, a spreading-wing excavator and a wall pile construction method according to an embodiment will be described with reference to the attached drawings. Note that in this specification and the drawings, substantially the same constituent elements may be given the same reference numerals to omit redundant explanation.

[Spreading wing excavator according to embodiment]
First, an example of a wide-wing excavator according to an embodiment will be described with reference to FIGS. 1 to 5. Here, FIG. 1 is a side view of an example of a spread-wing excavator according to an embodiment, and FIG. 2 is a front view of an example of a spread-wing excavator body included in the spread-wing excavator according to the embodiment. Further, FIG. 3 is a side view of an example of the expanded-wing excavated body in the direction of the arrow III in FIG. 2, and FIG. 4 is a view of the expanded-wing cutter in the direction of the arrow IV in FIG. FIG. 3 is a perspective view of the tip viewed diagonally from below. Furthermore, FIG. 5 is a side view of an example of a rotational drive means included in the winged excavating body.

For example, when constructing a wall pile having a general part of the rectangular parallelepiped-shaped wall pile and an enlarged part located on at least one of two wide sides of this general part, the wing-spreading excavator 50 constructs a wall pile of a rectangular parallelepiped-shaped wall pile. This excavator is used to create the widening hole D2 from the general hole D1 (or guide hole), and the general section hole D1 is created using a horizontal multi-axis excavator, etc., as described later. The general section is carried out by an excavator. In addition, the wall pile to be constructed has a plurality of protrusions or knots intermittently in the extending direction of the wall on both of the two wide sides of the general part of the rectangular parallelepiped wall pile, or on one of the two wide sides. There are some forms in which a widened part is formed in the shape of a shape, and a form in which a widened part continuous in the extending direction of the wall is formed.

The expanded-wing excavator 50 includes a base machine 10 consisting of a crawler crane that can freely run on the ground surface of the ground G, a wire 20 suspended from the boom of the base machine 10, and an expandable machine attached to the tip of the wire 20. It has a wing excavation body 30. In addition to the crawler crane, the base machine 10 may be another heavy machine such as a truck crane that is movable and capable of wiring the wide-wing excavated body 30 into an excavation hole via the wire 20.

The expanded wing excavation body 30 includes a frame 31 constructed by assembling steel materials, a stabilizer 32 that is extendable and retractable toward the hole wall side on the side of the frame 31, and a pivot shaft 34 at the lower end of the frame 31 that is rotatable. It has a plurality of expanded wing cutters 33 attached thereto.

The general part creation hole D1 shown in FIG. 1 is illustrated so that the wall thickness direction is visible, and the direction perpendicular to the wall thickness direction of the wall pile (extension direction of the wall pile) is the direction perpendicular to the plane of the paper. The illustrated widening cutter 33 rotates in the X1 direction and the X2 direction, which are the wall thickness directions, about a rotation shaft 34 extending in a direction perpendicular to the wall thickness of the wall pile, thereby forming a widening portion creation hole D2. Create. In other words, unlike the conventional openwork excavation method (SATT method) in which the expanding blade cutter rotates in a direction perpendicular to the wall thickness direction of the wall pile and excavates directly under the buried object, the expanding method The rotation directions of the blade cutters 33 differ by 90 degrees. In FIG. 1, a wall pile creation hole D is shown which is formed by creating widening part creation holes D2 on two wide sides of the general part creation hole D1, respectively. If there is a boundary between adjacent lands such as a public-private boundary on the left side of hole D1, widening hole D2 is created only on the right side of the wide side of general hole D1, which is the opposite side of the adjacent land boundary, so that the wall pile Creation hole D is formed.

Further, the spreading-wing excavator 50 shown in FIG. It is familiar to By operating the mud removal pump 40, the mud excavated by the spread-wing cutter 33 can be drained to the ground, which is similar to general horizontal multi-axis excavation equipped with a mud removal mechanism. Like the machine, the wide-wing excavator 50 can also remove mud.

As shown in FIGS. 2 and 3, one rotation shaft 34 extends from the lower end of the frame 31 in a direction perpendicular to the wall thickness of the wall pile, and a plurality of rotation shafts 34 (in the illustrated example Three expanded blade cutters 33 are rotatably arranged in parallel. In this way, the illustrated example of the expanded-wing excavator 50 is a single-row multi-shaft type (single-row three-shaft type) excavator. In addition, in FIG. 2 etc., illustration of the water supply pump is omitted.

Among the three expanded blade cutters 33, the left and right end expanded blade cutters 33 are equipped with a rotary motor 35 (an example of a rotation drive means) for rotating themselves, and the central expanded blade cutter 33A is equipped with a gear ring. It is rotatable by the driving force transmitted from the rotary motor 35 on the left side via the rotary motor 35 . Therefore, as shown in FIG. 4, the rotation of the left end expanded blade cutter 33 in the Y1 direction causes the central expanded blade cutter 33A to rotate in the Y2 direction via the gear. The right end widening cutter 33 is rotated in the Y2 direction by its own rotary motor 35 independently of the central widening cutter 33A.

As shown in FIG. 2, the expanded blade cutters 33, 33A include a shaft 33a that rotates about a rotation axis 34, and a plurality of drilling bits 33b disposed around the shaft 33a, and further includes: Their tips have a plurality of radial blades 33c extending radially outward, and a plurality of drilling bits 33d are provided at intervals on the bottom surface of each radial blade 33c. Adjacent spread-wing cutters 33 and 33A are arranged so that their excavation bits 33b partially overlap each other in such a manner that they do not interfere with each other. Therefore, when each shaft 33a of the expanded blade cutters 33, 33A rotates to excavate, no area is left unexcavated, and the entire area is uniformly excavated by the three expanded blade cutters 33, 33A.

Since the central wing-spreading cutter 33A is not equipped with the rotary motor 35 on its head, the hollow shaft 33a can be communicated with the flow pipe 38 leading to the sludge pump 40.

In addition, as shown in FIG. 3, a plurality of stabilizers 32 that can be expanded and contracted in the X3 direction toward the hole wall side are arranged at the upper, lower, left, and right positions of the frame 31, and by appropriately expanding each stabilizer 32, the Attitude control of the winged excavation body 30 can be executed while taking reaction force from the wall. That is, after the attitude of the spread-wing excavator 30 is controlled by each stabilizer 32, each spread-wing cutter 33, 33A is rotated in the same direction to a desired angle in the X1 direction or the X2 direction about the rotation axis 34. Thereby, it becomes possible to create the widened part created hole D2 with high excavation accuracy on at least one of the two wide sides of the general part created hole D1. Note that by adjusting the amount of expansion by the stabilizer 32, it is possible to create the general portion creation hole D1 with various wall thicknesses.

In addition, in FIG. 3, the widening part creation hole D2 is created by forming an over-digging part D3 below the general part creation hole D1. As a result, the excavation mud generated during the creation of the widening section creation hole D2 can be temporarily stored in the surplus excavation section D3, and the general section excavator such as a horizontal multi-shaft excavator or a wide-wing excavator 50 It becomes possible to drain the excavated mud from the excess excavation part D3.

In addition, as shown in FIG. 4, each of the expanding blade cutters 33, 33A has a plurality of radial directions extending radially outward from the central axis (center point P) of the expanding blade cutters 33, 33A at their tips. It is provided with blades 33c1 and 33c2, and a plurality of drilling bits 33d1 and 33d2 are provided at intervals on the bottom surface of each radial blade 33c1 and 33c2.

In both of the expanded blade cutters 33 and 33A, the plurality of excavation bits 33d1 and 33d2 of the respective radial blades 33c1 and 33c2 are respectively provided at different positions in the radial direction. With this configuration, when the spread-wing cutters 33, 33A rotate, all the excavation bits 33d1, 33d2 with different rotation trajectories (rotation radii) are connected to the ground at the tips of the spread-wing cutters 33, 33A and below without any gaps. It becomes possible to cut (roughen the bottom) the slime (or mud cake) that forms on the bottom of the hole wall as described in . Although not shown, in addition to the illustrated example having a plurality of drilling bits 33d1 and 33d2, there is also a configuration in which the bottom surface of each radial blade is a flat claw type scraper, and a configuration in which the bottom surface of each radial blade is a flat claw type scraper. A configuration may also be adopted in which a plurality of excavation bits are provided on the bottom surface and the bottom surface of some of the other radial blades is a flat claw type scraper, in which both an excavation bit and a scraper are provided.

Further, as shown in FIG. 5, the rotation of the plurality of spread blade cutters 33, 33A about the rotation shaft 34 is controlled by two hydraulic cylinders 37 (rotation (one example of a driving means). As shown in FIG. 5, when rotating the plurality of expanded blade cutters 33, 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. A plurality of expanded wing cutters 33, 33A can be simultaneously rotated in the X1 direction via a link 37b rotatably attached to the tip of the rod 37a. On the other hand, when rotating the plurality of expanded blade cutters 33, 33A in the X2 direction, which is the right direction, by extending the piston rod 37a of the hydraulic cylinder 37 on the left side in the Z2 direction, the tip of the piston rod 37a is rotated. The plurality of expanded blade cutters 33, 33A can be simultaneously rotated in the X2 direction via the rotatably attached link 37b.

Although not shown in the drawings, the central widening cutter 33A has a mud drainage passage in the center of the shaft 33a, and for example, removes the excavated mud generated during the creation of the widening section creation hole D2 shown in FIG. By operating the sludge pump 40, sludge can be drained onto the ground via the sludge channel and the flow pipe 38. Further, the expanded blade cutter 33A may have a double tube structure having an inner tube and an outer tube. In this form, the inner pipe serves as a sludge drainage passage, and the outer pipe serves as a water supply passage that supplies fluid provided from the water supply pump to the excavation bits 33b and 33d. For example, even if drilling mud adheres to the excavation bits 33b and 33d when the spread-wing cutter 33 excavates a sticky silt layer, the excavation bit 33b uses the fluid provided from the water supply pump via the water supply passage. , 33d, the drilling mud can be removed from the drilling bits 33b, 33d. In this way, in the form in which the spread-wing cutter 33A located in the center among the three spread-wing cutters 33, 33A has a double pipe structure having a mud drainage passage and a water supply passage, in FIG. A water supply pump and a water supply tank (both not shown) are further mounted on the .

According to the expanded wing excavator 50, the expanded wing excavation body 30 suspended by the wire 20 is wired to the general section creating hole D1 to create the widened section creating hole D2 without applying a Kelly bar. Since the expanded wing excavation body 30 can be driven underground, the widened portion creation hole D2 can be created while responding to various excavation depths. Further, by controlling the attitude of the expanded wing excavation body 30 while taking a reaction force to the hole wall with the stabilizer 32, the widened portion forming hole D2 can be created with excellent excavation accuracy.

[Construction method of wall pile according to embodiment]
Next, an example of the wall pile construction method according to the embodiment will be described with reference to FIGS. 6 and 7. Here, FIG. 6 is a process chart of an example of the wall pile construction method according to the embodiment, sequentially from (a) to (e), and FIG. ) to (i) are process charts of an example of the method for constructing wall piles according to the embodiment. In the construction method shown in FIGS. 6 and 7, the widening section creation hole D2 is created using the widening excavator 50 having the single-row multi-axis type widening excavating body 30 shown in FIGS. 1 through 5, and the wall piles are installed. This is a construction method.

In step (a), for example, a general section excavator 70 consisting of a horizontal multi-axis excavator with a low head is used to create a general section hole D1 of a rectangular parallelepiped wall pile. The left and right pair of cutters are horizontal biaxial cutter drums 71 disposed at the lower end of the excavator body, and are connected to a hydraulic unit via a power cable, and are rotated by the driving force of the hydraulic unit to loosen the ground. . Further, the mud removal pump 72 is connected to a sand separator (not shown) via a hose, and is configured to suck up sand and water from inside the hole and send it to the sand separator. Here, muddy water (stabilizing liquid) for protecting the hole wall is injected into the hole (the above is Step A).

After the general section drilling hole D1 is created, in step (b), the general section excavator 70 and the wide-wing excavator 50 are replaced, and a , the wing-spreading excavated body 30 is suspended to a predetermined depth of the general section creation hole D1. Then, the attitude of the expanded-wing excavated body 30 is controlled while applying a reaction force to the hole wall using the plurality of stabilizers 32 of the expanded-wing excavated body 30.

Next, in step (c), excavation is performed while rotating the plurality of expanded blade cutters 33 to the left side of the general part creation hole D1 in the X1 direction to a predetermined rotation angle around the rotation axis 34, A widening part forming hole intermediate body D2' is created on the left side of the general part forming hole D1. Here, the widening part creation hole intermediate body D2' is created to a position shallower by the depth t than the design depth of the widening part creation hole D2 (see (f) of FIG. 7, etc.) to be finally created. This is a created hole. This depth t can be set to about 50 mm, for example.

Here, in creating the widened part forming hole intermediate body D2', the widened part forming hole intermediate body D2' is created by forming an over-digging part D3 below the general part forming hole D1. As a result, the excavation mud generated during the creation of the widening section creation hole intermediate body D2' can be temporarily stored in the over-excavation section D3.

Next, in step (d), excavation is performed while rotating the plurality of expanded blade cutters 33 to the right of the general part creation hole D1 in the X2 direction to a predetermined rotation angle around the rotation axis 34, Also on the right side of the general section forming hole D1, a widening section forming hole intermediate body D2' is formed. The widening section forming hole intermediate body D2' created here is also formed to a position shallower by the depth t than the design depth of the widening section forming hole D2 (see (g) in FIG. 7, etc.) to be finally created. This is the hole that has been created (the above is Step B).

Next, in step (e), the wide-wing excavator 50 and the general section excavator 70 are exchanged, and the general section excavator 70 drains the excavated mud temporarily stored in the surplus excavation section D3 to the outside. In addition, in step (c) and step (d), by operating the mud removal pump 40, a part of the excavated mud can be drained by the spread-wing excavator 50 (the above is Step C).

After removing the excavated mud from the extra excavation part D3, in step (f) of FIG. The expanded wing excavator 30 is suspended to a predetermined depth, and the stabilizer 32 controls the attitude of the expanded-wing excavator 30 while taking a reaction force against the hole wall. Then, by excavating to the design depth while rotating the plurality of expanded blade cutters 33 to the left side of the general area creation hole D1 in the X1 direction up to a predetermined rotation angle around the rotation axis 34, the general area creation hole D1 is excavated to the design depth. A widening portion forming hole D2 is created on the left side of the hole D1. In this excavation, by excavating the ground at a location corresponding to the unexcavated depth t, the bottom D2a of the widening section creation hole D2 is dug out, and the rough mud generated during bottom digging is left over. It is stored in section D3.

Next, in step (g), excavation is performed while rotating the plurality of expanded blade cutters 33 to the right of the general part creation hole D1 in the X2 direction to a predetermined rotation angle around the rotation axis 34, A widening section forming hole D2 is also formed on the right side of the general section forming hole D1. In this excavation as well, by excavating the ground at a location corresponding to the unexcavated depth t, the bottom D2a of the widening section creation hole D2 is dug out, and the rough mud generated during bottom digging is left over. It is stored in section D3.

In this way, by creating the widening section forming hole D2 while roughening the bottom D2a of the widening section forming hole D2, slime (or mud cake) remains on the bottom surface D2a of the widening section forming hole D2, and the remaining slime It is possible to prevent wall piles from being constructed that have structural weaknesses due to such problems (hereinafter referred to as Step D).

Next, in step (h), the wide-wing excavator 50 and the general excavator 70 are replaced again, and the general excavator 70 drains the rough mud temporarily stored in the excess excavation section D3 to the outside. As a result, as shown in step (i), a wall pile creation hole D is created, which is formed by the general part creation hole D1 and the left and right widened part creation holes D2.

At this time, the depth of the extra excavation part D3 and the height of the cutter drum 71 are set so that the upper end of the cutter drum 71 of the general part excavator 70 is deeper than the bottom surface D2a (lower end) of the widening part creation hole D2. There is. In this way, by making the upper end of the cutter drum 71 deeper than the bottom surface D2a (lower end) of the widening section creation hole D2, the rough mud (removed slime) collected by the cutter drum 71 is cleaned to the bottom. It can be prevented from being returned to the bottom D2a of the widened portion forming hole D2 (the above is Step E).

After the wall pile creation hole D is created, although not shown, a reinforcing bar cage is installed in the general part creation hole D1, and concrete is poured into the general part creation hole D1 and the widened part creation hole D2 to form the widened part. Construct the wall piles that have the following (above, Step F).

According to the illustrated wall pile construction method, by applying the wide-wing excavator 50 when creating the widening section creating hole D2, the widening section creating hole D2 can be created while responding to various excavation depths. Further, by controlling the attitude of the expanded wing excavation body 30 while taking a reaction force to the hole wall, the widened portion creation hole D2 can be created with excellent excavation accuracy. Furthermore, in the B process of creating the widening part creation hole, the widening part creation hole is not created to the design depth, but is created to a shallower depth than the design depth, and in the subsequent D process, the widening part creation hole is created using the widening part excavator 50. By creating the creation hole D2 to the design depth and scouring the bottom D2a of the widening part creation hole D2, the slime (or mud cake) formed by solidifying the muddy water (stabilizing liquid) is transferred to the widening part creation hole D2. It is possible to eliminate the problem of slime remaining on the bottom D2a of the wall, and to prevent the construction of wall piles that have structural weaknesses due to slime. In addition, when there is a boundary between adjacent lands such as a public-private boundary on one side of the general area creation hole D1, the widened area creation hole D2 is created only on one side, which is the opposite side of the adjacent land boundary, and wall piles are constructed.

Although not shown in the drawings, a method may also be used in which the widening section creation hole D2 is created using a widening excavator having a double-row multi-axis widewing excavating body, and the wall piles are installed. In this method, drilling is performed by simultaneously rotating multiple spread-wing cutters to the left and right sides of the general hole to a predetermined rotation angle around two rows of rotation axes. It becomes possible to efficiently create widening portion creation holes on the left and right sides, respectively.

It should be noted that other embodiments may be implemented in which other components are combined with the configurations listed in the above embodiments, and the present invention is not limited to the configurations shown here. . In this regard, changes can be made without departing from the spirit of the present invention, and can be appropriately determined depending on the application form.

10: Base machine 20: Wire 30: Spreading wing excavation body 31: Frame 32: Stabilizer 33: Spreading wing cutter 33a: Shaft 33b: Drilling bit 33c, 33c1, 33c2: Radial wing 33d, 33d1, 33d2: Drilling bit 34: Rotation axis 35: Rotation drive means (rotation motor)
36: Gear ring 37: Rotation drive means (hydraulic cylinder)
37a: Piston rod 37b: Link 38: Flow pipe 40: Sludge pump 50: Spreading wing excavator 70: General excavator (horizontal multi-axis excavator)
71: Cutter drum 72: Sludge pump G: Ground D: Wall pile creation hole D1: General part creation hole D2: Widening part creation hole D2a: Bottom D2': Widening part creation hole intermediate D3: Excavation part

Claims (3)

A method for constructing a wall pile having a general part of a rectangular parallelepiped wall pile and an enlarged part on at least one of two wide sides of the general part, the method comprising:
A step of creating a general section hole for the rectangular parallelepiped wall pile using a general section excavator equipped with a cutter drum;
A widening hole is created on at least one of the two wide sides of the general section hole using a widening excavator. A step B in which an over-excavation part is provided at the lower end of the over-excavation part, and excavation mud from when the widening part creation hole is created is stored in the over-excavation part;
C step of draining the excavation mud accumulated in the over-excavation section by the general section excavator;
By drilling the widening section creation hole to the design depth with the widening excavator, the bottom of the widening section creation hole is roughed, and the rough mud generated during bottom roughening is collected in the over-digging section. D step of keeping
an E step of removing rough mud accumulated in the over-excavation section by the general section excavator;
F step of installing a reinforcing bar cage in the general part creation hole, pouring concrete into the general part creation hole and the widening part creation hole, and constructing a wall pile having a widening part,
The wing-spreading excavator is
a base machine; and a wide-wing excavation body suspended from the base machine by a wire; It is a wide-wing excavator that creates
The expanded wing excavation body is
A frame having a rotation axis extending in a direction perpendicular to the wall thickness of the wall pile in a plan view, and having a stabilizer that takes a reaction force to the hole wall;
a winged cutter that is rotatable in the wall thickness direction of the wall pile with respect to the rotation axis;
Rotation drive means for rotating the expanded blade cutter with respect to the rotation axis;
a rotational drive means for rotating the expanded blade cutter;
A method for constructing a wall pile, characterized in that a plurality of drilling bits are provided on the bottom surface of the expanded wing cutter. 2. The wall pile construction method according to claim 1 , wherein in the step E, the upper end of the cutter drum suspended in the over-digging part is set to be deeper than the lower end of the widening part creation hole. The wall pile construction method according to claim 1 or 2 , characterized in that the B step to the E step are performed respectively on two wide surfaces of the general section creation hole.

Images